Systematic Application Technique using Several Effective Fungicides for Simultaneous Control of Stem-end Rot and Anthracnose Disease of Mango

Abstract

In order to develop an effective common control management for stem-end rot and anthracnose disease of mango based on fungicides, we evaluated the sensitivity of registered fungicides to the causal fungi of two diseases, and the efficacy of a systematic application of fungicide combinations during the active growth period of mango. Of the 10 registered fungicides tested, five (mancozeb wettable powder, azoxystrobin flowable, kresoxim-methyl dry flowable, basic copper sulfate wettable powder, and captan wettable powder) were found to have a high inhibitory effect on the conidial germination and mycelial growth of the causal fungus of stem-end rot, Lasiodiplodia theobromae, and two causal fungi of anthracnose, Colletotrichum siamense and C. fioriniae. In contrast, mepanipyrim flowable, iminoctadine albesilate acid chloride wettable powder and triflumizole wettable powder had no inhibitory effects on this fungus. The two causal fungi of anthracnose showed different sensitivity to iprodione wettable powder, mepanipyrim flowable, triflumizole wettable powder and iminoctadine albesilate acid chloride wettable powder in the inhibition of conidial germination. In the field trials conducted in two fields between 2012 and 2014, various combinations of the five fungicides that exhibited high in vitro antifungal activity against all three causal fungi were systematically applied between apical bud formation or flowering and pre-harvest (prior to bagging). During those years, these fungicide combinations exhibited stable protection against post-harvest fruit damage caused by either disease. Although phytotoxicity due to the systematic application of fungicides was observed in 3.2% of fruit in the 2013 trial, it was not observed in either 2012 or 2014. The meta-analysis of the five trials conducted over the three-year period revealed that the incidence of both diseases decreased significantly in mango fruit, receiving systematic fungicide application compared to untreated mango fruit, to approximately 24% and 23% of the incidence in untreated fruit for stem-end rot and anthracnose, respectively. The results above demonstrate that the systematic application of fungicide combinations is an effective means for controlling stem-end rot and anthracnose disease of mango.