Soybean Disease Ratings and Yields 2006 Test Summaries

Transcription

1 Soybean Disease Ratings and Yields 2006 Test Summaries Variety Reactions to: Frogeye Leaf Spot (FLS) Sudden Death Syndrome (SDS) Septoria Brown Spot Stem Canker (SC) Anthracnose Foliar Fungicides and Asian Soybean Rust (ASR) by Melvin A. Newman, Professor University of Tennessee UT Extension Department of Entomology and Plant Pathology Jackson, TN And Amber Brasfield, Lab Assistant Blake Brown, Superintendent, RECM Pat Donald, Nematologist, USDA/ARS Savannah Grooms, Lab Assistant Bob Hayes, Superintendent, WTREC Josh Johnson, Plotman Jake Mallard, Plotman James McClure, Research Associate Gordon Percell, Research Associate Wyveta Percell, Senior Lab Assistant Drew Phillips, Plotman Bryan Powers, Plotman Jason Williams, Research Associate Bob Williams, UT Extension Area Specialist Ryan Zawacki, Senior Plotman Funds provided by: Tennessee Soybean Promotion Board Go to for more soybean data. 0

2 Table of Contents Introduction... 2 Soybean Disease Loss Estimate for Tennessee (Chart 2006)... 3 REPORTS Evaluation of Soybean Cultivars for Resistance to Foliar Diseases... 4 Evaluation of Soybean Cultivars for Resistance to Stem Canker Fungicide Efficacy and Application Timing Soybean Cyst Nematode Sampling and Advisory Program Soybean Rust RATINGS AT THE RESEARCH AND EDUCATION CENTERS AT MILAN AND JACKSON Table 1 Maturity Group V (Early)... 6 Table 2 Maturity Group IV (Late)... 7 Table 3 Maturity Group IV (Early)... 8 Table 4 Maturity Group III... 9 Table 5 Yields for 90 Varieties (Sprayed and Unsprayed) FOLIAR FUNGICIDE TRIALS AT MILAN AND JACKSON Table 6 Azoxystrobin for Quality and Yield Improvements Table 7 Performance of Foliar Fungicides for Soybean Table 8 Regional Frogeye Leaf Spot Table 9 Efficacy of Punch and Charisma on ASR Table 10 Topsin M, KFD, Muscle, and Echo for ASR Table 11 Laredo EC and Enable 2F for ASR Control Table 12 Headline and Caramba Efficacy for ASR Table 13 Efficacy and Selectivity of Topguard for ASR Table 14 Folicur, Stratego, and Absolute for ASR STANDARDIZED TESTS (County tests) Table Standard Group V Early Season Table Standard Group IV Late Season Table Standard Group IV Early Season Table Standard Group III Roundup Ready

3 INTRODUCTION Funds provided by the Tennessee Soybean Promotion Board have made it possible to continue testing for disease and nematode control strategies. Some accomplishments of the major projects include the following examples: Disease ratings for Frogeye Leaf Spot (FLS), Septoria Brown Spot, Sudden Death Syndrome (SDS), Stem Canker (SC), and Anthracnose: Each year soybean producers are provided a new list of soybean varieties with disease ratings for the most damaging diseases and nematodes. This has been a tremendous, no-cost aid in reducing diseases and increasing yields. Producers have UT results either in hard copy or on the internet (utcrops.com). Soybean breeders and commercial seed producers are using this data to bring more disease-resistant varieties to the soybean farmer. This year 202 varieties were tested in all disease nurseries, many in two locations. Foliar fungicide testing with varieties: This year, 90 commercially available varieties were sprayed with a foliar fungicide to determine the profitability of spraying a foliar fungicide. As a result, producers are able to select varieties that respond to a foliar fungicide. Soybean producers in TN now spray 40-50% of the soybean acreage. Foliar Fungicides for Disease Control: This year, 209 treatments were applied in 22 trials in four locations. Spraying a fungicide at growth stage R3 is the most cost effective. Spraying at R5 usually produces a slight increase in yield. Cyst nematode survey and sampling program: Approximately 144,875 acres have been sampled by the GPS nematode units funded by the TSPB since this program started in Nearly half of those acres have been identified as positive for cyst nematodes. With this information, producers are better able to select varieties with resistance to their race of SCN and reduce the damage caused by this pest. The discovery of new races (race 2 & 5) of SCN existing in large areas of the state led specialists to recommend new resistant varieties. Some producers report an increase in yields of as much as 15 bushels per acre. This program has encouraged producers to do more SCN sampling on their own. Greenhouse screening for SCN: This year 88 commercially available varieties were screened by Dr. Pat Donald USDA/ARS at the Jackson greenhouse for reaction to SCN Races 2, 3 and 14. Data from Race 2 (HG Type ) is presented in this publication. Of the varieties tested, 87 of them were susceptible to Race 2. This is consistent with characterization of problem fields in Tennessee where high populations of SCN are most commonly Race 2. In general: Due to the grants awarded by the TSPB and USDA/ARS for disease and nematode projects, producers have become more aware of the damage from diseases and nematodes. They are using information generated from disease ratings, fungicide trials and variety testing to reduce diseases and increase profits. The seed industry also relies on this information to make major marketing decisions. Breeders use this information to evaluate their new selections before releasing them for production. Use of this information has had a positive, far-reaching effect on soybean production in Tennessee by making the production of soybeans more profitable. 2

