Biology Reference
In-Depth Information
If borax has been used for root crops, boron-
tolerant cabbage should follow before beans in
the rotation.
In fruits, calcium deficiency shows first in the
roots, which are short and stubby with a profuse
growth behind the tips that have died back. Basal
immature peach leaves sometimes have reddish
discolorations, and twigs may die back. Corn and
legumes require large amounts of calcium, which
may become unavailable under conditions of
high soil acidity.
Brown Bark Spot
Brown Bark Spot of fruit trees. Perhaps this is
arsenical injury from residue in the soil.
Catface
Brown Heart
Fruit deformity, due to insects or growth
disturbances.
Brown Heart of turnip, cabbage, cauliflower.
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Boron Deficiency.
Chlorine Injury
Bud Drop
A tank of chlorine gas for the swimming pool
carelessly opened too close to trees and shrubs
causes foliage browning and sometimes death.
Leaf margins are sometimes killed by chlorine
gas from manufacturing processes.
In sweet pea very young flower buds turn yellow
and drop off when there is a deficiency of phos-
phorus and potassium during periods of low light
intensity. Water sparingly at such periods; avoid
excess of nitrogen. Gardenias often drop their
buds when taken from greenhouses to dry
homes, but there is also bud drop in greenhouses
with high soil moisture, high temperature, and
lack of sunlight in winter.
Chlorosis
Yellowing or loss of normal green color may be
due to deficiency of nitrogen, magnesium, or man-
ganese. Occasionally boron deficiency or toxicity,
insufficient oxygen to the roots in a waterlogged
soil, or alkali injury may cause chlorosis but in the
majority of cases, and particularly with broad-
leaved evergreens, it occurs because iron is
unavailable in an alkaline soil.
Calcium Chloride Injury
Trees may be damaged when this dust-laying
chemical is washed off country roads or drive-
ways down to roots.
Iron Deficiency.
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Chlorosis
Calcium Deficiency
Hydroponically grown basil with interveinal
chlorosis associated with CO2 enrichment.
All plants require calcium, which is built into
walls of cells, neutralizes harmful by-products,
and maintains a balance with magnesium and
potassium. Calcium is leached out of the soil as
calcium carbonate and should be replaced by
adding ground limestone, or dolomite (calcium
magnesium carbonate), or gypsum (calcium sul-
fate), which does not increase the pH of the soil.
Copper Deficiency
Exanthema or dieback of fruits - apple, apricot,
citrus, olive, pear, prune; failure of vegetables on
muck soils. Copper deficiency in fruits
is
