The Identification and Chemical Control of a New Leaf Disease of Alpinia zerumbet (Pers.) Burtt. et Smith

Purposes In the cultivation process, one unknown leaf disease of Alpinia zerumbet was found. Plant pathogens was isolated and identified. The effective fungicides against the plant pathogens were screen in this study.

Methods Plant pathogenic was isolated and determined with Koch’s postulates and identified based on morphology and molecular system data. The antifungal effect of seven chemical fungicides on the pathogen was studied by drug-containing plate method.

Results Plant pathogenic fungus was identified as a species of Neopestalotiopsis. 75% chlorothalonil, 80% mancozeb and chlorothalonil 57.6% crown had no good inhibition effect against the Neopestalotiopsis sp.. Antifungal effects of 25% prochloraz and 70% thiophanate methyl were relatively better than others, of which EC₅₀ were 0.150 3 and 0.872 3 g/mL respectively.

Conclusion Neopestalotiopsis sp. as a plant pathogenic fungus was firstly found from the leaves of A. zerumbet. The plant disease caused by Neopestalotiopsis sp. was named as A. zerumbet cercospora leaf spot. 25% prochloraz EC has the best control effect against this plant pathogenic fungus in seven chemical fungicides used. 25% prochloraz EC could be used as alternative chemical fungicides to control the disease of alpinia zerumbet cercospora leaf spot.