4 2006 Soybean Disease Loss Estimate for Tennessee %Loss 1 Anthracnose (Colletotrichum truncatum) 2 2 Bacterial diseases (Pseudomonas syringae, P. syringae pv. tabaci, 0 Xanthomonas campestris) 3 Brown leaf spot (Septoria glycines) 4 4 Charcoal rot (Macrophomina phaseolina) Diaporthe/Phomopsis complex (Diaporthe & Phomopsis spp.) 2 6 Downy mildew (Peronospora manshurica) 0 7 Frogeye leaf spot (Cercospora sojina) 4 8 Fusarium wilt & root rot (Fusarium spp.) 0 9 Other 0 10 Phytophthora root & stem rot (Phytophthora sojae) Pod & stem blight (Diaporthe phaseolorum var. sojae) Purple stain (Cercospora kikuchii) Rhizoctonia aerial blight (Rhizoctonia solani) 0 14 Sclerotinia stem rot (Sclerotinia sclerotiorum 0 15 Seeding disease (Rhizoctonia, Pythium & Fusarium spp.) 1 16 Southern blight (Sclerotium rolfsi) 0 17 Soybean cyst nematode (Heterodera glycines) 4 18 Root-knot (Meloidogyne spp.) Other nematodes 0 20 Stem canker (Diaporthe phaseolorum var. meridionalis) 1 21 Sudden death syndrome (Fusarium solani Form A) Virus Brown stem rot (Phialophora gregata) 0 24 Soybean rust (Phakopsora pachyrhizi) 0 Total Per Cent Loss to Disease = Total soybean production in your state for 2006: 42,940,000 (in bushels) Total acres of soybeans harvested in 2006: 1,130,000 State Average for 2006: 38 (bushels/acre) 3

5 Report for 2006 Melvin A. Newman, Professor Title: Evaluation of Soybean Cultivars for Resistance to Frogeye Leaf Spot (FLS), Septoria Brown Spot, Anthracnose, and Sudden Death Syndrome (SDS). Personnel: Melvin A. Newman, Professor Bob Williams, Extension Area Specialist Blake Brown, Superintendent-Research and Education Center at Milan (RECM) Objectives: Evaluate the effect of natural infections of FLS (Cercospora sojina), Septoria Brown Spot (Septoria glycines), Anthracnose (Colletotrichum truncatum), and SDS (Fusarium solani f. sp. glycines) on available soybean cultivars. Make this information available to soybean producers in a timely fashion. Increase the exposure of the Soybean Promotion Board and the University of Tennessee to the soybean producers of Tennessee concerning their cooperative efforts to improve the economics of production through better disease control. Help Tennessee soybean growers increase yields and profits. Procedures: Equipment: A 1.9-acre soybean plot was planted no-till at the RECM on May 19, 2006, with a four-row Case I.H. 900 planter with cone seed-box attachments. Plot information: The 90 varieties were planted in four-row plots with 36" centers and 22 long. Each plot was randomized and replicated three times. Irrigation was provided with a center pivot system. Each plot was split (side-by-side) with 2 rows being sprayed and 2 rows left unsprayed. Disease ratings: Ratings were taken: Sept.08 = MG III; Sept. 11 = MG IVE; Sept.15 = IVL; Sept.21 = MG VE. The rating scale was 0-10 with 0 = no detectable disease and 10 = complete defoliation and severe yield loss. FLS occurrence was moderate this season. Observations and Conclusions: (See chart 1 and tables 1-4). Maturity Group V (Early): FLS ratings for the early MG V varieties ranged from 0 to 1.7 for the sprayed and 0 to 8.7 for the unsprayed. Average yield was 59.9 Bu/A for sprayed and 52.6 Bu/A for unsprayed. The sprayed varieties were all in the zero or low ratings groups. Seven varieties with no FLS symptoms averaged 58 Bu/A. Fourteen varieties in the low category averaged 61 Bu/A. The unsprayed varieties were about evenly divided among the zero to moderate categories. Six varieties with no FLS symptoms averaged 50 Bu/A, six varieties in the low category averaged 53 Bu/A, and 8 varieties in the moderate group yielded an average of 55 Bu/A. One variety in the severe category yielded 48 Bu/A. Spraying increased the yield an average of 7.3 Bu/A. Maturity Group IV (Late): FLS ratings for 27 varieties in the late MG IV test ranged from 0 to 3 for the sprayed varieties and 0 to 8.3 in the unsprayed ones. Average yield for the sprayed varieties was 63.4 Bu/A and was 53.6 Bu/A for the unsprayed. All the sprayed varieties were in the zero or low ratings groups. Nine varieties with no FLS symptoms yielded an average 62 Bu/A, and 18 varieties in the low group averaged 64 Bu/A. The unsprayed varieties were about evenly spread through all ratings categories. Seven varieties with no FLS symptoms averaged 53 Bu/A, and 9 varieties in the low category yielded an average 54 Bu/A, while the moderately susceptible and the severely susceptible groups both had average yields of 53 Bu/A. Spraying increased the yield average 9.8 Bu/A. Maturity Group IV (Early): There were 21 varieties tested in this group, and their average FLS ratings ranged from 0 to 2.7 for the sprayed ones and 0 to 8.3 for the unsprayed ones. All the sprayed varieties were in the zero and low categories. Three varieties with no FLS averaged 56 Bu/A, and 18 varieties in the low group yielded an average 63 Bu/A. Most of the unsprayed varieties were in the two middle ratings groups. The yield averages for the varieties in the zero, low and moderate groups were all 53 Bu/A. The one variety with severe symptoms yielded 47.1 Bu/A. Spraying increased yields an average 9.5 Bu/A. 4

