Biology Reference
In-Depth Information
Roses have often survived submersion in salt
water during hurricanes. Roadside trees, and
e specially maples, may be injured by salt used
on highways during the winter. Either sodium
chloride or calcium chloride may be harmful.
Scald
Scald, of apple. Asphyxiation injury to fruit in
storage from accumulation of harmful gases;
most important when immature fruit is stored
without adequate ventilation at too high temper-
ature and humidity. Wrapping fruit in oiled paper
or packing with shredded oiled paper, and storage
near 32
F, with a high concentration of carbon
dioxide at the start, control scald.
Fig. 5
Ozone Injury on Tobacco
processes. Acute smoke injury shows in rapid
discoloration of foliage, defoliation, sometimes
death. Conifer needles turn wine red, in whole or
part, then brown. Leaves of deciduous trees have
yellow to dark brown dead areas between veins,
with tissue next to larger veins remaining green.
Chronic injury results in unhealthy, stunted trees,
but less apparent discoloration and defoliation.
Roses, grapes, and legumes are seriously injured.
Gladiolus leaves appear burned from the tips
down.
Control of injurious smoke must be at the
source - by filters, tall smokestacks, neutralizing
the acid gases, or using them in the manufacture
of sulfur and sulfuric acid.
Scorch
▶
Leaf Scorch
.
Shot Berry
Shot Berry, of grape. Defective pollination.
Smog Injury
Unsaturated hydrocarbons and ozone in the atmo-
sphere are the cause, with many kinds of plants
injured in the Los Angeles area. Tan lesions
appear on fern leaves in 24 h with necrosis in 24
more (
Fig. 5
). Many ornamentals and vegetables
are injured, with annual loss $3 million. Spraying
carnations in greenhouses with Vitamin
C prevents sleepiness from smog. Some green-
houses have installed activated-carbon filters for
polluted air.
Soot Injury
City trees and shrubs acquire an accumulation of
soot, the solid residue of smoke, which screens
out the sunlight. Evergreens can be sprayed with
a soapy solution of Calgon (sodium hexameta-
phosphate), followed by syringing with clear
water.
Smoke Injury
Stigmonose
The most important agent in smoke injury is
sulfur dioxide, a colorless gas with a suffocating
odor released from smelters and many industrial
Dimpling of fruit by insect punctures.
