Silver scurf, black scurf and dry rot

Transcription

1 Silver scurf, black scurf and dry rot Ragnhild Nærstad Norwegian Institute for Agricultural and Environmental Research Bioforsk Plant Health and Plant Protection Division

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3 . 14 ha -> 35 tons = 25 t/ha (1 7 t/ha) 3 growers, 1 8 ha of potatoes per grower

4 Silver scurf Helminthosporium solani

5 Silver scurf Potato is the only known host plant Survives as a saprophyte in soil, and multiplies on senescent plants of many species Tubes can become infected in the growing season, at harvest or during storage Needs humid conditions to infect, the infection speed increases with temperature Under optimal conditions the fungus needs 9 hours to penetrate into the cells

6 Silver scurf Infected cells die, loose their pigments and become filled with air > silvery lesions Increased the water loss in infected tissue -> shrinking Inoculum sources: Seed tubers (and soil) PCR results from 28-29: a lot of inoculum in seed tubers and low levels in soil

7 Control measures Silver scurf Crop rotation + avoid cereals as the last crop before potatoes Shorter growing seasons (presprout seed tubers)+ shorten the period between haulm killing and harvest Suppressive soils Low plant density Dry curing Cold storage and no condense Seed treatment: Fungazil (imazalil), Maxim (fludioxonil), Emesto (penflufen), Emesto silver (penflufen + protioconazol), Serenade (Basillus subtilis) In furrow fungicide application: Amistar (azoxystrobin)

8 Black scurf Rhizoctonia solani

9 Sclerotia and hypha

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11 Black scurf Rhizoctonia solani (Thanatephorus cucumeris) Sunken dark brown lesions on sprouts, stems, stolons and roots Infections in stolons early in the season -> tuber abortion, new tubers is developed higher up -> more small tubers and more green tubers

12 Control measures Black scurf Crop rotation, several years without potatoes Suppressive soils Shorter growing seasons + shorten the period between haulm killing and harvest -> less sclerotia on tubers Dry curing Cold storage and no condense Seed treatment: Rizolex (tolclofosmethyl), Monceren (pencycuron), Maxim (fludioxonil), Emesto (penflufen), Emesto silver (penflufen + protioconazol)

13 Silver scurf Silver scurf Black dot

14 Plug test - incubation test - distinguish between different types of scurfs - visualize latent infection

15 Occurrence of skin blemish diseases in Norway after 4-6 month of storage, 247 potato lots: Nærstad R, Dees MW, Le VH, Holgado R, Hermansen A Silver scurf (Helminthosporium solani) 11-13% (1%) Black dot (Colletotrichum coccodes) (8%) Common scab (Streptomyces spp.) 6-7% (5-7%) Powdery scab (Spongospora subterranean).7-2% (7%) Skin spot (Polyscytalum pustulans).2-1.7% (8%) Black scurf (Rhizoctonia solani).8% (8%)

16 Root lesion nematodes Paratylenchchus spp. in 6% of scabby lesions

17 Decision making in potato skin blemish diseases control using real-time diagnostic methods; Norwegian results from 29 and 21 R. Nærstad, A. Hermansen, V.H. Le, G. Lund, M. Skogen, M.B. Brurberg

18 Sampling 4 locations each year in 29 and 21 + questionaries From each location: Samples of soil and seed tubers at planting Samples of soil in August Samples of progeny tubers at harvest Assessed for the presence of pathogens by real-time PCR Tubers were also assed for the presence of pathogens by plug tests Pathogens: Black dot (Colletotrichum coccodes) Skin spot (Polyscytalum pustulans) Common scab (Streptomyces spp.) Silver scurf (Helminthosporium solani) Powdery scab (Spongospora subterranean) Black scurf (Rhizoctonia solani)

19 Real-time PCR protocols SCRI protocols: Common scab (Cullen and Lees, 27) Powdery scab (van de Graaf et al., 23) Silver scurf (Cullen et al., 21) Black scurf (Lees et al., 22) Black dot (Cullen et al. 22) Fungal pathogens based on ITS regions Streptomyces based on nec gene Ribosomale RNA gener: ITS 18S gen 5.8S gen 26S gen