6 Maturity Group III: FLS ratings for 21 varieties in this group ranged from 0 to 4 for the sprayed ones and 0 to 9.7 for the unsprayed ones. The sprayed varieties were mostly in the zero to low category with only one in the moderate group. Two varieties with no FLS averaged 62 Bu/A, 18 varieties in the low ratings group averaged 52 Bu/A, and the one in the moderate group yielded 57 Bu/A. The unsprayed varieties were spread over all ratings categories. Two varieties with no FLS averaged 51 Bu/A, nine with low ratings averaged 45 Bu/A, six with moderate symptoms yielded an average 47 Bu/A, and four with severe symptoms averaged 41 Bu/A. Spraying increased average yields 7.9 Bu/A. All maturity groups had some varieties with no FLS symptoms. The MG III varieties had the lowest average yields of all maturity groups tested and the highest average FLS rating. The MG IVL had the highest average yields but not the lowest average FLS ratings. The MG III had the largest percentage of varieties with severe symptoms. Chart 1 Average FLS Rating Foliar Fungicide Spray Tests Average Frogeye Leaf Spot Ratings Research and Education Center at Milan MG III (21 varieties) MG IV E (21 varieties) MG IV L (27 varieties) MG V E (21 varieties) Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed None (0) Low (1-3) Mod. (4-6) Severe (7-10) Aver. Bu/a Aver. FLS Rating Highest yielding variety FLS for highest yielding variety Lowest yielding variety FLS for lowest yielding variety * 0* 0* 5.3 1* 0* 0* *Please note that these varieties had high ratings for other foliar diseases (Tables 1-4). 5

7 Table 1 Resistance to FLS in 21 MG V (early) Soybean Varieties Location: RECM A4 Investigator: Dr. Melvin Newman Character Rated Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Rating Date 10/24/06 10/24/06 Yield 9/21/06 9/21/06 9/21/06 9/21/06 10/24/06 10/24/06 9/21/06 Rating Data Type YIELD YIELD Difference FLS FLS Br. Spot Br. Spot Anthrac. Anthrac. SDS Rating Unit BU/A BU/A BU/A SCN (Race 2) Greenhouse Screening Allen S Armor S 1 Asgrow Croplan RC S Delta Grow S Delta King S Delta King S D & PL S Dyna-Gro 33B S Dyna-Gro 33X S Excel S FFR S FFR S Gutwein/GH S Hornbeck S Pioneer 95M S Progeny MS Progeny S Stine S USG MS Vigoro 52N S LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Left 2 rows of all varieties were sprayed with 9 oz/a Headline % Induce at R3 on Aug. 2. Footnote: S = Susceptible to Race 2 (HG Type ) of soybean cyst nematode; MS = Moderately Susceptible 1 Variety not tested. Note: Pioneer 95M60 and Merschman X were resistant to SCN Race 2 in greenhouse testing. 6

8 Table 2 Resistance to FLS in 27 MG IV (late) Soybean Varieties Location: RECM A4 -- Investigator: Dr. Melvin Newman Character Rated Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Rating Date 10/24/06 10/24/06 Yield 9/15/06 9/15/06 9/15/06 9/15/06 10/24/06 10/24/06 9/15/06 Rating Data Type YIELD YIELD Difference FLS FLS Br. Spot Br. Spot Anthrac. Anthrac. SDS Rating Unit BU/A BU/A BU/A SCN (Race 2) Greenhouse Screening AgVenture 46-J S Armor 47-G S Asgrow S Asgrow S Croplan RC S Crow's S Delta Grow S Delta Grow S Delta King S Delta King S Delta King S D & PL S Dyna-Gro 36Y S Excel S FFR S Gutwein/GH S Merschman Dallas S NK Brand S 49-Q S Pioneer 94B S Pioneer 94M S Progeny S Progeny MS Schillinger S Stine S Trisler S USG S Vigoro 49N S LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Left 2 rows of all varieties got 9 oz/a Headline % Induce at R3 on July 24. Footnote: S = Susceptible to Race 2 (HG Type ) of soybean cyst nematode; MS = Moderately Susceptible 7

9 Table 3 Resistance to FLS in 21 MG IV (early) Soybean Varieties Location: RECM A4 Investigator: Dr. Melvin Newman Character Rated Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Rating Date 10/24/06 10/24/06 Yield 9/11/06 9/11/06 9/11/06 9/11/06 10/24/06 10/24/06 9/11/06 Rating Data Type YIELD YIELD Difference FLS FLS Br. Spot Br. Spot Anthrac. Anthrac. SDS Rating Unit BU/A BU/A BU/A SCN (Race 2) Greenhouse Screening Armor 45-M S Asgrow S 1 Asgrow Croplan RC S Crow's MS DeKalb S DeKalb S Delta Grow MS D & PL DPX S Dyna-Gro S Excel S FFR MS Gutwein/GH S Gutwein/GH S Merschman Rocky S Pioneer 94M S Progeny S Trisler S USG 74C S Vigoro 42N S Vigoro 44N S LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Left 2 rows of all varieties got 9 oz/a Headline % Induce at R4 on July 24. Footnote: S = Susceptible to Race 2 (HG Type ) of soybean cyst nematode; MS = Moderately Susceptible 1 Variety not tested. 8

