Does <i>Pestalotiopsis royenae</i> Cause Leaf Streak of Large Cardamom?

Abstract

Leaf streak caused by Pestalotiopsis royenae (Guba) Steyaert has been reported as a new disease of large cardamom (Amomum subulatum). It is characterized by rectangular spots running parallel to the veins. P. royenae was isolated onto potato dextrose agar from the infected portion of the plant. In the pathogenicity test, disease symptoms were not present on inoculated plant and on detached leaf in vitro after 20 days. During 2014-2016, a survey in various large cardamom plantations of Sikkim revealed the presence of tea mosquito bugs on the infected parts of A. subulatum. The spots did not show any growth. Different sized spots have been noticed on the infected leaf produced by different instars. At the initial stage, these symptoms appear on the young and tender leaves of large cardamom. Tea mosquito bugs were collected from the infested leaves and allowed to feed under controlled conditions, which produced similar type of leaf streak symptoms in large cardamom and also in other non-host crops like maize and turmeric.The results reveal that the cause of leaf streak is due to feeding injury of tea mosquito bugs and rule out P. royenae as a pathogen causing leaf streak disease symptoms. Pestalotiopsis sp. was also isolated as endophyte from large cardamom.

WITHDRAWN: Leaf Blight Caused by Colletotrichum Fructicola of Large Cardamom (Amomum Subulatam Roxb.) an Important Cash Crop Grown in Sikkim, India

“…So far pathogens like Fusarium sp., Rhizoctonia sp. are also reported for other fungal diseases of large cardamom 2,3,4 . However, till date only few survey and scienti c reports are available mainly describing the severity of the problem with no proper identi cation of causal organism.…”

“…According to studies, various factors are responsible for the current situation including non-availability of quality planting materials, climate change, lack of irrigation facilities during dry season, open cultivation, inadequate nutrient management, unscienti c methods of cultivation, diseases and pests, etc. As a result large cardamom plantation is disappearing in the region at an alarming rate 1,2,3,4 . Most importantly large cardamom production has gone down drastically due to various types of fungal diseases 3,4,5,6 .…”

“…As a result large cardamom plantation is disappearing in the region at an alarming rate 1,2,3,4 . Most importantly large cardamom production has gone down drastically due to various types of fungal diseases 3,4,5,6 .…”

“…Reports reveal reduction of large cardamom plantation in the region is due to various rot diseases among which blight is highly destructive one in Sikkim and Darjeeling 1,3 . Initially due to this infection lesions are formed on leaves and pseudostem and then gradually affected pseudostems become necrotic resulting in lodging and death of tillers.…”