For a disease to take hold, three elements must be present: the
disease agent itself (usually in the soil); a host crop which is
susceptible to the disease; and the right weather conditions,
especially appropriate temperature and humidity. If any one of these
three elements is absent, there will be no problem. The odds are
definitely in your favor.
You have some control over these three elements getting together in
your garden. You can prevent diseases by rotating crops. Avoid
planting crops of the same family in the same soil for three seasons,
if possible. This should be enough time for most disease agents to
die off. Plant disease resistant varieties.
Stagger the times you plant your vegetables. Put in seeds or young
plants at several-day intervals and plant different varieties. They
won't all be at the same stage of maturity this way, and if an insect
or disease attacks, the chances are better that more of your crop will
escape damage. This also stretches your harvest time.
Many diseases need wet conditions to spread, so water only when
necessary to maintain a steady supply of moisture in the garden.
Water early in the day, so the plants have a chance to dry off before
evening. Also be careful not to handle plants, especially beans and
vine crops, when they're wet.
Always get rid of badly diseased plants as soon as you spot signs of
trouble; burn them or throw them out. Don't compost them or leave
them in the garden to spread the disease further.
For a detailed list of insects and diseases in the home garden, the
U.S. Department of Agriculture booklet Insects and Diseases of
Vegetables in the Home Garden is helpful. You can get one by
writing to Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402. A faster way might be to call your
local Extension Service to see if they have any on hand.
Copyright NGA
Reprinted with permission HouseNet, Inc.
Basic Disease Control