Effect of girdling and root pruning on vegetative growth, fruit metabolites and yield of pear grown under sub-tropical conditions

Excessive vegetative growth in semi-soft pear is a limiting factor for optimum fruit production under sub-tropical conditions of north-western India. Therefore, the present studies were conducted to regulate the vegetative growth and improve fruit yield, quality and associated biochemical parameters of pear cultivar ‘Punjab Beauty’ by girdling and root pruning techniques. The significant increase in fruit set, retention, yield, total phenolics content, flavonoid content and C:N ratio of bark and spur was registered with root pruning at 60 cm as compared to control and the other treatments viz; trunk girdling, limb girdling, root pruning at 40 cm and sub limb girdling. However, fruits with maximum size, weight, total soluble solids (TSS), TSS/Acid ratio were attained with the trunk girdling. The limb girdling and root pruning at 40 cm also enhanced fruit quality but sub-limb girdling did not create significant impact. The fruits of the root pruned trees exhibited a slower oxidation of the total phenol content by inhibiting the activity of polyphenol oxidase and thus retaining higher total phenolic content as compared to control. Hence, root pruning at 60 cm exhibited promising results for controlling vegetative growth, improving yield and fruit biochemical attributes in pear.