Efecto de herbicidas sobre plantas y semillas de Rottboellia cochinchinensis (Lour.) W. Clayton, en caña de azúcar.
Effect of herbicides on plants and seeds of itchgrass (Rottboellia cochinchinensis (Lour.) W. Clayton) in sugarcane. An experiment was carried out to evaluate the effectiveness of several herbicides commonly used in sugarcane on the control of itchgrass (Rottboellia cochinchinensis) and their effect on its seed bank. The experiment was established in a plot sown with the sugarcane variety MEX 69-290 in Cosamaloapan, Veracruz, Mexico, during the 2000 rainy season. Nine treatments were evaluated: 1. Tebuthiuron (1500 g/ha), 2. Diuron/hexazinone (1634.4/204.3 g/ha), 3. Diuron (2400 g/ha), 4. Ametrine/2,4-D (1225/650 g/ha) 5. Ametrine/2,4-D + Diuron/hexazinone (735/390 + 544.8/68.1 g/ha), 6. Tebuthiuron + Diuron/hexazinone (1000 + 817.2/102.2 g/ha), 7. Tebuthiuron + Diuron (1000 + 1200 g/ha), 8. Tebuthiuron + Ametrine/2,4-D (1000 + 490/260 g/ha) and 9. Weedy control. ARandomized Complete Block Design with four replications was utilized. Itchgrass control was evaluated at 15, 30, 60 and 90 days after application (DAA). Soil samples (0-20 cm deep) were taken at 0, 30, 90, 120 and 150 DAA. The soil from each experimental plot was put in a tray and watered daily. Itchgrass seedlings that emerged during 75 days were counted. The best itchgrass control was obtained with tebuthiuron at 1500 g/ha; a good control was also obtained with tebuthiuron + diuron at 1000 + 1200 g/ha and tebuthiuron + diuron/hexazinone at 1000 + 817.2/102.2 g/ha. All herbicide treatments had a significant reduction in the emergence of itchgrass seedlings which varied from 59 to 96%, compared with the weedy control.