engleski

Long-term effects of soil tillage on weed populations in winter wheat

Field experiments were conducted in winter wheat on lessive pseudogley soil in Northeastern Croatia from 1997 to 2006. The objective of this long-term study was to evaluate the effects of three tillage systems (conventional - mouldboard plow, CT ; chisel plow, CP ; disk harrow, DH) upon species composition, weed density and weed dry weight, not using herbicides, as useful information to improve integreated weed management in cereal crops. Annual broad-leaved weeds dominated with 24 species compared with 11 perennials and 3 annual grasses. Weed species which occured in all three tillage systems at more than one shoot m-2 were: Ambrosia artemisiifolia L., Chenopodium album L., Galium aparine L., Matricaria inodora L., Polygonum aviculare L. ; Calystegia sepium (L.) R. Br., Convolvulus arvensis L. Equisetum arvense L. Cirsium arvense (L.) Scop. and Apera spica-venti (L.) PB. Annual broad-leaved weed density in the CT system was statistically similar to that in the DH system in 7 out of 9 years. M. inodora tended to have higher populations in the DH system, especially in wet seasons of 2002 and 2004. C. album showed high variations among years and tillage systems, but it had the highest populations in the DH system during the drought season of 2003. P. aviculare showed a marked and statistically significant response to CT system, whereas A. artemisiifolia's response to tillage was not consistent. Most annual species including grass species of A. spica-venti were not favoured by any tillage system. Annual broad-leaved weeds comprised 63%, 50% and 41% of total dry weight in CT, CP and DH tillage systems, whereas perennial weeds comprised 3%, 26% and 44%, respectively. Reduced CP and DH tillage systems increased density and dry weight of some perennial weed species which associated with these tillage systems. C. arvense was the most important perennial weed on disk harrowed plots, after three years of experiment.

winter wheat ; soil tillage systems ; weed species ; weed density ; weed dry weight

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