Time of residual herbicide application in cabbage: efficacy, benefits and risks

Abstract

The goal of this study was to evaluate herbicides for weed control in cabbage, pushed with the fact that pendimethalin is on EFSA's candidate for substitution list (CfS). The field experiment was conducted during 2024 at the experimental station of the Institute for Vegetable crops Smederevska Palanka. The study was established as a full randomized complete block design. All herbicides were applied with abattery powered backpack sprayer “Farm® KF-16C-47” which delivers a constant pressure. For this study a four nozzle boom with Lechler IDK12002 nozzles have been used to deliver 200 L of water ha-1 by 200 kPa pressure and the speed of 3.84 km h-1 (±10%). Herbicides were applied without adjuvants on three ways: 1) incorporation (PPI) a) napropamide 1800 g a.i. ha-1 and b) napropamide 900 g a.i. ha-1 + clomazone 96 g a.i. ha-1 and 2) preemergence (PRE-EM) c)pendimethalin 1650 g a.i. ha-1 and 3) postemergence (POST-EM)d)flumioxazin 40.8 g a.i. ha-1, e) dimethenamid-P 500 g a.i. ha-1 and f)metazachlor 500 g a.i. ha-1 + clomazone 96 g a.i. ha-1.Herbicides were applied without adjuvants.The most dominant weed species were:Ambrosia artemisiifolia L, Galinsoga parviflora (Cav.), Hibiscus trionum L, Polygonum lapathifolium L. and Portulaca oleracea L. Herbicide efficacy and crop injury were estimated every 7 days after treatment (DAT). The field was cultivated on 29th of April, whereby cabbage variety Ditmar was transplanted on 7th of May for POST-EM treatments and 17th of May for PPI and PRE-EM treatments whereby the herbicide application followed 10 days after and 7 days before transplanting respectively. The results varied among treatments, whereby treatments a), b) and c) provided excellent weed control 28 DAT without crop injury. Treatments d) and f) provided excellent weed control 14 DAT but not 21 DAT. Treatment e) provided poor weed control 14 DAT. Treatments which included clomazone or flumioxazin caused slight crop injury. All mentioned herbicides can be used for weed control in Ditmar cabbage variety with some minor crop injuries. A lower herbicide efficacy of POST-EM herbicides could be because of the long period between field cultivation and transplanting. Further research needs to be conducted. The research presented in this article is part of the research project number 451-03-66/2024- 03/200216 and 451-03-65/2024-03/200383 funded by the Ministry of Education and Science, Republic of Serbia