Rootstock screening for greenhouse tomato production under a coconut coir cultivation system

ABSTRACT Grafting is an important means to overcome the obstacles of continuous cropping of solanaceous vegetables. The objective of this subject was to evaluate the performance of different rootstocks in grafted tomato (Solanum lycopersicum L.) under coconut coir cultivation. This research was carried out on a scion ‘Ruifen 882’ grafted onto four rootstocks (‘Guangzhen 1’, ‘Zhenai 1’, ‘Ganzhen 1’, and ‘Guozhen 1’) in comparison with non-grafted and self-grafted ‘Ruifen 882’ plants. The experiment was conducted in a greenhouse environment and adopted the casing grafting method with three replicates; 20 plants per replicate were employed in a randomized block design. The following variables were analyzed: graft survival rate, growth parameters (plant height, stem diameter, fresh and dry weight of above-ground part and under-ground part, root-shoot ratio and strong seedling index), physiological characteristics (chlorophyll and mineral element contents), fruit yield, and fruit quality (hardness, soluble solid, soluble sugar, titratable acid, vitamin C and lycopene). The results of growth monitoring indicated that grafting could improve the growth and development of tomato plants at the seedling stage and ‘Ruifen 882’/‘Guozhen 1’ (R/GUO) had high grafting survival rate of nearly 98%, which is close to the self-grafted plants. Physiological analysis showed that R/GUO and ‘Ruifen 882’/‘Zhenai 1’ (R/ ZA) significantly increased the chlorophyll content and absorption of K, Ca, Mg, Fe, Na, Mn and Cu. On fruit yield, grafts ‘Ruifen 882’/‘Ganzhen 1’ (R/GAN) and R/GUO had better performance. Comprehensive analysis showed that the best results for tomato scion growth, development, fruit quality and yield were observed with the graft combination R/GUO.