Impact of Grafting on Watermelon Growth, Fruit Yield and Quality

Grafting is an alternative approach to reduce crop damage resulting from soil-borne pathogens and increases plant abiotic stress tolerance, which in turn increases crop production. The purpose of this study was to determine whether grafting could improve plant growth and fruit quality of watermelon through monitoring the changes induced by different rootstock-scion combinations. Watermelon (Citrullus lanatus) cv. Aswan F₁ was grafted into five rootstocks (Nun 6001 F₁, Strongtosa F₁, Tetsukabuto F₁, Ferro F₁ and Shintoza F₁) hybrids between Cucurbita maxima and Cucurbita moschata. Highest vegetative growth and fruit yield were obtained by ‘Nun 6001 F₁’ as a rootstock using the tongue approach method. Grafting reduced significantly sex ratio by reducing the number of male flowers. Grafting increased significantly lycopene content in fruit flesh by 57% over the control treatment, but did not affect soluble solids content (SSC). One third of the control non-grafted plants died and Fusarium oxysporum was isolated as the responsible pathogen. These results indicate that grafting watermelon onto specific rootstock influences growth, productivity, and quality of the fruit as well as disease resistance. Grafting can be suggested as an alternative method to control of Fusarium wilt in watermelon production.