Influência de fatores epidemiológicos na podridão de Alternaria em uva var. Itália

Abstract

The grape variety of Italy is the main table grapes exported by Brazil mainly in the region of the São Francisco, but has major problems that arise after the harvest, among them is the rot. Among several agents of rot in grapes is of alternaria rot caused by Alternaria alternata which has caused great losses to producers and consumers. Objective was to verify the influence of different concentrations of inoculum (103, 104, 105,106 e 107 conídios/mL), wet period (0, 12, 24, 36 e 48 h) and temperature (10, 15, 20, 25, 30 e 35ºC) on the development of two isolates of A. alternata grape var. Italy, in addition to possible physical-chemical changes (pH, TSS, TA and ascorbic acid) in grape. Bunches of grape apparently free of disease in commercial maturation stage were inoculated by two most aggressive isolates were selected for the test of aggression, with 10μL of suspensão A. alternata, and concentration of 106 conidia/mL showed the greatest lesion size, no significant difference between different periods of wetness and temperature of 25°C favored the development of rot and temperature 10°C is recommended for storage for seven days without affecting the physical-chemical and providing the decrease in disease severity.