2015 Field Trials Report. GRDC Project: Australian Cereal Rust Control Programme (ACRCP) Integrated Fungicide Management (IFM) Programme

Transcription

1 2015 Field Trials Report GRDC Project: Australian Cereal Rust Control Programme (ACRCP) Integrated Fungicide Management (IFM) Programme GRDC Project No: FAR00002 May 30 th 2016 Foundation for Arable Research Australia Phone Post 23 High Street Inverleigh VIC 3321 Website ABN N. Poole & T. Wylie 1

2 Table of Contents ABSTRACT... 3 INTRODUCTION... 7 Trial 1. Evaluating the interaction between new generation fungicide application and genetic resistance for the control of stripe rust (Puccinia striiformis) in wheat... 8 Trial details... 8 RESULTS... 9 Trial 2. Evaluating the interaction between new generation fungicide application and genetic resistance for the control of leaf rust (Puccinia triticana) in wheat Trial details RESULTS Trial 3. Evaluating the interaction between new generation fungicide application and the adult plant resistance genes Yr 18 and the combination of Yr18 & 29 in Near Isogenic Lines (NIL) of Avocet for the control of stripe rust (Puccinia striiformis) Trial details RESULTS Trial 4. Evaluating the interaction between the strobilurin based fungicide Amistar Xtra and the genetic resistance of four cultivars for the control of stripe rust (Puccinia striiformis) Trial details RESULTS ACKNOWLEDGEMENTS Front cover Photo Courtesy Dr Karanjeet Sandhu, Sydney University 2

3 ABSTRACT Four field research trials were run as part of the 2015 the Integrated Fungicide Management research programme (ACRCP project GRDC code FAR 00002) to test the impact of new generation fungicides (triazole FRAC Group 3, strobilurin FRAC Group 11 & succinate dehydrogenase inhibitors (SDHIs) FRAC Group 7) for stripe rust control (Puccinia striiformis f.sp. tritici) on commercial cultivars and Near Isogenic Lines (NILs) and leaf rust control (Puccinia triticana) in commercial cultivars. Trial 1 FAR W15-20 Cobbitty, NSW The trial was sown on May at Sydney University s Horse Unit paddock adjoining the Plant Breeding Institute near Cobbitty ( S, E) to evaluate the influence of fungicide application on cultivars with intermediate resistance to stripe rust (Puccinia striiformis f.sp. tritici) protected by APR genes (Yr 18 and Yr 29). The trial was inoculated with stripe rust prior to fungicide application and irrigated through the course of the season. The trial tested the performance of six different fungicide products and timings in the commercial cultivars Corack (rated moderately susceptible MS for stripe rust (source NSW DPI) known APR gene Yr 29), Trojan (rated moderately resistant MR for stripe rust APR gene Yr29) and Elmore CL Plus (rated moderately resistant moderately susceptible MR-MS APR genes Yr 18 and Yr29). The influence of cultivar resistance and fungicide application on stripe rust infection was assessed on individual leaf layers in the crop canopy as the percent leaf area of active infection (active pustules present) and total area of necrosis resulting from stripe rust infection (total area of active infection and leaf damage caused by stripe rust without pustule expression). The differences in stripe rust severity resulted in significant fungicide yield responses ranging from t/ha in Corack (MS) to no significant responses in Elmore CL Plus (MR-MS) and Trojan (MR). Disease control & green leaf retention (GLR) The severity of stripe rust infection and total leaf necrosis due to the disease was greatest in Corack the MS rated cultivar with leaf damage reaching 25% on the top two leaves of the crop canopy by early grain fill (GS75). In contrast the leaf necrosis with Elmore CL Plus MR-MS rated never exceeded 9% on flag and flag-1 (F-1) with stripe rust necrosis in Trojan being the lowest and never exceeding 5% on the flag leaf throughout the growing season. The severity of leaf necrosis was similar to that recorded in the 2014 trials with approximately three times the level of damage on the flag leaf in Corack as compared to Elmore CL Plus. The greater difference was in relation to active pustulation observed in the three cultivars, in comparison to total leaf necrosis. At peak infection on the flag leaf recorded at ear emergence, active stripe rust pustules covered approximately 8% of the leaf compared to total necrosis of almost 12%. In contrast the active infection with pustules present on Elmore CL Plus and Trojan was less than 1% with the total necrotic areas registering 3.5% and 1.5% respectively. Active infection recorded at the end of flowering 18 days later showed a significant reduction in active pustulation but total leaf necrosis had increased. With Corack the highest level of active pustulation was approximately 35% of the final leaf damage recorded, whilst with Elmore CL Plus and Trojan the damage caused by disease pustules was approximately 10% of the total necrosis area recorded. The more resistant cultivars Elmore CL Plus and Trojan recorded lower levels of leaf damage and less active pustulation. In terms of fungicide application there were few significant differences in product performance amongst the three treatments (Opus, Radial and F1/14) in stripe rust control when products were applied as two spray programmes. There was however a consistent trend up to early grain fill suggesting superior stripe rust control and increased green leaf retention on the upper leaf canopy with the strobilurin mixture Radial and the SDHI based mixture F1/14. This difference with both products (in stripe rust control on the flag leaf based on the two spray programmes) was statistically superior to Opus when assessed during grain fill (8 October) on the most susceptible cultivar Corack. 3

4 The highest levels of head infection were evident in Corack (26.9 grain sites infected/head approximately 60% infection) with all fungicide treatments significantly reducing infection, however the single fungicide application at head emergence was statistically superior to all other treatments except the two spray of F1/14 and Opus applied at GS31 and GS39. The head emergence spray was applied too late to prevent stripe rust necrosis in the foliage with Corack. Yield & quality Fungicide treatment significantly increased yield and test weight with Corack, with later fungicide timings at flag leaf and head emergence being superior to an early 1 st node fungicide. The superiority of the head emergence spray (which failed to control the disease on the top three leaves) was explained by the prevention of head infection (76% control of head infection). There was no difference in the yield performance of the two spray programmes based on Opus, Radial and F1/14 and no significant advantage of two sprays over a single fungicide, however the high degree of lodging in fungicide treated plots may have made results more variable and influenced these results. With Elmore CL Plus (MR-MS) and Trojan (MR) there were no significant yield or quality increases associated with any of the fungicide treatments. With Trojan, fungicide treatments appeared to reduce yield, although with all but one treatment the decrease was not statistically significant. This yield decrease may have been associated with the high degree of lodging in this cultivar, which showed a trend for lodging to be greater in fungicide treated crops, possibly as a result of thicker crop canopies that had higher GLR lower in the canopy (F-2) than the untreated control. Trial 2 FAR W15-21 Hamilton, Victoria The trial was sown on April at Southern Farming Systems field research site at Tarrington near Hamilton in Victoria s high rainfall zone (HRZ) (37 47'7.02"S, 142 6'8.92"E) to evaluate the influence of fungicide application on cultivars with intermediate resistance to leaf rust (Puccinia triticana) where some of the protection is provided by APR genes (Lr 34 and Lr 46). The trial was bordered by susceptible spreaders which were inoculated with leaf rust spores (mixed pathotypes derived from Victoria - sourced from Agriculture Victoria) and planted with over 100 spreader plants. The trial tested the performance of fourteen different fungicide products and timings in the commercial cultivars Bolac (rated moderately susceptible MS for leaf rust (Agriculture Victoria) containing known APR gene Lr 34) and Phantom (rated moderately resistant moderately susceptible MR-MS containing APR gene Lr 46). The influence of cultivar resistance and fungicide application on leaf rust infection was assessed on the flag leaf in the crop canopy as the percent area of active infection (active pustules present) and area of necrosis resulting from leaf rust infection. The late onset of leaf rust infection in this trial resulted in low levels of the disease (1% severity & 40% disease incidence) that were not cost effective to control. Fungicide application did not produce significant yield responses in either Bolac or Phantom, however the research did highlight differences in the efficacy of fungicides tested. It confirmed that the ear emergence (GS59) fungicide timing was more effective than early fungicide applications at the start of stem elongation (GS31) for the control of leaf rust. Although disease pressure was extremely low there was evidence that epoxiconazole with azoxystrobin (Radial ) and the experimental fungicide FAR F1/14 were superior to tebuconazole (e.g. Folicur ) when applied in two spray programmes at GS31 and GS39. Trial 3 FAR W15-22 Cobbitty, NSW The trial was sown on May at Sydney University s Horse Unit adjacent to the PBI complex near Cobbitty adjacent to trial 1 W15-20 ( S, E) to evaluate the influence of fungicide application in Near Isogenic Lines (NILs) of wheat based on an Avocet background. The three lines evaluated differed in the presence of Adult Plant Resistance (APR) genes Yr18 and Yr29 which are known to confer stripe rust protection. The lines evaluated were NIL+Yr18, NIL Yr18+29 and the 4

5 original Avocet cultivar which is susceptible to stripe rust. The trial was inoculated with stripe rust (pathotype 134E16A ) prior to fungicide application and irrigation was provided through the course of the season. The trial tested the performance of three different fungicide products/product mixtures (epoxiconazole, epoxiconazole + strobilurin, epoxiconazole + SDHI) that were applied in two spray programmes at GS31 and GS39 growth stages. Influence of germplasm The onset of disease infection was slower in 2015 than it had been in 2014, although inoculation was provided in the same time period as 2014, a result of lower early spring temperatures in The combination of two APR genes in NIL Yr18+29 conferred significantly better protection against stripe rust infection and resultant levels of necrosis on the top three leaves of the crop canopy than the Avocet S and NIL+Yr18 lines. The effects of NIL+Yr18 in conferring protection to the top three leaves was intermediate in effect between Avocet S and the NIL Yr In terms of head infection, only NIL Yr18+29 conferred significantly better control than Avocet S and overall the levels of resistance conferred to the head were not as great (30% less head infection with NIL Yr18+29 than observed in Avocet S) as that observed in the top three leaves of the crop. The results with disease control were similar to green leaf retention (GLR) findings, NIL+Yr18 and Avocet S showing large and significant increases in GLR due to fungicide application and NIL+Yr18+29 showing smaller non-significant increases. The rank order of the green leaf retention differences due to the genetics was similar on all three top leaves particularly at the grain fill stage of development. There was a significant difference in yield between the three lines (p<0.001) when averaged over all fungicide treatments with Avocet S giving an average yield of 2.79t/ha, Avocet NIL Yr t/ha and Avocet NIL Yr t/ha. Fungicide control There were few significant differences in stripe rust control between the different fungicide treatments when applications were made at GS31 or GS39 or at both of these timings in two spray programmes. Fungicide application at ear emergence GS59 was the only timing to give significant control of head infection when analysed over the three lines, however this timing was applied too late to provide effective control of stripe rust for the top three leaves of the canopy when applied to Avocet S. Only the Avocet S gave a significant yield response to fungicide application, fungicide treatments yielding between t/ha more than the untreated. Neither NIL lines gave a significant response to fungicide, although with NIL Yr18 the lowest yielding treatment was the untreated crop. In part lodging may have prevented responses to fungicides being greater in this experiment. Despite increased green leaf retention recorded on the top three leaves and overall increases in plot NDVI scores with fungicide applications in NIL Yr18+29 no significant yield increases over the untreated were observed. All cultivars in the trial were subject to lodging which made the trial more variable (cv 13%) however there was no evidence that lodging was more severe in fungicide treated NIL Yr18+29 plots. Grain quality The principal grain quality differences were observed in Avocet S which had the highest level of stripe rust infection. Where fungicide application was made to the head at GS59 it significantly improved screenings (3%) relative to treatments that controlled the disease in the foliage, which had 5-7% infection and were applied at GS31 & GS39. Where the crop received no fungicide the screening levels with Avocet S were significantly higher than all other treatments (11%). Despite the lack of disease control on the top three leaves of the crop canopy with the ear applied fungicide the effect on grain quality was significantly superior to all other treatments that gave good control of stripe rust in the upper crop canopy. This would indicate that fungicide timed at head emergence can result in 5

