Developmental patterns in wheat and resistance to cereal aphids

Abstract

As wheat develops it varies in its suitability for the grain aphid, Sitobion avenae, so the duration of each developmental stage determines aphid population growth. Simulations of aphid population development on spring and winter wheat cultivars revealed that, as the length of the preferred earing phase was found to be relatively constant, peak population size is determined by the number of aphids at ear emergence. This can be reduced by growing early-maturing varieties, which in terms of crop developmental stage effectively delays the start of the spring migration. Breeding wheat that matures as early as winter barley would greatly reduce the number of aphid outbreaks and make the prophylactic spraying of insecticides unnecessary.