Abstract
Extensive surveys of the major citrus groves in Punjab (Faisalabad, Sahiwal, T.T. Singh, Sargodha and Bhalwal) and N.W.F.P (Haripur, Peshawar and Mardan) and ELISA tests revealed that CTV is prevalent and now is an emerging important disease. The citrus trees were found to be infected regardless of scion-rootstock combination. Maximum incidence of CTV was recorded at Bhalwal in the Punjab; 44.61% and 48.46% in 2006-07, and Mardan in N.W.F.P, 37.39% and 40.86% respectively. CTV infection was confirmed by DAS-ELISA in sweet orange, kinnow and grapefruit showing mean OD405nm values of 0.60, 0.42 and 0.31 respectively. Similarly Mardan showed the highest infection with the mean ELISA values of 0.52, 0.34 and 0.20 in sweet orange, kinnow and grapefruit respectively. Among the varieties, sweet orange showed a significant increase of CTV in 2007 in Punjab as compared to other varieties. Twig portion of the kinnow in N.W.F.P was found to contain high concentration of CTV.