Mango (Mangifera indica L.) Germplasm Screening Against Burl: Effect on Plant Morphology and Graft-incompatibility and Orchard Topography in India

Abstract

Diagnostic surveys were conducted during 2015 and 2016 for screening the susceptible mango germplasm. About five hundred mango germplasm were screened against burl throughout the country. It is a typically swelling of the trunk and branches. Significant variation was observed in shape, colour, site of burl formation, surface, side of burl formation, site of gummosis, branching pattern and canopy of burl-affected trees. The incidence of burl in twenty-three mango germplasm in different parts of India and its effect on yield was also observed. Highest incidence was observed in ‘Arka Aruna’, ‘Mahuvas’, ‘Seedling’, ‘Tree 253’, ‘Mehmud Vikarabad’, ‘Hybrid 10’, ‘Khaja Pasand’, ‘Gopalbhog’, ‘Malai’, ‘Seedling’ 68 and ‘Seedling’ 307 germplasm. Information was also collected on the relationship between the growth of the burl and the age of the trees in ‘Langra’, ‘Bathua’, ‘Sukul’, Banganpalli, ‘Mehmud Vikarabad’, ‘Khaja Pasand’ and ‘Rajapuri’ germplasm. The size of the burl coincides with age of the trees from 25 to 90 years. Orchards topography also play major role in disease incidence and intensity. Maximum fruit yield, minimum disease incidence and intensity recorded in bottom land. Maximum incompatibility, incidence percentage and disease severity were observed in grafted trees while no incidence was observed in non-grafted/’Seedling’ trees reported first time. Hence, the source of burl inoculum was scions taken from infected old mother trees for propagation. These findings may have implications in the understanding of this new woody disease in mango trees.