Banded herbicide application in a conventional sunflower production system

Abstract

Banded herbicide applications with hooded field sprayers (HFS) provide safer applications in many crops. The aim of this paperis to show the effectiveness and safeness of selective and nonselective herbicide applications in a conventional sunflower productionsystem (CSPS) using a combined hooded field sprayer (CHFS). Glyphosate interrow and aclonifen or quizalofop-P-ethyl intrarow wereapplied in fields cropped with nonglyphosate-resistant sunflower varieties in Ankara, Tekirdağ, and Tokat Provinces of Turkey in 2015and 2016. In Ankara and Tekirdağ, glyphosate caused limited injury to sunflower at 28 days after treatment (DAT), and aclonifen createdtransient phytotoxicity in 2015. Glyphosate was applied with aclonifen at 1.44 + 0.75 and 2.88 + 0.75 kg ai $ha^{–1}$ or quizalofop-P-ethyl1.44 + 0.05 and 2.88 + 0.05 kg ai $ha^{–1}$ using band application units of CHFS together. Aclonifen and quizalofop-P-ethyl were also usedat 0.75 and 0.05 kg ai $ha^{–1}$, respectively, using the conventional application unit of CHFS. Glyphosate + aclonifen (1.44 + 0.75 and 2.88 +0.75 kg ai $ha^{–1}$) provided higher weed control and sunflower seed yield compared with the other treatments. Aclonifen (0.75 kg ai $ha^{–1}$)controlled many competitive arable weeds and increased sunflower seed yield, except in Tokat in 2016, where common cocklebur waspresent in the field, which is not in the range of aclonifen. Weed control by glyphosate + quizalofop-P-ethyl (1.44 + 0.05 and 2.88 + 0.05kg ai $ha^{–1}$) was limited because broadleaf weeds covered the sunflower fields where the trials were conducted. Quizalofop-P-ethyl (0.05kg ai $ha^{–1}$) alone and untreated control were associated with the lowest sunflower seed yield. It is concluded that banded application ofglyphosate is safe and effective in sunflowers. Applying glyphosate with aclonifen and quizalofop-P-ethyl with CHFS helps to save timeand money, and mitigate $CO_2$ emission.