3. Managing competition between cultivated plants and weeds by cultivation methods and selective use of herbicide 3.3. Effect of sowing time and primary cultivation on weed infestation in different crops
1994
Amann, A. | Hurle, K.
Good weed management must be integrated into the production system. In order to achieve integration the effects of all agricultural measures on weed infestation have to be considered. In this paper results of a 2 year field experiment in which the effect of sowing time and primary cultivation on the weed seed bank, weed infestation, probability of weed emergence, and crop yield are described. The crops were: winter rape, winter wheat, spring barley and maize. Primary cultivation included ploughing and shallow tine cultivation. For each crop an early and a late sowing date, which differed 3-4 weeks, was chosen. No weed control measures were carried out. Ploughing led to 40-80% less infestation than tine cultivation. Due to shallow tine cultivation weed seeds accumulated in the upper soil layer from which weeds emerge preferably, and therefore gave heavy infestation. On average late sown crops had 30% less weeds than early sown crops. Except for winter wheat late sowing resulted in 20-60% less crop yield compared to the early sowing date, and with ploughing yield were 20-35% higher than with shallow cultivation. The results demonstrate that the kind of primary tillage, and the sowing time do have a strong effect on weed infestation. Although under the present economic conditions the effect of these measures will not suffice, they are worthwhile to be considered under conditions where effective direct control measures are not available
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