20 DNA-analysis Soil samples (SCRI protocol) Tuber samples Peel homogenized in Homex (SCRI protocol) Extraction robot (Molgene)

21 Example of amplification plot

22 %S-Silver scurf-progeny tubers PCR-Silver scurf-seed tubers %S-Silver scurf-seed tubers Silver scurf Helminthosporium solani Good correlation between plugtest and PCR results High level of inoculum in seed tubers Low level of inoculum in soil Low correlation between inoculum in seed tubers and progeny tubers Scatterplot of %S-Silver scurf-seed tub vs PCR-Silver scurf-seed tu , 4,4 4,8 5,2 5,6 PCR-Silver scurf-seed tubers Scatterplot of %S-Silver scurf-progeny vs PCR-Silver scurf-progeny year Scatterplot of PCR-Silver scurf-seed tu vs PCR-Silver scurf-progeny 5,6 5,2 4,8 year , , PCR-Silver scurf-progeny tubers PCR-Silver scurf-progeny tubers 4 5

23 Sclerotia- Seed tubers %R-Black scurf-seed tubers Sclerotia-progeny tubers Black scurf Rhizoctonia solani Good correlation between: sclerotia plug-test plug-test PCR results Low level of inoculum in soil in spring, a slight increase in the autumn, but did not correlate with the black scurf in the progeny Low correlation between inoculum in seed and progeny tubers Scatterplot of Sclerotia-progeny tubers vs %R-black scurf-progeny t %R-black scurf-progeny tubers Year Scatterplot of Sclerotia- Seed tubers vs PCR-black scurf- seed tubers 2,5 Scatterplot of %R-Black scurf-seed tube vs PCR-black scurf- seed tu 5 2, 4 1,5 3 1, 2,5 1, PCR-black scurf- seed tubers PCR-black scurf- seed tubers 5 6

24 Conclusion from quantitative PCR diagnostics of soil and tubers Skin spot, powdery scab and black dot: disease increased with inoculums on the seed tubers. For black dot and powdery scab it also increased with soil inoculums Common scab, silver surf and black scurf: other factors than inoculums level were more important for disease incidence in the progeny tubers

25 Harvest, curing and storage strategies 3 trials, 11 and 22 days from haulm killing to harvest 4 harvest dates Curing: 7% RH and 9% RH Storage: Directly to 4 o C and slowly to 4 o C

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30 Seed treatment at planting (6 trials/year) Control Rizolex Maxim 1 % progeny tubers with sclerotia (25 and 26) % plugs with black scurf hyfae (27) % plugs with silver scurf (27) Both Maxim (fludioxonil) and Rizolex (tolclofosmethyl) reduces black scurf in the progeny tubers (sclerotia og hypha) Maxim reduces silver scurf in the progeny

31 6 Effect of humidity during curing and Amistar in furrow Control Humid curing Control Dry curing Amistar Humid curing Amistar Dry curing 1 % plugs with silver scurf % plugs with black scurf hyfae % plugs with skin spot

32 All treatments reduced the amount of R. solani sclerotia and hypha on the progeny tubers Amistar and Emesto also reduced the frequency of silver scurf latent infections (plug test) In 28 and 21 there were attack of black dot at one location and in these trials there were less black dot in the Amistar treatment % reduction of black scurf hyfae Rizolex Emesto Amistar Emesto dust Emesto silver Prestige % reduction of silver scurf Rizolex Emesto Amistar Emesto dust Emesto silver Prestige % reduction of black dot Rizolex Emesto Amistar Emesto dust Emesto silver Prestige

33 Fusarium dry rot Important disease of potato affecting tubers in storage Caused by several fungal species in the genus Fusarium Fusarium dry rot of seed tubers can reduce crop establishment by killing developing potato sprouts Crop losses can be up to 25%

34 Symptoms Originate in wounds created by mechanical damages or desprouting during handling Surface lesions appears as dark depressions and wrinkled areas of skin Concentric rings can be observed in case of heavy infection Fusarium dry rot can be recognized based on white, pink or orange colored mycelium proliferation on the tuber surface Photos: J. Gomez

