Root distribution and activity in grape cultivars as influenced by systems of training

Abstract

Studies on the distribution pattern of root density and activity using radioactive 32P were carried out in four grape cultivars namely, Thompson Seedless, Gulabi, Black Champa and Bangalore Blue as influenced by three systems of training viz., bower, kniffin and head systems. Of the four cultivars studies, root density was found to be the highest in cultivar Bangalore Blue followed by Thompson Seedless, Gulabi, Black Champa. All the cultivars had greater root density nearer the trunk at 50 cm radial distance and at a shallow depth of 0-15 cm in the soil. In all the cultivars the highest root density was observed in the vines trained on bower system. Bower trained vines showed a greater root spread as compared to those on kniffin and head systems. Root activity was the highest in cultivar Gulabi as indicated by greater absorption of 32P followed by Thompson Seedless and Black Champa. The lowest activity was noticed in the cultivar Bangalore Blue. In all the cultivars Thompson Seedless and Bangalore Blue root activity was more nearer the trunk (40 cm radial distance) at a depth of 15 cm under all the training systems. On the other hand, in the cultivars Gulabi and Black Champa, the activity was more widespread even up to 120 cm radial distance and up to, 30 to 45 cm depths. Even though, the total root activity under different training systems did not differ significantly, the spatial distribution of root activity varied. In general, both root density and activity were found to decrease with increasing depths and radial distances in all the cultivars except in Black Champa. Mathematical functions worked out for fitting root activity as a function of depths and distance indicated that only in Bangalore Blue and Thompson Seedless the spatial distribution was system followed by kniffin and head systems.