10 Table 4 Resistance to FLS in 21 MG III Soybean Varieties -- Location: RECM A4 -- Investigator: Dr. Melvin Newman Character Rated Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Sprayed Unsprayed Rating Date 10/24/06 10/24/06 Yield 9/08/06 9/08/06 9/08/06 9/08/06 10/24/06 10/24/06 9/08/06 Rating Data Type YIELD YIELD Difference FLS FLS Br. Spot Br. Spot Anthrac. Anthrac. SDS Rating Unit BU/A BU/A BU/A SCN (Race 2) Greenhouse Screening AgVenture S Armor 42-P MS Asgrow S Asgrow Asgrow Asgrow S Croplan RC S DeKalb S DeKalb S Delta Grow MS Delta King 39T S Excel S FFR MS Gutwein/GH S Gutwein/GH S NK Brand S37N MS NK Brand S39K S Pioneer 93M S Pioneer 93M S Progeny S Vigoro 39N S LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Left 2 rows of each plot R3 with 6 oz/a Headline % Induce on July 11. Soybean producers should consider the variety reactions to FLS as well as other diseases and nematodes. In these tests, all the maturity groups were about equally susceptible to FLS. In general, FLS disease pressure was low in this location this year. Variety response ranged from no disease symptoms (0) to severe (9.7). Producers should use this information to select varieties that have low susceptibility to FLS. The yield difference could be as much as 10 Bu/A, even with only moderate disease pressure. Footnote: S = Susceptible to Race 2 (HG Type ) of soybean cyst nematode; MS = Moderately Susceptible 1 Variety not tested. 2 This variety was found to be a maturity group IV. It was previously named Armor 39-P7. 9

11 Report for 2006 Melvin A. Newman, Professor Title: Evaluation of Soybean Cultivars for Resistance to Stem Canker. Personnel: Melvin A. Newman, Professor Bob Williams, Extension Area Specialist Bob Hayes, Superintendent-West Tennessee Research and Education Center (WTREC) Objectives: Inoculate and rate the available varieties for resistance to stem canker. Trials will be done at the WTREC. Make readily available to producers a more reliable list of cultivars resistant to stem canker. Reduce yield loss from stem canker and hence increase the net income of Tennessee soybean growers. Provide valuable information to soybean breeders about the relative susceptibility or resistance of their breeding lines. Increase the exposure of the Soybean Promotion Board and the University of Tennessee to the producers of Tennessee concerning their cooperative efforts to improve the economics of production through better disease management. Procedures: 1. Inoculum: Diaporthe phaseolorum var. meridionalis (DPM), the fungus that causes stem canker, was grown in the lab for three months on both PDA agar and on sterile white grain sorghum seeds. Starting when soybean plants were at the V 3 growth stage, plots were field-inoculated four times on a weekly basis twice with infected grain sorghum and twice with a spore suspension grown on PDA. 2. Equipment: The plot was planted on May 8 at the WTREC with a four-row Case IH 900 planter with Almaco seed cone attachments. 3. Plot information: Plots were two rows wide, spaced at 36", and 25' long. Each variety was randomized and replicated three times in a complete block design. Dual Magnum and Scepter herbicides were sprayed at 1.5 pt/a in 15 gallons of water/a and B.C. after planting. A total of 90 varieties were replicated three times. 4. Disease ratings: No disease ratings were made this year because there was no stem canker in any of the plots. Even the most susceptible varieties were free of stem canker. Observations and Conclusions: In general, stem canker symptoms were not produced in these plots this year due to poor disease conditions, although everything was done to increase stem canker in the plot. Environmental conditions play a big role in disease development. Disease occurrence is a complicated process involving a susceptible host, pathogen, and the correct environment. If one or more of these factors are lacking, disease will not occur. Apparently, one of these factors was missing this year. However, because this field has a history of heavy pressure from Septoria Brown Spot, the first replicate of each variety was sprayed with Headline plus a triazole at growth stages R3 and R5. The first two reps were then harvested, and the results are in Table 5. Please note that this represents the results of only one rep. 10

12 Table 5 Yields for 90 Varieties (Sprayed/ Unsprayed) MG V Early Character Rated sprayed unsprayed Rating Date 10/03/06 10/03/06 Rating Data Type yield yield Rating Unit bu/a bu/a Allen Armor Asgrow Croplan RC Delta Grow Delta King XTJ 753 (5367) Delta King D & PL Dyna-Gro 33B Dyna-Gro 33X Excel FFR FFR Gutwein/GH Hornbeck Pioneer 95M Progeny Progeny Stine USG Vigoro 52N Grand Mean MG IV Early Character Rated sprayed unsprayed Rating Date 10/03/06 10/03/06 Rating Data Type yield yield Rating Unit bu/a bu/a Armor 45-M Asgrow Asgrow Croplan RC Crow's DeKalb DeKalb Delta Grow D & PL DPX Dyna-Gro Excel FFR Gutwein/GH Gutwein/GH Merschman Rocky Pioneer 94M Progeny Trisler USG 74C Vigoro 42N Vigoro 44N Grand Mean MG IV Late Character Rated sprayed unsprayed Rating Date 10/03/06 10/03/06 Rating Data Type yield yield Rating Unit bu/a bu/a AgVenture 46-J Armor 47-G Asgrow Asgrow Croplan RC Crow's Delta Grow Delta Grow Delta King Delta King Delta King 49D D & PL Dyna-Gro 36Y Excel FFR Gutwein/GH Merschman Dallas NK Brand S 49-Q Pioneer 94B Pioneer 94M Progeny Progeny Schillinger Stine Trisler USG Vigoro 49N Grand Mean MG III Character Rated sprayed unsprayed Rating Date 10/03/06 10/03/06 Rating Data Type yield yield Rating Unit bu/a bu/a AgVenture Armor 39-P Asgrow Asgrow Asgrow Asgrow Croplan RC DeKalb DeKalb Delta Grow Delta King 39T Excel FFR Gutwein/GH Gutwein/GH NK Brand S37N NK Brand S39K Pioneer 93M Pioneer 93M Progeny Vigoro 39N Grand Mean

