2,4-D Hormesis Effect on Soybean

Abstract

The hormesis effect of 2,4-D, applied at two stages of soybean development, on the physiological components of crop yield, was investigated. Soybean seeds of the cultivar ‘AG 3680 IPRO’ were sown in pots containing 7 L of a substrate and kept in a greenhouse. A randomized complete block design with four replicates was used. Eighteen treatments were tested, arranged in a split-plot scheme. The plots consisted of two stages of herbicide application (V4 and V6), and the split-plots were arranged by nine 2,4-D doses (0, 5, 10, 15, 20, 25, 30, 40, and 50 g ha-1). At the time of harvest, 100 days after sowing, significant interactions between crop development stages and 2,4-D doses were observed for the number of nodes in the main stem (NNMS) and the number of pods per plant (NPP). Both NNMS and NPP were not affected by 2,4-D during V6, but they increased with doses up to 20.2 g ha-1 and 22.5 g ha-1, respectively, during V4 and declined at higher doses according to a quadratic model, thus characterizing hermetic effect. Regardless of the application stage, the number of grains per plant and weight of a thousand grains were reduced as doses increased. However, the grain number and grain mass per plant reached maximum values for doses of 20.3 g ha-1 and 12.9 g ha-1, respectively. It was concluded that 2,4-D causes hormesis effects on the soybean crop ‘AG 3680 IPRO’ pot-grown in greenhouse conditions, regardless of the application stages herein tested.

Simulated rainfall following the preplant application of 2,4-D and dicamba in soybean

“…Likewise, several reports in the literature document the minimal effects of 2,4-D applied at preplanting in susceptible crops (Prostko et al 2003, York et al 2004, Thompson et al 2007, Silva et al 2011, Oliveira et al 2015, Sperry et al 2017. In addition, the soybean dry matter accumulation was higher than in the untreated control ( Figure 2C), a fact that may be explained by the occurrence of hormesis (Silva et al 2019).…”

Respostas morfofisiológicas de cultivares de trigo à aplicação de sais de 2,4-D amina e colina

“…Em soja, Silva et al (2019) ao aplicarem doses próximas a 13 g ha -1 de e.a. de 2,4-D sal amina em plantas no estádio V4, verificaram maior quantidade de massa seca o que proporcionou incremento na produtividade da cultura, devido ao efeito de hormesis que o herbicida promoveu na cultura, fato esse que também pode ter ocorrido nas cultivares que apresentaram maior acumulo de massa seca da parte aérea no presente estudo.…”

Glyphosate hormesis variation in common bean due to nitrogen coverage

“…Marandu (Nascentes et al, 2015) and sugarcane and eucalyptus (Nascentes et al, 2017). In addition, another herbicidal molecule has shown results, such as 2,4-D in soybean (Silva et al, 2019). On the other hand, Ries et al (1967) and Pulver and Ries (1973) developed considerable evidence that low doses of the triazine chemical group simazine herbicide could improve nitrogen metabolism in some cultures, but this information has not been explored.…”