Grass growth in different parts of England in relation to invertebrate numbers and pesticide treatment

Abstract

Abstract Ryegrass swards at fourteeo widely separated sites in England were assessed for yield, botanical composition and invertebrate populations, with and without insecticide treatment during a 4‐year period. Treatment with insecticide reduced the numbers of almost all invertebrate groups sampled and increased grass growth at some time at all but one site. Annual DM output was increased by 0–32% depending upon the site concerned. Evidence is presented which suggests that the yield increases were due to the suppression of aphids, plant‐sucking bugs, stem‐boring fly larvae, and perhaps nematodes.