Barley Yellow Dwarf Virus Effects on Wheat Water and Nitrogen Use Efficiency.

Barley yellow dwarf (BYD) is one of the most common viral diseases of wheat and barley that results in significant yield losses. The objectives were to determine the N uptake and yield responses to N rates in infected and unaffected plants, to determine impacts of BYD virus infection on water uptake and water use efficiency, and to evaluate BYDV infection on water uptake at different rates of N. Nitrogen was applied at four rates: 0, 120, 240, and 360 lbs/acre to the pots, and three BYD virus infection treatments included control (with no aphids released in the cages), viruliferous aphids (killed 10 days after release by insecticide spray), and viruliferous aphid (maintained until harvest). Results indicated that shoot biomass, tissue N concentration, N uptake, N and water use efficiency were decreased in the treatment with BYD virus and aphids compared to the control.