6 significant lifts in quality in comparison to crops where disease was controlled in the foliage but no protection was put in place for the head itself. It could be argued that in a trial scenario re infection from neighbouring untreated plots creates more disease pressure than would be the case in commercial crops where the disease has been controlled in the foliage. Whilst this maybe the case the influence of an ear applied fungicide on grain quality in a scenario that was too late to protect the foliage does have commercial relevance in situations where stripe rust epidemics result in high levels of inoculum present at head emergence. No differences in screening were observed in NIL Yr18 and NIL Yr18 + Yr29. Trial 4 FAR W15-23 Cobbitty, NSW This small plus and minus fungicide trial was set up alongside FAR W15-20 and FAR W15-22 and inoculated with stripe rust (pathotype 134E16A ) at the same time as the other two trials. Two applications of Amistar Xtra applied at GS31 and GS39 at 400ml/ha significantly reduced stripe rust necrosis on the flag leaf from more than 50% to less than 5% in Condo (MS-S rated for stripe rust), Mace (S-VS) and Cobra (MS-S) when assessed at the early grain fill stage (GS71-75). With the more resistant cultivar Trojan fungicide application reduced flag leaf necrosis from 6% down to less than 1%, however the difference was not statistically significant. Fungicide application was observed to significantly reduce head infection with Mace and Condo but the reduction observed with Cobra (37.2% down to 24.8% infection) was not significant. Trojan which had only 6% necrosis of the flag leaf produced 1% head infection when untreated with fungicide and did not benefit significantly from fungicide to prevent head infection. With Condo which had the highest level of head infection (75.5% infection) fungicide application reduced this to 46%, bearing in mind that neither fungicide in the two spray programme was applied to the head directly. Fungicide application resulted in significant yield increases over the untreated in Cobra (3.0t/ha response), Condo (2.8t/ha) and Mace (3.1t/ha). Yields were taken from just over 2t/ha to just over 5t/ha with fungicide. In contrast, Trojan gave a significant yield response of 1.1t/ha compared to 3t/ha with the other three cultivars. There was a significant interaction (p<0.001) between cultivar and fungicide application since Trojan untreated with fungicide yielded the same as Mace, Condo and Cobra treated with fungicide. Despite the extremely low levels of stripe rust necrosis recorded in Trojan the late season assessments of green leaf retention revealed significantly higher NDVI plot scores and significantly better GLR on the flag where the crop was fungicide treated. This late season green leaf retention and control of stripe rust necrosis resulting from fungicide application has resulted in a significant yield increase which was not apparent in the adjacent trial W15-20 where there was no yield increase from the application of fungicide and less evidence of green leaf retention differences on the flag leaf. Trojan in the neighbouring W15-20 trial did respond with increased GLR on flag-2 but there was less evidence of increased green leaf retention in the upper part of the canopy. In part this may have been due to greater azoxystrobin content in 400ml/ha Amistar Xtra (160g/ha ai over two sprays) compared to Radial at 420ml/ha (62.5g/ha ai over the two sprays), however the triazole component is also different Amistar Xtra being based on cyproconazole (64g/ha ai) as opposed to epoxiconazole with Radial (62.5g/ha ai). 6

7 INTRODUCTION This project is funded by GRDC (FAR 00002) as part of the Australian Cereal Rust Control Programme Objective To evaluate the performance of fungicide application in commercial Australian cultivars and Near Isogenic Lines (NILs) with intermediate resistance to stripe rust and leaf rust and the presence of known adult plant resistance genes Yr18 and Yr29 for stripe rust control and Lr34 and Lr46 for leaf rust control. Specifically the individual trial objectives were as follows: Evaluate the disease control, green leaf retention, and yield and quality response given by the azole fungicide epoxiconazole with and without SDHI or strobilurin fungicide in two cultivars of intermediate resistance to stripe rust (Puccinia striiformis) and leaf rust (Puccinia triticina) in wheat. To evaluate how newer strobilurin and SDHI fungicides applied at three key growth stages GS31 (1 st node), GS39 (flag leaf) and GS59 (ear emergence) interact with APR expression. To determine whether the benefits of epoxiconazole with or without strobilurin addition allow a single spray to replace a two spray programme based on the commercial standard tebuconazole applied at 62.5g/ha ai. 7

8 Trial 1. Evaluating the interaction between new generation fungicide application and genetic resistance for the control of stripe rust (Puccinia striiformis) in wheat Trial details FAR Code FAR W15-20 Location Horse Unit, Nr Cobbitty, NSW (Irrigated) Collaborator PBI Cobbitty, NSW (Dr K. Sandhu) Target disease Stripe rust (Puccinia striiformis) Rotation position 1 st wheat after break METHOD Treatment List i) Cultivars - sown at 200 seeds/m 2 (based on 14m x 1.25m plots = 17.5m 2 ). Elmore CL Plus rated MR-MS for stripe rust - known APR genes Yr Corack rated MS for stripe rust - known APR genes Yr29 Trojan rated MR for stripe rust - known APR genes Yr29 Note: resistance ratings for stripe rust are clearly influenced by resistance genes (major & minor) other than the known APR genes. Resistance ratings taken from NSW DPI Guide. All seed Hombre treated. ii) Trt No Fungicide treatment and timing Treatment Rate Active ingredient (A.I) (ml/ha) A.I applied g/ha Treatment Timing * 1 Untreated 2 Opus 125 SC 250 x 2 Epoxiconazole 62.5 GS31 + GS39 3 Radial 420 Epoxiconazole + Azoxystrobin GS31 4 Radial 420 Epoxiconazole + Azoxystrobin GS39 5 Radial 420 Epoxiconazole + Azoxystrobin GS59 6 Radial 420 x 2 Epoxiconazole + Azoxystrobin GS31 + GS39 7 FAR F1/14** 500 x 2 GS31 + GS39 **Confidential product not currently registered for use in the Australian broad acre cropping Trial design: Split plot design (3 Cultivars x 7 Fungicide treatments x 4 replicates = 84 harvestable plots). Sowing date: 13 th May 2015 Inoculation Application 1 Application 2 Application 3 Date 24 July July August 2015 Growth Stage Z31 Z31 & 32 Z37&38 Rate: Infected pots 2 mg/ml 2 mg/ml Pathogen 134E16A E16A E16A Method Pots were placed in buffer lines Spray using Herbi Spray using Herbi Approximately 2 mg of spores per ml of light mineral oil (Univar Solvent L naphtha 100, Univar Australia Pty Ltd) were used and approximately 500 ml of dilution was used for each field inoculation. 8

9 Fungicide applications Applications were targeted to be made at identical growth stages for the three cultivars rather than a set calendar date. Trojan and Elmore CL Plus developed slower than Corack. Application 1 Application 2 Application 3 Date 20 th July - Corack 29 th July Trojan & Elmore CL Plus 28 th August - Corack 31 st August Trojan & Elmore CL Plus Growth Stage Z31 Z39 Z59 Water Rate 100 L/ha 100 L/ha 100 L/ha Method Sprayer Sprayer Sprayer Notes Nozzle DG Teejet VP Nozzle DG Teejet VP 14 th Sept Corack 21 st Sept Trojan & Elmore CL Plus Nozzle DG Teejet VP Assessment Technique Assessment Scale Description Disease Severity % 0 % No infection present, 100 % - Total leaf area infected LAI. 10 stems assessed per plot or whole plot assessment Disease Incidence % % of assessed components with infection. 10 stems assessed per plot or whole plot assessment Green leaf retention (GLR) % 0 % - No green area remaining 100% - Leaf fully green. 10 stems assessed per plot Grain Yield t/ha Measured using small plot harvester Grain Quality % and kg/hl Protein, screenings and specific weight Statistical Analysis All data from this trial was analysed using a confidence interval of 95% unless otherwise specified. All mention of significant differences contained within this report refer to statistically significant differences. RESULTS i) Disease infection and Green leaf retention (GLR) Baseline Assessment - 7th August 2015: The baseline assessment was conducted on untreated plots on the 7 th August 2015, with cultivars at GS 30-32, Corack being the most advanced. Following inoculation stripe rust was first observed in the trial on 7 th August on the lower leaves in Trojan (Table 1). Table 1. Severity (% of leaf area infected) and incidence (% of assessed leaves infected) of active stripe rust on the top three fully unfolded leaves in untreated plots. Disease Severity Disease Incidence (%) Cultivar Flag-2 Flag-3 Flag-4 Flag-2 Flag-3 Flag-4 Corack Elmore Trojan

10 Assessment 2 24 th August 2015 Corack GS43, Elmore GS33 & Trojan GS33-37 Very low levels of stripe rust were recorded at this assessment on flag-2 and flag-3. Only untreated plots were assessed on the 24 th August (Table 2). Disease severity was recorded at % with incidence at 10 35% depending on cultivar. Table 2. Severity (% of leaf area infected) and incidence (% of assessed leaves infected) of active stripe rust on the top four fully unfolded leaves in untreated plots. Disease severity (%) Disease incidence (%) Cultivar Flag Flag-1 Flag-2 Flag-3 Flag Flag-1 Flag-2 Flag-3 Corack Elmore Trojan Assessment 3-10 th September 2015; Corack GS51 (first spikelets of ear visible), Elmore CL Plus GS47, Trojan GS45 Stripe rust infection developed rapidly from the flag leaf emergence assessment. The severity of infection was significantly higher in Corack than Elmore and Trojan at the booting to early ear emergence (Table 3). There was a significant interaction between fungicide treatment and cultivar on the top three leaves of the crop canopy for active stripe rust recorded (Table 4). Fungicide treatment gave a significant reduction in disease levels in Corack but with the most resistant cultivar Trojan there was no significant effect of fungicide application and significantly less disease in the Trojan untreated plots. In Corack all treatments significantly reduced stripe rust necrosis, two spray programmes of Radial and F1/14 were significantly more effective on the flag leaf than Opus. The GS31 application timing generated significantly better control than the targeted GS39 spray in terms of necrosis prevention, due to poor weather delaying the application of the flag spray until booting (GS45-47). Table 3. Influence of cultivar on the severity of stripe rust (active rust postulation and total necrosis), assessed on flag, flag-1 and flag-2, on the 10 th September, GS45-51 (mean of fungicide treatment). Disease Severity Cultivar Flag Flag-1 Flag-2 Active Total Active Total Active Total Corack 2.5 a 6.4 a 1.7 a 4.4 a 0.6 a 1.5 b Elmore 0.2 b 1.4 b 0.6 b 4.4 a 0.2 b 2.7 a Trojan 0.1 b 0.5 c 0.3 b 2.0 b 0.4 ab 1.5 b Mean LSD P Val <0.001 <0.001 <0.001 < <0.001 Table 4. Interaction between cultivar and fungicide on the severity of stripe rust (active pustulation and total necrosis), assessed on flag, flag-1 and flag-2, on the 10 th September, GS Disease Severity Cultivar & Fungicide Flag Flag-1 Flag-2 Active Total Active Total Active Total Corack 10

11 Untreated 8.1 a 11.9 a 4.7 a 7.9 a 1.4 ab 2.7 bc Opus GS b 6.2 b 0.5 cde 3.8 c-g 0.2 d 0.5 g Radial GS b 3.2 cde 0.1 de 1.8 g-k 0.0 d 0.3 g Radial GS b 6.2 b 1.1 c 3.9 c-f 0.9 bc 2.1 b-e Radial GS a 11.3 a 5.0 a 8.6 a 1.5 a 3.2 ab Radial GS b 2.6 c-f 0.2 de 1.9 g-k 0.1 d 0.5 g FAR F1/14 GS b 3.3 cd 0.5 cde 3.0 e-j 0.4 cd 1.0 efg Elmore Untreated 0.7 b 3.5 c 2.1 b 7.6 ab 0.5 cd 3.2 ab Opus GS b 1.6 d-g 0.4 cde 5.4 cd 0.3 d 2.5 bcd Radial GS b 0.3 g 0.0 e 2.5 f-k 0.1 d 2.7 bc Radial GS b 1.7 c-g 0.2 de 5.8 bc 0.3 cd 3.3 ab Radial GS b 2.4 c-f 1.3 bc 4.8 cde 0.4 cd 4.0 a Radial GS b 0.2 g 0.0 e 2.5 f-k 0.1 d 1.5 c-g FAR F1/14 GS b 0.4 g 0.1 de 2.5 f-k 0.0 d 1.8 c-f Trojan Untreated 0.5 b 1.5 efg 1.3 bc 3.6 d-h 0.8 c 2.5 bcd Opus GS b 0.1 g 0.1 de 1.8 h-k 0.2 d 1.3 d-g Radial GS b 0.1 g 0.0 e 1.0 k 0.1 d 0.6 fg Radial GS b 0.2 g 0.1 de 1.5 ijk 0.4 cd 1.8 c-f Radial GS b 1.3 fg 1.0 cd 3.4 d-i 1.5 a 3.1 ab Radial GS b 0.1 g 0.0 e 1.3 jk 0.0 d 0.9 efg FAR F1/14 GS b 0.0 g 0.0 e 1.2 jk 0.0 d 0.3 g Mean LSD P Val <0.001 <0.001 < Assessment 4 - Assessed on the 28 th September 2015 Corack GS71 (grain 90% formed), Elmore GS69 (grain 30% formed) & Trojan GS69 (grain 20% formed) At this assessment there no significant differences in the performance of fungicide programmes on the flag leaf except where a single late fungicide had been applied targeted at ear emergence (GS59). However with Corack the late applied flag leaf spray at GS45-47 resulted in significantly more disease on flag-1 (Table 6). Table 5. Influence of cultivar on the severity of stripe rust (Active and Total), assessed on flag and flag- 1, and the green leaf retention (GLR) of flag-2, assessed on the 28 th September. Disease Severity Cultivar Flag Flag-1 Flag-2 Active Total Active Total GLR Corack 0.3 a 10.9 a 0.1 a 11.4 a 82.4 b Elmore 0.0 b 2.9 b 0.0 a 5.5 b 81.9 b Trojan 0.1 ab 1.8 b 0.0 a 2.9 c 91.9 a Mean LSD P Value < <0.001 <

