Written Paper

Biology and response of Monochoria vaginalis (Burm. f.) Presl. to selected herbicides at different growth rate [study conducted in the Philippines]  [1981]

Lamid, Z. University of the Philippines at Los Banos, College, Laguna [Corporate Author]

Access the full text

Pot experiments were conducted at an open space in the Department of Agronomy, University of the Philippines at Los Banos from February to August 1981 to study growth and development of M. vaginalis to determine the growth stages of the weed that can be effectively controlled by recommended rates of granular 2,4-D-IPE, butachlor and thiobencarb; to determine the effect of these recommended herbicide treatments on rice when applied at the susceptible growth stages of the weed; and to investigate the influence of nitrogen on the effect 2,4-D on the weed. Water depth of 1.0 cm from soil surface induced 94% germination of M. vaginalis seeds under water, soil and air temperature ranges of 22.5 to 30.9 C, respectively. The plant produced 3 leaf forms namely, sessile-elongated, petiolated-ovate and petiolated-cordate. Optimum growth occurred from the sixth to the eight week after sowing. Each plant produced an average of 4.45 suckers, 23 spike inflorescences, 235 capsules and 61, 195 seeds. M. vaginalis was effectively controlled by granular 2,4-D starting from the fourth leaf stage onwards. Pre-emergence application of the herbicide and application at the second leaf stage resulted in ineffective control of the weed. Butachlor effectively controlled the weed when applied pre-emergence or post-emergence. Nitrogen promoted vigorous weed growth but did not influence the effect of 2,4-D on the weed. Dry matter and yield components of rice were not significantly affe
cted by applications of 2,4-D butachlor and thiobencarb.