Several factors have helped spread the disease. The area of land devoted to the cultivation of maize has grown, especially in the moist, mid-altitude grasslands where leafhoppers breed. Where farmers use irrigation to produce a second crop during the dry season, the plants become particularly susceptible because with few other plant hosts available large numbers of leafhoppers descend upon the crops. Furthermore, most farmers grow the traditional open pollinated varieties of maize, which MSV quickly destroys. The common staggering of sowing dates also increases the severity of the disease.
Maize streak is harmless if it occurs more than eight weeks after the maize crop has germinated.
In areas with longer growing seasons, where farmers sow maize on two or three different dates, the disease easily spreads from older to younger crops as the season progresses, leaving behind rows and rows of stunted, withered stalks. Control options Farmers currently have few options for controlling maize streak. Besides, the relief provided by chemicals would present a hazard to human health and the environment. It would also be short-lived. Insects resistant to commercially available products would soon evolve, as Helicoverpa and many other pests have done.