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ABIOTIC DISEASES PART #2
BY GEORGE EDGAR
Last week I
wrote about the definition of “Abiotic Diseases”. I mentioned that
abiotic diseases are caused by environmental conditions such as wind,
water, and temperature, or genetic disorders. “More importantly, abiotic
diseases also may cause symptoms that may be confused with symptoms
caused by biotic diseases or pests.” (1)
When the cause
of a plant health problem is not readily diagnosed, it’s important to
take a systematic approach and carefully consider site conditions,
weather condition, care of the plant, and the known biotic disease
agents of that plant. The
first important step is to determine the identity of the plant and its
requirements for healthy growth.
“There are a
few clues to look for that will help you distinguish between abiotic and
biotic disease problems.
·
Abiotic
damage often occurs on many plant species. Drought stress or chemical
drift will likely cause damage on several types of plants in a yard or
garden. In contrast biotic disease problems are more limited to a
certain species. The fungi that cause tomato blight do not cause damage
on sweet corn for example.
·
Abiotic
damage does not spread from plant to plant over time.
·
Biotic
diseases sometimes show physical evidence (signs) of the pathogen, such
as fungal growth, bacterial ooze, or nematode cysts, or the presence of
mites or insects.” (4)
“1. Iron chlorosis,
(A common nutrient deficiency in alkaline
soils), 2. Planting depth, (Planting
too deep reduces available oxygen to the roots &
causes trunk decay), 3. Circling and
girdling roots, (Constricting roots that
reduce proper flow of
water and nutrients), 4. Mechanical
damage, (Practices that result in physical
damage of plant tissue), 5. Packaging
material, (Foreign materials left on plants
that ultimately
restrict growth), 6. Excessive
irrigation, (Practices that deplete oxygen
from the root zone), 7. Summer scorch. (When
plants cannot physically translocate enough
water to leaf
margins), 8. Herbicide damage,
(Practices that cause spray or drift that
damages non-
target plants), 9. Winter damage, (Fluctuations
in temperatures that ultimately damage plant tissues), and 10. Salt damage. (High
levels of salt reduce the plant’s ability to uptake water
(chemical drought)” (3)
Remember what References: (1) (2) Abiotic Diseases
by
(3) “Top 10 Abiotic Disorders and
Cultural Problems of Wood Ornamentals” by JayDee Gunnell and Jerry
Goodspeed, Horticulture Agents, Cooperative Extension Service at Utah
State University. (extension.usu.edu/files/publications/publication/Horticulture_
PlantProblems_2010-02pr.pdf)” (4) Biotic vs.
Abiotic-Distinguishing Disease Problems from Environmental Stresses” by Copyright 2016 |