Printer Friendly

Branches wilting? Maybe it's verticillium.

A branch withers on your olive tree, then another wilts a few weeks later. In spite of regular watering, the lower branches and growing tips of your tomato plants droop and dry up.

These symptoms, though different, suggest verticillium wilt, a soil-borne fungus disease that attacks about 150 common plants, including avocados, camphors, caneberries, rose, strawberries, and some weeds. Often just one side of a plant is affected.

Even before symptoms appear in summer, the damage has been done. During cool spring weather, verticillium in the soil germinates, invades the roots of a susceptible plant, and fouls the plant's water-conducting tissues.

As hot weather arrives and leaves begin to lose water faster than roots can take it in, one or more of the host's plugged branches die of thirst. A cross-section of a cut branch often reveals olive green, brown, or black sapwood.

Verticillium persists in soil for up to 20 years. For this reason, rotation planting of nonsusceptible crops is usually ineffective. Ditch irrigation, tools and equipment, and infested soil--even blowing dust--introduced into the garden can spread the disease. Cuttings taken from infected plants can also become diseased. What to do about verticillium wilt

No fungicide or soil fumigant controls this persistent fungus, but you can minimize the damage by deep but infrequent irrigation. If an infected plant has been neglected, water and fertilize it; don't overwater or feed infected trees or shrubs that have lush growth.

With proper care, mildly infected trees often recover, but the disease can flare up again, especially if the soil goes dry. Wilting greatly reduces tomato crops.

You can circumvent verticillium by planting wilt-resistant species. for a list (also including susceptible plants), send $1.25 to ANR Publications, University of California, 6701 San Pablo Ave., Oakland 94608. California residents include 8 cents sales tax. Ask for leaflet 2703.

Another precaution is to make sure tomato seedlings or seed packet labels have a V after the variety name.

Veticillium can be confused with other diseases; to be sure of your diagnosis, call your county extension office.
COPYRIGHT 1984 Sunset Publishing Corp.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1984 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Date:Jun 1, 1984
Previous Article:The street trees were in trouble, so they put on a street fair.
Next Article:Summer strolling through Berkeley's "pocket garden" parks.

Related Articles
Mite and fungus: foe and friend?
Terrorists in your tomato patch.
Reducing cotton production costs: a new system offers alternatives for cotton stalk management.
Olive tree decline.
Five tomato questions.
Challenges facing mushroom disease control in the 21st century.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters