Rate Response of Halosulfuron, Trifloxysulfuron, and Thifensulfuron-methyl on Three Common Weed Species of Field Grown Caladiums [<i>Caladium bicolor</i> (Aiton) Vent.]

Abstract

Broadleaf weeds are a persistent problem in field grown Caladium production due in part to the lack of registered post-emergence herbicides. Previous research found that many caladium varieties tolerate post emergence sprays of halosulfuron, trifloxysulfuron, and thifensulfuron-methyl. Research was conducted at the Gulf Coast Research and Education Center (GCREC) in 2014 to determine the minimum rate needed to achieve adequate control of common purslane (Portulaca oleracea), spotted spurge (Euphorbia maculata), and morning glory (Ipomoea cordatotriloba). Experiments were set up as randomized complete-block designs with four blocks. Spotted spurge and common purslane were grown in pots in a greenhouse whereas the morning glory trial was set up in the field at the GCREC. Halosulfuron was applied at 0, 13.12, 26.25, 52.5, 105, and 210 g·ha^-1 (ai), trifloxysulfuron was applied at 0, 5.25, 10.5, 21, 42, and 84 g·ha^-1 (ai), and thifensulfuron-methyl was applied at 0, 1.75, 3.5, 7, 14, and 28 g·ha^-1 (ai). Thifensulfuron-methyl achieved the greatest common purslane control with 82% control at 7 g·ha^-1 (ai). Trifloxysulfuron achieved 100% spotted spurge control at 21 g·ha^-1 (ai). Thifensulfuron-methyl and trifloxysulfuron achieved 91% and 87% control with 28 and 42 g·ha^-1 (ai), respectively. Our results indicate that adequate control of common problematic weeds in field grown caladiums can be achieved with the herbicides evaluated.