The influence of different farming systems on the population dynamics of aphids and their predators in winter wheat

Published source details Henze M. & Sengonca C. (1993) The influence of different farming systems on the population dynamics of aphids and their predators in winter wheat. Mitteilungen der Deutschen Gesellschaft für allgemeine und angewandte Entomologie, 8, 615-622.
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This study is summarised as evidence for the following.

	Action	Category
	Reduce fertilizer, pesticide or herbicide use generally Action Link

Reduce fertilizer, pesticide or herbicide use generally

A replicated, controlled study in summer 1989-1990 in eight sites on one arable farm near Bonn, Germany (Henze & Şengonca 1993) found that a 50% reduction in pesticide application could control an aphid (Aphidoidea) outbreak as efficiently as the normal application. In farming systems with no insecticide use at all, natural predators reduced aphid populations to the same low levels (<5 aphids/plant), but the population decline occurred one week later than in the systems with pesticide use. Predatory arthropod populations also declined after pesticide treatment. Predator levels remained rather low in the normal pesticide system, however in the 50% reduced pesticide system they recovered in three weeks after pesticide application. Four farming systems were compared with two replicates each: conventional farming (normal pesticide use), integrated farming (50% reduction in pesticide use), ‘minimum’ farming (no insecticides, strongly reduced herbicide use) and ‘no pesticide’ farming (no pesticide use). Aphids and their predators were counted visually and with sweep nets once a week from April.