Author(s): GOMIDE, C. A. de M.; PACIULLO, D. S. C.; BRIGHENTI, A. M.; CASTRO, C. R. T. de; SOUZA SOBRINHO, F. de

Summary: Reducing herbicide doses in the desiccation of cover crops for straw production in crop-livestock integration systems has economic and environmental impact. However, the recommendations for herbicide doses contained in the product leaflets do not take into account the mass of forage to be desiccated. The objective of this study was to evaluate the effect of different doses of glyphosate on the desiccation of U. ruziziensis cv. BRS Integra with different forage masses. The doses of acid equivalent (ae) of glyphosate evaluated were 240, 480, 960 and 1,920 g/ha, (Roundup Original®Plus 480 g/L) associated with three forage masses (1,700, 5,000 and 7,000 kg DM/ha). The masses were obtained by cutting the plots at 10, 30 and 50 cm, followed by 28 days of regrowth. The experiment was carried out in a randomized block design in a split-plot scheme, with four replications. The evaluations of the desiccation were carried out at 10 and 15 days after application (DAA) of the treatments based on the SPAD indices. The data were subjected to regression analysis and quadratic equations were adjusted for each assessment moment, considering 80% control as the minimum limit. For the lowest forage mass there was no effect of the doses in any of the evaluation periods, with the average control of 87.4%. For the intermediate forage mass, the 80% control occurred at 10 DAA for the dose of 720 g ae/ha and, at 15 DAA, with the dose of 610 g ae/ha. In the highest forage mass, the control occurred at 10 and 15 DAA with doses of 797 g ae/ha and 667 g ae/ha, respectively. It is concluded that the dose of glyphosate capable of providing satisfactory desiccation of BRS Integra must be adjusted depending on the forage mass and the interval between desiccation and planting. (Support Fapemig: APQ 03630-23)

Publication year: 2024

Types of publication: Abstract in annals or event proceedings

Unit: Embrapa Dairy Cattle

Keywords: Brachiaria, Dessecação, Forragem, Glifosato, Herbicida