Comparative response of clonal rootstocks and heights of grafting on growth and leaf biochemical parameters of nursery apple plants

Abstract

Investigation was undertaken to study the response of different clonal rootstocks and grafting heights on vegetative growth and leaf biochemical parameters of the scion cultivars. Two scion cultivars i.e., Vance Delicious (standard type) and Starkrimson (spur type) were tongue grafted on two clonal rootstocks i.e., M-9 (dwarf) and MM-106 (semi-vigorous) at five different heights, i.e., 10 cm, 15 cm, 20 cm, 25 cm and 30 cm. The results obtained revealed that apple cultivar Starkrimson grafted on clonal rootstock M-9 at 15 cm height and Vance Delicious grafted on MM-106 at 10 and 20 cm height had highest graft take success (92.33%). Earliest bud break was recorded in Vance Delicious grafted on M-9 rootstock at 30 cm height. Vance Delicious grafted on MM-106 at 20 cm height had highest final plant height at the end of growing season (82.60 cm). Leaf total sugars content was found highest (4.17%) in Vance Delicious grafted at different heights on MM-106 rootstock. However highest leaf starch content (4.86%) was recorded in Vance Delicious grafted on MM-106 rootstock at 10 cm, 15 cm and 25 cm heights. Highest leaf chlorophyll content (3.28 mgg-1fresh wt.) was recorded in Vance Delicious grafted on M-9 rootstock at 20 cm height. Longest stomata (23.17 µm) were recorded in Vance Delicious grafted at 10 cm height on MM-106 rootstock however highest stomatal breadth (15.30 µm) was recorded in cultivar Vance Delicious grafted at 25 cm height on MM-106 rootstock. Stomatal density (376.33 stomata mm-2) was highest in Starkrimson grafted at 20 cm height on M-9 rootstock.