Seasonal effects on outbreak of yellow mosaic disease in released cultivars of mungbean (Vigna radiata) and urdbean (Vigna mungo)

In India, the diseases like Yellow Mosaic Disease (YMD) have an immense economic significance and addressed as a major impediment against increasing productivity of urdbean [Vigna mungo (L) Hepper] and mungbean [Vigna radiata (L.) Wilczek]. The present attempt was made to ascertain the resistance potential of released varieties of mungbean (65) and urdbean (28) during kharif 2013 and 2014 under natural conditions against the YMD. There was considerable variability among tested varieties of mungbean and urdbean with respect to disease reaction and average disease score. The weather parameters like temperature and relative humidity showed direct effect on incidence of yellow mosaic virus or white fly population. Three varieties of mungbean, viz. PDM 139, ML 818 and MUM 2 and five varieties of urdbean, viz. LBG 645, IPU 2-43, Uttara, UG 218 and NDU 5-7 witnessed highly resistant reaction against YMD over the years. It was also found that the incidence of yellow mosaic virus was less in the varieties released for North India as compared to central and south India and the varieties released in the recent past have better tolerance. Therefore, these varieties can be used in biotic stress breeding programme and these resistance sources may be used as donor in the future breeding programme for evolving YMD resistant varieties.