Diseases |
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Curly top | Suspected zucchini yellows + watermelon mosaic virus | Verticillium wilt |
Insect/Mite Pests |
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Aphids | Squash bug | Western flower thrips |
Abiotic Problems |
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Edema |
(Click on photo to enlarge)
Diseases
Disease: Curly top
Pathogen: Various strains of Beet curly top virus (BCTV), which are vectored by the beet leafhopper (Circulifer tenellus)
Host crops: Numerous plant species including many vegetables such as bean, beet, carrot,eggplant, coriander, pepper, potato, tomato, various cucurbits such as squash, cucumber, pumpkin, watermelon, etc.
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Symptoms of curly top on pumpkin leaves. Note yellowing of the foliage. | |||
Photo Source: Ken Eastwell, Washington State University virologist | Photo Source: George Clough, Oregon State University | Photo Source: Phil Ham, OSU plant pathologist |
Online Resources:
Pacific Northwest Plant Disease Management Handbook: Squash (Cucurbita spp.) – Curly Top
Disease: Powdery mildew
Pathogen: Golovinomyces cichoracearum (formerly Erysiphe cichoracearum) and Podosphaera fuliginea (formerly Sphaerotheca fuliginea)
Host crops: All cucurbit vegetables (e.g. cucumber, cantaloupe, melon, pumpkin, andsquash). There are different races of the pathogens.
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Photo Source: G.Q. Pelter |
Online Resources:
Cucumber, Pumpkin, Squash: Powdery Mildew, Washington State University Hortsense
Disease: Root Rot
Pathogen: Pythium
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Photo Source: Jenny Glass |
Online Resources: Pacific Northwest Plant Disease Management Handbook: Watermelon (Citrullus lanatus) – Damping-off
Pacific Northwest Plant Disease Management Handbook: Cucumber (Cucumis sativus) – Damping-off
Disease: Suspected zucchini yellows + watermelon mosaic virus
Pathogen:
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Photo Source: G.Q. Pelter |
Online Resources:
Disease: Suspected virus
Pathogen: Unknown
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Photo Source: G.Q. Pelter |
Online Resources:
Disease: Verticillium wilt
Pathogen: Verticillium species
Host crops: Numerous vegetables including many brassica vegetables (but not broccoli), cucumber, eggplant, pepper, potato, pumpkin, radish, spinach, tomato, watermelon, etc.
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Photo Source: D.A. Inglis |
Online Resources:
Cucumber, Pumpkin, Squash: Verticillium wilt, Washington State University Hortsense
See Diseases, pests, and other problems common to many vegetables: Verticillium wilt.
Insect/Mite Pests
Common name: Bean aphid, green peach aphid, melon aphid, and potato aphid
Latin binomial: Aphis fabae , Myzus persicae, Aphis gossypii, and Macrosiphum euphorbiaerespectively
Host crops: In addition to tomato, eggplant and pepper, bean, melon, sweet corn, corn seed, carrot, cucumber, and eggplant the bean aphid can feed on spinach, Swiss chard, squash, pumpkin, and beet. The green peach aphid can feed on potato, tomato, eggplant, pepper, broccoli, cabbage, spinach, Swiss chard, squash, pumpkin, beet and many weed species including Brassicaceae (cruciferous) weeds. The melon aphid can feed on cucumber, melon, pumpkin, squash, spinach and spinach seed. The potato aphid can feed on cucumber, potato, melon, tomato, pumpkins, squash, and corn seed.
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Photo Source: Michael Bush, WSU Extension, Yakima, WA |
Online Resources:
Pacific Northwest Insect Management Handbook: Vegetable crop pests-Aphid
Pacific Northwest Insect Management Handbook: Pumpkin and squash – Aphid
Common Insect & Mite: Aphids, Washington State University Hortsense
See Diseases, pests, and other problems common to many vegetables: Aphids
For aphids on other crops see: potato, and squash
Common name: Squash bug
Latin binomial: Anasa tristis
Host crops: Cucurbit vegetables (e.g. pumpkin and squash).
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Photo Source: Michael Bush, WSU Extension, Yakima, WA |
Online Resources:
Pacific Northwest Insect Management Handbook. Chapter: Vegetables, Section: Pumpkin and Squash, pt.2.
Vegetables: Cucumber, Pumpkin, Squash: Squash bug.. Washington State University Hortsense.
See See Diseases, pests, and other problems common to many vegetables: Squash bug.
Common name: Western flower thrips
Latin binomial: Frankliniella occidentalis.
Host crops: Basil, Broccoli, Cabbage, Cauliflower, Cucumber, Onion, Potato, Pumpkin, Squash,Tomato and Watermelon.
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Photo Source: Michael Bush, WSU Extension, Yakima, WA |
Online Resources:
Western Flower Thrips Thysanoptera: Thripidae Frankiniella occidentalis,
Cucurbits: Thrips, UC IPM Online, University of California
See Diseases, pests, and other problems common to many vegetables: Western flower thrips.
Abiotic Problems
Problem: Edema
A physiological Problem: prominent when air is cooler than the soil, soil moisture is high, and relative humidity is high. The low plant transpiration rates combined with an increase in water absorption by roots from the soil leads to increased cell turgor pressure, resulting in eruption of epidermal cells as the inner cells enlarge. Protrusion of the inner cells causes epidermal cells to die and discolor, resulting in a ’warty’ appearance that can be misidentified as a disease. In addition to foliar symptoms on some hosts, many cucurbit crops develop wart-like protruberances on the fruit.
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Photo Source: Lindsey du Toit, Washington State University. | Photo Source: Phil Hamm, Oregon State University. |
Photo Source: Lindsey du Toit, Washington State University. |
Online Resources:
http://www.omafra.gov.on.ca/english/crops/facts/00-031/#oedema