Alternativas para el control de hongos postcosecha en naranjas valencia (Citrus sinensis)

the purpose of this study was to establish the effectiveness of the fungus trichoderma harzianum, chitosane and sodium bicarbonate for postharvest fungus control of valencia oranges. we used 120 valencia oranges using 24 oranges per group. each of the groups was immersed in one of the following treatments: t. harzianum cultures (1x109 spores/ml), chitosane (2%), sodium bicarbonate (1%) and running water (witness); the remaining 24 oranges did not receive any treatment, and were considered as the control group. the oranges were later stored in plastic containers with absorbent paper during 14 days at 27oc to determine fungus growth or any other alteration. four fungi species developed in the control group: penicillium digitatum (80%), penicillium italicum (10%), colletotrichum gloeosporioides (5%) and cladosporium herbarum (5%) with significant differences among fungi (p<0.05). in the witness group there was only p. digitatum (29.1%), and in the groups treated with chitosane and sodium bicarbonate there was only non-fungal rotting in 20.8% and 41.6%, respectively. the oranges treated with t. harzianum did not present fungi or any other alteration during the 14 treatment days, and there were significant differences (p<0.05) as to presence of fungi or alterations during treatment. this suggests that it is possible to perform a post harvest control of oranges with the t. harzianum fungus.