12 Table 6. Interaction between cultivar and fungicide on the severity of stripe rust (Active and Total), and the green leaf retention (GLR) of flag-1, assessed on the 28 th September. Disease Severity GLR Cultivar & Fungicide Flag Flag-1 Flag-1 Active Total Active Total GLR Corack Untreated 1.1 a 18.9 b 0.1 ab 22.8 a 61.3 h Opus GS c 6.9 cd 0.0 b 6.5 b-e 91.0 a-d Radial GS bc 7.4 cd 0.3 a 4.9 c-g 91.3 a-d Radial GS c 7.9 cd 0.0 b 10.3 b 82.8 de Radial GS c 24.6 a 0.1 b 25.8 a 62.1 h Radial GS c 4.7 def 0.0 b 5.1 c-g 94.4 abc FAR F1/14 GS bc 5.8 cde 0.0 b 4.5 d-g 93.7 abc Elmore Untreated 0.0 c 8.9 c 0.0 b 10.4 b 70.6 gh Opus GS c 1.0 fg 0.0 b 4.1 d-g 85.3 cde Radial GS c 0.9 fg 0.0 b 3.2 d-g 86.5 b-e Radial GS c 1.8 efg 0.0 b 6.1 b-f 81.1 ef Radial GS c 7.3 cd 0.0 b 9.7 bc 72.4 fg Radial GS c 0.6 g 0.0 b 2.9 d-g 86.4 b-e FAR F1/14 GS c 0.2 g 0.0 b 2.5 efg 90.8 a-d Trojan Untreated 0.7 ab 5.0 cde 0.1 ab 5.5 b-g 86.0 b-e Opus GS c 0.2 g 0.0 b 1.2 fg 96.6 a Radial GS c 0.2 g 0.0 b 1.1 g 97.7 a Radial GS bc 0.9 fg 0.0 b 2.1 efg 93.4 abc Radial GS bc 5.7 cde 0.1 b 7.8 bcd 79.5 efg Radial GS c 0.4 g 0.0 b 1.3 fg 95.2 ab FAR F1/14 GS c 0.1 g 0.0 b 1.2 fg 95.2 ab Mean LSD P Val < < Assessment 5-8 th October 2015 Corack GS75-77 (mid late milk stage), Elmore GS73 (early mid milk stage) & Trojan GS73 (early mid milk stage) Averaged over all fungicide treatments including the untreated Corack had significantly more head infection and flag leaf necrosis than Elmore and Trojan (Table 7). There were no differences between Elmore and Trojan other than significantly more GLR with Trojan in the lower canopy (F-2). 12

13 Table 7: Influence of cultivar on the severity of stripe rust (grain sites infected in the head and total necrosis assessed on flag and flag-1), and the green leaf retention (GLR) of flag-2, assessed on the 8 th October (mean of fungicide treatment). Disease Severity GLR Cultivar Head Flag Flag-1 Flag-2 Grain sites/head Necrosis Necrosis GLR Corack 14.3 a 10.3 a 13.2 a 66.1 b Elmore 1.3 b 2.3 b 4.5 b 66.9 b Trojan 0.3 b 1.4 b 2.7 b 78.5 a Mean LSD P Val <0.001 <0.001 < Corack recorded the highest level of head infection (26.9 grain sites infected/head approx 60% infection) with all fungicide treatments significantly reducing infection, however the single application of Radial at head emergence was statistically superior to all treatments other than two spray of F1/14 and Opus applied at targeted growth stages of GS31 and GS39 (Table 8). Elmore CL Plus and Trojan had less than two grain sites per head infected resulting in fungicide treatment having no significant effect. Fungicide treatment produced a significant reduction in flag leaf and flag-1 necrosis in Corack and significantly enhanced GLR of the lower crop canopy. The most effective treatments were the two spray applications of Radial and F1/14 which were significantly more effective at preventing necrosis on flag-1. GS59 head emergence sprays whilst providing effective control of head infection did not prevent significant leaf loss in the upper canopy. Trojan and Elmore CL Plus had the same trends in disease control at much lower levels of infection. The differences between treatments and between treated and untreated were of less significance. The only significant effect of fungicide application in Trojan was recorded in the lower crop canopy GLR on flag-2, where the late ear emergence treatment and untreated crops were more senesced. The impact of two fungicide applications at GS31 and GS45-47 with Corack was significantly greater than the application a single fungicide at either GS31 or GS45. In contrast with Elmore CL Plus and Trojan the differences in head infection, flag and flag -1 necrosis and GLR on flag -2 due to either two sprays or one spray were never significant if fungicide was timed in the period from GS Table 8. Interaction between cultivar and fungicide on the severity of stripe rust incidence on the head, Necrotic infection assessed on flag and flag-1, and green leaf retention (GLR) of flag-2, on the 8 th October Incidence Disease Severity GLR Cultivar & Fungicide Head Flag Flag-1 Flag-2 Grain sites/head Necrosis Necrosis GLR Corack Untreated 26.9 a 24.1 a 34.5 a 25.7 h Opus GS cd 9.5 c 9.7 cd 75.0 a-f Radial GS b 7.0 cd 11.1 c 79.3 a-e Radial GS bc 7.0 cd 8.3 cde 69.6 b-f Radial GS de 17.9 b 21.3 b 45.8 g 13

14 Radial GS bc 3.3 d-g 3.7 def 84.5 a-d FAR F1/14 GS cd 3.6 d-g 4.1 def 82.6 a-d Elmore Untreated 1.4 f 4.7 def 9.6 cd 56.9 fg Opus GS f 2.0 efg 4.4 def 69.6 b-f Radial GS f 1.4 efg 2.0 ef 67.0 c-f Radial GS f 1.6 efg 5.5 c-f 69.9 b-f Radial GS f 5.7 cde 7.0 c-f 61.7 efg Radial GS f 0.7 fg 1.3 f 70.2 b-f FAR F1/14 GS ef 0.2 g 2.1 ef 72.8 a-f Trojan Untreated 0.4 f 3.3 d-g 6.6 c-f 65.8 def Opus GS f 0.2 g 1.1 f 83.4 a-d Radial GS f 0.3 fg 0.9 f 78.9 a-e Radial GS f 0.5 fg 1.4 f 90.3 a Radial GS f 4.4 d-g 6.6 c-f 58.9 fg Radial GS f 0.8 fg 1.3 f 85.4 abc FAR F1/14 GS f 0.3 fg 0.9 f 86.8 ab Mean LSD P Val <0.001 <0.001 < Assessment 6-2 nd November, Corack GS85-87, Elmore Cl Plus GS83-85 & Trojan GS83-85 The trial was affected by lodging (Table 9). The earliness of lodging which started in mid-october is likely to have influenced yield, particularly with Elmore CL Plus and Trojan where the lodging was more severe. With Trojan there was an indication that fungicide treatment may have increased the lodging index but the differences are not significant (Table 10). Table 9: Influence of cultivar on the %lodging, lodging severity (0-5 scale 0 = no lodging, 5 completely flat) and lodging index (0-500 scale - % lodging x severity) of cultivars (mean of fungicide treatment) assessed on the 2 nd November, 2015 Lodging Index Cultivar Lodged Area Lodging Severity Lodging Index Corack 13.6 c 1.3 c 22.7 c Elmore 80.0 a 3.9 a a Trojan 58.8 b 3.6 b b Mean LSD P Val <0.001 <0.001 <

15 Table 10. Influence of fungicide treatment on the lodging in Trojan assessed on the 2 nd November, 2015 Lodging Index Fungicide Lodged Lodging Lodging Area Severity Index Untreated Opus GS Radial GS Radial GS Radial GS Radial GS31 + GS FAR F1/14 GS Mean LSD P Val The later maturity of Elmore CL Plus and Trojan were apparent in crop canopy greenness scores taken with the hand Held Greenseeker and assessments of green leaf retention on the flag leaf and flag-1 (Table 11). Table 11. Influence of cultivar on NDVI and green leaf retention (GLR) of the flag and the flag-1, assessed on the 2 nd November (mean of fungicide treatment). Canopy Greenness Cultivar NDVI Green Leaf Retention Plot Flag Flag-1 Corack 0.36 b 52.7 b 27.7 c Elmore 0.57 a 77.5 a 58.4 a Trojan 0.58 a 73.8 a 49.8 b Mean LSD P Val <0.001 <0.001 <0.001 The influence of fungicide treatment on crop canopy greenness was also apparent in the NDVI and green leaf retention scores (Table 12) with significant interactions between fungicide treatment and cultivar being recorded (NDVI p=0.059, flag 0.011). With Corack there were significant greening benefits to fungicide application with two fungicides giving better results than single fungicides. In Trojan there were no significant greening benefits due to fungicide application. Table 12. Influence of cultivar and fungicide on the NDVI (scale 0-1) and the green leaf retention (GLR) of the flag and flag 1, assessed on the 2 nd November. Canopy Greenness Cultivar & Fungicide NDVI Green Leaf Retention Plot Flag Flag-1 Corack Untreated 0.29 f 20.0 g 0.0 f Opus GS de 67.5 b-e 47.5 a-d Radial GS e 52.5 ef 27.5 de Radial GS e 47.5 f 16.3 ef 15

16 Stripe rust necrosis flag leaf (%) Radial GS e 55.0 def 20.0 ef Radial GS de 60.0 c-f 32.5 cde FAR F1/14 GS d 66.3 b-e 50.0 abc Elmore Untreated 0.54 c 70.0 a-d 44.0 a-d Opus GS ab 85.0 a 66.3 a Radial GS a 81.3 ab 65.0 a Radial GS abc 75.0 abc 57.5 ab Radial GS bc 71.3 abc 52.5 abc Radial GS abc 76.3 ab 60.0 ab FAR F1/14 GS abc 83.8 a 63.8 ab Trojan Untreated 0.57 abc 75.0 abc 48.8 a-d Opus GS a 76.3 ab 55.0 ab Radial GS abc 73.8 abc 50.0 abc Radial GS abc 71.3 abc 48.8 a-d Radial GS abc 76.3 ab 50.0 abc Radial GS a 71.3 abc 53.8 abc FAR F1/14 GS ab 72.5 abc 42.5 bcd Mean LSD P Val ii) Disease progress Combining the stripe rust infection data taken during the course of the season enables the disease progress graphs to be developed for the different fungicide treatments on the crop canopy leaves. Influence of fungicide treatment on the flag leaf necrosis Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS32 24th Aug GS43 10th Sept GS51 28th Sept GS71 8th Oct GS75 Figure 1. Stripe rust necrosis assessed on the flag leaf of Corack (MS rated) 16

17 Stripe rust necrosis flag leaf (%) Stripe rust necrosis flag leaf (%) Stripe rust necrosis on the flag leaf was significantly reduced by all fungicide treatments except the single timing of fungicide applied at ear emergence. There was no difference between the other fungicide treatments with all treatments keeping necrosis below 10% compared to the 25% infection in the untreated Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS31 24th Aug GS38 10th Sept GS47 28th Sept GS69 8th Oct GS73 Figure 2. Stripe rust necrosis assessed on the flag leaf of Elmore CL Plus (MR-MS rated) All fungicide treatments except the single ear emergence spray kept stripe rust necrosis below 2.5% infection compared to 10% in the untreated flag leaves. Trojan necrosis levels were half those observed in Elmore CL Plus peaking at 5% necrosis on the flag leaf Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS30 24th Aug GS33 10th Sept GS45 28th Sept GS69 8th Oct GS73 Figure 3. Stripe rust necrosis assessed on the flag leaf of Trojan (MR rated) 17

18 Stripe rust necrosis flag-1(%) Stripe rust necrosis flag-1(%) Influence of fungicide treatment on the flag leaf minus 1 necrosis Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS32 24th Aug GS43 10th Sept GS51 28th Sept GS71 8th Oct GS75 Figure 4. Stripe rust necrosis assessed on the flag-1 of Corack due (MS rated) Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS31 24th Aug GS38 10th Sept GS47 28th Sept GS69 8th Oct GS73 Figure 5. Stripe rust necrosis assessed on the flag-1 of Elmore CL Plus (MR-MS rated) 18

