11 research outputs found
Is the cardamom whitefly Kanakarajiella cardamomi (David and Subralllaniam) a vector of Nilgiri Necrosis Virus disease of cardamom Elettaria cardamomum Maton?
The vector and mode of transmission of the Nilgiri Necrosis Virus (NNV) disease affecting cardamom. Elettaria cardamomum Matoh is 'unknown so far. More than 70 whitefly borne viral diseases have been reported on cultivated plants and weeds from ttopical and subtropical regions (Cohen 1990). Muniappa (1980) in his critical review listed 65 viral diseases transmitted by whiteflies. The present studies were carried out to determine whether the cardamom whitefly, Kanakarajiella cardamomi (David and Subramaniam), an important pest on cardamom, acts as a vector of the NNV disease.
 
Influence of abiotic factors on population build up of cardamom whitefly Kanakarajiella cardamomi (David and Subramaniam) on cardamom (Elettaria cardamomum Maton)
The seasonal occurrence and influence of abiotic factors on population build up of cardamom whitefly Kanakarajiella cardamomi on cardamom (Elettaria cardamomum) was assessed during 1989-1990 at Lower Pulneys in Tamil Nadu (India). K. cardamomi persisted throughout the year with a maximum egg population of 9.09 per leaf during October 1989 and a minimum of 0.33 per leaf during June and August 1990; maximum nymphal population was 8.66 per leaf during October 1989 and minimum was OA9 per leaf during August 1990. Maximum temperature and relative humidity exhibited a significant negative association with population build up of eggs and nymphs; however, none of the abiotic factors had signifiant partial correlation coefficient with egg. and nymphal population. From the multiple regression equation constructed with R' value, it was attributed that the abiotic components had only 24 and 43% influence on the population build up of K. cardamomi eggs and nymphs, respectively.