Ácido salicílico como atenuador de fitotoxicidade causada pelo flumioxazin na cultura do trigo

Abstract

PALAVRAS-CHAVE RESUMO:O ácido salicílico (AS) pode ser usado como atenuador de estresses causados por herbicidas em plantas e, assim, viabilizar a utilização de flumioxazin na cultura do trigo. Diante disso, objetivou-se avaliar o efeito do AS como atenuador de fitotoxicidade causada por flumioxazin na cultura do trigo. Realizou-se um experimento em campo, de maio a setembro de 2015, no delineamento em blocos casualizados com quatro repetições. Os tratamentos aplicados foram: controle (sem herbicida, sem AS e capinado); flumioxazin (40 g.ha -1 ); flumioxazin + AS em mistura de calda (40 g.ha -1 + 0,5 mM); flumioxazin + AS em mistura de calda + AS 7 dias após a aplicação (DAA) do herbicida (40 g.ha -1 + 0,5 mM + 0,5 mM); AS (0,5 mM). Foram realizadas avaliações de índice SPAD, fitotoxicidade, massa de mil grãos, peso hectolitro e produtividade. A mistura de AS com flumioxazin aumentou em 7% o índice SPAD aos 21 DAA, reduziu em 30% a fitotoxicidade aos 28 DAA e elevou em 3,43% a produtividade em relação à aplicação isolada de flumioxazin. A aplicação adicional de AS aos 7 DAA reduziu a fitotoxicidade em até 50%, aumentou em até 8,72% o índice SPAD e possibilitou ganhos de 1,49% na produtividade e de 5,46% no peso hectolitro, quando comparado ao herbicida aplicado isoladamente. A aplicação de AS atenuou o estresse causado por flumioxazin no trigo. ABSTRACT: Salicylic acid (SA) may be used as attenuator of stress caused by herbicides

Effect of salicylic acid in two stages of application on wheat crop

“…No phytoxication symptoms caused by salicylic acid (SA) application were observed at both stages of wheat plants (data not shown). When evaluating SA application as an attenuator of herbicide phytotoxication in soybean (Dias et al, 2019) and wheat (Dias et al, 2017), these authors found no symptoms in SA treated plants, demonstrating the feasibility for its use.…”

“…Salicylic acid (SA) is a signaling compound and signal amplifier of phenolic origin, which is related to several regulatory functions in plant metabolism (Mazzuchell et al, 2014). Exogenous application of SA, at low concentrations, enhances pathogen control response and induction of disease resistance (Rivas-San Vicente & Plasencia, 2011), plays an important role on germination, regulation of plant growth and development (Sharafizad et al, 2013), fruit production, water and nutrient uptake and transport (Hayat et al, 2010b), photosynthetic rate, stomatal conductance and transpiration (Hayat et al, 2010a), acts as an important non-enzymatic antioxidant agent, activating the response and defense mechanisms to environmental stresses (Hayat et al, 2010a;Kang et al, 2014), herbicide intoxication (Dias et al, 2017), as well as increasing the biomass of the aerial part (Villanueva-Couoh et al, 2009), plant roots (Martín-Mex et al, 2013) and grain yield (Martín-Mex et al, 2012) of treated plants.…”

Alternative products to control late season diseases in soybeans

“…Resistance induction is defined as the activation of the plant's ability to defend itself against a broad spectrum of pathogens after appropriate stimulation (DIAS et al, 2019). Unlike gene-to-gene interactions that govern specific genetic resistance, the so-called "acquired systemic resistance" (ASR) is not specific and is expressed throughout the plant after being induced (DALLAGNOL et al, 2006).…”

Interference of post-emergent herbicides with wheat (Triticum aestivum L.) productivity parameters/ Interferência de herbicidas pós-emergentes sobre parâmetros produtivos do trigo (Triticum aestivum L.)

“…Herbicide application causes crop toxicity and requires enzymatic metabolism for inactivation or hydroxylation of the herbicide molecules into non-toxic products before it reaches the site of action in the cell and causes damage to the plant. This herbicide inactivation is energetically costly, can compromise crop development and, consequently, reduce final productivity (Dias et al, 2017;Queiroz, et al, 2017;Rubenich et al, 2017).…”

“…Further, grain weight is influenced by the average amount of seeds in each ear, such that, a lower grain production in the ear promotes a higher weight of the individual grains. This is explained by the effect of the herbicide on the plant, which interferes with photosynthesis and reduces energy conversion, resulting in lower production of photoassimilate that is essential for grain filling (Dias et al, 2017).…”