Studies on competition in stands of winter barley with companion plants
1990
Schumann, H. (Bonn Univ. (Germany). Lehrstuhl fuer Speziellen Pflanzenbau und Pflanzenzuechtung. Inst. fuer Pflanzenbau) | Heyland, K.-U.
Two year field experiments within the rotation sugar beet -winter wheat - winter barley were carried out on two locations in the Rhine area to investigate competitive relations between winter barley and companion plants. Creating a model of competition clover (Trifolium repens L.) and grass (Lolium perenne L.) were established as underseeds in crop plant populations besides a different terminated application of herbicides. Effect of defined companion plant population on yield formation of winter barley is demonstrated. Importance of cultivation system and environment (location and year's weather) for competition relations in crop stands are discussed. Companion plant competition appears early in winter barley's development and reduces number of grains per ear, in case of very strong growth also ear density. The amount of competition in mixed stands results from the competitive power of companion and crop plant. This is influenced by composition, density and beginning of growth of the companion plant population and by seed system, winter kill and nitrogen management of the barley. Possibility of compensation is given by nitrogen supply in the reduction period of number of grains per ear. Environment and not competitive effects are able to vary grain weight in such a way that yield losses were watched contradicting the competitive situation. In respect of this number of grains per square metre influenced by competition relations is taken for determining yield loss in a model. Possible applications in practice were discussed
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