SPAD Total Chlorophyll as an Initial Indicator of the Effect of 2,4-D Dimethyl Amine Herbicide for Lowland Rice and Barnyardgrass Weed

Abstract

Barnyardgrass populations (Echinochloa crus-galli) can inhibit the growth and yield of lowland rice. The use of herbicides as an alternative control can affect the growth of lowland rice, especially the total chlorophyll content. This study was to obtain initial information on the effect of the 2,4-D dimethyl amine herbicide by detecting the total chlorophyll of lowland rice and barnyardgrass. A completely randomized block design with a non-factorial was selected in this study. 40 populations of barnyardgrass from Serdang Bedagai District, North Sumatra, Indonesia, and a population for comparison were sprayed with the herbicide 2,4-D dimethyl amine at a dose of 1,080 g ai ha−1 with three replications. This study was conducted from August to October 2022 and the parameters were analyzed using one-way ANOVA as well as followed by the Duncan test at P<0.05. The findings showed that the effect of the 2,4-D dimethyl amine herbicide was safe by 70.73 % for lowland rice. There was a significant decrease in the total chlorophyll of barnyardgrass exposed to the 2,4-D dimethyl amine. A decrease in the total chlorophyll can be used as initial information to indicate the effect of the 2,4-D dimethyl amine.