19 Stripe rust necrosis flag-1(%) Untreated Opus 250 ml GS31+39 Radial 420ml GS31 Radial 420ml GS39 Radial 420ml GS59 Radial 420ml GS31+39 FAR F1/14 500ml GS th Aug GS30 24th Aug GS33 10th Sept GS45 28th Sept GS69 8th Oct GS73 Figure 6. Stripe rust necrosis assessed on the flag-1 of Trojan (MR rated) Flag leaf necrosis due to stripe rust infection was significantly reduced by fungicide treatment in all three cultivars, however with the more resistant cultivars Elmore CL Plus and Trojan the level of necrosis in the untreated was reduced to below 10% of the flag leaf affected area compared to 25% with Corack. In addition with Corack there was a significant benefit to applying two fungicides compared to a single application of Radial. The more resistant nature of Elmore CL Plus and Trojan makes it difficult to see any advantage to two fungicides over one. There was no specific benefit associated with one particular timing, provided the fungicide was applied in the GS31-39 timing window (Figures 1-3). iii) Yield and quality data a) Influence of cultivar on yield There was no significant difference in yield between the three cultivars in the trial (Table 24). Screenings and test weight were significantly higher with Elmore CL Plus and Trojan with TSW significantly lower when compared to Corack. Table 24. Influence of cultivar on yield (t/ha) and grain quality (test weight (kg/hl), screenings (%) and thousand seed weight (g)) of wheat harvested on the 26 th November (mean of fungicide treatments). Yield and grain quality Cultivar Yield Test weight Screenings TSW Corack 5.39 a 70.0 c 1.3 c 40.3 a Elmore CL Plus 5.37 a 76.8 a 3.2 b 32.3 b Trojan 5.39 a 75.3 b 5.4 a 31.7 b Mean LSD P Val <0.001 <0.001 <

20 b) Influence of fungicide on yield & quality Averaged over all three cultivars there was no significant yield response to fungicide treatment (Table 25), however this disguised a significant interaction between cultivar and fungicide treatment (Table 26). Fungicide treatments had no significant on screenings and TSW but did increase test weight. Table 25. Influence of fungicide on the yield characteristics, yield (t/ha), test weight (kg/hl), screenings (%) and thousand seed weight (g), assessed on the 2 nd November (mean of cultivars). Yield and grain quality Fungicide Yield Test weight Screenings TSW Untreated 5.4 a 72.7 c 3.6 a 34.0 a Opus GS a 73.9 b 3.3 a 34.7 a Radial GS a 73.8 b 3.6 a 35.5 a Radial GS a 74.1 b 3.0 a 34.7 a Radial GS a 74.4 ab 3.1 a 34.7 a Radial GS31 + GS a 74.1 b 3.2 a 35.1 a FAR F1/14 GS a 75.2 a 3.4 a 34.7 a Mean LSD P Val c) Interaction between cultivar and fungicide treatment Fungicide treatment significantly increased yield and test weight in Corack, with later fungicide timings at flag leaf and head emergence being superior (not significant) to an early 1 st node fungicide. There was no difference in the performance of two spray programmes based on Opus, Radial and F1/14 and no significant advantage of two sprays over a single fungicide. Fungicide treatment in Elmore CL Plus and Trojan generated no significant yield or quality differences. Fungicide treatments applied to Trojan reduced yield, although with all but one treatment the decrease was not significant. This yield decrease may have been associated with the high degree of lodging in this cultivar, which showed a trend to be greater in fungicide treated crops. Table 26. Influence of cultivar and fungicide on yield (t/ha) and grain quality, test weight (kg/hl), screenings (%) and thousand seed weight (g), assessed on the 2 nd November Yield and grain quality Cultivar & Fungicide Yield Test weight Screenings TSW Corack Untreated 4.6 c 66.6 j 1.6 ghi 38.3 a Opus GS ab 70.9 ghi 1.2 i 39.8 a Radial GS bc 69.4 i 1.2 i 41.4 a Radial GS ab 69.7 hi 1.1 i 40.7 a Radial GS ab 71.2 gh 1.5 hi 40.5 a Radial GS abc 69.8 hi 1.0 i 41.6 a FAR F1/14 GS abc 72.3 fg 1.9 f-i 39.8 a Elmore Untreated 5.5 abc 77.0 ab 3.2 ef 32.3 b Opus GS abc 76.8 ab 3.0 e-h 33.1 b 20

21 Yield (t/ha) Radial GS abc 76.3 abc 3.3 def 32.4 b Radial GS abc 76.7 ab 3.1 efg 32.4 b Radial GS abc 77.2 a 3.4 c-f 32.2 b Radial GS abc 77.0 ab 3.2 ef 32.4 b FAR F1/14 GS ab 76.6 abc 3.4 c-f 31.6 b Trojan Untreated 6.1 a 74.4 de 5.9 ab 31.6 b Opus GS bc 74.0 ef 5.7 ab 31.2 b Radial GS abc 75.7 a-d 6.4 a 32.6 b Radial GS abc 75.9 a-d 4.8 bcd 31.0 b Radial GS abc 74.9 cde 4.5 b-e 31.6 b Radial GS ab 75.4 b-e 5.5 ab 31.4 b FAR F1/14 GS abc 76.7 ab 4.9 abc 32.7 b Mean LSD P Val Corack Elmore Trojan Untreated Opus GS31+39 Radial GS31 Radial GS39 Radial GS59 Radial GS31+39 Fungicide product and timing Figure 2. Influence of fungicide product and timing on yield (t/ha) FAR F1/14 GS31+39 DISCUSSION Significant yield responses from foliar fungicides were limited to Corack which correlated to a greater degree of stripe rust necrosis observed in the top three leaves of the crop canopy. There was no difference in yield performance due to fungicide product and timing. Protection provided by a GS31 fungicide in this cultivar did not result in a significant yield response over the untreated whilst a GS45-47 (mid booting) timed spray (delayed from GS39 by poor spraying weather) did generate a significant response. Elmore CL Plus and Trojan displayed a greater level of stripe rust resistance with significantly less necrosis in the upper crop canopy. Due to less necrosis in the untreated the impact of fungicide application was much smaller with no significant yield increases and no difference in stripe rust necrosis and yield of different fungicide strategies. 21

22 Trial 2. Evaluating the interaction between new generation fungicide application and genetic resistance for the control of leaf rust (Puccinia triticana) in wheat Trial details FAR Code FAR W15-21 Location Hamilton, VIC (Dryland) Collaborator Southern Farming Systems (SFS) Target disease Leaf rust (Puccinia titicina) Rotation position 1 st wheat after break METHOD Treatment List i) Cultivar Bolac rated MS for leaf rust based on Lr34 Phantom rated MR-MS for leaf rust based on Lr46 ii) Trt No Fungicide treatment and timing Treatment Rate Active ingredient (A.I) (ml/ha) A.I applied g/ha Treatment Timing * 1 Untreated 2 Opus 125 SC 250 Epoxiconazole GS31 3 Opus 125 SC 250 Epoxiconazole GS39 4 Opus 125 SC 250 Epoxiconazole GS59 5 Opus 125 SC 250 x 2 Epoxiconazole 62.5 GS31 + GS39 6 Radial 420 Epoxiconazole + Azoxystrobin GS31 7 Radial 420 Epoxiconazole + Azoxystrobin GS39 8 Radial 420 Epoxiconazole + Azoxystrobin GS59 9 Radial 420 x 2 Epoxiconazole + Azoxystrobin GS31 + GS39 10 FAR F1/14 Epoxiconazole + SDHI GS31 11 FAR F1/14 Epoxiconazole + SDHI GS39 12 FAR F1/14 Epoxiconazole + SDHI GS59 13 FAR F1/14 Epoxiconazole + SDHI GS31 + GS39 14 Folicur 145 x 2 Tebuconazole (control) 125 GS31 + GS39 15 Untreated Trial design: Split plot design where cultivar is the main plot and fungicide treatment is the sub plot (2 Cultivars x 15 Fungicide treatments x 4 replicates = 120 harvestable plots in total). Sowing date: 30 April 2015 Inoculation Application 1 Application 2 Application 3 Date 18 August 18 August 29 September Growth Stage Phantom: GS32 Bolac: GS32 Phantom: GS55-59 Bolac: GS65 Rate 200 plants 100 Plants Pathogen 104-1,3,4,6,7,8,9,10,12+Lr37 Method Spreader plants Spore suspension Spreader plants 22

23 Fungicide application Application A Application B Application C Application Date 17 Aug 13 Sept 30 Sept (GS on the 4th Sept) Growth Stage - Phantom GS32 (F-1 50% emg) GS37 GS55-59 Growth Stage - Bolac GS32 (F-1 50% emg) GS37-42 GS65 Equipment 9L Steel 2m Hand boom 9L Steel 2m Hand boom 9L Steel 2m Hand boom Nozzle brand Lurmark Lurmark Lurmark Nozzle type Flat Fan Flat Fan Flat Fan Nozzle size 01F-80 01F-80 01F-80 Spray Volume (L/ha) Assessment technique Assessment Scale Description Disease Severity % 0 % No infection present, 100 % - Total leaf area infected LAI. 10 stems assessed per plot Disease Incidence % % of assessed components with infection. 10 stems assessed per plot Green leaf retention (GLR) % 0 % - No green area remaining in the plant component or crop 100% - Fully green with no senescence NDVI (Normalized Difference scale Each plot scanned with a hand held Vegetation Index) Lodging Index Area (%) Severity (0-5) Greenseeker Area of plot lodged assessed as a percentage and the severity of lodging (0-standing, 5-flat) multiplied together to generate a lodging index. Grain Yield t/ha Measured using a plot harvester Grain Quality %, kg/hl and g Protein, screenings, specific weight and thousand grain weight RESULTS i) Disease infection The trial was assessed on the 18 th August, 4 th September, 23 rd September, 29 th September and 13 th October without leaf rust being identified in the trial. In a neighbouring trial, leaf rust was first found in the plots on the 13 th October. Trial was assessed on 30 th October at GS85-87, for incidence and severity of disease and the associated impact on green leaf retention (GLR) (Table 1 & 2). Both cultivars carried very low levels of disease (less than 3% severity) with significantly more leaf rust on Phantom but more STB infection on Bolac. 23

24 Table 1. Influence of cultivar on the severity of Septoria tritici blotch (STB), leaf rust (LR) severity, active (A) and necrotic (N), and green leaf retention (GLR) of the flag leaf, assessed on the 30 th October, GS85-87 (mean of fungicide treatments). Cultivar Flag Leaf Septoria Active LR Necrotic LR GLR Phantom 0.3 b 0.4 a 0.1 a 59.6 b Bolac 0.8 a 0.2 b 0.1 a 71.7 a Mean LSD (0.05) P Val < <0.001 Table 2. Influence of fungicide on the severity of Septoria tritici blotch (STB), active (A) and necrotic (N) Leaf Rust (LR) and green leaf retention (GLR) of the flag leaf, assessed on the 30 th October, GS85-87 (mean of cultivars). Fungicide Flag Leaf Septoria Active LR Necrotic LR GLR Untreated 2.19 a 0.51 abc 0.14 a 61.4 bc Opus GS d 0.68 a 0.08 abc 66.3 abc Opus GS d 0.23 def 0.04 bc 67.5 abc Opus GS cd 0.00 f 0.00 c 64.2 abc Opus GS31+GS d 0.15 def 0.03 c 67.9 abc Radial GS d 0.64 a 0.03 c 69.1 ab Radial GS d 0.24 def 0.04 bc 62.8 bc Radial GS d 0.03 f 0.08 abc 64.8 abc Radial GS31+ GS d 0.09 def 0.05 abc 69.3 ab FAR F1/14 GS bc 0.49 abc 0.06 abc 59.7 c FAR F1/14 GS d 0.29 cde 0.06 abc 71.5 a FAR F1/14 GS d 0.06 ef 0.06 abc 64.5 abc FAR F1/14 GS31 + GS d 0.14 def 0.01 c 66.7 abc Folicur GS31 + GS d 0.33 bcd 0.06 abc 66.3 abc Untreated 1.44 b 0.56 ab 0.13 ab 63.7 abc Mean LSD P Val <0.001 < All fungicide treatments gave significant control of STB, with the earlier fungicide timing at GS31 and two spray approaches giving better control than other treatments, although differences were not significant. With very low levels of leaf rust infection later fungicide timings at GS59 (ear emergence) and two spray programmes applied at GS31 & 39 were significantly more effective than the early GS31 timings which were most efficacious for STB. These effects of different optimal fungicide timings for the two foliar diseases are reflected in the disease incidence assessments (Table 3 & 4). Table 3. Influence of cultivar on the incidence of Septoria tritici blotch (STB) Leaf Rust (LR) incidence, active (A) and necrotic (N), of the flag leaf, assessed on the 30 th October, GS85-87 (mean of Fung. trts). Cultivar Flag Leaf STB Active LR Necrotic LR Phantom 7.7 b 23.2 a 4.2 a Bolac 20.3 a 17.0 b 4.3 a Mean LSD P Val <

