Contact Us
University of California Cooperative Extension Ventura County
669 County Square Drive, Suite 100
Ventura, CA 93003
Phone: 805.645.1451
Fax: 805.645.1474
Office Hours:
Monday - Friday from 9 a.m. to 4 p.m.
The office will be closed for the following holidays:
March 29 – Ceaser Chavez Day
May 27 – Memorial Day
June 19 – Juneteenth
July 4 - Independence Day
Tomato Problems
First let me say that Santa Maria, and the Central Coast in general – at least the area that is in the “fog belt” – is not an ideal location to grow tomatoes. Tomatoes like sunny, warm weather in order to produce good fruit. The “summer” of 2005 has been cool with lots of fog and overcast conditions, which are not favorable to good tomato production. Botrytis gray mold is a fungus that can cause a dieback and cane blight. Usually the fungus establishes itself on dying or injured leaves. It then can progress down the leaf petiole into the main stem. Often the cane above this point of entry will collapse. At times a large oval lesion will form on the cane at the leaf base. The leaf and cane are often covered with a gray-black, fuzzy growth of the fungus. Removing old senescent leaves from the base of the tomato plants helps reduce infection sites.
One of the causes of yellowing, dying leaves at the base of the plant is nitrogen deficiency. If you have not fertilized your tomatoes since early summer, a fertilization to increase plant vigor may be helpful in slowing or stopping plant decline.
Do you have nematodes in your garden? Rootknot nematodes attack the roots of the vines causing galls or “knots” to form. The feeding of the nematodes results in slow growing plants, causes leaves to yellow and die, and can cause a general decline in growth and vigor of your tomatoes. If you find rootknots on your tomatoes, there is nothing you can do this season. However, next year do not plant your tomatoes in the same location, or at least use nematode-resistant varieties in your garden.
Tomato russet mites may cause a leaf blight and plant decline. Russet mites usually are first evident at the base of the plant and on the basal parts of individual leaves. As the mites feed, they cause a browning and bronzing of leaves that eventually results in death of the foliage. The mites can be seen using a 10x magnifying glass and will appear as tiny, yellow, cigar-shaped bodies among the leaf hairs.