Revista Brasileira De Herbicidas 2012; 11(1): 96-107
Glyphosate deposition with different aprayer nozzles in burndown of Panicum maximum plants
The objective of this work was to evaluate the deposition of a tracer solution constituted by glyphosate (2,160 g ha-1) + FD & C No. 1 (2,000 ppm) blushing with different sprayer nozzles in burndown of Panicum maximum cv. Mombaça plants, besides the losses quantification of the sprayer to the soil. A randomized complete block design was used with four replications. Each experimental unit consisted of three lines with 5m long, spiced of 1.0 m. Treatments were applied 12 months after P. maximum seeding, and 40 days before application, a cut was conducted to become the area uniform. The following sprayer nozzles were evaluated: fat flan nozzle XR 110015 VS (100 L ha-1) and XR 11002 VS (200 L ha-1), cone nozzle TX-4 VS (100 L ha-1) and TX-8 VK (200 L ha-1), air induction nozzle AI 11002 VS (200 L ha-1) and double flat fan nozzle TJ 60 11002 VS (200 L ha-1). Immediately after application, 25 tillers per replication were collected and washed separately leaves and stem of each one in 150 ml of distilled water, for later quantification of the tracer in a spectrophotometer. Obtained data were adjusted to a regression curve by Gompertz model. All treatments were effective in burndown P. maximum plants, independently of the spray nozzles or used volume used, which suggests the possibility of reducing application volume and herbicide dosage in burndown desiccation the studied specie, considering the use of systemic herbicide. However, there was difference in the quantity, as well as in the uniformity of solution distribution sprayed in the evaluated targets in relation to spray nozzles used, and consequently of used volume. The cone nozzle TX-VK 8 (200 L ha-1), provided less spray deposition on the soil.
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