25 Table 4. Influence of fungicide on the incidence of Septoria tritici blotch (STB) Leaf Rust (LR) incidence, active (A) and necrotic (N), of the flag leaf, assessed on the 30 th October, GS85-87 (mean of cultivars). Fungicide Flag Leaf Septoria Active LR Necrotic LR Untreated 42.5 a 33.8 ab 7.5 ab Opus GS de 41.3 a 7.5 ab Opus GS c 16.3 def 3.8 abc Opus GS bc 0.0 g 0.0 c Opus GS31+GS e 13.8 d-g 2.5 abc Radial GS e 36.3 a 2.5 abc Radial GS cde 18.8 cde 3.8 abc Radial GS cd 1.3 g 7.5 ab Radial GS31+ GS e 7.5 efg 3.8 abc FAR F1/14 GS ab 32.5 abc 3.8 abc FAR F1/14 GS e 21.3 b-e 3.8 abc FAR F1/14 GS cde 3.8 fg 2.5 abc FAR F1/14 GS31 + GS e 11.3 efg 1.3 bc Folicur GS31 + GS cde 27.5 a-d 5.0 abc Untreated 31.3 ab 36.3 a 8.8 a Mean LSD P Val <0.001 < In contrast to the leaf rust ratings Phantom (MR-MS) had similar levels of leaf rust incidence to Bolac (MS) (Table 5). Product performance compared as the two spray programmes applied at GS31 & GS39 indicated that Radial and the coded fungicide FAR F1/14 were significantly more effective at controlling leaf rust than Folicur (tebuconazole) (Figure 1 & 2). Epoxiconazole (Opus) gave similar results to FAR F1/14 but was not statistically superior to Folicur. Table 5. Influence of fungicide and cultivar on the incidence of Septoria tritici blotch (STB), Leaf Rust (LR) incidence, active (A) and necrotic (N), of the flag leaf, assessed on the 30 th October, GS Fungicide Flag Leaf Septoria Active LR Necrotic LR Bolac Phantom Bolac Phantom Bolac Phantom Untreated 52.5 a 32.5 bc 27.5 a-d 40.0 a 10.0 abc 5.0 abc Opus GS def 2.5 ef 40.0 a 42.5 a 12.5 ab 2.5 bc Opus GS bc 2.5 ef 10.0 def 22.5 a-e 0.0 c 7.5 abc Opus GS c 20.0 cde 0.0 f 0.0 f 0.0 c 0.0 c Opus GS ef 0.0 f 15.0 c-f 12.5 def 5.0 abc 0.0 c Radial GS def 0.0 f 30.0 a-d 42.5 a 2.5 bc 2.5 bc Radial GS c-f 2.5 ef 15.0 c-f 22.5 a-e 0.0 c 7.5 abc Radial GS bc 5.0 def 0.0 f 2.5 ef 0.0 c 15.0 a Radial GS ef 0.0 f 2.5 ef 12.5 def 7.5 abc 0.0 c FAR F1/14 GS ab 22.5 cd 27.5 a-d 37.5 ab 2.5 bc 5.0 abc FAR F1/14 GS ef 0.0 f 27.5 a-d 15.0 c-f 5.0 abc 2.5 bc FAR F1/14 GS cd 5.0 def 5.0 ef 2.5 ef 5.0 abc 0.0 c FAR F1/14 GS ef 0.0 f 5.0 ef 17.5 b-f 2.5 bc 0.0 c Folicur GS c-f 5.0 def 15.0 c-f 40.0 a 0.0 c 10.0 abc Untreated 45.0 ab 17.5 c-f 35.0 abc 37.5 ab 12.5 ab 5.0 abc Mean LSD

26 P Val Folicur GS31 + GS39 FAR F1/14** GS31 + GS39 Radial GS31+ GS39 Opus GS31+GS39 Untreated % leaf rust incidence GS85-87 Figure 1. % incidence of active leaf rust present in late grain fill GS85-87 (mean of Bolac and Phantom) Folicur GS31 + GS39 FAR F1/14** GS31 + GS39 Radial GS31+ GS39 Opus GS31+GS39 Untreated % STB incidence GS85-87 Figure 2. % incidence of Septoria leaf blotch present in late grain fill GS85-87 (mean of Bolac and Phantom) ii) Green leaf retention Differences in crop canopy greenness recorded as NDVI (Normalised Difference Vegetative Index) with the Greenseeker were very small with few significant differences (Table 6). There were no consistent differences between fungicides and the untreated or between products in this trial. Table 6. Influence of fungicide on the NDVI of the crop canopy, assessed on the 30 th October, GS (mean of cultivars). NDVI Fungicide 29 Sept 13 Oct 23 Oct 30 Oct 9 Nov Untreated c d a abc a Opus GS ab abc a abc a Opus GS bc a-d a bc a Opus GS abc bcd a abc a Opus GS31+GS a abc a abc a 26

27 Radial GS ab abc a abc a Radial GS ab abc a c a Radial GS ab bcd a bc a Radial GS31+ GS ab a a abc a FAR F1/14 GS abc a-d a abc a FAR F1/14 GS bc ab a a a FAR F1/14 GS ab cd a c a FAR F1/14 GS31 + GS a abc a abc a Folicur GS31 + GS ab a-d a abc a Untreated bc abc a ab a Mean LSD P Val iii) Grain Yield (t/ha) and Quality Influence of cultivar Averaged over all treatments there was no difference in yield between Bolac and Phantom, although Bolac produced statistically superior grain protein, test weight and lower screenings (Table 7). Table 7: Influence of cultivar treatment on grain yield (t/ha) and quality, test weight (kg/hl), protein (%) and screenings % (2.2mm) (mean of fungicide treatments). Grain Yield and Quality Cultivar Yield Test weight Protein Screenings Phantom 5.22 a 71.3 b 11.5 b 6.5 a Bolac 5.08 a 73.2 a 12.5 a 5.2 b Mean LSD P Val <0.001 <0.001 Influence of fungicide Fungicide application resulted in no significant yield benefit over the untreated crop (Table 8). The same was the case when grain quality was considered. There was a trend for the two spray programmes to produce the highest yields but the differences were not statistically significant. Table 8: Influence of fungicide treatment on grain yield (t/ha) and quality, test weight (kg/hl), protein (%) and screenings % (2.2mm) (mean of cultivars) Grain Yield and Quality Fungicide Yield Test weight Protein Screenings Untreated 5.00 a 73.6 a 12.6 a 5.3 c Opus GS a 72.5 a 12.0 abc 5.8 bc Opus GS a 68.7 b 11.5 c 7.7 a Opus GS a 70.6 ab 12.4 ab 6.9 ab Opus GS31+GS a 72.5 a 12.2 abc 6.0 bc Radial GS a 74.0 a 12.1 abc 4.9 c 27

28 Radial GS a 72.2 a 12.1 abc 5.7 bc Radial GS a 71.6 ab 12.2 abc 5.9 bc Radial GS31+ GS a 72.3 a 12.2 abc 5.2 c FAR F1/14 GS a 71.7 ab 11.8 bc 5.7 bc FAR F1/14 GS a 73.4 a 12.2 abc 5.4 bc FAR F1/14 GS a 72.3 a 11.8 abc 5.5 bc FAR F1/14 GS31 + GS a 73.0 a 11.9 abc 5.7 bc Folicur GS31 + GS a 72.6 a 11.5 bc 5.9 bc Untreated 5.13 a 72.9 a 12.0 abc 5.9 bc Mean LSD P Val Differences in grain quality were relatively small when the influence of fungicide application was considered for individual cultivars (Table 9). Table 9: Influence of fungicide and cultivar on grain quality test weight (kg/hl), protein (%) and screenings % (2.2mm) Grain Yield and Quality Fungicide Test weight Protein Screenings Bolac Phantom Bolac Phantom Bolac Phantom Untreated 74.5 ab 72.8 abc 13.5 a 11.7 b-f 5.0 d-g 5.6 b-g Opus GS ab 70.8 a-d 12.4 a-d 11.6 c-f 5.1 c-g 6.6 a-g Opus GS d 70.8 a-d 12.0 b-e 11.0 ef 7.3 abc 8.0 a Opus GS abc 69.0 cd 12.8 ab 11.9 b-e 6.1 a-g 7.7 ab Opus GS31+GS abc 71.6 abc 12.8 ab 11.7 b-f 5.3 c-g 6.8 a-e Radial GS a 72.9 abc 12.4 a-d 11.7 b-f 4.3 g 5.4 c-g Radial GS a 69.6 bcd 12.7 abc 11.6 c-f 4.4 g 7.0 a-d Radial GS abc 70.3 a-d 12.7 abc 11.8 b-f 5.2 c-g 6.7 a-f Radial GS31+ GS abc 71.1 a-d 12.6 a-d 11.9 b-e 4.7 efg 5.8 b-g FAR F1/14 GS a-d 72.2 abc 12.9 ab 10.7 f 5.6 b-g 5.8 a-g FAR F1/14 GS abc 73.2 abc 12.4 bcd 12.0 b-e 4.5 fg 6.3 a-g FAR F1/14 GS abc 70.8 a-d 12.6 a-d 11.0 ef 4.9 d-g 6.2 a-g FAR F1/14 GS31+GS abc 72.3 abc 12.4 a-d 11.5 def 4.7 efg 6.7 a-f Folicur GS31 + GS a 70.4 a-d 12.1 b-e 11.0 ef 5.7 b-g 6.1 a-g Untreated 74.4 ab 71.3 a-d 12.0 b-e 11.9 b-e 4.9 d-g 6.9 a-e Mean LSD P Val

29 DISCUSSION The late onset of leaf rust infection resulted in low levels of leaf rust (1% severity & 40% disease incidence) that were not cost effective to control. Fungicide application did not produce significant yield responses in either Bolac or Phantom, however the research did highlight differences in the efficacy of fungicides tested and confirmation that ear emergence fungicide timing was more effective than early fungicide applications at the start of stem elongation (GS31). Although disease pressure was extremely low there was evidence that epoxiconazole with azoxystrobin (Radial ) and the experimental fungicide FAR F1/14 were superior to tebuconazole when applied in two spray programmes at GS31 and GS39. 29

30 Trial 3. Evaluating the interaction between new generation fungicide application and the adult plant resistance genes Yr 18 and the combination of Yr18 & 29 in Near Isogenic Lines (NIL) of Avocet for the control of stripe rust (Puccinia striiformis) Trial details FAR Code FAR W15-22 Location Horse Unit, Nr Cobbitty, NSW (Irrigated) Collaborator PBI Cobbitty, NSW (Dr K. Sandhu) Target disease Stripe rust (Puccinia striiformis) Rotation position 1 st wheat after break METHOD Treatment List i) Cultivar 1. Avocet S no APR protection against stripe rust 2. NIL Avocet + Yr NIL Avocet + Yr 18 + Yr 29 ii) Trt No Fungicide treatment Treatment Rate Active ingredient (A.I) (ml/ha) A.I applied g/ha Treatment Timing * 1 Untreated 2 Opus 125 SC 250 x 2 Epoxiconazole 62.5 GS31 + GS39 3 Radial 420 Epoxiconazole + Azoxystrobin GS31 4 Radial 420 Epoxiconazole + Azoxystrobin GS39 5 Radial 420 Epoxiconazole + Azoxystrobin GS59 6 Radial 420 x 2 Epoxiconazole + Azoxystrobin GS31 + GS39 7 FAR F1/14** GS31 + GS39 Note: Treatment 6 was excluded from the trial report due to errors in spray application Trial design: Split plot design (3 Cultivars x 7 Fungicide treatments) x 3 replicates = 63 harvestable plots in total). Sowing date: 13 May 2015 Inoculation Application 1 Application 2 Application 3 Date: 24 July July August 2015 Growth Stage: Z31 Z31 & 32 Z37&38 Rate: Infected pots 2 mg/ml 2 mg/ml Pathogen: 134E16A E16A E16A Method: Pots were placed in buffer lines Spray using Herbi Spray using Herbi Approximately 2 mg of spores per ml of light mineral oil (Univar Solvent L naphtha 100, Univar Australia Pty Ltd) were used and approximately 500 ml of dilution was used for each field inoculation. 30

31 Fungicide application Application 1 Application 2 Application 3 Date: 29 th July 28 th August NIL Yr st Sept Yr29 & Avocet S 31 st August NIL Yr18 Growth Stage: Z31 Z39 Z59 Water Rate: 100 L/ha 100 L/ha 100 L/ha Method: Sprayer Sprayer Sprayer Notes: Nozzle DG Teejet VP Nozzle DG Teejet VP Nozzle DG Teejet VP Assessment Technique Assessment Scale Description Disease Severity % 0 % No infection present, 100 % - Total leaf area infected LAI. 10 stems assessed per plot or whole plot assessment Disease Incidence % % of assessed components with infection. 10 stems assessed per plot or whole plot assessment Green leaf retention (GLR) % 0 % - No green area remaining 100% - Leaf fully green. 10 stems assessed per plot NDVI (Normalized Difference Vegetation Index) 0 1 scale Each plot scanned with a hand held Greenseeker Grain Yield t/ha Measured using small plot harvester Grain Quality % and kg/hl Protein, screenings and specific weight Statistical Analysis All data from this trial was analysed using a confidence interval of 95% unless otherwise specified. All mention of significant differences contained within this report refer to statistically significant differences. 31

