Competition of Florida Beggarweed and Sicklepod with Peanuts II. Effects of Cultivation, Weeds, and SADH

Abstract

When peanuts (Arachis hypogaeaL.) were not kept weed-free, a single cultivation 4 weeks after emergence increased yields substantially over those of non-cultivated peanuts. Cultivation had no effect, however, when peanuts were maintained weed-free for 4 or 8 weeks. The length of the weed-free periods, cultivation, and the presence or absence of peanuts all strongly influenced the density of the sicklepod (Cassia obtusifoliaL.) plants which grew above the canopy of peanut foliage. Peanut foliage, which was released from weed-free maintenance at 8 weeks but then competed with sicklepod until harvest, reduced the green weight of sicklepod 95 to 98% thus illustrating the competitive capacity of the peanut plant. Moderate stands of Florida beggarweed [Desmodium tortuosum(Sw.) DC] did not markedly affect yield of peanuts. Application of a growth regulator, succinic acid, 2,2-dimethylhydrazide (SADH), did not influence weed competition or yield of in-shell peanuts consistently at any of the three locations. Quality analyses showed that treatment variables did not modify the taste of peanuts; however, in some experiments, components of the market grade of in-shell peanuts were changed by SADH, cultivation, length of the weed-free period, and cultivation X length of the weed-free period.