3 to 5 aphids per ear in winter wheat - a new control threshold?
1994
Holz, F. (Martin-Luther-Univ. Halle-Wittenberg, Halle (Germany). Inst. fuer Phytopathologie und Pflanzenschutz) | Wetzel, T. | Freier, B.
This contribution is dealing with cereal aphids and their influence on the yield of winter wheat. There are discussed the problems of forecast and decision making for the control of aphids as direct damaging pest. From field data it may be concluded, that aphids dwelling on the ear (Sitobion avenae) are much more important than aphids living on the vegetative parts of the plant (Metopolophium dirhodum, Rhopalosiphum padi). The present state of knowledge permits to define the damage threshold by 12 to 15 aphids/ear to the time of maximum abundance. Supposing a mean course of gradation the control threshold is determined by 3 to 5 aphids/ear for the time of the end of flowering/early milky ripe stage of the winter wheat (DC 69/73). Especially for difficult situations the application of decision making aids or of a catalogue of case studies based on a simulation model is recommended for a stronger differentiation and higher reliability of decisions
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