Articles
OUTBREAK OF A PHYTOPLASMA DISEASE OF PEACH IN THE NORTHWESTERN HIMALAYAS OF INDIA
Article number
472_98
Pages
737 – 742
Language
Abstract
During 1988, a malady with characteristic yellow type symptoms was noticed in a few trees of commercial cultivars (July Elberta and Sunhaven) in the Rajgarh peach valley of the State famous for the production of good quality fruits.
Recent surveys in 1996 of 80 orchards, including various nurseries, revealed the prevalence of such symptoms with little variation at many locations with an incidence as high as 70 %. Visible symptoms of the disease started appearing after 7–8 weeks of foliation in the form of chlorosis of leaves with typical longitudinal upward rolling and occasional red spotting.
Later, the foliage turned pale to yellow-red in color.
The infected trees or branches in a partially infected trees bear small sized, shriveled fruits which drop prematurely in the case of severe infection.
The disease has been found to be graft transmissible.
Fluorescent microscopic studies (DAPI test) revealed the presence of phytoplasma in phloem sections prepared from roots, twigs, and petiole mid veins of a diseased tree.
Antibiotic treatment during the month of September by injecting an OTC hydrochloride solution resulted in symptom remission in the subsequent year.
Based on these studies, the disease has been identified to have phytoplasma-like etiology and symptoms resembling those of X-disease of peach which is prevalent in North America.
Recent surveys in 1996 of 80 orchards, including various nurseries, revealed the prevalence of such symptoms with little variation at many locations with an incidence as high as 70 %. Visible symptoms of the disease started appearing after 7–8 weeks of foliation in the form of chlorosis of leaves with typical longitudinal upward rolling and occasional red spotting.
Later, the foliage turned pale to yellow-red in color.
The infected trees or branches in a partially infected trees bear small sized, shriveled fruits which drop prematurely in the case of severe infection.
The disease has been found to be graft transmissible.
Fluorescent microscopic studies (DAPI test) revealed the presence of phytoplasma in phloem sections prepared from roots, twigs, and petiole mid veins of a diseased tree.
Antibiotic treatment during the month of September by injecting an OTC hydrochloride solution resulted in symptom remission in the subsequent year.
Based on these studies, the disease has been identified to have phytoplasma-like etiology and symptoms resembling those of X-disease of peach which is prevalent in North America.
Authors
P.D. Thakur, A. Handa, S.C. Chowfla, G. Krczal
Keywords
India, peach, phytoplasma
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