Identification, assessment of diseases and agronomic parameters of Curcuma amada Roxb (Mango ginger)

Highlights

• Mango ginger (Curcuma amada Roxb.), as undervalued crop, has no published information on its agronomy and pathology.

• Minimum of 24 weeks from emergence of sprouts is suggested, to harvest mature rhizomes.

• Mango ginger is affected with fungal diseases as leaf blight, leaf spots and rhizome rots.

Abstract

Many diseases affect plants, causing physiological dysfunctions and structural deviation from normal. The effects of plant diseases on yield and quality of crops have been documented. Little, however, is known about the pathology and agronomy of Mango ginger (Curcuma amada Roxb.), an under-cultivated crop. The present study was carried out to assess disease incidence and severity of associated fungal diseases of Mango ginger; assess rhizome yield loss due to disease; isolate and identify fungal pathogens associated; evaluate growth parameters of Mango ginger. Mango ginger plants began showing symptoms of leaf spot and leaf blight at first week and at fifth week after emergence, respectively; at twenty-fourth week some rhizomes were visually observed to be affected with rot. Cercospora curcumae, Phyllosticta zingiberi and Colletotrichum capsici; C. gloeosporioides, Alternaria alternata and Rhizoctonia solani; R. solani, Fusarium solani and Pythium aphanidermatum were frequently found associated with leaf spot, leaf blight and rhizome rot, respectively. Correlation coefficient of: Spot Disease Incidence with plant height was −0.04 and −0.05 for 2016 and 2017, respectively; number of leaves in progression with age was significant at p < 0.01 in 2016 (0.63) but insignificant in 2017 (0.32). Also, correlation coefficient of Blight Disease Incidence: with plant height was significant at p < 0.01 in the year 2016 (0.94) and 2017 (0.92); with number of leaves as age progressed was 0.54 and 0.70 for 2016 and 2017, respectively, and significant at p < 0.01. Percentage losses of 3.25 and 3.02, at harvest, due to rhizome rot were recorded for 2016 and 2017, respectively. This study revealed the occurrence of diseases, associated with fungi and fungus-like organisms, and their effect on Mango ginger plants.