32 RESULTS i) Disease infection Assessment of the trial on the 7 th August did not reveal stripe rust infection in any of the trial plots. Baseline Assessment - 24 th August Stripe rust infection was at low levels of severity on F-2 and F-3, Avocet S recoded just less than 3% infection on F-3. The influence of the APR genes on the infection level was clearly demonstrated in the NIL set at flag leaf emergence (Table 1). Table 1. Influence of adult plant resistance genes on disease severity and incidence assessed on the 24 th August at GS37-39 Disease Severity Disease Incidence Flag Flag-1 Flag-2 Flag-3 Flag Flag-1 Flag-2 Flag-3 Avocet S NIL YR NIL YR18+YR Assessment 2-10 th September Avocet S GS49 (late booting stage), NIL Yr18 GS45 (mid booting stage) & NIL Yr18+29 GS51 (early ear emergence stage) The influence of two APR genes in the NIL Yr18+29 significantly reduced active infection on F-1 and F- 2 at the late booting stage and there was a clear trend for reduced infection with NIL Yr18 (Table 2). Table 2. Influence of adult plant resistance genes on the severity of active stripe rust and total leaf area affected by stripe rust on flag, flag-1 and flag-2 when assessed on the 10th September at GS45-51 (mean of fungicide treatments) Disease Severity Flag Flag-1 Flag-2 Active Total Active Total Active Total Avocet S 1.4 a 1.8 a 5.4 a 9.5 a 3.2 a 6.5 a NIL YR a 2.7 a 5.6 a 12.2 a 1.2 ab 3.7 ab NIL YR18+YR a 1.3 a 0.5 a 1.9 b 0.1 b 0.6 b Mean LSD P Val Note: assessment excludes plots to be treated with fungicide at GS59 When averaged over the three lines fungicides applications applied at GS31 and/or at GS39 significantly reduced stripe rust infection on the top two leaves (Table 3). Table 3. Influence of fungicide on the severity of active stripe rust and total leaf area affected by stripe rust on flag, flag-1 and flag-2 when assessed on the 10th September at GS45-51 (mean of plant resistance genes) Disease Severity Flag Flag-1 Flag-2 32

33 Active Total Active Total Active Total Untreated 4.4 a 6.7 a 13.7 a 17.9 a 4.6 a 8.5 a Opus GS b 0.4 b 1.9 b 4.9 b 0.9 ab 2.0 b Radial GS b 0.3 b 0.7 b 4.1 b 0.2 b 1.4 b Radial GS b 1.2 b 1.7 b 7.8 b 1.7 ab 4.9 ab Radial GS Radial GS FAR F1/14 GS b 1.0 b 1.1 b 4.7 b 0.2 b 1.1 b Mean LSD P Val Note: Due to a plot spraying error the data for two sprays of Radial has been omitted. Assessment excludes plots to be treated with fungicide at GS59 Assessment 3-28 th September, 2015 Avocet S GS67 (flowering stage), NIL Yr18 GS65 (mid flowering stage) & NIL Yr18+29 GS69 (late flowering stage), Assessment of the flag leaf showed the presence of APR genes significantly reduced both active infection and necrosis due to the disease (average of all fungicide treatments) (Table 3). On F-1 two genes gave superior control of active infection and leaf necrosis to one APR gene as well as superior green leaf retention (GLR) on flag-2. Table 3. Influence of adult plant resistance genes on the severity of active stripe rust and total leaf area affected by stripe rust on flag and flag-1 when assessed on the 28 th September at GS69, GLR assessed on flag-2 (mean of fungicide treatments). Disease Severity and GLR Cultivar Flag Flag-1 Flag-2 Active Total Active Total GLR Avocet S 16.6 a 31.0 a 0.6 a 29.2 a 61.0 b NIL YR b 16.5 b 0.6 a 20.1 b 63.5 b NIL YR18+YR b 8.2 c 0.1 b 4.6 c 74.3 a Mean LSD P Val <0.001 < < All fungicide treatments significantly reduced active infection, total stripe rust necrosis on the top two leaves and increased green leaf retention on F-2 except the ear emergence timed spray. Whilst this timing significantly reduced active infection on the flag compared to the untreated it was applied too late to prevent high levels of necrosis on the top three leaves (Table 4). Table 4. Influence of fungicide on the severity of active stripe rust and total leaf area affected by stripe rust on flag and flag-1 when assessed on the 28 th September at GS69, GLR assessed on flag-2 (mean of plant resistance genes). Disease Severity and GLR Fungicide Flag Flag-1 Flag-2 Active Total Active Total GLR Untreated 16.3 a 41.0 a 1.3 a 42.3 a 44.6 c 33

34 Opus GS bc 8.1 bc 0.5 b 8.7 b 72.8 ab Radial GS b 12.8 b 0.1 b 4.9 b 81.7 a Radial GS bc 8.6 bc 0.2 b 9.7 b 68.1 b Radial GS bc 35.6 a 0.2 b 36.9 a 50.0 c Radial GS FAR F1/14 GS c 5.1 c 0.2 b 5.2 b 80.2 a Mean LSD P Val <0.001 < <0.001 <0.001 Table 5. Influence of adult plant resistance and fungicide application on the severity of active stripe rust and total leaf area affected by stripe rust on flag and flag-1 when assessed on the 28 th September at GS565-69, GLR assessed on flag-2. Disease severity and GLR Cultivar & Fungicide Flag Flag-1 Flag-2 Active Total Active Total GLR Avocet S Untreated 37.5 a 63.3 a 1.3 ab 71.5 a 26.5 f Opus GS cde 12.8 d-g 1.3 abc 12.6 de 64.8 cd Radial GS b 24.2 cd 0.2 bcd 3.6 ef 87.0 a Radial GS bcd 12.2 d-g 0.3 bcd 9.8 def 70.8 a-d Radial GS bc 64.9 a 0.0 d 72.2 a 32.3 f Radial GS FAR F1/14 GS c-f 8.4 efg 0.5 bcd 5.6 def 84.2 abc NIL+YR18 Untreated 7.6 c-f 41.4 b 2.3 a 46.0 b 41.2 ef Opus GS f 7.5 efg 0.2 bcd 11.1 def 70.8 a-d Radial GS ef 7.7 efg 0.0 d 10.4 def 72.9 a-d Radial GS def 10.3 efg 0.3 bcd 15.8 d 66.4 bcd Radial GS f 26.2 c 0.5 bcd 28.6 c 58.2 de Radial GS FAR F1/14 GS f 5.6 fg 0.1 bcd 8.7 def 71.5 a-d NIL+YR18+YR29 Untreated 3.8 def 18.2 cde 0.3 bcd 9.3 def 66.2 bcd Opus GS f 3.9 fg 0.0 d 2.4 ef 82.9 abc Radial GS ef 6.5 efg 0.0 d 0.8 f 85.0 ab Radial GS f 3.3 g 0.1 bcd 3.5 ef 67.2 bcd Radial GS f 15.7 c-f 0.0 d 10.0 def 59.4 de Radial GS FAR F1/14 GS f 1.4 g 0.0 cd 1.3 f 84.8 ab Mean LSD P Val < <

35 Assessment 4-8 th October Avocet S GS75 (mid milk stage), NIL Yr18 GS75 (mid milk stage) & NIL Yr18+29 GS77 (late milk stage) One APR gene in NIL Yr18 significantly reduced leaf area necrosis on the flag leaf and F-1 as well as increasing GLR on F-2, however averaged over all fungicide treatments it was ineffective against head infection relative to NIL Yr18+Yr29 which was superior in all aspects of assessment (Table 6). Table 6. Influence of adult plant resistance genes on the severity of active stripe rust on the head, necrotic infection on flag and flag-1, and green leaf retention on flag-2, when assessed on the 8 th October at GS75-77 (mean of fungicide treatments) Disease severity and GLR Cultivar Head Flag Flag-1 Flag-2 Infection Necrotic Necrotic GLR Avocet S 8.8 ab 52.0 a 39.8 a 31.1 c NIL+YR a 14.7 b 23.9 b 42.4 b NIL+YR18+YR b 7.6 c 6.4 c 54.9 a Mean LSD P Val <0.001 <0.001 <0.001 Only the GS59 ear emergence fungicide application of Radial gave significant control of stripe rust infection in the head, although the level of control was relatively poor compared to that achieved on the foliage with earlier spray timings (Table 7). All spray programmes except the GS59 spray application significantly reduced stripe rust necrosis on the flag and F-1 compared to the untreated giving approximately 70-80% control of the necrosis. Table 7. Influence of fungicide on the severity of active stripe rust on the head, necrotic infection on flag and flag-1, and green leaf retention on flag-2, when assessed on the 8 th October at GS75-77 (mean of plant resistance genes) Disease severity and GLR Fungicide Head Flag Flag-1 Flag-2 Infection Necrotic Necrotic GLR Untreated 10.4 a 43.8 a 51.5 a 19.7 c Opus GS a 15.1 b 9.6 b 53.2 ab Radial GS a 17.3 b 10.1 b 53.2 ab Radial GS a 14.7 b 12.6 b 43.1 b Radial GS b 42.3 a 46.0 a 29.9 c Radial GS FAR F1/14 GS ab 15.2 b 10.2 b 57.5 a Mean LSD P Val <0.001 <0.001 <0.001 The same treatment patterns were observed in all three lines, although the overall levels of necrosis were progressively lower with NIL Yr18 and NIL Yr18+29 (Table 8). Fungicides were still giving significant improvements in GLR with the most resistant line NIL Yr18+29, there was a trend for fungicide treated crops to be superior to the untreated although not significant. 35

36 Table 8. Interaction between adult plant resistance in Avocet NILs and fungicide application on the severity of necrotic infection on flag and flag-1 and green leaf retention on flag-2, when assessed on the 8 th October at GS75-77 Disease severity and GLR Cultivar & Fungicide Head Flag Flag-1 Flag-2 Infection Necrotic Necrotic GLR Avocet S Untreated 8.6 a-f 85.5 a 88.0 a 3.7 f Opus GS a-d 31.0 b 15.9 de 35.4 bcd Radial GS ef 39.8 b 15.1 def 44.0 abc Radial GS abc 35.8 b 18.0 d 44.2 abc Radial GS c-f 87.2 a 86.3 a 7.2 ef Radial GS FAR F1/14 GS a-f 32.8 b 15.2 def 51.9 ab NIL+YR18 Untreated 13.9 a 33.3 b 54.3 b 20.3 def Opus GS a-f 9.8 d 10.6 def 61.6 a Radial GS a-d 6.0 d 14.1 def 54.7 ab Radial GS ab 2.3 d 15.6 de 34.2 bcd Radial GS def 26.2 bc 36.9 c 27.8 cde Radial GS FAR F1/14 GS c-f 10.2 cd 11.7 def 55.8 ab NIL+YR18+YR29 Untreated 8.8 a-f 12.6 cd 12.3 def 35.0 bcd Opus GS def 4.5 d 2.3 ef 62.7 a Radial GS a-e 6.1 d 1.1 f 61.0 a Radial GS def 6.1 d 4.1 def 51.0 ab Radial GS f 13.4 cd 14.7 def 54.8 ab Radial GS FAR F1/14 GS b-f 2.6 d 3.8 def 64.7 a Mean LSD P Val < Disease progress Looking at the disease assessments over the season allowed disease progress on the flag leaf to be plotted (Figure 1-3). The graphs show that the total level of damage is reduced by the presence of two APR genes in NIL Yr18+Yr29 and that the differences in the effect of products and timings are reduced (Figure 3). With NIL Yr18 carrying only the protection of one APR gene the fungicide programmes applied at GS31 and or at GS39 gave similar results with both being superior to the GS59 spray that was clearly applied too late to protect the flag leaf. 36

37 Total Stripe Rust Severity Flag Total Stripe Rust Severity Flag Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 1. Avocet S - Total stripe rust necrosis on the flag leaf (GS39 GS77) Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 2. NIL Yr18 - Total stripe rust necrosis on the flag leaf (GS39 GS77) 37

38 Total Stripe Rust Severity Flag-1 Total Stripe Rust Severity Flag Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 3. NIL Yr Total stripe rust necrosis on the flag leaf (GS39 GS77) Disease progress on flag -1 (F-1) was no different to the flag leaf with the GS59 ear emergence spray giving the poorest protection of the second leaf layer. There were few differences between other fungicide treatments due to the later onset of disease. The result was that there were no significant advantages to the two spray programmes or early GS31 timings in the more susceptible lines Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 4. Avocet S - Total stripe rust necrosis on the flag - 1 (GS39 GS77) 38

