Influence of grafting and rootstock on root traits, growth and cycloneinduced plant damage in sugar apple in eastern coastal region of India

Abstract

Studies were conducted to assess the impact of grafting approach and rootstock on root traits, plant growth, leaf nutrient status, yield and cyclone-induced plant damage in sugar apple during 2014-19. In situ and ex situ grafting of sugar apple was done on A. squamosa and A. reticulata rootstock and their performance was assessed on various parameters. Well-developed root system in terms of spread, tap root length, proportion of primary and secondary roots, root/shoot ratio (0.29) and enhanced trunk cross sectional area, leaf area (30.69 cm2), total chlorophyll content (3.07 mg/g), leaf nutrient content and fruit yield were recorded in in situ grafted plants having A. squamosa rootstock. Sugar apple exhibited stionic compatibility with its own rootstock, whereas it was incompatible with A. reticulata, as it was evidenced from poor growth of root system and above ground plant parts. When cyclone-induced plant damage (Fani cyclone) was taken in account it was observed that in situ composite plant grafted on its own rootstock exhibited substantially low intensity of plant damage with markedly low percentage of severely damaged plants (1.2%). On the other hand ex-situ grafted plants were severely damaged by cyclone (21.7%). Correlation studies indicated that deep root system possessed by in situ grafted plants was instrumental not only in minimising cyclone-induced plant damage, but also in improving leaf nutrient status, plant growth and yield.