Influence of bentazone reduced rate on weed control efficacy in potato

Abstract

Based on the recommendations to reduce the application rate of bentazone to ≤ 1000 g a.i/ha/year (due to the risk of its leaking into groundwater, especially in the conditions of high precipitation), we investigated the efficacy of this herbicide in the weed control in potato crops during 2013. The experiments were conducted in accordance with standard EPPO method, under field conditions on the localities of Altina and Padinska Skela. Commercial formulation Basagran (480 g of bentazone/l) was applied as post-em treatment in two application rates: 2 l/ha and 3 l/ha. Standard treatment with metribuzine was also applied - commercial formulation Velton WP (700 g of metribuzine/kg) both as pre-em and post-em, with the application rates of 0.75 kg/ha - 1.5 kg/ha and 0.5 kg/ha - 0.75 kg/ha, respectively. Reducing the application rate resulted in the decrease of efficacy in the case of the high abundance of weed population (Amaranthus retroflexus) or in the case of herbicide application to weeds in older growth stages (Chenopodium album). Suppressive effect on perennial weed species was also reduced.

Tokom 2013. godine, shodno preporukama za ograničenje primene bentazona na maksimalno 1000g/ha u vegetaciji (zbog opasnosti od dospevanja u podzemne vode u uslovima veće precipitacije), ispitana je efikasnost herbicida na bazi bentazona u suzbijanju korova u usevu krompira. Ogledi su izvedeni u skladu sa standardnom EPPO metodom, u poljskim uslovima (lokaliteti Altina i Padinska Skela). Preparat Basagran (480 g /l bentazona) primenjen je post-em u količinama 2 i 3 l/ha preparata. Kao standard, preparat Velton WP (700 g/kg metribuzina) primenjen je pre-em u količinama 0,75 i 1,5 kg/ha i post-em 0,5 i 0,75 kg/ha. Smanjenje količine primene rezultiralo je smanjenjem efikasnosti kada su pojedini korovi (Amaranthus retroflexus) prisutni u visokoj brojnosti, ili su korovi (Chenopodium album) bili u starijim fazama razvoja u vreme primene herbicida. Supresivno delovanje na višegodišnje korovske vrste je takođe umanjeno.