Controle pós-colheita da podridão parda do pessegueiro com fungicidas em pré-colheita e Trichoderma em pós-colheita

Abstract

The aim of the present work was to evaluate the efficiency of pre-harvest application of fungicides on control of brown rot on postharvest and verify their effect when associated with fungal antagonists, ensuring efficiency in the control of disease and quality of fruit. We evaluated the effect of application of fungicides on pre-harvest in the control of brown rot after 15 and 40 days of refrigerated storage of fruits, in addition to the association of fungicides with postharvest treatment with the fungus antagonist, Trichoderma harzianum. To do this, were established two experiments. At the first, phytosanitary programs (active ingredients) were evaluated: [1] control (application of water); [2] captan; [3] iprodione; [4] iminoctadine; [5] tebuconazole; [6] procymidone; [7] azoxystrobin; [8] difenoconazole; [9] fungicide (azoxystrobin/difenoconazole); [10] fungicide (trifloxystrobin/tebuconazole); [11] sequence iminoctadine + captana; [12] sequence of iprodione + iminoctadina; [13] sequence of tebuconazole + captan; [14] sequence of tebuconazole + iprodione. All treatments were applied in the pre-harvest phase, in recommended doses for culture. After harvesting the fruits were stored at -0.5 °C for 15 and 40 days. In the second experiment were evaluated the pre-harvest application of following products: [1] control (application of water); [2] captan; [3] iprodione; [4] iminoctadine; [5] tebuconazole. After harvesting the fruits were stored at -0.5 °C for 40 days and following, in half of the fruits of each treatment was applied the antagonist Trichoderma harzianum, through immersion. Both experiments were evaluated after exposure of fruit to 20 °C for a period that varied from four to 12 days, depending on the storage time of each experiment. The parameters evaluated were: incidence of brown rot, percentage of healthy fruits, respiratory rate, ethylene production and skin browning. Until the time of harvesting the fungicide which best controlled the brown rot was the difenoconazole, whereas, the fungicides tebuconazole and iminoctadina have satisfactory results in control of brown rot, after 15 and 40 days of refrigerated storage. The use of Trichoderma harzianum has no effect on postharvest control of brown rot, however, when associated with fungicides is effective in the control of Rhizopus stolonifer. Pre-harvest application of fungicide captan and postharvest of Trichoderma harzianum affect postharvest quality of fruits, causing skin browning.