Chemical weed control in lupins

Abstract

The response of weeds and narrow-leaved lupins (Lupinus angustifolius) to a number of pre-planting, pre-emergence and post-emergence applied herbicides was evaluated in six field trials between 1970 and 1973. Applied six weeks post-emergence, fluometuron and propazine at 0.75, 1.5 and 3.0 kg, carbetamide at 1.5, 2.0 and 3.0 kg, simazine at 1.5 and 3.0 kg, and chlortoluron at 3.0 kg a.i. ha-1 gave good control of annual weeds present. Only carbetamide 1.5, 2.0 and 3.0 kg, propazine 0.75 and 1.5 kg and simazine 1.5 kg a.i. ha-1 increased grain yield. Decreasing yield with increasing dose rate in the case of fluometuron and propazine in this situation suggested some crop toxicity. Applied pre-planting and incorporated, alachlor 1.0 and 2.0 kg, di-allate 0.84 kg, nitralin 0.6 and 1.2 kg and trifluralin 0.56 kg a.i. ha-1 gave good grass control and, in general, increased yield. They had no effect on the majority of broadleaf species present. Applied pre-emergence, alachlor, propazine and simazine at 1.0 and 2.0 kg, fluometuron at 1.0 to 4.0 kg and pronamide at 0.8 and 1.6 kg a.i. ha-1 in general gave good weed control and increased grain yield. All except alachlor affected both grasses and broadleaf species. The results, however, were seriously affected by rainfall incidence. The results are discussed in terms of the response to incorporation, rainfall incidence and temperature on the activity of specific herbicides.