APPLICATION OF GRAFTING AS A TOOL FOR IMPROVING MORPHOLOGICAL AND PHYSIOLOGICAL TRAITS OF CUCUMBER PLANTS GROWN UNDER NET-HOUSE CONDITIONS

The use of grafted seedlings has become a globally important agricultural practice in many parts of the world for the production and protection of cucurbitaceous crops from soil-borne pathogens and nematodes in absence of crop rotation, especially since 2005 when the application of methyl bromide has been prohibited. Various biotic and abiotic conditions in addition to incompatibility between scions and rootstocks dramatically restrict use of grafted cucumber transplants in the commercial production of greenhouse cucumber in Egypt. In this study, we investigated the performance of a commercial greenhouse cucumber hybrid (Vivasun) grafted on some local hybrids of cucurbits’ rootstocks at the Experimental Station, Faculty of Agriculture, Cairo University under shade house conditions during summer 2020. The experiment was carried out in a randomized complete block design with ten treatments i.e. eight local hybrid rootstocks, (Gourd 1, Gourd 8, Gourd 16, Squash 6, Squash 13, Winter squash 15, Winter Squash 7 and Wild cucumber: Cucumis zambianus ), a commercial Cucurbita interspecific hybrids (Super Shintosa F1) and Vivasun F1 (ungrafted control) and three replication. The performance of greenhouse grafted cucumber varied according to the use of rootstocks. Under the conditions of slant cut grafting method which is used commercially for cucurbits grafting, the highest percentage of successful grafting was recorded for grafting onto wild cucumber (80.0%) while the lowest value was observed for grafting on squash (27.5%). Comparing with non-grafted plants, grafting on squash 13: Cucurbita pepo (PI 1635 X PI 1642) and squash 6: Cucurbita pepo (PI Coby X C. pepo PI Eskandarani) caused a significant increase in all traits of the plant growth (plant length, inter-node length, leaf area and leaf perimeter) , photosynthesis rate , macro (N, P, K, Ca, Mg) and micro (Fe and Zn) elements, early and total fruit yield, and fruit diameter but it reduced stomatal conductance and transpiration. These two rootstocks had no markable effect on TSS% in fruits. On the contrary, grafting on winter squash 7: Cucurbita maxima (PI 512727) × C. maxima (Local cultivar, Awam) or wild cucumber: Cucumis zambianus (PI 505597 X PI 505586) either significantly reduced the traits under study or gave low values as compared to the non-grafted control.