Effect of Certain Rootstocks on Vegetative, Reproductive Growth and Yield of Cashew Cultivars

Vigour reduction through dwarf rootstocks is an essential element of high density planting systems. Cashew is a vigorous evergreen perennial woody plant that is traditionally cultivated in a low density planting system. The present investigations were carried out at ICAR-Directorate of Cashew Research, Puttur, Karnataka, India to find out the effects of vigour controlling rootstocks on vegetative growth and yield of cashew cultivars. The experiment was laid out in a randomized block design with twelve combinations of scion/rootstock with three replications. Different growth habits of four cashew varieties scions (Ullal-3, VRI-3, NRCSel-2 and Vengurla-4) grafted on two dwarfing rootstocks (NRC-492 and Taliparamba-1) and one vigorous rootstock (Vengurla-4) were studied. The results revealed that various stionic combinations varied to growth and yield parameters. Significant interactions indicated that Taliparamba-1 (dwarfing rootstock) with VRI-3 consistently reduced the growth and vigour based on their lower mean tree height, plant volume, TCSA and canopy spread. Stionic combination of VRI-3/ NRC 492 recorded the highest cumulative nut yield of 16.77 kg/ tree (5 seasons of cropping). Based on observation on growth and yield of various stionic combinations revealed that NRC 492 could be used as a rootstock to induce semi dwarfism with a higher nut yield.