Effect of thermal and in vitro fungicide treatments on pathogens of the genus Fusarium associated with maize seeds

Abstract

Stalk rot in maize plants is commonly associated with manyspecies of the genus Fusarium. This disease affects the seedbedand the establishment of maize crops because of seedscontaminated with different pathogens of this genus. Maizecrops in the Ubate Valley, in the province of Cundinamarca,are currently infected by this disease, which reduces the yieldand final quality of the maize seeds. This research evaluatedthe effects of thermal and fungicide treatments on pathogensof the genus Fusarium associated with maize seeds. Seeds weretreated at 50°C, 55°C and 60°C with dry heat and hot water. Mycelial colonization of seeds, germination percentage, seedling length, and fresh weight were evaluated as variables. In in vitro tests, the fungicides fludioxonil + metalaxyl-M, tebuconazole + trifloxystrobin, prochloraz + difenoconazole and carboxin + captan were evaluated at 0.5, 1.0 and 1.5 the commercial dose on the radial growth and conidial germination of Fusarium subglutinans and Fusarium graminearum isolates. The most effective heat treatments on Fusarium colonization of maize seeds were obtained with the two heat sources at 55°C without a significant reduction in the percentage of germination and seedling length and fresh weight. Commercial doses of theevaluated fungicides completely inhibited the radial growthof F. graminearum and only commercial doses of carboxin +captan and prochloraz + difenoconazole completely inhibited F. subglutinans growth. Germination inhibition of F. subglutinansand F. graminearum conidia was found with fludioxonil + metalaxyl-M at the three evaluated doses.

Fusarium species that cause corn stalk rot in the Ubaté valley of Cundinamarca, Colombia

“…These observations are also in contrast to the more severe symptoms observed in the field study, that used untreated corn seeds. Similar positive results have been reported for the thermal treatment of corn seeds and other cereals (Clear et al, 2002;Coutinho et al, 2007;Bennett & Colyer, 2010;Piñeros-Guerrero et al, 2019). The lack of continuity of the necrotic area in nodes and internodes can be explained by the morphology and development of corn plants, which is used by Fusarium spp.…”

Uso de los pesticidas y su efecto en el cultivo de Zea mays: Una revisión de la literatura

“…La eficacia de los fungicidas contribuye a salvaguardar la vitalidad y productividad de las plantas de maíz al protegerlas de las infecciones fúngicas. Es importante destacar que la aplicación correcta y en el momento adecuado de estos fungicidas puede marcar una diferencia significativa en la salud de los cultivos y en los rendimientos obtenidos (Piñeros-Guerrero et al, 2019).…”

“…Un aspecto importante es la aparición de cepas de hongos resistentes a estos productos químicos. De manera similar a las plagas de insectos, la exposición constante a los fungicidas puede conducir a la evolución de hongos patógenos con menor susceptibilidad a sus efectos (Piñeros-Guerrero et al, 2019). La resistencia debilita la eficacia de los tratamientos y complica el control de enfermedades fúngicas en el futuro.…”

Morphological and pathogenic characterization of Fusarium oxysporum in lulo (Solanum spp.)

“…The fungus infects the plant through the roots and colonizes the vascular system. Furthermore, during plant colonization, the pathogen also infects the seed as a means of transmission of the disease (Ochoa, 2002;Guerra-Fuentes et al, 2019;Piñeros-Guerrero et al, 2019).…”