Die Bodenkultur - Journal for Land Management, Food and Environment
B. Varga, Z. Svečnjak and A. Pospišil:
Grain yield and yield components of winter wheat grown in two management systems
Field studies in a winter wheat-maize-soybean crop rotation were conducted in northwestem Croatia in 1996 and 1997 to determine the effect of intensive (IMS) and extensive (EMS) management systems on the grain yield and yield components of 8 regional winterwheat cultivars grown at two sowing rates (440 and 770 seeds m-2 ) . IMS consisted of ploughing at 30-32 cm, fertilisation with 194 kg N ha-1, 130 kg P ha-1, 130 kg K ha-1, and intensive crop protection (herbicide, fungicide, and insecticide applications). EMS involved ploughing at 20-22 cm, fertilisation with 59 kg N ha-1, 104 kg P ha-1 and 104 kg K ha-1, and herbicide application. Average grain yield was 37.5 % higher in IMS than in EMS, although ear number per square meter increased only by 10.6 %, indicating the importance of grain production per ear as a yield component. Higher sowing rate increased ear number per square meter and grain yield in both management systems, and was shown to be a necessary practice for achieving the maximum grain yield in IMS. In the two growing seasons, some cultivars responded differently for grain yield, ear number per square meter, and test weight only in IMS, indicating that responses of cultivars to management inputs can depend on environmental influences. Test weight and 1OOO-kernel weight were highly affected by growing season and cultivar in both management systems. 1OOO-kernel weight was lower in IMS, and at higher sowing rate in both management systems. Test weight was not significantly affected by the management system, but it demonstrated a trend to increase at higher sowing rate in IMS.
Key words: Triticum aestivum, cultivar, fertilisation, sowing rate, test weight.