Evaluation of resistance to imazalil, prochloraz and azoxystrobin of Colletotrichum gloeosporioides (Penz.) Penz. y Sacc. isolates, and control of mango (Mangifera indica L.) anthracnosis during postharvest.
Gutiérrez-Alonso J. G., Gutiérrez-Alonso O., Nieto-Ángel D., Téliz-Ortiz D., Zavaleta-Mejía E., Delgadillo-Sánchez F., Vaquera-Huerta H.
Author Affiliation: SEMINIS, Estación de Investigación Bajío, Rancho El Refugio, 1a Frac. Apdo. Postal 16, Apaseo El Grande, Guanajuato, México 38160, Mexico.
Revista Mexicana de Fitopatología 21 : 379-383
Abstract : The fungicides imazalil, prochloraz and azoxystrobin were assessed for their efficacy in controlling anthracnose (Colletotrichum gloeosporioides [Glomerella cingulata]) on mango cv. Haden fruits, as well as for its capacity to induce resistance in isolates of the fungus obtained from affected mango fruit in the Mexican producing regions (Veracruz, Guerrero, Michoacan, Sinaloa, and Chiapas). Imazalil lethal concentration (LC50) was 39 ppm on isolate Ver-1, while for isolates Mich and Sin, it was 18 and 16 ppm, respectively. Prochloraz had an LC50 of 21 ppm for Ver-2 and 16 ppm for Sin. Azoxystrobin had an LC50 that fluctuated between 0.000006 and 0.01 ppm for all isolates. The effectiveness tests for the control of the disease during postharvest and under laboratory conditions confirmed the presence of resistance to imazalil, since no significant differences (p=0.05) with on disease severity relative to the control were recorded. Prochloraz and azoxystrobin were statistically similar (p=0.05) in their ability to control anthracnose nevertheless, in the latter case, there were lower LC50 values for the different isolates of C. gloeosporioides.