Disease Management Updates of Cucurbits and Tomatoes

Mohammad Babadoost University of Illinois [email protected]

2015 Vegetable Production Guide _______________________________________

 Table 33 (pages 74-76): common and scientific names of vegetable pests  Table 12 (page 37): yields of vegetables (updated)  White rust: added to cole crops  Bacterial fruit blotch: new recommend.  Merivon fungicide: Brassica leafy green, cole crops, cucurbits, onion  Priaxor fungicide: fruiting vegetable  Aoroach fungicide: legumes

Updates on Vegetable Diseases ______________________________________

 2015 Vegetable Production Guide  Disorders on cucurbits  Powdery mildew of pumpkins  Downy mildew of cucurbits  Bacterial spot of cucurbits  Leaf mold of tomatoes  Septoria leaf blight of tomatoes  Bacterial diseases of tomatoes

Babadoost

Updates on Vegetable Diseases ______________________________________

 Disorders on cucurbits  Effects of low temperatures  Fertilizer effect  Moisture and muskmelon rot  Edema on white pumpkin

Babadoost

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Watermelon plants affected by low temperature (~ 32F).

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Muskmelon plants affected by low temperature (~ 32F).

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Muskmelon plants affected by fertilizer

Edema on white pumpkin (Moonshine) in IL in 2014

Moisture effect on muskmelon, Illinois 2014

Powdery mildew: fruit stems Babadoost

Fungicides for Cucurbit Powdery Mildew _______________________________________

Most effective fungicides in my trials: Quintec, Procure, Fontelis, Torino, Pristine, Quadris Opti, Microthiol

Updates on Vegetable Diseases ______________________________________

 Downy mildew of cucurbits

(cucumbers & melons)

 Quintec was the most effective  Alternate Quintec with another fungicide  Strobilurins are good for 10-14 days, others for 7 days (max: 10 days)  3-6 sprays are needed  Scout inside canopy, apply at first sign  Plan for spray during Jul 20 – Sep 10 Babadoost

Pseudoperonospora cubensis

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Downy mildew on cucumber Babadoost

Downy mildew on melon

Management of Downy Mildew of Cucurbits

Management of Downy Mildew of Cucurbits

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 Effective fungicides

 Monitoring pathogen movement

 Mandipropamid (Revus)

(www.ces.ncsu.edu/depts/pp/cucurbit)

 Field scouting is very important  Accurate disease diagnosis is needed  Do not plant seed from infected plant

 Fungicide applications Babadoost

Management of Downy Mildew of Cucurbits

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 Propamocarb (Previcur Flex)  Dimethomorph (Forum, Acrobat)  Famoxadone + cymoxanil (Tanos)  Cyazofamid (Ranman)  Zaxomide + mancozeb (Gavel)  Ametoctradin + dimethomorph (Zampro)  Chlorothalonil (Bravo Weather Stik) Babadoost

Updates on Vegetable Diseases .

 Effective Fungicide Control  Prior to the infection, apply Bravo Weather Stik (preventive)  At the first sign of the disease, spray plants with one of the effective fungicides (Revus, Tanos, Ranman) mixed with Bravo Weather Stik  Weekly applications of the fungicides throughout the season is needed Babadoost

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 Bacterial spot of cucurbits (gourd, pumpkin, winter squash)

Xanthomonas cucurbitae

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Collapse of pumpkin fruit infected by Xanthomonas cucurbitae

Bacterial spot on squash fruit

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Bacterial Spot of Pumpkins & Squash, 2012-Midwest State Illinois Iowa

Fields Fields with Infected surveyed (no) infect fruit (%) fruit (%) 70 14

Indiana Kansas Michigan Missouri Ohio

10 10 5 5 13

Wisconsin Total

6 133

60 (86%) 14 (50%) 10 (100%) 10 (100%) 3 (60%) 3 (60%) 13 (100%) 5 (83%) 118 (88%)

Babadoost

Bacterial Spot of Pumpkins & Squash, 2013-Midwest Fields Fields with Infected surveyed (no) infect fruit (%) fruit (%)

State

20

Illinois

57

52 (91%)

18

14

Iowa

8

8 (100%)

18

56

Indiana

8

6 (75%)

18

17

Kansas

10

10 (100%)

36

5

Michigan

13

8 (62%)

12

43

Missouri

6

6 (100%)

17

43

Nebraska

9

9 (100%)

10

15

Ohio

10

10 (100%)

54

Wisconsin

6

5 (83%)

23

127

114 (90%)

0-93% (23)

0-98% (25)

Total

Lesions: small brown necrotic lesions (Magic Lantern)

UIUC

Lesions: water-soaked angular lesions with beige centers (Autumn Wing)

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Bacterial Spot: Conclusions ___________________________________________

 Bacterial spot: a serious threat to

Lesions: translucent necrotic centers with narrow brown halo (Harris Moran)

Updates on Vegetable Diseases ______________________________________

 Leaf mold of tomatoes: an emerging disease in Illinois  Septoria leaf blight of tomatoes: the most widespread disease of tomatoes in Illinois  Bacterial diseases of tomatoes: the most important diseases of tomatoes in Illinois

production of pumpkin and winter squash in the Midwest.  Pathogen survival: X. cucurbitae survives in plant tissues in the field for longer than 24 months.  Disease control: no highly effective chemicals or biocontrol agents. Plant pathogen-free seed, crop rotation for 3 years, spray Quintec.

