Management of Rhizoctonia in Sugarbeet

Transcription

1 Office: Management of Rhizoctonia in Sugarbeet 2019 SMBSC Production Seminar, Willmar, MN Ashok K. Chanda Assistant professor/ Extension Sugarbeet Pathologist Northwest Research and Outreach Center, Crookston Dept. of Plant Pathology, University of Minnesota

2 Summary of Field Samples No. of Fields Rhizoctonia Aphanomyces Rhizoctonia + Aphanomyces Cause of Problem Fusarium 7 Chemical

3 Rhizoctonia + Aphanomyces July 21, 2015

4 Damping-off

5 Crown and Root Rot

6 Crown and Root Rot

7 Crown and Root Rot

8 Rhizoctonia affects Yield Yield T/A Resistant and Moderately Susceptible Varieties r = y = x R² = Rhizoctonia Root Rot Rating

9 Rhizoctonia Fungus Rhizoctonia solani 13 Anastomosis groups Sugarbeet- Anastomosis groups AG 2-2 (seedling and adult) and AG 4 (seedling) AG 2-2 has intraspecific groups (ISGs) AG 2-2 IIIB and AG 2-2 IV Both ISGs cause same symptoms on sugarbeet Both occur in MN/ND (Windels, 2009)

10 AG 2-2 IV vs AG 2-2 IIIB RRV (460 cultures): AG 2-2 IV most common (66%) So. MN (504 cultures): AG 2-2 IIIB most common (56%) (Windels, 2010)

11 Management of Rhizoctonia Early planting

12 Management of Rhizoctonia Early planting Crop Rotation Length of rotation Weed control Crop choice

13 Soybeans

14 Soybeans No emergence with Rhizoctonia in the furrow

15 Navy beans

16 Navy beans

17 Navy beans

18 Management of Rhizoctonia Early planting Crop Rotation Crop choice Length of rotation Weed control Resistant varieties

19 Rhizoctonia rating scale Reynolds et al.

20 Rhizoctonia & Resistant Variety (~3.4) No. plants/100 ft. of row "ST 60 F Soil temp. ( F) Date

21 Rhizoctonia & Moderately Resistant Variety (~4.0) No. plants/100 ft. of row "ST 60 F Soil temp. ( F) 5/26 6/2 6/9 6/16 6/23 6/30 7/7 7/14 Date 7/21 7/28 8/4 8/11 8/18

22 Rhizoctonia & Susceptible Variety (~5.3) No. plants/100 ft. of row "ST 60 F Soil temp. ( F) Date

23 Management of Rhizoctonia Early planting Crop Rotation Crop choice Length of rotation Weed control Resistant varieties At-planting fungicides Seed treatment

24 Seed treatments SDHI class of fungicides Single site of action (Succinate DeHydrogenase Inhibitor) Inhibit fungal respiration

25 Seed treatments Kabina 14 g (Penthiopyrad, 2014) Vibrance 1.5 g (Sedaxane, 2016) Systiva 5 g (Fluxapyroxad, 2017) Metlock Suite [Metconazole + Rizolex) + Kabina 7g (Penthiopyrad), 2014) From 2017, 100% seed is treated for Rhizoctonia and treatment depends on the seed companies choice

26 Seed treatments No. plants per 100 ft of row Non-inoculated Systiva + 15 g Stamina Met. Suite + 7 g Kabina 14 g Kabina ST 2 g Vibrance Days after planting Untreated control

27 Seed treatments No. plants per 100 ft of row Kabina 14 g Metlock Suite + Kabina 7 g Systiva 5 g Vibrance 1.5 g Untreated control Days after planting

28 Seed treatments No. plants/100 ft of row Untreated Kabina Metlock Suite + Kabina Systiva Vibrance Days after planting

29 Benefits of seed treatments Sugarbeet seedlings are very susceptible to Rhizoctonia early on Genetic resistance is not expressed until 6-8 leaf stage Effective protection of seedling (4-5 weeks) Ease of use -It comes with seed Safety No plugged nozzles

30 Management of Rhizoctonia Early planting Crop Rotation Crop choice Length of rotation Weed control Resistant varieties At-planting fungicides Seed treatment In-furrow application

31 In-furrow treatments No. plants per 100 ft of row Quadris I-F 10 fl oz Satori I-F 10 fl oz Xanthion I-F fl oz Headline I-F 9 fl oz Untreated control Days after planting

