The effect of trifluralin on weeds of beans

Abstract

The effect of trifluralin on weeds and its influence on bean production was studied in field trials at the Experimental Station of Ponta Grossa, Paraná, in 1968 and 1969. Several levels of trifluralin were tested, as well as the effects of EPTC and a mixture of trifluralin plus EPTC. A control, cultivated plots, and a trifluralin level combined to one cultivation were also considered for further comparison. Treflan (45% of trifluralin) and Eptam-6E (77% of EPTC) were the available herbicides chosen. The main weeds which occurred in the experimental areas were Brachiaria plantaginea (L.) Hitch., Digitaria sanguinalis (L.) Scop. and Raphanus raphanistrum, L. The results show that trifluralin gave good control effect on grasses but not on broadleaves. Better results were obtained under higher soil humidity conditions. Doses of 0,90, 0,75 and 0,68 l/ha of trifluralin showed good weed control, improving bean yield. Under low soil humidity conditions, higher doses were more efficient. At levels higher than 1,35 l/ha, trifluralin caused stand damage. The application of 0,37 l/ha of trifluralin was the most favorable treatment on an economic basis, when one cultivation was performed during the whole cycle of the culture. Levels of 0,75 and 0,56 l/ha were less efficient than normal cultivation. Eptam-6E, at the dose of 3,08 l/ha, was not an efficient weed control.