Using herbicides in spring rapeseed and effect on quantity and quality parameters of yeald.

Possibility to chemically control weeds in spring rapeseed has been tested in two locations ( Novi Sad and Kragujevac) and following herbicides (a.i.) : trifluralin, clomazone, quizalofop-p-ethyl and clopyralid. We tested the effect of the herbicides on yield and hectoliter weight of seed and oil and protein contents in seed. In the trial in Kragujevac, a large number of weed species were present, with somewhat increased density and uneven distribution of weed plants. This was particularly evident with grassy weeds and with the species Rubus caesius in several plots. Rapeseed yield and quality were determined by measuring and analyzing the following parameters: grain yield (kg/plot (30 m2), hectoliter weight, oil content (%) and protein content (%) in seed.Basic statistical calculations of rapessed yield and quality were done by the t-test. The tested herbicides showed no adverse effect on the yield and hectoliter weight of seed in either location, with the exception of quizalofop-p-ethyl in Kragujevac, which affected the control variants. Oil content was negatively affected by the combination, trifluralin + clopyralid in the location of Novi Sad and by quizalofop-p-ethyl in the other location. Trifluralin and quizalofop-p-ethyl exhibited a negative effect on protein content in the location of Novi Sad, while there were no statistically significant negative effects in the other location.