39 Total Stripe Rust Severity Flag-1 Total Stripe Rust Severity Flag Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 5. NIL Yr18 - Total stripe rust necrosis on the flag leaf - 1 (GS39 GS77) Untreated Opus GS Radial GS31 Radial GS39 Radial GS59 FAR F1/14 GS Aug - GS39 10 Sept - GS Sept - GS69 8 Oct - GS75-77 Figure 6. NIL Yr Total stripe rust necrosis on the flag leaf - 1 (GS39 GS77) Assessment 4-2 nd November Dough development GS80-85 Green leaf retention measured on the top two leaves and as a whole plot score with the Greenseeker revealed that two APR genes gave superior NDVI scores and flag leaf GLR than the NIL Yr18 protected by one APR gene (Table 9). 39

40 Table 9. Influence of adult plant resistance genes in on the overall NDVI and green leaf retention of flag and flag-1, assessed on 2 nd November at GS (averaged over all fungicide treatments) NDVI and Green Leaf Retention Cultivar NDVI (0-1) Flag (GLR) Flag-1 (GLR) Avocet S 0.40 c 13.9 c 4.2 b NIL+YR b 51.9 b 34.4 a NIL+YR18+YR a 67.2 a 39.4 a Mean LSD P Val <0.001 <0.001 <0.001 All fungicide treatments enhanced NDVI plot readings and GLR on the top two leaves of the crop canopy relative to the untreated (Table 10). Table 10. Influence of fungicide on the overall NDVI and green leaf retention of flag and flag-1 assessed on 2 nd November at GS (averaged over all lines) NDVI and Green Leaf Retention Fungicide NDVI (0-1) Flag (GLR) Flag-1 (GLR) Untreated 0.42 d 25.6 b 11.7 c Opus GS bc 53.9 a 34.4 ab Radial GS bc 43.3 a 25.0 b Radial GS c 45.0 a 24.4 b Radial GS ab 43.3 a 24.4 b Radial GS FAR F1/14 GS a 55.0 a 36.1 a Mean LSD P Val < All three lines showed NDVI increases over the untreated when fungicide was applied, though the differences were smaller where the NIL was protected by two APR genes. There were few differences in GLR between fungicide treatments, although two sprays of FAR F1/14 and Opus were consistently recorded as amongst the highest for crop canopy greenness scores. Table 11. Influence of adult plant resistance genes in different Avocet NILs and fungicide on the overall NDVI and green leaf retention of flag and flag-1, assessed on 2 nd November at GS (averaged over all lines) NDVI and Green Leaf Retention Cultivar & Fungicide NDVI (0-1) Flag (GLR) Flag-1 (GLR) Avocet S Untreated 0.31 i 0.0 h 0.0 f Opus GS fgh 28.3 d-g 10.0 ef Radial GS gh 13.3 gh 1.7 ef Radial GS h 8.3 gh 3.3 ef Radial GS fg 11.7 gh 1.7 ef Radial GS FAR F1/14 GS f 21.7 fgh 8.3 ef NIL+YR18 40

41 Untreated 0.45 f 26.7 efg 15.0 def Opus GS de 56.7 abc 40.0 abc Radial GS cde 43.3 c-f 30.0 cd Radial GS de 63.3 abc 40.0 abc Radial GS cde 51.7 bcd 31.7 bcd Radial GS FAR F1/14 GS bcd 70.0 ab 50.0 ab NIL+YR18+YR29 Untreated 0.49 e 50.0 b-e 20.0 de Opus GS abc 76.7 a 53.3 a Radial GS ab 73.3 ab 43.3 abc Radial GS bcd 63.3 abc 30.0 cd Radial GS abc 66.7 abc 40.0 abc Radial GS FAR F1/14 GS a 73.3 ab 50.0 ab Mean LSD P Val Crop Lodging The trial lodged at the grain fill stage, in the Avocet S plots there was evidence that fungicide application resulted in increased lodging both in terms of area lodged and severity (Table 12). This effect is likely to have been due to the severe influence of disease at grain fill, reducing the weight of the head to the extent that there was not weight in the head to lodge the crop. This effect was not observed in NIL Yr18 or NIL Yr18 + Yr29, although the trend for the fungicide treated plots to lodge was apparent in NIL + Yr18. Table 12. Influence of the interaction of adult plant resistance genes and fungicide on the lodging characteristics of Avocet NILs when assessed on the 2 nd November at GS Lodging Cultivar & Fungicide Lodged lodging lodging area severity index Avocet S Untreated 31.7 d 2.0 c 63.3 e Opus GS a 4.0 a a Radial GS ab 3.3 ab bcd Radial GS bc 3.0 b cd Radial GS c 3.0 b d Radial GS FAR F1/14 GS ab 3.3 ab abc NIL+YR18 Untreated 76.7 ab 3.0 b bcd Opus GS ab 3.3 ab abc Radial GS ab 3.3 ab abc Radial GS ab 3.3 ab a-d Radial GS ab 3.3 ab a-d 41

42 Radial GS FAR F1/14 GS ab 3.7 ab abc NIL+YR18+YR29 Untreated 78.3 a 3.3 ab abc Opus GS a 3.3 ab abc Radial GS ab 4.0 a ab Radial GS ab 3.7 ab abc Radial GS ab 3.7 ab abc Radial GS FAR F1/14 GS a 3.7 ab ab Mean LSD P Val < ii) Grain Yield and Quality Influence of Avocet NIL (mean of 7 fungicide treatments) When all fungicide treatments including the untreated were averaged NIL Yr18+Yr29 significantly out yielded NIL Yr18 which in turn significantly out yielded the Avocet S (Table 13). The yield increase was mirrored in TSW and Test weight that was ranked the same. Screenings were significantly higher with Avocet S. Table 13. Influence of adult plant resistance genes in Avocet NILs on yield (t/ha), test weight (kg/hl), screenings (%) and TSW (g), assessed at harvest November 26 Grain Yield and Quality Cultivar Yield Test weight Screenings TSW Avocet S 2.74 c 67.9 b 6.3 a 26.8 c NIL+YR b 72.6 a 2.4 b 29.8 b NIL+YR18+YR a 73.7 a 2.2 b 33.2 a Mean LSD P Val <0.001 <0.001 <0.001 <0.001 Influence of fungicide application (mean of 3 Avocet lines) There was no significant difference in crop yields (p=0.055) when fungicide treatments were averaged across the three Avocet lines, although principally due to the influence of Avocet S the untreated crop produced the lowest yield and highest screenings (Table 14). Table 14. Influence of fungicide on yield (t/ha), test weight (kg/hl), screenings (%) and TSW (g), assessed at harvest November 26 Grain Yield and Quality Fungicide Yield Test weight Screenings TSW Untreated 2.96 b 70.3 b 5.5 a 29.0 b Opus 250ml/ha GS a 71.1 b 3.4 bc 29.6 b Radial 420ml/ha GS a 70.0 b 3.8 b 30.1 b Radial 420ml/ha GS a 70.8 b 3.7 b 29.1 b Radial 420ml/ha GS a 74.5 a 2.2 c 32.5 a Radial 420ml/ha GS

43 FAR F1/14 500ml/ha GS a 71.6 b 3.2 bc 29.4 b Mean LSD P Val < Influence of Avocet lines and fungicide application There was no significant interaction (p=0.146) between Avocet line and fungicide treatment, indicating that the pattern of response to fungicide in the three lines was similar (Table 15 & Figure 1). However the yield response to fungicide with Avocet S was statistically significant with all treatments, in contrast the NILs gave no significant yield increases to fungicide application. With Avocet S there was no difference in yield response between the different fungicide treatments. Despite its lack of disease control in the top three leaves a GS59 ear emergence spray in Avocet S resulted in significantly higher test weights and lower screenings than any other fungicide treatment. In terms of test weight no other fungicide treatment was superior to the untreated. The trends on grain quality effects of GS59 sprays was repeated with the Avocet NILs but the differences were smaller with these more resistant lines and in some cases not significant. Table 15. Influence of the adult plant resistance genes in Avocet NILs and fungicide on yield (t/ha), test weight (kg/hl), screenings (%) and TSW (g), assessed at harvest November 26 Grain Yield and Quality Cultivar & Fungicide Yield Test weight Screenings TSW Kg/hL % g Avocet S Untreated 1.66 g 65.7 d 11.1 a 24.0 i Opus GS def 67.4 d 5.6 b 26.8 ghi Radial GS ef 65.9 d 7.0 b 26.4 hi Radial GS c-f 67.3 d 5.9 b 26.3 hi Radial GS f 72.7 b 3.0 cd 30.1 c-h Radial GS FAR F1/14 GS c-f 68.3 cd 5.1 bc 27.3 f-i NIL+YR18 Untreated 3.48 b-e 72.5 b 2.9 cd 30.4 b-g Opus GS a-d 72.1 b 2.1 d 31.3 b-e Radial GS c-f 71.5 bc 2.7 d 29.7 d-h Radial GS a-d 71.4 bc 2.7 d 27.2 f-i Radial GS a-d 74.5 ab 2.0 d 31.7 b-e Radial GS FAR F1/14 GS b-e 73.4 ab 1.9 d 28.4 e-h NIL+YR18+YR29 Untreated 3.73 a-d 72.7 b 2.5 d 32.5 a-d Opus GS ab 73.8 ab 2.3 d 30.8 b-f Radial GS ab 72.7 b 1.8 d 34.2 ab Radial GS abc 73.6 ab 2.3 d 33.8 abc Radial GS a 76.1 a 1.8 d 35.7 a Radial GS FAR F1/14 GS a-d 73.2 ab 2.6 d a-d 43

44 Yield (t/ha) Mean LSD P Val Avocet S NIL+YR18 NIL+YR18+YR Untreated Opus GS31+39 Radial GS31 Radial GS39 Radial GS59 FAR F1/14 Fungicide product and timing GS31+39 Figure 1. Interaction between APR and fungicide strategy on Yield (t/ha) DISCUSSION The impact of adult plant resistance (APR) genes Yr18 alone and Yr18+Yr29 combined clearly improved the disease resistance of Avocet, reducing both active stripe rust and stripe rust necrosis. The impact of two APR genes on the disease levels was proven to be superior to the activity of Yr 18 alone and resulted in significantly lower head infection in the untreated crop. The greater protection given by two APR genes also resulted in superior yields over Nil Yr18 which had only one APR gene conferring protection. Fungicide application resulted in significant increases in green leaf retention (NDVI) with all cultivars but only translated to significant yield increases with Avocet S where the differences in green leaf retention were greatest. Although there were differences in fungicide response over the untreated the overall pattern of fungicide response was similar in the three lines, with no significant differences in yield due to number of fungicides, timing or product. Quality parameters were influenced more strongly particularly in Avocet, with fungicide application at GS59 significantly improving screenings (3%) relative to treatments that controlled the disease in the foliage (5-7% screenings). Despite the lack of disease control on the top three leaves of the crop canopy with the ear applied fungicide the effect on grain quality was significantly superior to all other treatments that gave good control of stripe rust in the upper crop canopy. This would indicate that fungicide timed at head emergence can result in significant lifts in quality in comparison to crops where disease was controlled in the foliage but no protection was put in place for the head itself. It could be argued that in a trial scenario re infection from neighbouring untreated plots creates more disease pressure than would be the case in commercial crops where the disease has been controlled in the foliage. Whilst this maybe the case the influence of an ear applied fungicide on grain quality in a scenario that was too late to protect the foliage does have commercial relevance in situations where stripe rust epidemics result in high levels of inoculum present at head emergence. 44

45 Trial 4. Evaluating the interaction between the strobilurin based fungicide Amistar Xtra and the genetic resistance of four cultivars for the control of stripe rust (Puccinia striiformis) Trial details FAR Code FAR W15-22 Location Horse Unit, near Cobbitty, NSW (Irrigated) Collaborator PBI Cobbitty, NSW (Dr K. Sandhu) Target disease Stripe rust (Puccinia striiformis) Rotation position 1 st wheat after break METHOD Treatment List i) Cultivar 1. Condo - MS-S rated for stripe rust 2. Cobra - MS-S rated for stripe rust 3. Mace - S-VS rated for stripe rust 4. Trojan - MR rated for stripe rust ii) Trt No Fungicide treatment Treatment Rate Active ingredient (A.I) (ml/ha) A.I applied g/ha Treatment Timing * 1 Untreated 2 Amistar Xtra 400 x 2 Azoxystrobin + Cyproconazole GS31 + GS39 Trial design: Split plot design (4 Cultivars x 2 Fungicide treatments) x 3 replicates = 24 harvestable plots Sowing date: 13 May 2015 Inoculation Application 1 Application 2 Application 3 Date 24 July July August 2015 Growth Stage Z31 Z31 & 32 Z37&38 Rate Infected pots 2 mg/ml 2 mg/ml Pathogen 134E16A E16A E16A Method Pots were placed in buffer lines Spray using Herbi Spray using Herbi Approximately 2 mg of spores per ml of light mineral oil (Univar Solvent L naphtha 100, Univar Australia Pty Ltd) were used and approximately 500 ml of dilution was used for each field inoculation. Fungicide application Application 1 Application 2 Application 3 Date 29 th July 28 th August 21 st Sept Growth Stage Z31 Z39 Z59 Water Rate 100 L/ha 100 L/ha 100 L/ha Method Sprayer Sprayer Sprayer Notes Nozzle DG Teejet VP Nozzle DG Teejet VP Nozzle DG Teejet VP 45

