Efecto del periodo libre de precipitacion luego de la aplicacion de glifosato en maicillo (Sorghum halepense (L.) Pers.) y chufa (Cyperus rotundus L.).
1993
Fernandez Garcia Huidobro Ximena | Wenzel M Andrea
The period between herbicide foliar application and rainfall or irrigation by microjet is critical for the efficacy of many herbicides. To quantify the rain-free period over the action of glyphosate in johnsongrass and purple nutsedge, a field experiment was conducted during February of 1992, in the locations of Paine and Colina, respectively. Using a randomized complete block design, two rates of glyphosate were studied: 0.96 and 1.92 kg ai/ha in johnsongrass, and 1.92 and 2.88 kg ai/ha in purple nutsedge using a split plot design in randomized blocks, and different rain-free periods. Simulated rains in both species at a rate of 12.5 mm were applied at 2, 4, 6, 8, 12 and 24 hours after herbicide application. A treatment which had no simulated rainfall and a treatment without an herbicide application were included. The applications were done on mature plants of johnsongrass obtained from rhizomes with an average height of 51.2 cm and in purple nutsedge with 9-11 leaves. The johnsongrass plants were collected 28 days after herbicide application; the purple nutsedge plants after 42 days, separating the aerial part from the underground part. A greater activity of the herbicide glyphosate was observed with an increase in the time intervals between herbicide application and simulated rainfall. After analyzing, in both species, the parameters of flowering, height, production of fresh and dry matter, production of rhizomes and tubers, number of buds of the rhizomes, rhizomes and tubers sprouting percentage, and long sprout of tubers, it was confirmed that the herbicide glyphosate, independent of the rates utilized, required a rain-free period that fluctuated between 12 and 24 hours in order to show its potential as herbicide.
显示更多 [+] 显示较少 [-]