Nursery and field evaluation of eggplant grafted onto unrooted cuttings of Solanum torvum Sw.

Solanum torvum is the eggplant (Solanum melongena) relative most commonly used for grafting even if the nursery production of eggplants grafted onto this rootstock has some issues related to its long, irregular and erratic germination and slow growth and development of seedlings. Unrooted cuttings harvested from stock plants could be an alternative propagation material to obtain S. torvum rootstocks and might allow to overcome nursery production issues for eggplant. The aim of this work was to evaluate eggplant suitability to be propagated by unrooted grafted cuttings using S. torvum as rootstock and the influence of this propagation technique on plant yield and fruit quality. A two years trial was performed in nursery and open field. The eggplant cultivar Birgah was used as the scion variety as well as the ungrafted controls (seedling control and unrooted cutting control). Two propagation techniques of the rootstock were evaluated using S. torvum and ‘Birgah’ eggplant (self-grafted): unrooted cuttings or seedlings. S. torvum showed to be suitable to be propagated by unrooted grafted cuttings. The joined healing and rooting had no negative effect on grafting success and plantlets quality. The use of unrooted cuttings of S. torvum, instead of seedlings, reduced considerably the length of propagation time. The shorter propagation time of the innovative propagation technique might permit propagators to overcome the propagation issues of S. torvum and to optimize the scheduling for grafted eggplant production. The use of S. torvum rootstock for grafting eggplant confirmed to enhance plant vigour and productivity. The plants produced from unrooted grafted cuttings of S. torvum showed no differences with the traditional grafted plants in field trials as regard fruit yield and quality. Thus, this innovative technique may be feasible for nursery and field production.