46 Assessment Technique Assessment Scale Description Disease Severity % 0 % No infection present, 100 % - Total leaf area infected LAI. 10 stems assessed per plot or whole plot assessment Disease Incidence % % of assessed components with infection. 10 stems assessed per plot or whole plot assessment Green leaf retention (GLR) % 0 % - No green area remaining 100% - Leaf fully green. 10 stems assessed per plot NDVI (Normalized Difference Vegetation Index) 0 1 scale Each plot scanned with a hand held Greenseeker Grain Yield t/ha Measured using small plot harvester Grain Quality % and kg/hl Protein, screenings and specific weight Statistical Analysis All data from this trial was analysed using a confidence interval of 95% unless otherwise specified. All mention of significant differences contained within this report refer to statistically significant differences. 46

47 RESULTS i) Disease and Green leaf retention assessments Baseline Assessment 7 th August Condo GS49, Mace GS37, Cobra GS43 and Trojan GS33 Table 1 shows the results of the baseline assessment carried out on the top four leaves of untreated plots after first fungicide application at GS31. Table 1. Disease severity and incidence in the untreated controls, on the 7 th August, 14 days after the GS31 application. Disease Severity (%) Disease Incidence (%) Untreated Flag Flag-1 Flag-2 Flag-3 Flag Flag-1 Flag-2 Flag-3 Cobra Condo Mace Trojan Assessment 2-28 th September Condo GS71 (grain 100% formed), Cobra & Mace GS71 (grain 50-60% formed) & Trojan GS69 Two sprays of Amistar Xtra significantly reduced stripe rust necrosis and increased green leaf retention in all cultivars except Trojan which showed the same trends however with much smaller, nonsignificant differences (Table 2). Table 2: Influence of fungicide and cultivar on the severity of active stripe rust and total leaf area affected by stripe rust on flag and flag-1, and green leaf retention on flag-1 when assessed on the 28 th September GS69-71 Disease Severity and GLR Fungicide and Cultivar Flag Flag-1 Active Total Active Total GLR Untreated Cobra 2.5 ab 46.2 b 0.0 a 64.4 b 16.3 de Condo 6.2 a 53.0 ab 0.3 a 70.0 b 25.3 d Mace 0.7 b 59.7 a 0.0 a 85.7 a 6.7 e Trojan 0.2 b 5.5 c 0.0 a 6.1 c 81.0 bc Amistar Xtra GS31+39 Cobra 1.9 ab 3.9 c 0.0 a 2.4 c 92.2 ab Condo 1.2 ab 3.6 c 0.0 a 3.7 c 92.1 ab Mace 1.4 ab 3.5 c 0.5 a 11.2 c 69.6 c Trojan 0.0 b 0.1 c 0.0 a 0.4 c 93.4 a Mean LSD P Val < <0.001 <

48 Assessment 3-9 th October 2015 Condo GS73 (early milky ripe), Cobra, Mace GS72 (early milky ripe) & Trojan GS71 (watery ripe) Fungicide applied at GS31 and GS39 significantly reduced head infection from an average of 38% severity to 21%, necrosis on the flag leaf decreased from 40% to 2% and on F-1 61% down to 8%. GLR on F-2 was improved from 19% to 77% (Table 3). Table 3. Influence of fungicide on the severity of stripe rust in the head, necrotic stripe rust on flag, and flag-1, and green leaf retention (GLR) on flag-2, when assessed on the 9 th October GS71-73 (mean of cultivars). Disease Severity Fungicide Head Flag Flag-1 Flag-2 Active Necrotic Necrotic GLR Untreated 38.0 a 40.0 a 60.7 a 19.4 b Amistar Xtra 21.4 b 2.2 b 8.0 b 77.3 a Mean LSD P Val <0.001 <0.001 <0.001 The differences in head infection between treated and untreated were only significant with Condo but cultivars showed a reduction in head infection where earlier fungicide had been applied to the crop canopy at GS31 & GS39. Trojan had significantly less head infection than the other three cultivars with Condo showing the highest levels of infection (Table 4 & 5). Table 4. Influence of cultivar on the severity of stripe rust in the head, necrotic stripe rust on flag and flag-1, and green leaf retention (GLR) on flag-2, when assessed on the 9 th October GS71-73 (mean of fungicide treatments) Disease Severity Cultivar Head Flag Flag-1 Flag-2 YR Necrotic Necrotic GLR Condo 60.8 a 27.1 a 40.3 b 44.8 b Cobra 31.0 b 26.9 a 40.4 b 45.8 b Mace 26.4 b 27.4 a 52.7 a 24.1 c Trojan 0.6 c 3.1 b 4.0 c 78.9 a Mean LSD P Value <0.001 <0.001 <0.001 <0.001 Table 5. Influence of fungicide and cultivar on the severity of stripe rust in the head, necrotic stripe rust on flag and flag-1, and green leaf retention (GLR) on flag-2, when assessed on the 9 th October GS Disease Severity and GLR Fungicide and cultivar Head Flag Flag-1 Flag-2 YR Necrotic Necrotic GLR Untreated Cobra 37.2 bc 52.2 a 76.0 a 5.5 d Condo 75.5 a 51.8 a 75.0 a 4.5 d 48

49 Mace 38.2 bc 50.2 a 84.7 a 1.3 d Trojan 1.0 e 5.9 b 7.2 bc 66.3 bc AmistarXtra GS31+39 Cobra 24.8 cd 1.7 b 4.8 c 86.0 ab Condo 46.0 b 2.3 b 5.6 c 85.0 ab Mace 14.6 de 4.5 b 20.8 b 46.8 c Trojan 0.2 e 0.4 b 0.7 c 91.5 a Mean LSD P Val < There was a low level of lodging in the untreated that was not apparent in the treated crop. Trojan exhibited slightly more lodging than the other cultivars but only in the untreated crop (Table 6). Table 6. Interaction between cultivar and fungicide on lodging characteristics (lodging area (%), lodging severity (scale 1-5) and the associated lodging index (area x severity)), assessed on the 2 nd November. Lodging Characteristics Fungicide and cultivar Lodging Area Lodging Severity Lodging Index Untreated Cobra 0.0 b 0.0 b 0.0 b Condo 13.3 b 2.0 a 26.7 b Mace 0.0 b 0.0 b 0.0 b Trojan 36.7 a 2.7 a a AmistarXtra GS31+39 Cobra 0.0 b 0.0 b 0.0 b Condo 3.3 b 0.7 b 6.7 b Mace 0.0 b 0.0 b 0.0 b Trojan 1.7 b 0.3 b 1.7 b Mean LSD P Val Trojan retained significantly more green leaf when visually assessed on the top two leaves of the canopy and when assessed with the Greenseeker recorded as NDVI. Irrespective of the method of assessing green leaf retention fungicide application significantly increased GLR in all four cultivars (Table 7). Table 7. Interaction between cultivar and fungicide on NDVI (normalised difference vegetative index) and green leaf retention (GLR) assessed on the 2 nd November NDVI and GLR Fungicide and cultivar NDVI Flag Flag-1 GLR GLR Untreated 49

50 Cobra 0.24 d 6.7 e 0.0 d Condo 0.20 e 1.7 e 0.0 d Mace 0.23 de 1.7 e 0.0 d Trojan 0.49 b 60.0 b 38.3 b AmistarXtra GS31+39 Cobra 0.37 c 36.7 cd 23.3 c Condo 0.24 d 25.0 d 11.7 cd Mace 0.34 c 46.7 bc 20.0 c Trojan 0.59 a 76.7 a 60.0 a Mean LSD P Val iii) Grain Yield and Quality Fungicide application resulted in significant yield increases over the untreated in Cobra (3.0t/ha response), Condo (2.8t/ha) and Mace (3.1t/ha). Yields were taken from just over 2t/ha to just over 5t/ha with fungicide (Figure 1). In contrast, Trojan showed a significant yield response of 1.1 t/ha compared to 3t/ha with the other three cultivars. There was a significant interaction (p=0.0004) between cultivar and fungicide application since Trojan untreated with fungicide yielded the same as Mace, Condo and Cobra with fungicide. Fungicide application improved all aspects of grain quality except with Trojan (Table 10). Table 8. Influence of fungicide on grain yield (t/ha) and grain quality (test weight (kg/hl), screenings (%) and thousand seed weight (g)) (mean of four cultivars) Grain yield and quality Fungicide Yield Test weight Screenings TSW Untreated 3.03 b 61.9 b 6.8 a 27.0 b Amistar Xtra 5.53 a 66.3 a 2.9 b 34.3 a Mean LSD P Val <0.001 <0.001 <0.001 <0.001 Table 9. Influence of cultivar on grain yield (t/ha) and grain quality (test weight, screenings and thousand seed weight (TSW)) (mean of fungicide treatments) Grain yield and quality Cultivar Yield Test weight Screenings TSW Condo 3.82 b 63.1 b 3.9 b 34.4 a Cobra 3.78 b 58.0 c 4.9 ab 27.2 b Mace 3.75 b 61.3 b 6.2 a 28.4 b Trojan 5.76 a 73.9 a 4.5 b 32.7 a Mean LSD P Value <0.001 < <

51 Yield (t/ha) Table 10. Interaction between cultivar and fungicide on grain yield (t/ha) and grain quality (test weight, screenings and thousand seed weight (TSW)) Grain Yield and Quality Fungicide and cultivar Yield Test weight Screenings TSW Untreated Cobra 2.28 c 55.1 e 7.7 b 22.7 d Condo 2.42 c 60.5 cd 5.6 c 29.6 c Mace 2.20 c 56.8 de 9.7 a 22.7 d Trojan 5.20 b 75.2 a 4.4 cd 32.9 b Amistar Xtra GS31+39 Cobra 5.28 b 60.9 c 2.2 e 31.7 bc Condo 5.23 b 65.7 b 2.1 e 39.2 a Mace 5.29 b 65.8 b 2.6 de 34.0 b Trojan 6.32 a 72.5 a 4.6 c 32.5 bc Mean LSD P Val < <0.001 < Figure 1. Influence of fungicide application on cultivar yield (t/ha) DISCUSSION Cobra Condo Mace Trojan Cobra Condo Mace Trojan Untreated Fungicide and cultivar AmistarXtra GS31+39 Despite the extremely low levels of stripe rust necrosis recorded in Trojan the late season assessments of green leaf retention revealed significantly higher NDVI plot scores and significantly better GLR on the flag where the crop was fungicide treated. This late season green leaf retention and control of stripe rust necrosis resulting from fungicide application has resulted in a significant yield increase in this trial which was not apparent in the adjacent trial W15-20 where no yield increase from the application of fungicide was observed. There was also less evidence of green leaf retention differences on the flag leaf in the neighbouring trial W15-20 which normally correlate to higher probabilities of a yield response. Trojan in the neighbouring W15-20 trial did respond with increased GLR on flag-2 but 51

52 there was less evidence of increased green leaf retention in the upper part of the canopy as was the case in this trial (W15-23). In part this may have been due to greater azoxystrobin content applied in 400ml/ha Amistar Xtra (160g/ha ai over two sprays) compared to Radial at 420ml/ha (62.5g/ha ai over the two sprays). This is difficult to confirm as although strobilurin rate is a key ingredient of increases in GLR the triazole component of the two products is different which might be a contributory factor. Amistar Xtra is based on cyproconazole (64g/ha ai) as opposed to epoxiconazole with the fungicide Radial (62.5g/ha ai), as both are very effective rust products and rates applied are similar it is likely that the azoxystrobin content would be a key factor of difference between the two products and the different results in neighbouring trials. The other factor that may be contributory to this result is the degree of lodging experienced in the two trials, Trojan in W15-20 lodging significantly more than the Trojan in trial W This may have resulted in less yield expression of smaller differences in GLR. ACKNOWLEDGEMENTS FAR wish to thank Dr Karanjeet Sandhu for his outstanding cooperation and assistance in setting up and managing the 2015 field trials at Horse Unit on the main farm at PBI. We would also like to acknowledge the support of Andrew McIntosh and Paul Lipscombe (Farm Manager) in bringing this field trials programme to fruition. At the Hamilton site we would like to acknowledge the input of the Southern Farming Systems trials team for their assistance in managing the trial Field Trials Research (FAR00002) Horse Unit, PBI Cobbitty (Photo courtesy of Dr Karanjeet Sandhu) 52