Selection of Resistant Varieties of Okra to Yellow Vein Clearing Mosaic Virus and Its Management

A two-factorial field experiment on okra was conducted at the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka from April to August 2015. The aim of the study was to find out the resistance of okra varieties against the Yellow vein clearing mosaic virus (YVCMV) and its management. Four varieties viz. BARI dherosh-1, Green finger, Nuffield and Orca onamika were selected as the first factor and two insecticides (Imidacloprid and Sobicron) and one botanical nutrient namely Peak performance nutrients (PPN) were used as the second factor. The plants were grown and natural inoculum was relied upon for the infection of YVCMV. Growth parameters, yield attributes, and physiological features were significantly affected by okra varieties and two selected insecticides and PPN combinations. YVCMV incidence was significantly varied with these combinations. Among the varieties, the lowest disease incidence was found in BARI dherosh-1 which showed high resistance. Green finger and Nuffield provided moderate resistance where Orca onamika was highly susceptible to the disease incidence. Application of Sobicron with PPN gave the lowest disease incidence while the control under the application of no insecticides and PPN gave the highest disease incidence. The availability of resistance sources against the virus is very limited among the cultivated okra varieties. Though BARI dherosh-1 provides resistance mechanism against the virus, Green finger and Nuffield which are moderate resistant can be developed as resistant cultivars through genetic regulation along with the molecular mechanism of resistance to YVCMV.