Photo Gallery of Vegetable Problems
Lettuce
(Click on photo to enlarge)
General Lettuce Disease Management
Common Diseases of Lettuce, New South Wales Department of Primary Industries, Australia. Includes photos of disease symptoms on lettuce.
Diseases
Disease: Anthracnose
Pathogen: Microdochium panattonianum
Photo Source: D.A. Inglis |
Photo Source: D.A. Inglis |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Lettuce (Lactuca sativa) – Anthracnose
Lettuce: Anthracnose, Washington State University Hortsense
Disease: Downy mildew
Pathogen: Bremia lactucae
Host crops: Lettuce and spinach.
Severe symptoms of lettuce downy mildew. | Sporulation of Bremia lactucae on the lower leaf surface. | Sporangiophores and sporangia of Bremia lactucae. | |
Photo Source: Lindsey du Toit |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Lettuce (Lactuca sativa) – Downy Mildew
See Lettuce: Downy Mildew. UC Pest Management Guidelines. UC IPM Online, University of California
See Models: Diseases: Lettuce: Downy Mildew. UC IPM Online, University of California
Disease: White Mold, lettuce drop, or Sclerotinia rot
Pathogens: Sclerotinia sclerotiorum
Host crops: Bean, various brassica vegetables, carrot, eggplant, lettuce, potato, tomato, etc.
On-Line Resources:
UC Pest Management Guidelines: Lettuce: Lettuce Drop. UC IPM Online. University of California.
Diseases of lettuce ( Lactuca sativa ) in Arizona: Leaf drop. Extension Plant Pathology, The University of Arizona.
Evaluation of Products to Manage Sclerotinia Leaf Drop of Lettuce in 2003. The University of Arizona Cooperative Extension.
Important New York Vegetable Diseases: LETTUCE: Drop (Sclerotinia sclerotiorum). Vegetable MD Online, Cornell University.
See Diseases, pests, and other problems common to many vegetables: White mold.
Insect/Mite Pests
Common name (of damaging stage): Wireworm (adults are called click beetles or snapping beetles)
Latin binomial: Ctenicera spp. and Limonius spp. Several kinds of wireworms are in the Pacific Northwest. Wireworms causing the most damage in irrigated areas are the Pacific Coast wireworm (Limonius canus), the sugar beet wireworm (L. californicus), the western field wireworm (L. infuscatus), and the Columbia Basin wireworm (L. subauratus). The Pacific Coast and sugar beet wireworms are the most common. Where annual rainfall is <15 inches, the Great Basin wireworm (Ctenicera pruinina) may be a problem, especially when irrigated crops are grown on sagebrush or dry wheat land. This species usually disappears after a few years of irrigation, but may be replaced by Limonius spp. which are favored by moist conditions. West of the Cascades, other wireworm species are pests, including Agriotes spp.
Host crops: All crops are susceptible to wireworm, but this pest is most destructive on beans, carrot, corn, grain, onion, potatoes, spinach seed crops, and other annual crops in the PNW.
Damage to Romaine lettuce caused by wireworms | |||
Photo Source: Photo courtesy of Rachel Bomberger, Washington State University |
Online Resources:
Pacific NorthwestInsect Management Handbook: Vegetable crop pests – Wireworm.
Managing Wireworms in Vegetable Crops. Ontario Ministry of Agriculture and Food
Wireworms. VegEdge, University of Minnesota.
Wireworm Field Guide - A guide to the identification and control of wireworms, Syngenta Crop Protection Canada, Inc.
Wireworm Biology and Nonchemical Management in Potatoes in the Pacific Northwest, N. Andrews, M. Ambrosino, G. Fisher, and S.I. Rondon, Pacific Northwest Extension Publication no. PNW607
See Diseases, pests, and other problems common to many vegetables: Wireworm.
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