Yield losses in off-season corn crop due to stalk rot disease

Abstract

The objective of this work was to assess yield losses due to stalk rot in corn (Zea mays) hybrids, as well as to identify the main pathogenic fungi responsible for the disease during the off-season, in the state of Tocantins, Brazil. Two field experiments were carried out, one with five hybrids, in 2015, and another with four, in 2016. Ears of healthy and stalk rot-infected plants were collected from each plot, at harvest. Ear size, grain and ear weights, and grain moisture content were measured. From each diseased plant, a stalk piece with two to three nodes was removed for pathogen identification and quantification. The most common pathogens were: Fusarium graminearum, Stenocarpella maydis, and Macrophomina phaseolina. All yield parameters were significantly lower in stalk rot-infected plants, with average losses of 30.6%, in 2015, and of 34.3% in 2016. The highest yield losses are observed in hybrids with the highest grain/ear weight ratio.

ATIVIDADE ANTIFÚNGICA DE ÓLEOS ESSENCIAIS FRENTE A Macrophomina phaseolina

“…é um patógeno necrotrófico com ampla distribuição geográfica, que infecta mais de 600 espécies de plantas como soja, feijão, milho, fumo, melão, algodão, citrus, plantas medicinais, e pode ser transmitido por sementes, requerendo o tratamento sanitário (MACHADO et al, 2006). O fungo tem capacidade de ocasionar perdas econômicas graves, com ocorrência elevada a cada ano no Brasil (ALMEIDA et al, 2014;COSTA et al, 2019). Na planta hospedeira, ele age secretando uma série de enzimas degradantes que despolimerizam os componentes da parede celular, como celulose, xilana, pectina, ácido poligalacturônico (JAVAID; SADDIQUE, 2012), o que ocasiona nas plantas infectadas sintomas aparentes como apodrecimento de raízes, plantas murchas e perecimento.…”

A Polysaccharide of Ganoderma lucidum Enhances Antifungal Activity of Chemical Fungicides against Soil-Borne Diseases of Wheat and Maize by Induced Resistance

“…Wheat root rot causes black lesions on the roots and bases and white heads that could even have empty spikes, resulting in a serious loss of wheat yield [8,9]. Maize stalk rot caused by Fusarium graminearum is a systemic soil-borne disease that seriously damages maize production [10]. Its outbreak is sudden and dramatic, which can directly affect the absorption of water and nutrients in maize plants and destruct their metabolic function, thus causing serious losses in maize yield and quality [11][12][13].…”

Gibberella ear and stalk rot caused by Fusarium meridionale and F. graminearum: aggressiveness and mycotoxin production in the field

“…In Brazil, GER and GSR are more prevalent in the southern subtropical climates where small grains are typically cultivated in a no-tillage system, and where FHB is of common occurrence leading to crop losses (Del Ponte et al 2009;Duffeck et al 2020). Ear and stalk rots caused by FGSC are increasing in importance as the application of improved technologies and agronomic practices that include irrigation and double-cropping have expanded (Costa et al 2019). The recent promulgation of mycotoxin limits for maize-based food and feed produced in Brazil (ANVISA 2011;, and the unpredictability of fungicide performance for disease control (Andriolli et al 2016), means that breeding for host resistance is a priority (Mesterházy et al 2012).…”