It is difficult
to kill them in this protected location, but you can get the adults, small
grayish-green flies, somewhat resembling leafhoppers, by spraying with
strong nicotine sulfate, 4 teaspoons per gallon, or with chlordane or
lindane in early June. If the appearance of the bush bothers you, clip off
the infested tips.
PEAR PSYLLA (Psylla pyricola).
This important pear pest of the Northeast
is now a menace in parts of the Northwest; it is confined to pear.
The adults resemble miniature cicadas; they are dark reddish brown,
with 4 wings, 1/10 inch long; nymphs are yellow, much smaller, ven
broad, very active. Both adults and nymphs are found on leaves and fruit
during the growing season, and these are often heavily coated with black
sooty mold growing in the copious honeydew. There may be heavy defoliation; fruit drops prematurely or is undersized and poor. Adults
winter under bark and lay eggs in spring in bark crevices or near buds;
these hatch when trees are in bloom. There may be 3 to 5 generations a
Control. Parathion has been successful for commercial growers. A dormant oil spray or a dinitro spray, such as Elgetol, sometimes makes summer spraying unnecessary. Nicotine sulfate or rotenone is fairly successful
against nymphs in summer.
A rot is a decay or disintegration of plant tissue. It may be a hard, dry
decay or a soft, squashy one. It may affect root or rhizome, stem, tree
trunk, blossom, or fruit. Some rots affect leaves as well, but foliage diseases are more often called leaf spots or blights.
BASAL ROT OF NARCISSUS (Fusarium oxysporum f. narcissi).
Rot begins at
the root plate at base of bulbs and extends through scales. It is dry
and spongy, and the tissue is brown. The fungus is spread during hot-
water treatments for bulb flies or nematodes unless formalin is added as
a disinfectant. It helps to dust bulbs with Arasan or Spergon before
BLACK ROT OF GRAPES (Guignardia bidwellii).
This is our principal grape
disease Leaves have reddish-brown spots filled with black pycnidia.
Fruit rot starts as a pale spot with the berry turning brown, then becoming a black, wrinkled mummy, either dropping or remaining in the
Control. Fermate is replacing bordeaux mixture. Spray immediately
before and after bloom, and repeat 10 to 14 days later.
BROWN ROT OF STONE FRUITS (Monilinia jructicola and M. laxa) our most
destructive disease of stone fruits, general on peach, plum, cherry,
occasional on apple and other fruits.