Potassium Bicarbonate on Stem End Root Avocado (Persea americana Mill. Var Hass)

Abstract

Background: Strict food safety regulations and a shift of the social trend towards consumption of foodstuffs produced without conventional pesticides motivate the search for new substances safe to humans and effective in the control of stem-end rot (SER) in ripening avocado fruit a damage caused by endophytic fungi, a cause of the loss of the fruit’s food quality during storage. The aim of this research was to assess the effect of the potassium bicarbonate (KHCO3) during the artificial induction of SER in Hass avocado as a possible postharvest application in avocado Material and Methods: Potassium bicarbonate was assessed as a generally recognized as safe (GRAS) substance for control of SER in avocado. We assessed the fungi sensitivity to conventional fungicides azoxystrobin, benomyl, copper sulfate and tiabendazole, rol of the presence of peduncle, index of severity of SER, and effectiveness of sodium bicarbonate in ‘Hass’ avocado fruits (Persea americana Mill.) that were artificially infected with the wild fungi Colletotrichum acutatum and Phomopsis viticola. Results: Presence in the fruit of peduncles did not prevent colonization by fungi. Of four fungicides used in avocado harvest, azoxystrobin exhibited a major effectiveness value. P. viticola was more sensible to assayed fungicides than C. acutatum. Potassium bicarbonate prevented artificially induced SER lowering the severity of the fungal damage with 40 to 50 % effectiveness. Conclusion: These results show that potassium bicarbonate is effective to reduce the incidence and severity of SER in ‘Hass’ avocado fruits, and motivate to pay more careful attention to the search for alternative disease control measures.