Utah Plant Disease Control No. 9
Revised June 1995

Seed Treatment for the Home Garden

Seed treatment is one of the easiest methods of disease control in the home garden. The fungicide surrounds and protects the germinating seed from the numerous soil-borne pathogens that cause damping-off. These fungal pathogens rot the seed before it emerges from the soil or kill the plants just after they emerge from the soil. Seed treatments will not control foliar diseases that may attack the plants later on in the season.

The main value of seed treatment is the increase in stand or the number of plants that emerge from the soil. Plants will also have healthy root systems which enable them to get a vigorous start. Another side benefit of seed treatment may be to reduce the introduction of disease-causing fungi found on the seed from getting into pathogen-free soil.

Some seed is already chemically treated. It is usually colored pink or green and is marked "treated." If untreated seed is purchased, the home gardener can treat seed with such chemicals as Thiram (Arasan, Tersan), or Captan, according to the manufacturer's recommendations.

Large seeds such as peas, beans, corn, etc., can be treated by placing the seed in a jar, spreading one to two teaspoons of the dry fungicide over the seed, and shaking or rotating the jar until each seed has been thoroughly coated with the chemical. To treat small paper packets of seed, tear off one corner of the packet. Put about twice as much fungicide in the packet as can be picked up on the first half inch of the flat end of a toothpick. Shake the packet until the seed is thinly coated with the chemical.

Use disposable gloves when planting treated seed, and wash your hands after handling the seed.

Sherman V. Thomson/Extension Plant Pathologist
Scott C. Ockey/Plant Disease Diagnostician

Listing of commercial products implies no endorsement by the authors or the Utah State Cooperative Extension Service. Criticism of products not listed is neither implied nor intended. Persons using such products are responsible for their use according to the current label directions of the manufacturer. Pesticide labels are legal documents, and it is a violation of federal and state laws to use a pesticide inconsistent with its labeling. The pesticide applicator is legally responsible for its prope
use. Always read and follow the label.