(198) Growth and Development of Watermelon Plants Grafted onto Citrullus Rootstocks Selected for Disease Resistance at Two Temperature Regimes

Abstract

<jats:p>Growth response of `Sambok Honey' watermelon grafted onto different rootstocks, including four <jats:italic>Citrullus</jats:italic> rootstocks and three other cucurbitaceous rootstocks, was evaluated at low and normal temperature regimes. Marked reduction in plant growth rate was observed in plants grown at low temperatures as compared to those grown at normal or optimal temperatures. Relative growth reduction rates were 40% to 48% for vine length, 39% to 51% for total leaf area, 37% to 60% for shoot fresh weight, and 50% to 79% for shoot dry weight, respectively. Watermelon rootstock PI 482322 showed comparable plant growth as the most popular rootstock (Shintozwa pumpkin) even at low temperatures. `Sambok Honey' watermelon grafted onto watermelon hybrids `PI 271969 × PI 296341' and `PI 271769 × Calhoun Gray', showed comparable plant growth as FR Dantos bottle gourd rootstock. Index of growth ability at low temperature (IGALT), which was calculated on the basis of reduced rate of vine length, dry weight, and leaf area, was comparatively high in <jats:italic>C. martinezii</jats:italic>, Shintozwa, PI 482322, and `PI 271769 × PI 296341' rootstocks (50% or higher) and lowest in own-rooted `Sambok Honey' or in watermelon plants on `Knight' rootstock. Watermelon hybrids `PI 271969 × PI 296341' and `PI 271769 × Calhoun Gray' exhibited better or at least comparable growth at low temperatures as compared to `FR Dantos', thus confirming the feasibility of using watermelon rootstocks even in winter greenhouse conditions.</jats:p>

Vegetable grafting: principles and practices

“…Some studies have evaluated disease-resistant Citrullus germplasm as putative watermelon rootstocks, finding high levels of grafting compatibility, shoot growth and fruit development comparable to rootstocks of Cucurbita and Lagenaria, and less effect on fruit quality, thus confirming the possibility of producing high-quality watermelons by using disease-resistant watermelon rootstocks (Huh et al, 2003).…”

“…There are only a few reports describing the use of wild Cucurbita spp. as rootstocks: Huh et al (2003) report a high level of grafting incompatibility of Cucurbita martinezii (syn. C. okeechobeensis subsp.…”

“…Evaluation and characterization of the diversity in C. metuliferus have been performed, allowing the selection of the most favourable types (Weng, 2010). Although C. metuliferus is genetically closer to melon, it is also a useful rootstock for cucumber (El-Eslamboly and Deabes, 2014), but is graftincompatible with watermelon, having negative impacts on productivity and fruit quality in some cases (Huh et al, 2003). For cucumber, Cucumis sativus var.…”

Tomato Grafting: A Global Perspective

“…Grafting success depends on many factors, but genotypic factors are considered to be the most important for compatibility or incompatibility of the scion and rootstock. It is evident that some graft combinations have a positive effect on vegetative growth and development whereas others have a negative effect that can result in growth suppression (Huh et al, 2003) and reduced yield (Yetisir et al, 2003) and fruit quality (Davis et al, 2008a). Graft incompatibility can occur despite a successful graft and may be attributed to factors such as weak graft union, failure of the grafted plants to grow, physiological incompatibility (due to lack of cellular recognition, wounding responses, and effects of growth regulators), or production of incompatibility toxins (Davis et al, 2008b).…”

Effect of different rootstocks on plant growth, yield and quality of watermelon

“…et al, 1981). Taken together, reports to date indicate that depending on the rootstock-scion selection, fruit yield and quality attributes may be either positively or negatively affected by grafting (Oda, 1999;Pulgar et al, 2000;Huh et al, 2003;Gao and Liao 2006;Xu et al, 2006 In Egypt, Mounir (1965) produced grafted watermelon plants on many rootstocks for protection from fusarium wilt. Kapiel et al (2005) observed that the fruit size of watermelons grafted to rootstocks having vigorous root systems is often significantly increased compared to fruits from intact plants.…”