13 Fungicide Efficacy and Application Timing Frogeye leaf spot (FLS) caused by the fungus Cercospora sojina has been observed in Tennessee for over thirty years, but until recently, it has caused only limited yield loss. However, for the last four years ( ) this foliar disease has reduced soybean yields state wide by an average 7.8% of the annual crop. It is possible that lack of crop rotation and planting of susceptible varieties have been responsible for some of the increase in severity of FLS. An increase in the number of reported races of this fungus may also play a role in the increased yield loss. Other foliar diseases such as Anthracnose (Colletotrichum truncatum) and Brown Spot (Septoria glycines) cause severe yield reduction and reduced seed quality, especially in rainy growing seasons. Producers can save significant yield loss by choosing resistant varieties and/or spraying with a recommended foliar fungicide. For the last four years, several experiments have been conducted at the Research and Education Center at Milan (RECM) under heavy FLS conditions to determine efficacy and the best application timing and rates for several foliar fungicides. Almost all fungicide applications increased yields, decreased frogeye leaf spot ratings and decreased defoliation significantly over the untreated check. In 2006, nine trials were conducted at Milan and Jackson, TN, to test the effectiveness against foliar diseases. Six of these were designed specifically for prevention of Asian Soybean Rust (ASR) (Phakopsora pachyrhizi). Since ASR did not occur in TN until after these crops were harvested, ratings were done for other foliar diseases. In an 11-treatment trial (06SBAZOX) at Milan, azoxystrobin formulations were compared to competitive standards to test their ability to protect soybean yield and improve quality. Another 12-treatment trial (06SBFFP) at Milan was designed to test the performance of several Headline rates and combinations along with standard products. The Regional Frogeye Leaf Spot trial (06SBRFE) was conducted to compare standard products already on the market for control of foliar diseases. Efficacy of Punch and Charisma on ASR (06SBPC) was designed to control ASR and late season diseases. A nine-treatment trial at Milan (06SBEMTOP) featured Topsin M, Echo, and Muscle in combination with other products to control rust and other foliar diseases. Laredo EC and Enable 2F were featured in a 12-treatment trial (06SBLAR) for rust control. At the WTREC, two trials were designed for control of ASR. One trial (06SBHFC) used Headline and Caramba at various rates and in many combinations for control of soybean diseases, including rust. The other trial (06SBTPGD) featured Topguard at three rates in different combinations and spraying times. Near the Jackson airport, Folicur, Stratego, and Absolute were sprayed at R3 and again 21 days later in a trial (06SBFSA) for control of rust. Since no rust was present, yields and defoliation rates are reported. Use of the products in these trials does not constitute a recommendation. Please consult your local Extension leader to see which fungicides used in these trials are cleared for use on soybean. 12

14 Table 6 Azoxystrobin for Quality and Yield Improvements Trial ID: 06SBAZOX Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/19/06 9/19/06 9/19/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Other Other Growth Appl Name Rate Rate Unit Stage Code Check Quadris 2.08 SC 4 flozpr/a R3 A Primary COC 1 % v/v R3 A Quadris 2.08 SC 5 flozpr/a R3 A Primary COC 1 % v/v R3 A Quadris 2.08 SC 5.5 flozpr/a R3 A Primary COC 1 % v/v R3 A Quadris 2.08 SC 6 flozpr/a R3 A Primary COC 1 % v/v R3 A Quilt 1.67 SC 14 flozpr/a R3 A Primary COC 1 % v/v R3 A Quadris Xtra 4 flozpr/a R3 A Headline 2.09 EC 4 flozpr/a R3 A Primary COC 1 % v/v R3 A Headline 2.09 EC 5.5 flozpr/a R3 A Primary COC 1 % v/v R3 A Headline 2.09 EC 6 flozpr/a R3 A Primary COC 1 % v/v R3 A Topsin M 0.5 lb/a R3 A Primary COC 1 % v/v R3 A LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst 13

