Update of Tomato Disease Research in Michigan: Bacterial Spot and Late Blight

Transcription

1 Update of Tomato Disease Research in Michigan: Bacterial Spot and Late Blight Dr. Mary Hausbeck Plant, Soil and Microbial Sciences Michigan State University

2 Bacterial Leaf Spot Xanthomas spp. formerly X. campestris pv. vesicatoria (4 races). Reclassified: X. vesicatoria. X. euvesicatoria (10 races, only species affecting pepper). X. perforans. X. gardneri.

3

4

5

6 Resistance to copper and antibiotics appears to becoming more common

7 Rethinking the Control Strategy for Bacterial Spot Role for copper may be secondary to other approaches with pathogen resistance. Seed treatment holds promise as bacterial contamination is a primary problem.

8 Bacterial Diseases: Products Tested Product A.I. Labeled Kocide 3000 WG copper hydroxide yes Quintec SC quinoxyfen yes Two plot locations: commercial grower and SWMREC

9 Disease severity (1=healthy, 10=100% diseased/defoliated) Bacterial Diseases on Tomato ab Eight sprays applied at 7-day intervals beginning 10 July Bars with a letter in common are not significantly different a ab b Untreated control Quintec SC 6 fl oz Kocide WG 1.25 lb Quintec SC 6 fl oz + Kocide WG 1.25 lb

10 Total yield (lb/10 ft) Healthy red yield (lb/10 ft) Healthy green yield (lb/10 ft) Bacterial Diseases on Tomato a a Untreated control ab ab Eight sprays applied at 7-day intervals beginning 10 July Bars with a letter in common are not significantly different ab a Quintec SC 6 fl oz ab b ab Kocide WG 1.25 lb b Total Healthy Red ab Healthy Green b Quintec SC 6 fl oz + Kocide WG 1.25 lb

11 Red fruit yield Healthy Diseased Untreated control Green fruit yield

12 Products Tested Product A.I. Labeled FRAC Dithane F-45 SC mancozeb yes M3 Kocide 3000 DF copper hydroxide yes M1 Quintec SC quinoxyfen 2(ee) 13

13 Untreated Quintec 4 fl oz

14 Quintec 4 fl oz + Kocide 1.25 lb

15 HB foliar severity (1=healthy, 12=100% diseased) Bacterial Bacterial Spot and Spot Canker on Tomato on Tomato b Horsfall-Barratt severity scale 3=>3%-6% plant area diseased 4=>6%-12% plant area diseased 5=>12%-25% plant area diseased ab ab a 9 foliar sprays applied at 7-day intervals b Inoculated with bacterial spot isolates sensitive to copper Bars with a letter in common are not significantly different Total yield (lb/5 plants) b a ab ab ab 20 Untreated inoculated Quintec 4 fl oz Kocide 1.25 lb Quintec 4 fl oz + Kocide1.25 lb Quintec 4 fl oz + Kocide 1.25 lb -alternate- Dithane F fl oz

16 Products Tested Product A.I. Labeled FRAC Actigard WG acibenzolar-s-methyl yes P AgriPhage SC bacteriophage yes NC Blight Ban Pseudomonas fluorescens yes* NC Cease SC Bacillus subtilis yes 44 Cueva SC copper octanoate yes M1 Double Nickel SC Bacillus amyloliquefaciens yes 44 K-Phite SC phosphorous acid salts yes 33 MilStop WP potassium bicarbonate yes NC Tanos WG famoxadone/cymoxanil yes 11/27 *Labeled for frost protection

