The brown plant hopper transmits the disease. The early in star nymphs of the insect are more efficient in transmitting the disease than older ones. Five-day-old nymphs are the most efficient transmitters. The virus is acquired within a feeding period of 24 hours.
Bacterial blight is a monsoon disease and its incidence and severity is very much influenced by rainfall, number of rainy days, and susceptibility of the cultivar and nitrogen fertilizer application. Severe epidemics recorded in 1979 and 1980 in northwestern India, reducing the grain yields drastically.
Age of seedling at transplanting has a direct bearing on the yield of the crop. In general, seedling having 3-4 leaves is considered ideal for transplanting.
The optimum age, however, depends upon the duration of variety, season, date of planting, system of raising nursery, tillering habit, inherent fertility and fertilizer management and cultural practices.