35 Fusarium dry rot in Norway P.H. Jensen, M.B. Brurberg & A. Hermansen Main goal: Find out which Fusarium spp. currently causes dry rot problems in Norway How: Potato samples collected from different regions in Norway over 3 seasons (21-213) artificial wounding + incubation isolation Photo: P. H. Jensen

36 Results from the growing season % of the tubers developed rots Fusarium Boeremia (Phoma) Penicillium Mucor Cylindrocarbon 49 % of rots were caused by Fusarium F. coeruleum (64%) F. avenaceum (31%) F. culmorum (4%) F. cerealis (1%) F. sambucinum (1%) Photo: P. H. Jensen

37 Fusarium coeruleum Fusarium cerealis Fusarium sambucinum Fusarium culmorum

38 Goal Develop multiplex real time PCR for Norwegian dry rots caused by Fusarium species and gangrene (Boremia foveata)

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40 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Monceren FS 25(Pencycuron) Inhibition of cell division, phenylureas, FRAC Code B4 Colletotrichum coccodes Polyscytalum pustulans ,1,1 1, 1, 1, Monceren FS25 (Pencycuron in ppm ) No8-Cc-16 No8-Cc-37 No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc-47 No8-Cc ,1,1 1, 1, 1, Monceren FS25 (Pencycuron in ppm ) No8-Pp-34 No8-Pp-43 No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 No8-Pp-15 Helminthosporium solani Rhizoctonia solani ,1,1 1, 1, 1, Monceren FS25 (Pencycuron in ppm ) No8-Hs-59 No8-Hs-6 No8-Hs-62 No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs-35 No8-Hs ,1,1 1, 1, 1, Monceren FS25 (Pencycuron in ppm ) No8-Rs-2 No8-Rs-25 No8-Rs-27 No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 No8-Rs-19

41 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Rizolex 5FW (Tolclofosmethyl) Lipid peroxidation, Aromatic Hydrocarbons, FRAC Code F3 Colletotrichum coccodes Polyscytalum pustulans ,1,1 1, 1, 1, Rizolex 5 FW(Tolclophosmethyl in ppm ) No8-Cc-16 No8-Cc-37 No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc-47 No8-Cc ,1,1 1, 1, 1, Rizolex 5 FW(Tolclophosmethyl in ppm ) No8-Pp-34 No8-Pp-43 No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 No8-Pp-15 Helminthosporium solani Rhizoctonia solani ,1,1 1, 1, 1, Rizolex 5 FW(Tolclophosmethyl in ppm ) No8-Hs-59 No8-Hs-6 No8-Hs-62 No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs-35 No8-Hs ,1,1 1, 1, 1, Rizolex 5 FW(Tolclophosmethyl in ppm ) No8-Rs-2 No8-Rs-25 No8-Rs-27 No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 No8-Rs-19

42 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Maxim 1 FS(fludioxonil) Inhibition of osmotic signal transduction, phenylpyrroles, FRAC Code E2 Colletotrichum coccodes Polyscytalum pustulans 12 1 No8-Cc-16 No8-Cc No8-Pp-34 No8-Pp ,1,1 1, 1, 1, Maxim 1 FS (fludioxonil in ppm ) No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc-47 No8-Cc ,1,1 1, 1, 1, Maxim 1 FS (Fludioxonil in ppm ) No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 No8-Pp-15 Helminthosporium solani Rhizoctonia solani 12 1 No8-Hs-59 No8-Hs No8-Rs-2 No8-Rs-25 8 No8-Hs-62 8 No8-Rs ,1,1 1, 1, 1, Maxim 1 FS (Fludioxonil in ppm ) No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs-35 No8-Hs ,1,1 1, 1, 1, Maxim 1 FS (Fludioxonil in ppm ) No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 No8-Rs-19

43 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Emesto(Penflufen) Inhibition of respiration complex II, Succinate DeHydrogenase Inhibitors, FRAC Code C2 Colletotrichum coccodes Polyscytalum pustulans ,1,1 1, 1, 1, No8-Cc-16 No8-Cc-37 No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc ,1,1 1, 1, 1, No8-Pp-34 No8-Pp-43 No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 BYF14182 (Penflufen in ppm ) No8-Cc-5 BYF14182 (Penflufen in ppm ) No8-Pp-15 Helminthosporium solani Rhizoctonia solani ,1,1 1, 1, 1, No8-Hs-59 No8-Hs-6 No8-Hs-62 No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs ,1,1 1, 1, 1, No8-Rs-2 No8-Rs-25 No8-Rs-27 No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 BYF14182 (Penflufen in ppm ) No8-Hs-41 BYF14182 (Penflufen in ppm ) No8-Rs-19

