Diagnóstico de enfermedades foliares en el cultivo de maíz (Zea mays) del cantón La Joya de Los Sachas provincia de Orellana.

Abstract

The objective of this research was to determine the presence of fungal pathogens that affect the foliar parts of the maize crop in the canton of La Joya de los Sachas, province of Orellana. This research was carried out at the Central Experimental Station of the Amazon of the National Institute of Agricultural Research of Ecuador (INIAP). The research analysis and data collection were carried out both in the field and in the laboratory. Descriptive statistics were used for data collection and processing, using statistical graphs with the help of the Microsoft Office Excel software package. Sampling was carried out in the agricultural zone of Joya de los Sachas canton, selecting plots of less than two hectares. Sampling consisted of collecting five symptomatic (diseased) leaves and was carried out in a targeted manner on plants with foliar lesions. The plant material was selected under totally aseptic conditions and under a laminar flow chamber, cut into pieces of approximately 0.5cm2 and sown in Petri dishes containing Papa Dextrose Agar (PDA) culture medium. Morphological characterization was performed based on microscopic observations, colony morphologies were identified using the dichotomous keys of imperfect genera. From the 20 points sampled, 97 fungi were isolated in vitro in synthetic medium such as PDA, of which six genera were identified among pathogens, saprophytes and decomposers of organic matter. It is concluded that genera such as Exserohilum, Colletotrichum, Curvularia, Fusarium, have been identified in all the places where corn is grown, and are responsible for causing considerable economic losses, so it is recommended to determine the influence of each of these pathogens on yield.