The combination of wind
and sun affects how quickly plant surfaces dry.
Faster drying generally reduces the opportunity
for infection. Wind can spread pathogens from
one area to another, even many miles. Wind and
rain together can be a deadly combination.
Windblown rain can spread spores from infected
plant tissue, blowing these pathogens to new
host plants. Sunlight is very
important to plant health. Plants that do not
receive the right amount of sunlight to meet
their cultural requirements become stressed.
This may make them more susceptible to
Soil type can affect
plant growth and also development of some
pathogens. Light sandy soil low in organic
matter favors growth of many types of nematodes.
Damping-off disease increases in heavy, cold,
water-logged soils. Soil pH affects pathogen
development in some diseases. Clubroot of
cabbage occurs in soils with a low pH, for
example. High soil pH is a factor in the
development of scab on potatoes.
Fertility affects a
plant's growth rate and ability to defend
against disease. Excessive nitrogen
fertilization can increase susceptibility to
pathogen attack. It causes formation of
SUCCULENT tissue and delays maturity. This can
contribute to certain patch diseases in lawns.
Nitrogen deficiency results in limited growth
and plant stress
which may cause greater disease susceptibility.