Author : Muhammad Ali

Summary : The effect of 1,8-naphthalic anhydride (NA) and N,N-diallyl-dichloroacetamide (R-25788) in protecting rice, corn, sorghum, and soybean from several herbicides were studied for five months under laboratory and simulated field conditions. NA increased root length of rice seedlings treated with butachlor, molinate, pendimethalin, and thiobencarb. Similar effect was noted with corn seedlings treated with butylate, ethyl dipropylthiocarbamate (EPTC), and vernolate. NA alone was phytotoxic to sorghum and soybean but it also reduced the inhibitory effect of butylate on shoot growth of sorghum. However, it failed to protect soybean from pendimethalin injury. R-25788 increased shoot and root growth of corn treated with EPTC but not with butylate and vernolate. Sorghum did not respond to R-25788 with butylate and EPTC. Vernolate was more phytotoxic to sorghum in combination with R-25788. NA increased the herbicidal effect of butylate, EPTC, and vernolate to rice plants, regardless of depth of planting or time of herbicide application. However, the NA gave partial protection to rice treated with oxadiazon and was magnified by planting deeper than 1 cm and applying oxadiazon before emergence. R-25788 gave better protection than NA against the phytotoxicity of EPTC in corn when EPTC was applied at 1.5 and 3.0kg/ha. Both antidotes were less effective in corn against butylate and vernolate, Butachlor phytotoxicity on sorghum was minimized by coating the seeds with NA. The same protection was achieved with pendimethalin but did not prevent the damage on the root system. NA did not protect soybean from pendimethalin, butralin, metolachlor, and EPTC.