Control de Datura ferox L. y Chenopodium album L. con glifosato aplicado en diferentes momentos y dosis en soja transgénica
Fecha
2003
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UNR Editora
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Se realizaron experimentos a campo durante 1998 y 1999 en Zavalla (Argentina) con el objetivo de evaluar el efecto del momento de aplicación y de la dosis de glifosato (74,7%) sobre el control visual, la producción de semillas y el peso seco de Daturaferox y Chenopodium album en un cultivo de soja resistente al herbicida. El diseño experimental utilizado fue de parcelas sub-divididas, con cuatro repeticiones. Las parcelas principales fueron asignadas a las dosis de 0, 125, 250, 500, 1000 y 2000 g ia/ha y en las subparcelas se asignó el momento de aplicación 30 (M1) y 45 (M2) días después de la siembra de soja. Se detectó interacción entre momentos y dosis de glifosato, pero no entre años. Las relaciones entre la dosis de glifosato, el porcentaje de control, la producción de semillas y el peso seco de ambas malezas ajustaron a modelos log-logísticos. En M1, con 2000 g ia/ha de glifosato, el porcentaje de control fue de 69% en D.ferox y 75% en C.album. En M2 el control fue 100% en ambas malezas. En M1, D. ferox y C. album produjeron semillas en todas las dosis evaluadas. En M2 hubo producción de semillas de D.ferox con dosis de 500 g ia/ha o menores y en C. album hasta con 1000 g ia/ha. El uso de 1000 g ia/ha de glifosato, en M2, redujo severamente el peso seco en ambas malezas. Aplicaciones a los 45 días de la siembra proveen un excelente control visual, de producción de semillas y de peso seco de las malezas estudiadas, mientras que a los 30 días de la siembra el control no es satisfactorio. Dosis de 1000 g ia/ha de glifosato aplicados a los 45 días de la siembra proporciona resultados similares a los obtenidos con 2000 g ia/ha.
Field experiments were done at Zavalla (Argentina) during 1998 and 1999 to evaluate the effect of application timing and glyphosate rate at 74,7% on visual control, seed production, and dry weight of Datura ferox and Chenopodium album at the end of the crop growing season of glyphosate-resistant soybean. The experiments were laid out with a split-split plot design with four replicates. The main plot was glyphosate rate 0, 125, 250, 500, 1000 y 2000 g ai/ha and the subplot was application timing 30 (M1) and 45 (M2) days after soybean planting. Interaction was detected between application timing and rates of glyphosate but not between years. Relationships between glyphosate rate and weed visual control in percentage, seed production and weed dry weight fitted to log-logistic models. In M1, with 2000 g ai/ha of glyphosate, visual control was 69% for D.ferox and 75% for C. album. In M2, control was 100% for both weed species. In M1, D. ferox and C. album produced seeds in all the evaluated rates. In M2, seed production in D. ferox occurred with 500 g ai/ha and lower rates and in C.album with 1000 g ai/ha and lower rates. With the 1000 g ai/ha glyphosate rate, in M2, weed dry weight was remarkably reduced in both weeds. Applications at 45 days after planting provided optimum visual control, and an excellent reduction in seed production and dry weight of D.ferox and C.album but in the first application date control was unsatisfactory. Rates of 1000 g ai/ha of glyphosate applied at 45 days after planting provided similar results to those obtained with 2000 g ai/ha.
Field experiments were done at Zavalla (Argentina) during 1998 and 1999 to evaluate the effect of application timing and glyphosate rate at 74,7% on visual control, seed production, and dry weight of Datura ferox and Chenopodium album at the end of the crop growing season of glyphosate-resistant soybean. The experiments were laid out with a split-split plot design with four replicates. The main plot was glyphosate rate 0, 125, 250, 500, 1000 y 2000 g ai/ha and the subplot was application timing 30 (M1) and 45 (M2) days after soybean planting. Interaction was detected between application timing and rates of glyphosate but not between years. Relationships between glyphosate rate and weed visual control in percentage, seed production and weed dry weight fitted to log-logistic models. In M1, with 2000 g ai/ha of glyphosate, visual control was 69% for D.ferox and 75% for C. album. In M2, control was 100% for both weed species. In M1, D. ferox and C. album produced seeds in all the evaluated rates. In M2, seed production in D. ferox occurred with 500 g ai/ha and lower rates and in C.album with 1000 g ai/ha and lower rates. With the 1000 g ai/ha glyphosate rate, in M2, weed dry weight was remarkably reduced in both weeds. Applications at 45 days after planting provided optimum visual control, and an excellent reduction in seed production and dry weight of D.ferox and C.album but in the first application date control was unsatisfactory. Rates of 1000 g ai/ha of glyphosate applied at 45 days after planting provided similar results to those obtained with 2000 g ai/ha.
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dosis reducidas, control de malezas, producción de semillas, peso seco, reduced rates, weed control, seed production, dry weight