INCIDENCE AND SEVERITY OF DAMAGE BY FUNGI IN RICE LINES SUBJECTED TO DOSES OF FERTILIZATION

Abstract

Background: In Mexico, rice crop production is limited by phytopathogenic fungi that cause diseases, some of which increase their incidence and severity when conditions such as high humidity and nutrient deficiency or excess occur. Objective: Determine the incidence and severity of the damage caused by phytopathogenic fungi in rice lines subjected to conditions of 100 % and 10 % nitrogen and phosphorous fertilization. Methodology: The experiment was carried out in the spring-summer 2021 cycle, at the Ébano-INIFAP Experimental Site, 136 rice lines were used and two treatments (100 % and 10 % nitrogenous and phosphorous chemical fertilization), were morphologically identified. phytopathogenic fungi and the incidence, severity, plant height and fresh biomass were measured. Results: Higher incidence and severity (27.5 % and <4 % respectively) were obtained in the rice lines subjected to the 10 % nitrogenous and phosphorous fertilization treatment. In both treatments Chiclayo 61 was identified as tolerant to damage from Alternaria sp., Curvularia geniculata and Fusarium equiseti, presenting incidence and severity of symptoms between 3.3 to 36.7 % and <1.5 %, respectively. On the other hand, plant height and fresh biomass showed higher values in the treatment with higher fertilization.Implications: High temperature and precipitation and nutritional deficiency increase damage by phytopathogenic fungi. Conclusion: The incidence and severity of the damage caused by Alternaria sp., Curvularia geniculata and Fusarium equiseti, in the crop increases when there are conditions of nutritional deficiency, in addition, nutrient-deficient plants have lower height and fresh biomass. Copyright