Selectivity of chemical weed control systems in conventional cotton

Abstract

-Cotton is highly susceptible to the interference imposed by weed community, being therefore essential to adopt control measures ensuring the crop yield. Herbicides are the primary method of weed control in large-scale areas of production, and usually more than one herbicide application is necessary due to the extensive crop cycle. This study aimed to evaluate the selectivity of different chemical weed control systems for conventional cotton. The experiment took place in the field in a randomized block design, with twenty nine treatments and four replications in a split plot layout (adjacent double check). Results showed that triple mixtures in pre-emergence increased the chance of observing reductions in the cotton yield. To avoid reductions in crop yield, users should proceed to a maximum mixture of two herbicides in pre-emergence, followed by S-metolachlor over the top, followed by one post-emergence mixture application of pyrithiobac-sodium + trifloxysulfuron-sodium.Keywords: Gossypium hirsutum, application modalities, tank mixture. Palavras-chave: Gossypium hirsutum, modalidades de aplicação, mistura em tanque. RESUMO -O algodoeiro apresenta elevada sensibilidade à interferência imposta pela comunidade infestante, sendo fundamental a adoção de medidas de controle para assegurar a produtividade da cultura. O manejo químico consiste no principal método de controle de plantas daninhas utilizado em áreas de produção de larga escala, sendo por vezes necessária mais de uma aplicação de herbicidas

Leaching of the S-metolachlor herbicide associated with paraquat or glyphosate in a no-tillage system

“…It has been applied as a preemergent or preplant incorporated herbicide to control monocots and dicots, acting to selectively inhibit shoots of maize (Arantes et al 2014), soybean (Steckel et al 2015), cotton (Barroso et al 2012) and sorghum crops, via association with herbicide safeners (Silva et al 2014).…”

Controle De Soja Voluntária Com Herbicidas Registrados Para Algodoeiro

“…Os dados referentes a avaliação de 21 DAA, indicam que o trifloxysulfuron isolado, e as associações de pyrithiobac ou trifloxysulfuron com glufosinate, proporcionaram elevados níveis de controle sobre as plantas voluntárias de soja (≥ 96,0%), assemelhando ao desempenho obtido com a aplicação do dicamba isolado, bem como das associações entre 2,4-D + glufosinate e dicamba + glufosinate (Tabela 4). Pyrithiobac e trifloxysulfuron são os únicos herbicidas com espectro de controle sobre plantas daninhas dicotiledôneas registrados para uso em pós-emergência do algodoeiro em cultivares convencionais, constituindo-se como ferramentais fundamentais para o manejo da comunidade infestante desta cultura (ARANTES et al, 2014). Além disso, Braz et al (2013a) já indicaram a possibilidade de uso destes herbicidas para o controle de soja RR ® , demonstrando que a eficácia dependente da dose utilizada, bem como estádio das plantas voluntárias no momento da aplicação.…”

Chemical management of weeds in cassava crop, cultivar ‘Santa Helena’

“…However, only a single application at pre-emergence is not sufficient to ensure control of weed plants during the CIPP of this crop. The use of tank mixtures and sequential applications have been proven to be interesting options to increase the spectrum of action and residual effect of herbicides on diverse crops such as cotton, soybean and maize (Arantes et al, 2014;Maciel et al, 2015;Vieira Júnior et al, 2015). These management strategies can also be used in cassava crops if we also consider that sulfentrazone and mesotrione are cassava selective herbicides and are alternatives for use at pre-emergence and post-emergence and tank mixed with other herbicides (Scariot et al, 2013;Costa et al, 2013a;Costa et al, 2015a).…”