Plant Pathology Infobytes
January 9, 1996
Quick-Start Tips For Vegetable Transplants
Many gardeners are getting ready to start their vegetable transplants indoors from seeds. This is a great way of kicking off the 1996 gardening season, but some gardeners have trouble producing high quality, vigorous transplants. While several things may be involved, the most common vegetable transplant production problem is associated with a disease known as "damping- off."
Damping-off is generally caused by Pythium or Rhizoctonia. These fungi frequently attack seed soon after they are planted and cause seed rot. Or, they may attack young seedlings following seed germination and cause death before the young plants have had a chance to emerge. In either case, the result is a low number of poor quality seedlings unsuitable for garden transplanting.
There are several ways to avoid transplant production problems caused by fungus damping-off. The following are recommended practices which should help gardeners produce higher quality vegetable transplants.
* Start with commercially prepared transplant growth medium. Commercial mixes (available at most garden supply stores) are generally free of damping-off pathogens, such as Rhizoctonia and Pythium. Do not use "woods soil" or garden soil for transplant production. Soil from these sources might not cause problems, but too often it's contaminated with fungi which cause damping-off. While it's possible to treat contaminated soil to rid it of pathogenic microorganisms, it's best to start right by using a commercially prepared growing mix.
* Use transplant production containers that are new or have been washed in a 10% solution of bleach (1 part bleach in 9 parts water).
* Make sure that the growth container has adequate drainage, since prolonged periods of excessively wet growing medium causes poor root system development.
* Plant disease-free seeds which have treated with a fungicide. Often, vegetable seeds brought from seed dealers are already treated (a reddish or pink seed color indicates treated seeds). If seeds are untreated, they may be treated by placing seeds and fungicide (captan or thiram are recommended) in a jar and gently shaking or rotating the container until all seeds are evenly coated. This is a good way of treating larger seeded crops. Smaller seeded vegetables, such as tomato and pepper, may be treated right in the seed packet by shaking a small amount of fungicide with the seed. Treated seed should be planted immediately.
- Plant seeds at the proper depth. Planting too deep delays emergence and leads to poor transplant quality.
- Don't overseed. This could lead to plant crowding and increased susceptibility to disease.
- Water as needed but avoid overwatering, which may also lead to disease problems.
- Use care not to apply too much nitrogen which makes seedlings more susceptible to Rhizoctonia damping-off.
- Germinate seeds and grow transplants under recommended temperature conditions.
- Provide plenty of light to promote good transplant growth.
If you have questions about how to grow your own vegetable transplants, feel free to check with us at your county Extension office.
Infobytes newsletter was written by the late Dr. Frank Killebrew, Extension Specialist.