Influence of herbicide residues in winter rapeseed on subsequently sown spring barley

摘要

In the Czech Republic winter rapeseed is grown at about 280 thousand hectares (10 %) of arable land. Plowing in due to non-emergence or bad wintering reaches up to 10 %. Alternative crop after plowed in rapeseed is very often spring barley. Some herbicides used in rapeseed influence with their residues yield ability and quality of subsequently sown spring cereals. The aim of our experiment is to find out response of spring barley to herbicide residues used in winter rapeseed, in case of malting barley sowing after plowed in winter rapeseed. Using two types of soil preparation - tillage and non-tillage system - we established small plot trials with winter rapeseed in August with following combinations: 1) control without herbicide, 2) trifluralin + napropamid, 3) trifluralin, 4) alachlor +clomacone, 5) metazachlor + quinmerac. In spring we terminated the experiment by disk tillage (simulation of winter rapeseed frost damage) and sew spring barley. The worst emergence rate of spring barley was found in option naproparnid + trifluralin (65,7 %), on the contrary the best emergence rate was found in option alachlor + clomaazone (81,5 %) and in control without herbicide (76,5 %). The highest number of spikes was formed by barley in varinats: alachlor + clomazone and metazachlor + quinmerac, on the contrary the lowest was in option napropamid + trifluralin. In variant napropamid + trifluralin grain yield decreased significantly (by 31%).The highest yield was obtained in variants: control without herbicide and alachlor + clomazone. Variants with tillage have better results in most monitored traits in comparison with non-tillage variants.