Evaluation of Herbicides for Weed Control on Sweet Potato Fields

Various commercially available herbicides were evaluated for weed control on sweet potato fields. The phytotoxicity of 15 herbicides was firstly tested in a chamber on sweet potato seedlings by foliar spray. Then, the 10 that showed no or low toxic effect on the seedlings were subjected to a field test. It was found that the applications of 25% rimsulfuron WDG at 90 g·hm^-2, 330 g·L^-1 pendimethalin EC at 1 800 mL·hm^-2, 900 g·L^-1 acetochlor EC at 1 050 mL·hm^-2, and 960 g·L^-1 s-metolachlor EC at 1 200 mL·hm^-2 were more effective in weed control than the others. The selected herbicides applied at the levels reduced more than 82% on weight of fresh weeds in 50 ds after spraying. In the subsequent multi-location field test, the foliar application of acetochlor or s-metolachlor exhibited superior weed control efficacy with safety. Consequently, it was deemed applicable on sweet potato fields.