17 Bacterial Disease on Tomato HB foliar severity (1=healthy, 12=100% diseased) foliar sprays applied at 7-day intervals in 50 gal water (unless otherwise indicated) 1 HB fruit lesion severity (1=healthy, 12=100% diseased) Horsfall-Barratt severity scale 5=>12%-25% tissue area diseased 6=>25-50% tissue area diseased 7=>50%-75% tissue area diseased a-c a-c a ab a-c a-c a-c a-c AgriPhage was not tankmixed Bars with a letter in common are not significantly different bc bc c 1 Untreated uninoculated Untreated inoculated K-Phite 3 qt Agri- Phage 2 pt Untreated uninoculated K-Phite 3 qt + Tanos 8 oz 14-day Blight Ban 7 oz/ 200 gal water Agri- Phage 2 pt K-Phite 3 qt K-Phite 3 qt + Tanos 8 oz 14-day Agri- Phage 2 pt Double Nickel 1 qt + Cueva 2 qt Cease 6 qt + MilStop 2 lb/ 100 gal water

18 Late Blight Phytophthora infestans. Same pathogen that infects potatoes. Pathogen spores spread through the air. Fungicides are typically needed.

19

20

21 Late Blight Tips Minimize leaf wetness Ensure good airflow Stay posted on late blight in the state/locale Scout and treat early

22 Products Registered for Tomato Late Blight Product A.I. FRAC Bravo Ultrex/WeatherStik chlorothalonil (Alternaria product) M5 Cabrio 20WG pyraclostrobin (Alternaria product) 11 Manzate 75DF mancozeb (Alternaria product) M3 Ariston chlorothalonil/cymoxanil M5/27 Curzate cymoxanil 27 Forum dimethomorph 40 Gavel mancozeb/zoxamide M3/22 Presidio fluopicolide 43 Previcur Flex propamocarb 28 Ranman cyazofamid 21 Reason fenamidone 11 Revus mandipropamid 40 Ridomil-based fungicides mefenoxam 4 Zampro 4.4SC ametoctradin/dimethomorph 45/40 Zing! SC zoxamide/chlorothalonil 22/M5

23 Late Blight on Tomato Disease severity b b Untreated control Nine sprays were applied at 5-7 day intervals. Same-colored bars with a letter in common are not significantly different. Disease severity Infected fruit a a a a a a a a a a Cabrio Bravo 0.75 lb WeatherStik -alt- 2 pt Bravo WeatherStik 2 pt Zampro 0.88 pt + R-56 1 pt Manzate 2 lb apps 1,3,8 Zampro 0.88 pt + R-56 1 pt apps 2,4,6,9 Bravo Ultrex 1.8 lb apps 5,7 Manzate 2 lb apps 1,3,8 Cabrio apps 2,4,6,9 Bravo Ultrex 1.8 lb apps 5, Infected fruit (%)

24 Products Tested Product A.I. Labeled FRAC Bravo WeatherStik SC chlorothalonil yes M5 Gavel DF mancozeb/zoxamide yes M3/22 K-Phite SC phosphorous acid salts yes 33 Mancozeb DF mancozeb yes M3 Previcur Flex SC propamocarb yes 28 Ranman SC cyazofamid yes 21 Zampro SC ametoctradin/dimethomorph yes 45/40 Zing! SC zoxamide/chlorothalonil yes 22/M5

25 Late Blight on Tomato Late blight foliar severity (1=healthy, 12=100% diseased) Late blight yield (lb/5 plants) b b Untreated control 7 foliar sprays applied at 7-day intervals Bars with a letter in common are not significantly different a a Horsfall-Barratt severity scale 4=>6%-12% plant area diseased 5=>12%-25% plant area diseased 8=>75%-87% plant area diseased a a a a a a a Zing! SC 36 fl oz Zing! SC 32 fl oz KPhite SL 1 qt + Sizer Xtra SL 1 gal + Bravo WS SC 1.5 pt Program A: Previcur Flex 1.5 pt + Mancozeb 2 lb B: Tanos 8 oz + Bravo WS 1.5 pt C,G: Zing! 32 fl oz + Induce D: Ranman 2.75 fl oz + Mancozeb 2 lb E: Zampro 14 fl oz + Bravo WS 1.5 pt F: Gavel 2 lb + Induce Program a Bravo WS SC 32 fl oz

26 Thank you Questions?