The efficiency of biological controllers and chemical products in the control of brown rot was investigated in a field experiment during the 2002 growing season in the municipality of Lapa-PR. The cultivar BR1 was used in the experiment. The objective of the experiment was to select treatments with biological control by comparing them with chemical treatments in management systems used in the region. The treatments were four antagonistics previously selected in a post-harvest study, the F1, F2, F4 isolates (Trichothecium roseum), F9 isolate (Penicillium sp) (in 16 applications), Integrated Peach Production (PIP) (nine applications), Ca and K phosphites + captan (11 applications), fungicide alternation (eight applications), conventional farm treatment (PC) (nine applications), sprayed from flowering to harvest, and a control without spraying. For assessment, the number of fruits per marked branch was counted after thinning and at the start of harvest. The disease incidence was determined for the fruit selected on the branches at harvest and at 3 and 5 days post harvest. The Integrated Peach Production (PIP), Ca and K phosphites + captan, and F4 isolate reduced the disease 95.5 63.6 and 68.2%, respectively, as compared with the control that showed 44% of the fruits harvested with brown rot at the 5th day. The treatments with fungicide alternation were the most effective, since no disease was observed on the fruits. However, a reduction of 76.5% in the number of fruits between thinning and harvest was noted as compared with 50% on average of other treatments, indicating a probable phytotoxic effect.
Monilinia fructicola; biological control; preharvest; phosphite
