Effect of pruning on root distribution in guava cv. allahabad safeda under ultra high density orcharding system

Investigations were carried out during 2009–10 at ICAR RCER, Research Centre, Ranchi, Jharkhand, India to study the effect of shoot pruning on pattern of root distribution in guava plants of cv. Allahabad Safeda in ultra-high density planting growing under alfisols of eastern India. Root samples were collected from rhizosphere of guava plants treated with six different pruning treatment during the previous two years. The pruning treatments consisted of combinations of different time of pruning (pruning once in May, Pruning once in October and pruning thrice a year in March, May and October) and different levels of pruning (pruning to 60% of canopy height, pruning to 80% of canopy height and pruning to 50% shoot length) and control (no pruning). Root samples were collected from two different depths of soil (0–15 cm and 15–30 cm) at the distances of 30 cm and 60 cm from trunk. Different pruning treatments differed significantly with respect to total weight of Grade-3 roots (diameter > 3mm) and pruning to 50% of shoot length, thrice a year resulted in significant reduction in the total weight of Grade-3 roots. Significant effect of different treatments could be recorded only in case of content of grade-3 roots at a distance of 30 cm from trunk at both the soil depths, total weight of Grade 3 roots at a distance of 30 cm from trunk, total weight of root at a distance of 30 cm from trunk and total root weight at a soil depth of 0–15 cm. With respect to root weight at 0–15 cm soil depth at a distance of 30 cm from the trunk, pruning thrice a year to 50% of shoot length resulted in the minimum weight of Grade-3 roots. Hence the study clearly indicated a drastic reduction in the partitioning of biomass towards root thickening in case of the treatment, pruning thrice a year to 50% of shoot length which resulted in the maximum fruit yield per plant.