Impact of grafting methods, scion materials and number of scions on graft success, vigour and flowering of top worked plants in tea (Camellia spp.)

Abstract

Flowering onset in newly developed tea clones is essential for their exploitation in hybridization programme for deriving genotypes with desirable traits. In this regard, three field experiments were carried out in top working technique to identify an appropriate grafting method, scion material and optimum number of scions per rootstock for obtaining maximum graft success, precocity and maximum number of flowers in a short duration. The newly released high yielding and superior quality clone TRF-4 was used as scions and the drought tolerant clone UPASI-9 field planted in 2006 was used as the rootstocks for all experiments. All the grafting methods and scion materials were evaluated in semi-hard green as well as on lignified brown primary shoots of the pruned rootstocks. Among the tested grafting methods, top-cleft and tongue grafting methods proved to be more suitable for obtaining high graft success, scion vigour and maximum number of flowers than saddle and side-cleft methods of grafting. When testing with different scion materials, the undetached rooted sleeve grown plants grafted by spliced approach grafting method gave the best graft success, scion vigour and maximum number of flowers than the detached scion materials used. Among the detached scion materials, scions consisting of one leaf and an internode proved to be the best scion material than two and three leaves and internodes in terms of graft take, flowering onset and flowering. Both semi hard, green shoots and brown lignified shoots of the rootstocks proved equally good for top working. The results of the experiment by grafting different numbers of scions per rootstock clearly indicated a gradual decrease in scion vigour and flowering when more number of scions was used. Therefore it is optimum to maintain 2–4 number of scions per rootstock for getting maximum numbers of flowers in a top worked plant.