15 Table 7 Performance of Foliar Fungicides for Soybean Trial ID: 06SBFFP Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/20/06 9/20/06 9/20/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Headline 6 fl oz/a R3 A Induce 0.25 % v/v R3 A Quadris 6 fl oz/a R3 A Primary COC 1 % v/v R3 A Stratego 6 fl oz/a R3 A Quilt 14 fl oz/a R3 A Primary COC 1 % v/v R3 A Headline SBR 7.8 fl oz/a R3 A Caramba 7.68 fl oz/a R3 A Folicur 4 fl oz/a R3 A Domark fl oz/a R3 A Laredo 7.04 fl oz/a R3 A Headline 3.6 fl oz/a R3 A Caramba 4.6 fl oz/a R3 A Headline 4.5 fl oz/a R3 A Induce 0.25 % v/v R3 A Check LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Table 8 Regional Frogeye Leaf Spot Trial ID: 06SBRFE Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/19/06 9/19/06 9/19/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Check Quadris 6.2 fl oz/a R3 A Quadris 6.2 fl oz/a R3, R5 A B Headline 6 fl oz/a R3 A Headline 6 fl oz/a R3, R5 A B Headline SBR 7.8 fl oz/a R3 A Headline SBR 7.8 fl oz/a R3, R5 A B Quilt 20 fl oz/a R3 A Quilt 20 fl oz/a R3, R5 A B Topsin M 0.5 lb/a R3, R5 A B Stratego 10 fl oz/a R3 A Stratego 10 fl oz/a R3, R5 A B LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst 14

16 Table 9 Efficacy of Punch and Charisma on ASR Trial ID: 06SBPC Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/21/06 9/21/06 9/21/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Punch 4 fl oz/a R3 A Punch 3 fl oz/a R3 A Charisma 10 fl oz/a R3 A Punch 3 fl oz/a R3 A Headline 4.5 fl oz/a R3 A Punch 3 fl oz/a R3 A Quadris 4 fl oz/a R3 A Headline 6 fl oz/a R3 A Quadris 6.2 fl oz/a R3 A Uppercut 4 fl oz/a R3 A Punch 3 fl oz/a R3 A Headline 4.5 fl oz/a R3 A Check LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Table 10 Topsin M, KFD, Muscle, and Echo for ASR Trial ID: 06SBEMTOP Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/21/06 9/21/06 9/21/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Check Topsin 16 fl oz/a R3, R5 BC KFD-09-01(Tri$um ) 4 fl oz/a R3, R5 BC Topsin 16 fl oz/a R3, R5 BC KFD-09-01(Tri$um ) 4 fl oz/a R3, R5 BC KFD fl oz/a R3, R5 BC Topsin 16 fl oz/a R3, R5 BC Quadris 3 fl oz/a R3, R5 BC Topsin 16 fl oz/a R3, R5 BC Headline 3 fl oz/a R3, R5 BC Echo 20 fl oz/a V5 A Muscle 4 fl oz/a R3 B Echo 20 fl oz/a V5 A Folicur 4 fl oz/a R3 B LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst 15

17 Table 11 Laredo EC and Enable 2F for ASR Control Trial ID: 06SBLAR Location: RECM A4 Investigator: Dr. Melvin Newman Crop Variety AG 4703 AG 4703 AG 4703 AG 4703 AG 4703 Rating Date 10/23/06 9/19/06 9/19/06 9/19/06 10/23/06 Rating Data Type YIELD FLS Br. Spot Defoliation Anthrac. Rating Unit BU/A % 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Laredo 7 fl oz/a R3, A+14d AB CoRoN 1 gal/a R3, A+14d AB Laredo 7 fl oz/a R3, A+14d AB Induce 0.25 % v/v R3, A+14d AB Laredo 5 fl oz/a R3, A+14d AB Headline 6 fl oz/a R3, A+14d AB CoRoN 1 gal/a R3, A+14d AB Laredo 5 fl oz/a R3, A+14d AB Topsin 15 fl oz/a R3, A+14d AB Induce 0.25 % v/v R3, A+14d AB Laredo 5 fl oz/a R3, A+14d AB Topsin 15 fl oz/a R3, A+14d AB CoRoN 1 gal/a R3, A+14d AB Laredo 7 fl oz/a R3 A Induce 0.25 % v/v R3 A Headline 7 fl oz/a A+14d B Induce 0.25 % v/v A+14d B Laredo 5 fl oz/a R3, A+14d AB Headline 6 fl oz/a R3, A+14d AB Induce 0.25 % v/v R3, A+14d AB Enable 2F 7 fl oz/a R3 A Primary COC 0.5 % v/v R3 A Headline 7 fl oz/a A+14d B Induce 0.25 % v/v A+14d B Laredo 7 fl oz/a R3 A Induce 0.25 % v/v R3 A Headline 7 fl oz/a A+21d C Induce 0.25 % v/v A+21d C Laredo 5 fl oz/a R3, A+21d AC Headline 6 fl oz/a R3, A+21d AC Induce 0.25 % v/v R3, A+21d AC Enable 2F 7 fl oz/a R3 A Primary COC 0.5 % v/v R3 A Headline 7 fl oz/a A+21d C Induce 0.25 % v/v A+21d C Check LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst CoRoN is B 16

