Wild Watermelon Emergence and Control

Abstract

Wild watermelon (Citrullus vulgarisSchrad. var.citroidesBailey) is a widespread problem in cotton (Gossypium hirsutumL.) and grain sorghum [Sorghum bicolor(L.) Moench] planted on sandy soils. Preplant herbicide treatments did not suppress wild watermelon emergence, dry matter, or melon production. Preemergence application of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] suppressed growth and controlled the weed. However, propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine] controlled and nearly eliminated melon production. Although postemergence application of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] was effective, most postemergence treatments gave erratic control, probably because of differences in vigor from seedlings emerging from varying depths. There was no difference in emergence from seed planted 2.5 to 10 cm deep. However, emergence was lower from seed planted 20 cm deep and seedlings were less vigorous from seed buried 10 cm or deeper.