Journal article

Publication year: 1989

Pages: 561-584

Journal: Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz = Journal of plant diseases and protection

Volume number: 96

Issue number: 6

ISSN: 0340-8159

Publisher: Ulmer

Abstract: 
From 1982 to 1985, 10 yield experiments were performed in winter wheat (after winter rape) at four locations near Kiel (Schleswig-Holstein, FRG [West Germany]), All plots were 12 m wide. In the multifactorial experiments, they covered an area of 0,2 ha each (1985: 0,02 ha), and in the monofactorrial experiments 36 m2. The amount of N-fertilizers and the intensity of plant protection were varied. Among the insect pests, only cereal aphids (Hom., Aphididae) were important. Their level of attack varied strongly between years and locations. The stenophagous aphid antagonists (Col., Coccinellidae; Dipt., Syrphidae; Hym., Aphidiidae and Entomophthorales) were of minor importance during the experiments. The low frequency of the Aphidiidae (primary parasitoids) could not be explained by the frequency of the hyperparasitoids. Insecticidal treatments resulted in significant reductions of aphid numbers only, when at the end of flowering aphid numbers per ear and flag leaf had exceeded distinctly the threshold of one aphid. The other pesticides and the amount of N-fertilizers had no significant influence on the aphid numbers in our field experiments. Among the wheat diseases, especially in powdery mildew (Erysiphe graminis f. sp. tritici), infestation levels varied strongly between years. The reaction to the different intensities of growing wheat was strongest in mildew, less in Septoria nodorum and Pseudocercosporella herpotrichoides, and absent in Gaeumannomyces graminis. In part II, the economic aspects of the different intensities of growing wheat will be shown.

Harvard Citation style: ALNAJJAR, A., BASEDOW, T. and SCHULZ, F. (1989) EFFECTS OF GRADUALLY DIFFERING INTENSITIES OF GROWING WHEAT ON PESTS AND DISEASES, YIELDS AND ECONOMY .1. PHYTOMEDICAL ASPECTS, Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz = Journal of plant diseases and protection, 96(6), pp. 561-584

APA Citation style: ALNAJJAR, A., BASEDOW, T., & SCHULZ, F. (1989). EFFECTS OF GRADUALLY DIFFERING INTENSITIES OF GROWING WHEAT ON PESTS AND DISEASES, YIELDS AND ECONOMY .1. PHYTOMEDICAL ASPECTS. Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz = Journal of plant diseases and protection. 96(6), 561-584.