Among the various diseases that attack mango crop, gummosis is of great economic importance since the trees die within a very short time.
The fungus responsible for mango decline is a common soil-borne saprophyte or wound parasite, distributed throughout the tropics and subtropics.
The trees show abundant gum secretion from branches and main trunk right from the tree base to tree top, wilting, dieback, vascular browning and death of several trees.
The observed gummosis in mango trees was often accompanied by damage caused by a new species of trunk borers.
The grubs cause severe damage by feeding on the bark inside the trunk, boring upward, making tunnels, thus weakening and causing hindrance to transport of water and nutrients from roots to shoots resulting in wilting and drying of the shoots.
Acting as a wounding agent and vector, the trunk borers probably assist in rapid spread of the disease in the orchard. Several chemicals tried to control mango decline show little or no success.
Turmeric plantation as intercrop in mango has been found not only to assist in suppressing the population of trunk borers, termites and gummosis causing pathogens in the soil, but also provided additional income from the harvest of the rhizomes, 9 months after planting.
Turmeric root exudates or curcumin in rhizomes present in soil probably assisted in disease suppression by reducing the activity and population of trunk borer larvae and soil-borne fungus.
The orchard was also found to be free from termite attack after planting turmeric as intercrop in mango.
Turmeric plantation as intercrop can find application in organic farming systems, to control various soil borne pests and diseases in several fruit orchards.
Principal scientistDivision of Fruits and Horticultural TechnologyIndian Agricultural Research Institute, New Delhi