Leaf Mold of Tomato ___________________________________

 Disease: a fungal disease  Pathogen: Fulvia fulva  Importance: an emerging disease in high tunnels, greenhouses, and fields  Conditions: high humidity

Babadoost

Babadoost

Leaf mold of tomato

Leaf Mold of Tomato _________________________________

 Major symptoms: Leaf spot and foliar blight

Babadoost

 Pale green lesions on upper leaf surface  Fungus sporulate on lower leaf surface  Infection first on old leaves  Leaves weather, plant dies

Upper leaf surface

Lower leaf surface

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Leaf Mold of Tomato ______________________________________

 Disease characteristics:

Leaf mold of tomato in a high tunnel

 Fungus can survive as conidia and sclerotia in plant debris, seed, and soil  Sclerotia produce conidia  Conidia initiate infection  Conidia are dispersed by water-splash, air current, mechanical means, insects  Spore germination: in water or >85% RH, at 39-93F (optimum 75-79C)  Symptoms appear 10 days after infection

Babadoost

Leaf Mold of Tomato

Leaf Mold of Tomato

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 Management: Cultural and Chemical  Cultural practices  Remove and destroy plant debris  Steam greenhouse at 135°F for 6 hrs  Have good air circulation, maintain RH below 85%  Avoid wetting leaves  Keep temp above 60°F at night

 Chemical

control:

 Fungicides: Chlorothalonil (e.g., Bravo, mancozeb, Maneb, Inspire Super, Quadris Top, Tanos Cover the foliage thoroughly with fungicides

Babadoost

Babadoost

Septoria Leaf Blight of Tomato ______________________________________

 Fungal Diseases:

Septoria lycopersici  Leaf disease causing rapid foliage blight  Seed- and residue-borne disease  Plant infection throughout the season

Septoria blight of tomato

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Septoria Leaf Blight of Tomato (Disease Management)

Septoria Leaf Blight of Tomato (Disease Management)

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 Plant pathogen-free seed

 Chemical control

 Crop rotation: 3 years  Remove plant debris after harvest  Control weeds

Quadris, Quadris Opti, Quadris Top Cabrio Reason, Scala, Gavel, Endura, Fontelis Maneb, Mancozeb, Chlorothalonil, Ziram Inspire Super

Quadris + a copper compound alternated with chlorothalonil (Bravo) + a copper compound

 Chemical control Babadoost

Babadoost

Bacterial canker

Bacterial Diseases of Tomato ____________________________________

 Bacterial canker: Clavibacter michiganense pv. michiganense

 Bacterial spot: Xanthomonas campesiris pv. vesicatoria

 Bacterial speck: Pseudomonas syringae pv. tomato Babadoost

Bacterial spot

Bacterial canker

Bird’s eye Babadoost

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Bacterial speck

Bacterial spot

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Bacterial Canker Bacterial Spot Bacterial Speck

Bacterial speck

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Managing Bacterial Diseases of Tomatoes _______________________________________

 Plant resistant/tolerant varieties, if available  Plant pathogen-free seed and seedlings  Plant treated seed  A 3-year crop rotation  Field sanitation: remove old material  Plant varieties separately  Control volunteer plants and weeds Babadoost

Managing Bacterial Diseases of Tomatoes ______________________________________  Use clean crates, boxes, and stakes  Scout your field weekly  Do not enter the field if the foliage is wet  Disinfest pruning tools  Avoid cull pile in the field  Spray plants with copper + mancozeb Actigard, Tanos, and Quintec may suppress disease development and spread Babadoost

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Managing Bacterial Spot of Tomatoes Treatment

Dis severity (%) # Spray Jul 17 Aug 18

Control (check)

0

9

50

Phyton 27AG (2 lb/A)

8

7

50

Copper Oxychloride (2 lb /A)

8

7

48

Mettle 125ME (8 oz/A)

8

6

55

GWN-10126 SC (32 fl oz/A)

8

9

55

Quadris 2.08SC (6.2 fl oz/A)

8

7

40

Affiance (10 fl oz/A)

8

6

48

Quintec+Kocide/mancozeb+Koc. 8

4

18

Quadris+Kocide/Bravo W.S.+Koc. 8

4

21

2015 Illinois Pumpkin Field Day _____________________________________ .

 Champaign, Illinois

 UIUC Vegetable Research Farm  September 2, 2015 (Wednesday)  10 a.m. – 2 p.m.  Free registration  Lunch will be provided Babadoost

Babadoost

Questions/Comments

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