Plant Diseases

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Small pink and translucent mite with eight legs, four stretched to the front and four stretched back, on a pale orange surface.
Event

Webinar: Citrus Leprosis Threat, Mites, and Mite Management

Event Date
Aug 27, 2025

Presenters: Dr. Sandipa Gautam, Cooperative Extension Area Citrus IPM Advisor, UC Agriculture and Natural Resources; Dr. Kris Godfrey, Project Scientist, Contained Research Facility, UC Davis; Dr. Daniel Carrillo, Assistant Professor, Entomology & Nematology Department, University of Florida; Tera Pitman…
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Green alfalfa field with scattered blooms of purple flowers blowing in the wind.
Event

Webinar: Pest Management in Alfalfa, Small Grains, and Garbanzo Beans

Event Date
Sep 24, 2025

This webinar is part of the UC Ag Experts Talk series. Dr. Michelle Leinfelder-Miles, Delta Crops Resource Management Advisor with the University of California Cooperative Extension, San Joaquin County, will discuss the principles of Integrated Pest Management and pest management in alfalfa, small grains,…
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Peach leaf curl on peach tree. J. Alosi
Article

Peach Leaf Curl

November 17, 2025
If you have peach or nectarine trees, winter is the time to spray them to prevent peach leaf curl. Peach leaf curl is a fungal disease that attacks peaches and nectarines. It appears in spring, causing new leaves to become reddish, puckered and severely distorted. This disease is caused by the fungus…
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Six circular cross-sections of a tree branch showing dark staining from a Bot canker infection.
Article

What is Bot Canker?

November 5, 2025
By Belinda Messenger-Sikes
Botryosphaeria canker, sometimes called Bot canker, is a common fungal disease that can affect many tree species including ash, eucalyptus, fig, maple, pistachio, and walnut. Plants infected with this disease typically develop cankers (dark sunken lesions in the bark) and can lose branches. The whole…
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Nice looking lettuce
Article

2025 Fusarium wilt of lettuce variety trial field day - Soledad

August 19, 2025
By Christopher A Greer
Please join us for the 2025 Lettuce Fusarium Wilt Trial Field Day in Soledad - August 26, 2025 10 am - 12 pm. Trials include variety evaluations, steam treatment evaluations, and fungicide evaluations. Pre-registration is strongly suggested. Please see full article for additional info and directions.
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Discoloration and distortion of peppers from Cucumber Mosaic Virus. Dennis H. Hall, UC IPM Program
Article

A Virus in the Garden – Part II

July 1, 2025
A virus can reduce a plant’s growth, lower its yield, and result in inferior fruit, vegetables and flowers. Viruses are often very host specific. Recognizing symptoms can help you take appropriate action, where possible, to manage a virus and hopefully prevent its spread. The following are several viruses…
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Tomato leaves with signs of Tobacco Mosaic Virus. Jack Kelly Clark, UC IPM Program
Article

A Virus in the Garden

June 24, 2025
Most gardeners are aware of plant diseases that can wreak havoc in their gardens. If you grow fruit trees, you may be confronted with curled, reddened peach leaves (peach leaf curl fungus). If you grow apples or pears, your trees may sometimes look like they were scorched with a blow torch (fire blight…
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