Physiological Performance of Seeds and Level of Herbicide Residues Depending on Application of 2.4-D in Wheat

Abstract

-Horseweed control through application of 2.4-D in the winter season is an alternative to manage biotypes resistant to herbicides that belong to other mechanisms of action. The objectives of this study were to assess the physiological quality of wheat seeds and determine the rate of 2.4-D residue, as function of application stages and herbicide rates. The treatments were arranged in factorial scheme, with three application stages (flowering, soft dough and hard dough), and four 2.4-D rates (0; 504; 1,008 and 2,015 g a.i. ha ). The application of 2.4-D in the wheat crop changed physiological seed quality by increased the rate and total percentage of germination. The application of 2.4-D resulted in herbicide accumulation in seeds, especially when application was carried out at the soft dough stage. Also, the increase in herbicide rate increased the level of residue in the seeds. However, regardless of stage of application for 2.4-D and herbicide rate in use, the values of residue found in the seeds were below the allowed maximum limit.Keywords: Triticum aestivum, weeds, germination, dry matter. RESUMO -O controle de buva através da aplicação de 2,4-D na estação hibernal de cultivo é alternativa para o manejo de biótipos com resistência a herbicidas pertencentes a outros mecanismos de ação. Os objetivos do estudo foram avaliar a qualidade fisiológica das sementes de trigo e determinar o resíduo de 2,4-D, em função do estádio de aplicação e de doses do herbicida. Os tratamentos foram arranjados em esquema fatorial, sendo três estádios de aplicação (florescimento, grão pastoso e massa firme) e quatro doses do herbicida 2,4-D (

Effects of high-dose 2,4-D on germination and initial development of Canavalia ensiformis (L.) DC.

“…Regarding the contact of 2,4-D with seeds, the literature can be conflicting. That is, some studies prove that the herbicide is capable of altering the physiological quality of seeds, such as wheat, resulting in increased speed and total percentage of germination, while accumulating in the grain, even in concentrations below the maximum permitted limit (AISENBERG et al, 2018). On the other hand, another study reported that wheat seeds pretreated with 10μM 2,4-D for 48h induced antioxidant activity and protective effect against salt stress (MOHSIN et al, 2020).…”