Biology Reference
In-Depth Information
(
Psylla pyricola
), now considered a virus disease
transmitted by the psylla.
Pepper Mild Mottle Tobamovirus
Infectious virus particles were found in water for
greenhouse irrigations.
Pear Stony Pit
On Bosc and other pears in Pacific Northwest.
Dark green areas appear just beneath epidermis of
fruit, 10 to 20 days after petal fall, resulting in
deeply pitted or deformed fruit at maturity, with
corky or necrotic hard tissue at base of pits. The
fruit is gnarled, hard to cut. Transmission is by
grafting; no insect vector is known. Bosc and
Anjou pears can be top-worked with Bartlett to
reduce losses from stony pit.
Pepper Mild Tigre' Bigeminivirus and
Pepper Texas Bigeminivirus
Both viruses are transmitted by
Bemisia tabaci
and spread in Texas and Mexico.
Pepper Strain of Alfalfa Mosaic
On pepper.
Pelargonium Flower Break Carmovirus
and Pelargonium Line Pattern
Carmovirus
Pepper Vein Banding Mosaic
Viruses are usually symptomless on
Pelargonium
or caused by flower streaking, line pattern or
chlorotic spotting. They are transmitted by
grafting and by contact between plants.
Probably caused by Potato Y Potyvirus, a new
disease in Florida. Plants are stunted with up to
50 % loss of marketable fruit. Vein clearing and
banding on leaves, fruit roughened with chlorotic
spots or stripes. Transmission is by green peach
and melon aphids. Eradicate deadly nightshade as
a weed host for 150 feet from peppers, or use
sunflower as a barrier.
Peony Leaf Curl
Plants half normal height, with crooked flower
stalks, curled leaves. Transmission is by grafting
but not contact; no insect vector is known.
Pepper Mottle Potyvirus
On pepper.
Peony Ring Spot ¼ Tobacco Rattle
Tobravirus
Phlox Streak
Marked yellow mosaic, irregular or in rings,
sometimes small necrotic spots.
Streaks evident in leaves and stems. Clearing of
veins is followed by necrosis in leaf veins and
petioles. Graft-transmissible.
Peperomia Ring Spot
Concentric brown, necrotic rings on leaves,
which may be cupped, curled, or twisted and
may fall. Severely affected plants are stunted.
Grower losses in Florida may be 25 %. Take
cuttings from healthy, vigorous plants.
Physalis Mosaic Tymovirus
Known as Belladonna Mottle Virus caused by
systemic mosaic or mottle.
