Impact of Grafting on Watermelon Fruit Maturity and Quality

Abstract

Watermelon (Citrullus lanatus) grafting has emerged as a promising biological management approach aimed at increasing tolerance to abiotic stressors, such as unfavorable environmental conditions. These conditions include environments that are too cold, wet, or dry, have soil nutrient deficiency or toxicity and soil or irrigation water salinity. Studies to date indicate that fruit yield and quality may be positively or negatively affected depending on rootstock-scion combination and growing environment. Growers need information regarding the general effect of rootstocks, as well as specific scion-rootstock interactions on fruit maturity and quality so they can select combinations best suited for their environment. This review summarizes the literature on watermelon grafting with a focus on abiotic stress tolerance and fruit maturity and quality with specific reference to hollow heart and hard seed formation, flesh firmness, total soluble solids, and lycopene content.

Biostimulatory Action of Vegetal Protein Hydrolysate and the Configuration of Fruit Physicochemical Characteristics in Grafted Watermelon

“…The evolution of fruit organoleptic characteristics during ripening is mainly determined genetically by the watermelon cultivar, but it can also be influenced by agrienvironmental factors, including grafting onto select rootstocks. In particular, grafting watermelon onto interspecific Cucurbita maxima × C. moschata rootstocks has been shown to retard fruit ripening, manifested in the delayed climax of fruit chroma development and the build-up of pulp lycopene and soluble carbohydrate content [9,19]. Analogous studies on the effect of plant biostimulants on the fruit ripening of watermelon are currently missing, although various biostimulant types appear to affect the fruit ripening process in several other crops.…”

Managing the Product Quality of Vegetable Crops under Abiotic Stress

“…Devi et al [11] contributed a review dealing with the effects of grafting on the fruit maturity and quality of watermelons. The publication summarizes the results of research activities on the impact of grafting watermelon scions on different rootstocks, with a focus on the formation of hollow hearts and hard seeds, flesh firmness, total soluble solid content, pH, titratable acidity, lycopene content and concentration of the non-essential amino acid citrulline, which can be of relevance for the cardiovascular system.…”

“…Two manuscripts describe either the effects of applying chemical substances such as gibberellic acid [9] or seaweed extract [10] on the yield and quality of vegetable crops. Grafting as a method to mitigate the impacts of abiotic stress in vegetables was elucidated by a research paper by Ellenberger et al [3] and in a review by Devi et al [11]. Elevated CO 2 levels were either used as pre-harvest conditions in combination with different nitrogen forms [5] or as post-harvest treatment combined with different methods of packaging [12].…”

“…In general, a large quantity of the contributions in this Special Issue present data on fruit vegetables such as watermelons, bitter gourd and tomatoes [2][3][4]9,11], with the latter being the focus of three publications. These crops were mostly grown in greenhouses [2][3][4], but some were grown in an open field [9] or under rain-out shelters [8].…”

Rootstocks Comparison in Grafted Watermelon under Water Deficit: Effects on the Fruit Quality and Yield

“…Grafting watermelon onto various cucurbit rootstocks is a widely practiced technique to improve fruit yield, quality, and resistance to biotic and abiotic stresses [ 15 , 16 , 17 ]. Abiotic stress tolerance of grafted plants is facilitated by the modifications in root traits, such as deeper and more extensive root systems, higher root hydraulic conductance, and faster induction of hormone accumulation [ 18 ]. The main cucurbit rootstocks include interspecific hybrids ( Cucurbita maxima × Cucurbita moschata ), bottle gourd ( Lagenaria siceraria ), and squash ( Cucurbita pepo ), and ( C. ficifolia ) [ 17 , 18 ].…”