18 Table 12 Headline and Caramba Efficacy for ASR Trial ID: 06SBHFC Location: WTREC 2 Investigator: Dr. Melvin Newman Crop Variety AG 4801 AG 4801 Rating Date 10/02/06 9/12/06 Rating Data Type YIELD Br. Spot Rating Unit BU 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Check Headline 4.4 fl oz/a R3, A+21d AB Caramba 7.7 fl oz/a R3, A+21d AB Headline 4.4 fl oz/a R3 A Caramba 7.7 fl oz/a R3 A Headline 3.6 fl oz/a A+21d B Caramba 6.1 fl oz/a A+21d B Headline 6.0 fl oz/a R3, A+21d AB Induce 0.25 % v/v R3, A+21d AB Headline 6.0 fl oz/a R3 A Induce 0.25 % v/v R3 A Caramba 8.0 fl oz/a A+21d B Headline 6.0 fl oz/a R3 A Induce 0.25 % v/v R3 A Headline 3.6 fl oz/a A+21d B Caramba 6.1 fl oz/a A+21d B Headline 4.4 fl oz/a R3 A Caramba 7.7 fl oz/a R3 A Caramba 8.0 fl oz/a A+21d B Headline 4.7 fl oz/a R3 A Folicur 3.6 F 3.2 fl oz/a R3 A Headline 3.6 fl oz/a A+21d B Folicur 3.6 F 2.4 fl oz/a A+21d B LSD (P=.05) Grand Mean Footnote: 0 = none; 10=worst 17

19 Table 13 Efficacy and Selectivity of Topguard for ASR Trial ID: 06SBTPGD Location: WTREC 2 Investigator: Dr. Melvin Newman Crop Variety AG 4801 AG 4801 Rating Date 10/02/06 9/12/06 Rating Data Type YIELD Brown Spot Rating Unit BU/A 0-10 Treatment Rate Growth Appl Name Rate Unit Stage Code Check Topguard 7 fl oz/a R3 A Topguard 14 fl oz/a R3 A Topguard 11 fl oz/a R3 A Topguard 11 fl oz/a R5 B Topguard 11 fl oz/a R3 A Topguard 14 fl oz/a R3 A Topguard 14 fl oz/a R5 B Topguard 7 fl oz/a R3 A Topguard 7 fl oz/a R5 B Topguard 7 fl oz/a R3 A Topguard 11 fl oz/a R5 B Topguard 7 fl oz/a R3 A Topguard 14 fl oz/a R5 B LSD (P=.05) Grand Mean Footnote: 0 = none; 10 = worst Table 14 Folicur, Stratego, and Absolute for ASR Trial ID: 06SBFSA Location: Airport Investigator: Dr. Melvin Newman Crop Variety AG 4801 AG 4801 Rating Date 10/13/06 10/03/06 Rating Data Type YIELD Defoliation Rating Unit BU/A % Treatment Growth Appl Name Rate Rate Unit Stage Code Check Folicur 3.6F 4 fl oz/a R3, A+21d AB Absolute 500 SC 5 fl oz/a R3, A+21d AB Stratego 10 fl oz/a R3, A+21d AB Induce % v/v R3, A+21d AB LSD (P=.05) Grand Mean

20 Report for 2006 Melvin A. Newman, Professor Title: Soybean Cyst Nematode (SCN) Sampling and Advisory Program Personnel: Melvin A. Newman, Principal Investigator Pat Donald. USDA-ARS, Nematologist Prakash Arelli, USDA-ARS, Soybean Breeder Objectives: Assist and stimulate producers into taking more SCN samples. Reduce loss from SCN and hence increase the net income of Tennessee soybean growers. Provide valuable information to soybean growers on control of SCN. Increase exposure of the Soybean Promotion Board and UT to the producers of Tennessee concerning their cooperative efforts to improve the economics of production through better disease and nematode management. Identify new races of SCN and help the producers devise control methods. Procedures: Two part-time college summer/fall assistants were hired to help producers obtain soil samples for SCN analysis. The County Extension Agents coordinated the program in those counties that had SCN problems. Each county was allocated a certain number of free samples based on their history of soybean acres. 1. Soil samples were analyzed for the number of SCN per pint of soil. 2. Upon receipt of the SCN analysis form, the Extension agent scheduled visits with each producer to build a variety selection strategy for SCN control. 3. Certain fields were selected by Dr. Patricia Donald, USDA/ARS, to be re-sampled and located by aid of the Global Positioning System (GPS) for race determination in the greenhouse. Results: The continuation of a soybean cyst nematode (SCN) sampling and survey program has shown that about 50 percent of the soybean acreage is infested with SCN. In 2006 (Jan.-Nov.), 660 soybean cyst nematode samples were pulled from 313 producer fields in 10 counties. Many more samples (hopefully, ) will be taken during the winter as weather permits. About 144,875 acres have been sampled since 1998, resulting in over 5,795 samples. It has also been shown that of the infested acres about 50 percent are infested with the new Race 2. There are no Roundup Ready varieties resistant to Race 2. The sampling program also has encouraged many producers to sample their soybean fields. Testing of several grower fields with Race 2 present may show the time it takes for another race to develop. Producer meetings, news articles and a soybean disease and nematode control ratings bulletin also help disseminate this information. 19

