engleski

Influence of soil tillage and low herbicide doses on weed dry weight and cereal crops yields

The influence of tillage systems (mouldboard, chisel, disk harrowing, mouldboard/disk harrowing, disk harrowing/mouldboard alternating every other year) and low herbicide doses of triasulfuron chlortoluron tank mixture on weed dry weight and crop yields was investigated in winter wheat and spring barley on lessive pseudogley soil in north-eastern Croatia over four years. The lowest total weed dry weight across years was in the conventional tillage with mouldboard plough (3.25 g m-2), whereas the greatest weed dry weight was found in disk harrowing (18.46 g m-2). No significant differences in total weed dry weight were observed between conventional and all other reduced tillage systems which showed average weed dry weight values of 7.92 g m-2. The best herbicide efficacy was achieved with the highest recommended herbicide dose (11.3 and 1185 g a. i. ha-1) which corresponded across tillage systems to 91% of relative weed dry weight reduction on average compared to untreated plots. One-half and one-quarter of the recommended herbicide dose decreased total efficacy on average by 12 and 19%, respectively in wheat, and by 6 and 15% respectively in barley compared to the highest dose, but still provided an efficient control of dominant annual broad-leaved weeds (94-96% control) in both crops. The dose reduction of herbicide had no significant effect on crop yields. The average yield from treated plots was 6% higher in wheat and 4% higher in barley compared to the untreated plots. No significant yield differences were observed between conventional tillage with mouldboard ploughing and all reduced tillage systems, although the average wheat yield of 5.7 t ha-1 and barley yield of 4.9 t ha-1 were the greatest after chisel ploughing. The yield responses of both crops were poorly correlated with total weed dry weight.

winter wheat ; spring barley ; soil tillage ; herbicide dose ; weed dry weight ; grain yield

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