Metabolic changes associated with growth of soybean as affected by pre-emergence application of metribuzin

Abstract

Pre-emergence application of metribuzin stimulated the accumulation of nitrogen, especially in the form of protein. The application of metribuzin induced marked suppression of carbohydrates. The soluble sugars and polysaccharides in nontreated control plants declined throughout the experimental period. The inhibitory effect of metribuzin on carbohydrates was concomitant with changes in photosynthetic efficiency, biosynthesis of pigments (chlorophyll), and the nucleic acid contents. The chlorophyll a/b ratio was not affected by metribuzin application.

Growth, carbohydrates and associated invertase and amylase activities in castor bean and maize as affected by metribuzin and NaCl

“…Several enzymes have been shown to be affected by herbicide trealments. The observed effects of herbicide on hydrolytic enzymes (ct-and 13-amylases, invertase and protease) were found to vary from one plant to another and appeared to be a function of the concentration used and duration of treatment 0Nybieralski and Wybierlaska 1984, Gabr et al 1988a, Hamed 1990).…”

Herbicides — A Double Edged Sword

“…In contrast, 0.5 R, 1R and 1.5 R of metribuzin stimulated total and protein-N accumulation in soybean. Consequently, protein content was increased while RNA and DNA levels decreased [26]. Protein content of soybean yield was reported to be increased by application of 100 ppm GA 3 (gibbrellic acid) and 2g/L Librel separately or together [27].…”

“…The total lipid content as well as gluco-and phospho-lipid content of maize seedlings markedly decreased by application of perfluidone while in sunflower cotyledons total lipids were not affected but glycolipids increased at the expense of phospholipids [62]. Also, a decrease in lipid synthesis in soybean by Isouron was reported [36] but an increase in seed oil of soybean was obtained by 0.5R or 1R metribuzin application [26].…”

“…Inhibition of the accumulated reducing sugars, sucrose and polysaccharides, in soybean leaves was observed in response to 1R and 1.5R metribuzin application and, consequently, seed carbohydrate content decreased with increasing metribuzin concentration [26]. Terbytryn herbicide was found to decrease starch content and increase sugar content in pre-emergence and post emergence applications [63].…”

“…Sakha 69) [28]. It was found that 100-seed weight of soybean was decreased by using metribuzin at rates of 0.5R, 1R and 1.5R [26]. Wheat yield was markedly increased by using tribenuron at a rate of 0-125g [77].…”