<b>Effect of foliar fungicide and plant spacing on the expression of lipoxygenase enzyme and grain rot in maize hybrids

Abstract

ABSTRACT. This study was carried out with the objective of evaluating the effect of fungicide application on grain rot in commercial maize hybrids and the relation between grain rot and the expression of lipoxygenase enzyme in grain in conventional row spacing of 0.70 m and reduced row spacing of 0.45 m. Treatments were made in a 3 x 8 factorial scheme, using three forms of management with fungicide (Trifloxystrobin + Prothioconazole) and eight maize hybrids divided into two groups (tolerant and susceptible) with three repetitions, totaling 72 plots in each environment (conventional and reduced spacing) in the 2013/2014 crop. The following characteristics were evaluated: grain rot percentage and lipoxygenase enzyme expression (LOX) in the grain. The hybrid and the fungicide utilized influenced the grain rot percentage. Grain rot percentage was reduced by the use of the fungicide, and the highest reduction was in susceptible hybrids with two applications, V8 and V8+VT. There was higher expression of LOX enzyme in maize hybrids that belong to the group tolerant of fungi that cause grain rot .The use of the fungicide in two applications, V8 (eight leaves) and VT (tasseling), increased the intensity of the LOX enzyme, which was more evident for the reduced spacing. Efeito de fungicida foliar e espaçamento de plantas na expressão da enzima lipoxigenase e podridão de grãos em híbridos de milho RESUMO. O objetivo deste trabalho foi avaliar o efeito da aplicação de fungicida sobre a podridão de grãos em híbridos comerciais de milho e a relação entre os grãos ardidos e a expressão da enzima lipoxigenase no grão, em espaçamento convencional de 0,70 m e reduzido de 0,45 m. Os tratamentos foram no esquema fatorial 3 x 8, com três formas de manejo com fungicida (Trifloxistrobina + Protioconazol) e oito híbridos de milho, sendo divididos em dois grupos (tolerantes e suscetíveis), com três repetições, totalizando 72 parcelas em cada ambiente (espaçamento convencional e reduzido), na safra agrícola 2013/2014. As seguintes caractrísticas foram avaliadas: porcentagem de grãos ardidos e expressão da enzima lipoxigenase (LOX) nos grãos. O fungicida reduziu a incidência de grãos ardidos, e a maior redução ocorreu nos híbridos suscetíveis, com duas aplicações, V8 e V8+VT. Houve maior expressão da enzima LOX em híbridos de milho pertencentes ao grupo tolerante aos fungos causadores de grãos ardidos. A aplicação do fungicida em duas aplicações, V8 (oito folhas) e VT (pendoamento), aumentou a intensidade da enzima LOX, mais evidente no espaçamento reduzido.Palavras-chave: LOX, podridão de espigas, controle químico, espaçamento reduzido, Zea mays.

Integrating a chemical fungicide and Bacillus subtilis BIOUFLA2 ensures leaf protection and reduces ear rot (Fusarium verticillioides) and fumonisin content in maize

“…In this study, the fungicide was efficient, although control efficacy varied with the disease evaluated (Tables 1–4). When fungicides are used as the sole disease management strategy, they may select for resistance in the pathogens and result in the loss of fungicide efficacy (Georgopoulos & Skylakakis, 1986; Kluge et al., 2017). In our work, fungicide applied twice resulted in higher grain yield compared to a single application.…”

Quality of Yellow Bell Pepper Fruits Cultivated in Fertilized Soil with Yellow Water and Cassava Wastewater

“…As well as Frizzone et al (2001), which found a thickness of the mesocarp of the bell pepper varying from 2.6 to 5.3 mm. Santos et al (2017) evaluating several bell pepper genotypes, obtained values of this between 4.17 and 7.70 mm.…”

Aflatoxin Biosynthesis, Genetic Regulation, Toxicity, and Control Strategies: A Review

“…Consequently, innovative, safe, and feasible approaches must supplement the established methods that present effectiveness and acceptability. Previous studies have proven that plant-based volatile compounds such as CO 2 [155], ethylene [156,157], crotyl alcohol [158,159], cotton-leaf volatiles [160], and corn-based volatiles [161,162] may hinder AF's biosynthesis. Plant-based volatile compounds in controlling AF contamination in crops are highly beneficial from a food safety perspective.…”