44 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Fungazil(Imazalil) Inhibition of sterol biosynthesis in membranes, DeMethylation Inhibitors, FRAC Code G1 Colletotrichum coccodes Polyscytalum pustulans 12 1 No8-Cc-16 No8-Cc No8-Pp-34 No8-Pp ,1,1 1, 1, 1, Fungazil 1SL (Imazalil in ppm ) No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc-47 No8-Cc ,1,1 1, 1, 1, Fungazil 1SL (Imazalil in ppm ) No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 No8-Pp-15 Helminthosporium solani Rhizoctonia solani 12 1 No8-Hs-59 No8-Hs No8-Rs-2 No8-Rs-25 8 No8-Hs-62 8 No8-Rs ,1,1 1, 1, 1, Fungazil 1SL (Imazalil in ppm ) No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs-35 No8-Hs ,1,1 1, 1, 1, Fungazil (Imazalil in ppm ) No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 No8-Rs-19

45 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Proline EC25 (Protiokonazol) Inhibition of sterol biosynthesis in membranes, DeMethylation Inhibitors, FRAC Code G1 Colletotrichum coccodes Polyscytalum pustulans ,1,1 1, 1, 1, Proline EC25 (Protiokonazol in ppm ) No8-Cc-16 No8-Cc-37 No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc-47 No8-Cc ,1,1 1, 1, 1, Proline EC25 (Protiokonazol in ppm ) No8-Pp-34 No8-Pp-43 No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 No8-Pp-15 Helminthosporium solani Rhizoctonia solani ,1,1 1, 1, 1, Proline EC25 (Protiokonazol in ppm ) No8-Hs-59 No8-Hs-6 No8-Hs-62 No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs-35 No8-Hs ,1,1 1, 1, 1, Proline EC25 (Protiokonazol in ppm ) No8-Rs-2 No8-Rs-25 No8-Rs-27 No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 No8-Rs-19

46 Growth in % of control Growth in % of control Growth in % of control Growth in % of control Amistar (azoxystrobin) + Salicylhydroxamic acid Inhibition of respiration complex III, Quinone outside inhibitors FRAC Code C3, Colletotrichum coccodes Polyscytalum pustulans ,1,1 1, 1, 1, No8-Cc-16 No8-Cc-37 No8-Cc-57 No8-Cc-1 No8-Cc-13 No8-Cc-19 No8-Cc-42 No8-Cc-43 No8-Cc ,1,1 1, 1, 1, No8-Pp-34 No8-Pp-43 No8-Pp-48 No8-Pp-53 No8-Pp-1 No8-Pp-5 No8-Pp-9 No8-Pp-11 No8-Pp-12 Amistar (Azoxystrobin in ppm ) No8-Cc-5 Amistar (Azoxystrobin in ppm ) No8-Pp-15 Helminthosporium solani Rhizoctonia solani ,1,1 1, 1, 1, No8-Hs-59 No8-Hs-6 No8-Hs-62 No8-Hs-67 No8-Hs-2 No8-Hs-21 No8-Hs-27 No8-Hs-29 No8-Hs ,1,1 1, 1, 1, No8-Rs-2 No8-Rs-25 No8-Rs-27 No8-Rs-13 No8-Rs-4 No8-Rs-11 No8-Rs-13 No8-Rs-14 No8-Rs-16 Amistar (Azoxystrobin in ppm ) No8-Hs-41 Amistar (Azoxystrobin in ppm ) No8-Rs-19

47 Application of seed treatment in autumn or spring? % control of silvers curf in progeny tubers Imazalil sulfat Fludioxonil Copperoxide Penflufen Autumn Spring Autumn + spring The control had silver scurf on 5% of the plugs and black scurf on 12 % of the plugs =>no significant differenses between treatments for black scurf.