Ecology, Environment and Conservation Paper

SURVEY AND CHARACTERIZATIONS OF SYMPTOMS OF THE SUNFLOWER LEAF CURL VIRUS DISEASE TRANSMITTED BY WHITEFLY

Deepa and Gururaj Sunkad

Abstract

Sunflower (Helianthus annuus) is one of the most important oilseed crops grown in India. In recent years, the crop suffers from sunflower leaf curl virus disease (SuLCV) with substantial losses in the yields. The present investigation on the survey was carried out in three districts of north eastern Karnataka. SuLCV disease incidence varied from location to location and also from season to season. During kharif, 2012, the disease incidence prevailed in almost all parts of Raichur, Yadgir and Koppal districts. Disease incidence ranged from 0-92 per cent and maximum incidence was in of Raichur (20.45%) followed by Koppal (15.67%) and Lingasugur (11.98 %). The least incidence was in Shorapur (2.50%). The highest mean incidence of 65.25% was recorded in the fields of MARS farm during kharif, 2012. During rabi/summer, 2012-13 also, disease incidence ranged from 0-80 per cent and the incidence in the season was also highest at the same location with 57.9%. Further, the survey data revealed that the disease incidence was more during kharif than rabi/summer. Infected plants shown symptoms were vein clearing and yellowing as the first visible symptom on new emerging leaves. Later, other symptoms observed on the plants were vein thickening, upward curling of leaves, reduction in leaf size and enations on the lower surface of the leaves and yellowing of bracts.