Ontogeny of spring wheat and barley infected with cereal cyst nematode (Heterodera avenae)

Abstract

A study of the effects of density (0, 150,300 or 450 juveniles) and time of inoculation (0, 7 or 14 days after sowing) with Heterodeva avenae on the growth of single plants of the susceptible wheat, Halberd, showed that only inoculation at sowing consistently affected growth and there was little difference between densities. Development of seminal, seminal laterals and nodal roots was delayed and the length of laminae of each of the first three leaves was shortened. Regular inoculations, until 25 days after sowing, of susceptible Halberd and resistant AUS 10894 wheat and susceptible Clipper and resistant Morocco barley resulted in reduced leaf area, delayed appearance of the earlier leaves and reduced numbers of spikelets per ear on Halberd, AUS 10894 and Clipper, but not Morocco. Following inoculation Halberd and Clipper had fewer leaves, and their time of ear emergence was later. These effects of H. avenae were attributed to induced nutrient and moisture stresses affecting cell division and development of the shoot apex. The maximum yield potential of cereals was therefore reduced.