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ABIOTIC DISEASES
BY GORGE
A few weeks
back in one of my articles I introduced the term “Abiotic”. I did not
have room to properly define and explain what the term means. So today I
am going to explain what Abiotic diseases are and why so many do not
understand their plants.
“Plant diseases
generally are classified as either biotic (caused by a pathogenic
parasite) or abiotic (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)
Some of the
common abiotic diseases include water stress (surplus or too little),
hail damage, animals, herbicide damage, and genetic disorders.
He goes on to
write, “To diagnose abiotic disease problems it is important to evaluate
the characteristics of the site, past weather condition, and the care
practices. In some cases, more than one abiotic factor may contribute to
the poor health of a plant. Plants that are growing under stressful
conditions may also be more prone to certain biotic disease problems,
such as fungal cankers.”
“A good
understanding of the growing requirements of plants and selecting the
right species for the conditions of the site can help prevent abiotic
stresses. Unfortunately, weather extremes cannot be controlled and are
common.” (2)
“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
PlantProblems_2010-02pr.pdf)” (4) Biotic vs.
Abiotic-Distinguishing Disease Problems from Environmental Stresses” by Copyright 2012 |