Herbicides application in sorghum stubble. Efficiency of high and low volume techniques
The use of low application rates in systemic herbicides spraying is a usual practice in Argentina. Field trials were carried out with a self propelled boom sprayer in sorghum (Sorghum bicolor (L.) Moench) stubble with the aim to evaluate the efficiency and drift risks of glyphosate application alternatives. Two spraying techniques were compared: High application rate (AV) with Teejet® TT 11002 nozzles and 70 l ha-1 and Low application rate (BV) with Albuz® AD5 AC13 hollow cone nozzles and 30 l ha- 1. Four downwind target areas were evaluated to determine the direct effects of the application and the accumulated sedimentation drift. Airborne was evaluated by vertical towers at 1, 2 and 3 m high. Droplets density (DD), coverage (C), Volume Median Diameter (VMD) were quantified by water sensitive cards and image processing software CIR 1,5® at the upper (ES) and lower level (EI) of sorghum cover residue. Solution recovery rate (E) was calculated from droplets stains and corrected by chromatography determination of solution recovery on Petri dishes. Both techniques exceeded the recommended droplet density for herbicides. The coverage was 13.77% and 11.06% for VA in ES and EI, while in BV it only reached values of 3.46% and 2.36%, with significant differences between treatments. E was 51.56% in AV and 21% in BV over ES. Weeds control near sorghum row crop may be compromised by the low amount of glyphosate that reaches this location. The BV technique reached glyphosate losses around 2 l ha-1 that were not deposited on the application object, increasing the risk of environmental contamination.
| Main Authors: | , , , , , , |
|---|---|
| Format: | Digital revista |
| Language: | spa |
| Published: |
Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata
2019
|
| Online Access: | https://revistas.unlp.edu.ar/revagro/article/view/7343 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|