Impact of grafting on growth vigor and fruit characteristics of watermelon hybrids

Abstract:

In central India's Gwalior-Chambal region, watermelon is the dominant summer cash crop, yet repeated monoculture has built up Fusarium wilt pressure to the point where many fields are no longer economically viable without grafting onto resistant rootstocks. This research evaluated the effect of four rootstocks—bottle gourd (Lagenaria siceraria), squash (Cucurbita maxima × C. moschata interspecific hybrid), citron melon (Citrullus amarus), and self-rooted control—on growth vigor, fruit quality, and yield of three watermelon scion hybrids (Arka Manik, Sugar Baby, Crimson Sweet) at RVSAU Gwalior and IGNTU Amarkantak during summer 2022-23. A factorial randomized block design with three replications was used. The interspecific squash rootstock produced the highest vine length (370 cm), fruit weight (9.1 kg), and marketable yield (42.7 t ha⁻¹)—a 38.3 percent increase over self-rooted plants. However, TSS was reduced by 1.1 °Brix on squash rootstock compared to self-rooted fruit. Bottle gourd rootstock gave a better balance between yield gain (23.5%) and TSS retention (−0.6 °Brix). Graft success rate was highest on the interspecific hybrid (94.2%) and lowest on citron melon (74.8%). The scion Arka Manik performed best across all rootstocks. These results confirm that grafting on bottle gourd or interspecific hybrid rootstock is a viable strategy for sustaining watermelon production in Fusarium-prone soils of central India.