Effects of hoeings and of other treatments on sunflower yield

Abstract

One field experiment was carried-out during 1989/90 at Estação Experimental Agronômica of Universidade Federal do Rio Grande do Sul, in Eldorado do Sul, RS, Brazil, with the objective of evaluate the potential injury of hoeings to sunflower. A complete randomized block design with six replications was used. Plots were maintained free of weeds during the growing season. The treatments tested were early hoeings with mechanical or hand hoeing, hilI cultivation, and chemical weed control alone or combined with late hoeing. Negative effects of hoeings were limited and difficult to demonstrate; however, hoeings performed early in the season, during the critical period of weed interference, increased sunflower height and number of achenes per plant. Achene yields were not affected by treatments. No advantage of using hilI cultivation was observed. Manual or mechanical hoeing were equivalent for all evaluations.