32 In-furrow treatments 2018 No. plants/100 ft of row Days after planting Xanthion I-F fl oz/a AZteroid I-F 11.9 fl oz/a Untreated control Quadris I-F 9.5 fl oz/a

33 Benefits In-furrow treatments Sanitizing the furrow (seedling + soil) More effective than seed treatments longevity up to 8-10 weeks (Windels, 2010) Risks Phytotoxicity cool weather and light soils Mixing with starter fertilizer and other chemicals Plugged nozzles

34 Azoxystrobin Just after mixing Quadris Satori Equation Starter

35 Azoxystrobin minutes after mixing Quadris Satori Equation Starter

36 Azoxystrobin hours after mixing Quadris Satori Equation Starter

37 Seed vs In-furrow fungicides Treatment No. harv. Roots/100 ft. RCRR (0-7) Yield RSA Seed treatments In-furrow treatments Contrast analysis p- value Seed Treatments 14 g Kabina ST Metlock Suite Met. Suite + 7 g Kabina 7 g Kabina ST 2 g Vibrance In-furrow 12 fl oz Headline IF 10 fl oz Quadris IF 10 fl oz Equation IF 10 fl oz Satori IF NS = not significantly different

38 Seed vs In-furrow fungicides No. of plants per 100 ft. row In-furrow fungicides Seed treatments Untreated control Days after planting Planted late June

39 Seed vs In-furrow fungicides Treatment No. harv. RCRR RCRR % Yield roots/100 ft (0-7) incidence ton A -1 RSA Mean of Seed trts Mean of In-furrow trts Contrast analysis P- value Seed Treatments 14 g Kabina ST Metlock Suite Met. Suite + 7 g Kabina 5 g Systiva 1.5 g Vibrance In-furrow 9 fl oz Headline IF 10 fl oz Quadris IF 10 fl oz Satori IF Xanthion (Headline + Integral, fl oz/a)

40 Seed vs In-furrow fungicides No. of plants per 30 m of row Seed treatments In-furrow fungicides Untreated control Days after planting

41 Seed vs In-furrow fungicides Treatment No. harv. RCRR Yield ton roots/100 ft (0-7) A -1 RSA Seed treatments In-furrow treatments Contrast analysis P- value Seed Treatments 14 g Kabina ST Metlock Suite Met. Suite + 7 g Kabina 5 g Systiva 1.5 g Vibrance NS NS NS NS In-furrow 10 fl oz Quadris 11.9 fl oz AZteroid Xanthion (Headline + Integral, fl oz/a) NS = not significantly different

42 Seed vs In-furrow fungicides No. plants/100 ft of row Seed treatments In-furrow treatments Untreated control Days after planting Planted early May

43 Seed vs In-furrow fungicides Treatment No. harv. RCRR Yield ton roots/100 ft (0-7) A -1 RSA Seed treatments In-furrow treatments Contrast analysis P- value Seed Treatments 14 g Kabina ST Met. Suite + 1 g Vibrance Met. Suite + 7 g Kabina 5 g Systiva 1.5 g Vibrance NS In-furrow 9.5 fl oz Quadris 11.9 fl oz AZteroid NS Xanthion (Headline + Integral, fl oz/a) Elatus 9.5 fl oz (* not registred for sugarbeet) NS = not significantly different

44 Management of Rhizoctonia Early planting Crop Rotation Crop choice Length of rotation Weed control Resistant varieties At-planting fungicides Seed treatment In-furrow application Postemergence fungicides

45 4-inch soil temp daily means F 65 F NWROC Wahpeton Renville 40 1-May 8-May 15-May 22-May 29-May 5-Jun 12-Jun 19-Jun 26-Jun 3-Jul 10-Jul 17-Jul 24-Jul 31-Jul 7-Aug 14-Aug 21-Aug 28-Aug 4-Sep 11-Sep 18-Sep 25-Sep Mean 4-inch soil temperature

46 Postemergence Application 2017 Quadris in a 7-inch band

47 Postemergence fungicides 2015 Quadris vs Generics RCRR Yield RSA Treatment (0-7) T/A Non-inoculated No-fungicide control R. solani-inoculated 14 fl oz/a 1.9 d 31.0 a 8066 a 14 fl oz/a 2.4 d 29.9 a 7908 a 14 fl oz/a 2.4 d 29.6 a 7790 a No-fungicide control 5.5 a 14.0 c 3411 c ANOVA P-value LSD (P = 0.05) Z

