The Interaction of Herbicide and Humic Acid on Azolla Control to Enhance the Yield of Rice (Oryza sativa)

To increase the rice yield by the interaction of herbicides and humic acid on Azolla control, an experiment was conducted in Amol, Mazandaran, in 2016 as a factorial experiment in randomized complete block design with three replications. Treatments consisted of herbicides application in five levels: 2-4-D SL72%, Bensulfuron methyl DF60% (Londax), bentazon SL48% (Bazagran), Oxadiargyl EC3% (Top Star) and control, and humic acid at three levels: 12, 6 and 0 lit/h (control, no humic acid). The results of this study showed that the simple effect of application of herbicides and humic acid on all traits was significant. Also, tillers number, panicle length, Azolla weight and rice yield were affected by the interaction of herbicides and humic acid. The lowest Azolla weight (115.33 g m-2) was obtained by the interaction of Oxadiargyl and 12 litha˗¹humic acid, and the highest grain yield (6871 Kg ha˗¹) was also observed in the same treatment.