Effect of emergence depth on velvetleaf (Abutilon theophrasti Med.) competition ability against maize (Zea mays L.)
2000
Lesnik, M. (Maribor Univ. (Slovenia). Agriculture Fac.)
In four field trials arranged in a split-split plot design, the effect of emergence depth of velvetleaf (Abutilon theophrasti Med.) on competition ability against maize, its response to control with pendimethalin and bromoxynil-octanoat, and the impact on maize yield were investigated. In two experiments, the reduction in the aboveground fresh weight of velvet leaf plants (AFW, kg m-2) after herbicide application was significantly higher in the case of plants emerging from 1 cm depth than in the plants emerging from 6 cm depth. Velvet leaf competition against maize significantly affected the rate of AFW reduction due to herbicide activity, since the decrease in AFW in pure stands of velvet leaf in all experiments was, on average, lower by 30 % than in stands where velvet leaf competed against maize. Despite the fact that both herbicides were less efficient in plants emerging from greater depths, in neither of four experiments a statistically significant effect on the rate of maize yield losses was established.
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