48 Postemergence fungicides 2015 Band vs Boradcast Treatment (Rates per Acre) RCRR (0-7) RCRR % Incidence Yield T/A RSA No fungicide control 3.7 a 75 a 23.2 c 7324 c 17.6 fl oz, 0.7 b 15 b 33.6 ab ab band 10 fl oz, band 0.9 b 16 b 33.5 ab a 14 fl oz, band 1.2 b 25 b 31.9 ab ab 14 fl oz broadcast 1.1 b 21 b 33.4 ab ab ANOVA P-value < < < LSD (P = 0.05) W

49 4-inch soil temp daily means F 65 F NWROC Wahpeton Renville 40 1-May 8-May 15-May 22-May 29-May 5-Jun 12-Jun 19-Jun 26-Jun 3-Jul 10-Jul 17-Jul 24-Jul 31-Jul 7-Aug 14-Aug 21-Aug 28-Aug 4-Sep 11-Sep 18-Sep 25-Sep Mean 4-inch soil temperature

50 Cultivar x postemergence interaction 30 on disease incidence - NWROC % RCRR incidence Resistant Susceptible (4.0) (4.8) Untreated 4-leaf 8-leaf Postemergence application

51 Cultivar x at-planting x postemergence interaction on disease incidence - SMBSC % RCRR incidence Resistant cultivar Untreated 4-leaf 8-leaf Quadris Systiva Untreated At-planting treatment % RCRR incidence Susceptible cultivar (4.0) (4.8) Untreated 4-leaf 8-leaf Quadris Systiva Untreated At-planting treatment

52 Benefits Postemergence fungicides If you are doing a row cultivation--throwing soil onto crowns Late season disease control (rain aug-sept) If sugarbeets are following Rhizoctonia-susceptible crops in a rotation Band application (preferred) severe disease pressure Broadcast application low disease pressure Risks Work better if applied before infection

53 Benefits Postemergence fungicides If you are doing a row cultivation--throwing soil onto crowns Late season disease control (rain aug-sept) If sugarbeets are following Rhizoctonia-susceptible crops in a rotation Band application (preferred) severe disease pressure Broadcast application low disease pressure Risks Work better if applied before infection

54 Take Home Message for 2019 Rhizoctonia risk (beets/100 ft. row at harvest) Your Variety choice Seed treatment In-furrow treatment Postemergence treatment Low ( ) Moderate Weak Yes Yes No No No Yes Specialty < 4.0 Rhizoctonia rating Moderate Weak > 4.4

55 Take Home Message for 2019 Rhizoctonia risk (beets/100 ft. row at harvest) Your Variety choice Seed treatment In-furrow treatment Postemergence treatment Low ( ) Moderate Weak Yes Yes No No No Yes Moderate ( ) Specialty Moderate Weak Yes Yes Yes No No No Yes/No (History) Yes Yes

56 Take Home Message for 2019 Rhizoctonia risk (beets/100 ft. row at harvest) Your Variety choice Seed treatment In-furrow treatment Postemergence treatment Low ( ) Moderate Weak Yes Yes No No No Yes Moderate ( ) Specialty Moderate Weak Yes Yes Yes No No No Yes/No (History) Yes Yes Severe (less than 130) Specialty Moderate Weak Yes Yes Yes No Yes Yes Yes Yes Yes

57 Summary- Rhizoctonia Management Seed treatments provide excellent early-season protection In-furrow applications Similar to seed treatments under low disease pressure Better than seed treatments under high disease pressure May reduce stands under cool and dry soil conditions Seed/in-furrow treatments can broaden the window to apply postemergence application (4 to 8 leaf stage) Postemergence application is most beneficial under moderate to heavy disease pressure especially if beets are following soybeans or edible beans Generic formulations of azoxystrobin are effective

58 Acknowledgements Sugarbeet Research and Education Board of Minnesota and North Dakota Grower cooperators Scott Pahl, Germains Seed Technology Seed, chemical, and allied industries American Crystal Sugar Company quality lab Minn-Dak Farmers Cooperative Southern Minnesota Beet Sugar Cooperative

59 Thank you! Jason Jeff Pratibha Hal Katie Alec Claire Karen Tim Muira Brandon Amanda Dr. Ian MacRae Tim