21 Report for 2006 Melvin A. Newman, Professor Project Title Asian Soybean Rust (ASR) Training of First Detectors and Triage Personnel Personnel Melvin Newman, Principal Investigator Richard Powell, Program Director, Western District Pat Donald, USDA-ARS, Jackson Angela Thompson, Soybean Specialist Bob Williams, Area Extension Specialist Wyveta Percell, Senior Lab Assistant Justification Asian Soybean Rust, caused by the fungus Phakopsora pachyrhizi was first discovered in Tennessee in samples of soybean leaves from Shelby Co., near Memphis, on December 1, 2004, and sent to Dr. Melvin Newman. The samples were quickly sent to USDA-APHIS personnel in Beltsville, Maryland, where they were confirmed by using a quick PCR procedure. Since the growing season was already over, there was no loss in production. Tennessee was the ninth state to confirm the presence of ASBR on the United States mainland since November 9, 2004, when the first samples were confirmed in Louisiana. Currently rust has been found infecting this year's soybeans in 230 different counties in 15 states. Including reports on kudzu, there is a total of 262 counties in 15 states with rust this year, including 19 in Tennessee. Unlike the 2005 season, more soybean rust finds are occurring up the Mississippi River Valley apparently from outbreaks in Louisiana. Asian Soybean Rust is a serious disease of soybean that can quickly destroy soybean yields by causing severe defoliation of the entire plant (from 10% to 80% loss in yield in many areas of the world). In recent years, ASBR has moved from South Africa to South America and now into the southern US. There are no resistant varieties, and there is little hope of obtaining durable resistance in the near future. The first line of defense against this wind-blown pathogen is the timely use of foliar fungicides. No one knows for sure where or when spores of this fungus will be deposited on Tennessee s crop. It is highly likely that it will overwinter in the extreme southern areas of the US where freezing temperatures rarely occur. There are 95 species of plants that are hosts to ASBR, including kudzu, winter vetch, alfalfa, lima beans, dry beans, and lupines. These hosts will surely play a role in the rust s ability to survive and spread into the soybean growing areas of the country. Southerly winds in the spring might carry rust spores hundreds of miles and deposit them in a large area. Soybean rust can reproduce in just a few days under warm, moist conditions and then spread even farther into other soybean growing areas. The amount of spread and damage will depend largely on the environmental conditions in the spring and summer. In order for producers to be able to effectively control soybean rust, they must spray fungicides before the rust pathogen gets started. Producers in Brazil report that they had success in 2004 with only two applications in most cases. But the first application must be sprayed on the soybeans before infections reach the 5-10% level. It will be very difficult for the untrained person to recognize early rust infections, since the symptoms are very much like other diseases that are common in Tennessee soybean fields. However, if producers wait until symptoms are obvious, it will be much more difficult to control and might take more fungicide sprays and obtain less control. Since this disease has never been seen by most producers and even very few researchers, it will be extremely difficult for most producers to accurately identify soybean rust in time to effectively spray a fungicide. Therefore, it is very clear that a training program aimed at educating and helping producers identify soybean rust is needed. If soybean rust is identified, producers will have to react very quickly to spray fungicides to protect their soybean crop from yield losses. The University of Tennessee Extension has developed an action plan for this very purpose. The plan aims to reduce the critical time lost due to confusion and misinformation once rust is re-confirmed in Tennessee or in surrounding states. It is critical that fungicides be applied before rust infections get started. 20

22 Procedures: It is extremely difficult to train key personnel on how to identify soybean rust without samples of the live rust in-hand. Slides and pictures do not adequately show the real size, shape and color of soybean rust. In order to equip our key Extension agents in soybean-growing counties where accurate diagnosis is critical, it is proposed that 20 key Extension agents and specialists tour soybean rust-infested plots, fields and greenhouses in the early summer of Several locations have been identified and are likely target areas for rust to infect during the spring. These areas along the gulf coast of Alabama, Georgia and Florida were infested early in Extension agents and specialists would visit such areas as soon as significant soybean rust is discovered before rust reaches Tennessee. Soybean rust pathologists would have field labs and microscopes available and provide expert training both in-field and in the lab. Having this expertise in Tennessee along with the use of sentinel plots and spore traps in many of the counties would surely be of great benefit when it comes to diagnosing soybean rust quickly with confidence and accuracy. Results: Soybean Rust Tour 2006 A total of 26 county agricultural agents, Extension specialists, lab technicians, and one USDA/ARS researcher took advantage of a Soybean Rust Educational Tour on August 17-19, The county agents were from soybean counties throughout the state. Three stops were pre-arranged. The first stop was Dothan, AL, where the tour participants were able to see their first real soybean rust samples on both kudzu and soybean leaves. Five microscopes were set up in a meeting room where there was ample time to observe rust pustules and spores. The next stop was at the University of Florida s Quincy Experiment Station. Dr. Jim Marois, Extension Plant Pathologist, gave a short presentation and then led the group to a soybean plot that was heavily infested with rust pustules. We set up a pop-up tent and five battery operated microscopes in the field. After almost three hours of observing soybean rust pustules with microscopes and hand lenses, we were off to another experiment station. Our next stop was at the University of Georgia Experiment Station at Attapulgus. Here, Dr. Layla Sconyers led us through soybean and kudzu plots that had only small amounts of soybean rust. This was a good exercise because it caused us to have to really look for rust pustules. We also had a demonstration on the use of the QuickStix method of rust identification. This is a simple five-minute test that gives a positive or negative result for soybean rust. Overall, comments from the participants were extremely favorable, and everyone felt that the time and money spent on this trip were well worth it. They all felt more confident in their ability to identify soybean rust for their producers should it hit Tennessee. It also gave them a better appreciation of how severe this disease can be. Responsibilities: Training leader and technical advisor Dr. Melvin Newman, UT Extension Plant Pathologist and cochairman of the soybean rust committee. Other trainers and plant pathologists Dr. Alan Windham, Dr. Steve Bost, Dr. Angela Thompson, Mr. Bob Williams and Dr. Darrell Hensley. Others assisting in coordination and administration Dr. Tim Cross (Assistant Dean of Extension), Dr. Richard Powell (co-chairman of soybean rust committee). 21