Oleg Oleg Feygenberg ^_ Agricultural Research Organization Volcani Center, 42718, Postharvest Science of Fresh Produce, Rishon Lezion, Israel;
Sonia Diskin ^_ Agricultural Research Organization, Volcani Center, Postharvest Science of Fresh Produce, Rishon LeZion , Israel;
Dalia Maurer ^_ Agricultural Research Organization Volcani Center, 42718, Postharvest Science of Fresh Produce, Rishon Lezion, Israel;
Noam Alkan ^_ Agricultural Research Organization Volcani Center, 42718, Postharvest Science of Fresh Produce, P.O.B 15159, HaMaccabim Road 68, Rishon LeZion 7505101, Rishon Lezion, Israel, 7505101;

Pathogenic fungi, as Botryosphaeriaceae family, can penetrate during flowering and endophytically colonize the stem of mango fruit (Mangifera indica) without causing any visible symptoms. Those fungi become active during abiotic stress or fruit ripening and cause stem and inflorescence dieback or fruit stem-end rot (SER). We hypothesized that antifungal treatments during the main event of Botryosphaeriaceae penetration would reduce the disease. Initially, we showed that treatments with Switch [fludioxonil and cyprodinil] during orchard flowering (cv. Keitt and Shelly) reduced the occurrence of pathogenic fungi in the fruit stem end and significantly reduced fruit's SER. As mango orchards are sprayed weekly against powdery mildew during flowering, we combined two treatments against powdery mildew with two treatments against both powdery mildew and SER-causing pathogens. Application of biological treatments of Serenade [Bacillus subtilis] or chemical treatments of Luna Tranquility [fluopyram and pyrimethanil] or Switch during flowering in 'Shelly' and 'Keitt' mango orchards significantly reduced inflorescence/stem dieback (up to 50%) and fruit drop and significantly increased the number of fruit per tree, which led to a significant increase in yield, up to 41%, in heavily infected orchards. In addition, this application during flowering (March-April) affected postharvest fruit quality (August-September) by a significant (p<0.005) reduction of incidence and severity of stem-end rots and even fruit side rot, without affecting fruit ripening and other quality parameters. While all fungicides were effective, the chemical fungicides were more effective than the biological fungicide. Thus, changing the powdery mildew fungicide regime to control also the Botryosphaeriaceae penetration during mango orchard flowering, led to reduced inflorescence/stem dieback, reduced fruit drop, increase in yield, and minimize postharvest decay.