Increasing Survival of Splice-grafted Watermelon Seedlings Using a Sucrose Application

Abstract

<jats:p>Rootstock regrowth can prevent effective healing of grafted vegetable seedlings and outcompete the scion for light, space, and nutrients later in production. Rootstock regrowth is especially problematic for watermelon (<jats:italic>Citrullus lanatus</jats:italic>) because the crop is most commonly grafted using methods where meristematic tissue remains on the rootstock. The objective of this study was to test whether sucrose solutions [0% (water control), 1%, 2%, and 3%] applied as a drench to rootstock seedlings before grafting would increase the survival of watermelon grafted using the splice method where both rootstock cotyledons were removed to eliminate meristem tissue and rootstock regrowth. Starch accumulation in rootstock seedlings was the highest for plants that received 3% sucrose solution (71%), followed by plants that received 2% sucrose solution (52%), 1% sucrose solution (29%), and water (6%) (<jats:italic>P</jats:italic> &lt; 0.0001). Survival (%) of splice-grafted watermelon seedlings 21 days after grafting was the greatest for plants that received 2% and 3% sucrose solution (89% and 82%, respectively), followed by plants that received 1% sucrose solution (78%), and was the lowest for plants that received water (58%) (<jats:italic>P</jats:italic> &lt; 0.0001). There was a significant interaction due to repeat for both starch accumulation and grafted transplant survival; however, environmental conditions were similar for both repeats: the daily average temperature was 23 °C, the relative humidity (RH) was 64% to 67%, and the daily average light intensity was 224–243 µmol·m<jats:sup>−2</jats:sup>·s<jats:sup>−1</jats:sup>. Furthermore, while the vapor pressure deficit from 1:00 to 6:00 <jats:sc>pm</jats:sc> was 2.49 kPa for repeat 1 and 1.42 kPa for repeat 2, plant survival was greater in repeat 1 than repeat 2. These results indicate that drench applications of sucrose solution to rootstock seedlings before grafting can increase grafting success when both cotyledons are removed from the rootstock before grafting, but further research is needed to optimize the environmental conditions for the survival of grafted plants.</jats:p>

Comparative Physiological and Biochemical Mechanisms in Di, Tri, and Tetraploid Watermelon (<em>Citrullus lanatus</em> L.) Grafted by Branches

“…The grafting process was performed after 15 and 20 days after rootstock seeds sowing. The splice grafting method was used [19] ( Figure S1). Rootstock seedlings were subjected to adaptation before and after grafting to increase the survival rate, as mentioned by [56,57].…”

Effect of Environment on Survival of Eggplant, Pepper, and Tomato in a Small-scale Healing Chamber

“…For example, the survival of watermelon (Citrullus lanatus) grafted using the splice grafting technique (both rootstock cotyledons were removed) was 89% when rootstocks received 2% sucrose solution before grafting and the rootstock stems had 52% starch accumulation. In comparison, rootstocks that were treated with water had 6% starch accumulation in the rootstock stems and grafting success was 58% (Dabirian and Miles, 2017). There are no reports regarding increasing the carbohydrate reserves of solanaceous crops before grafting, though previous research reports that when light is provided during the healing period, callus induction, growth and graft survival are improved (Afshari et al, 2011;Moon and Stomp, 1997;Nobuoka et al, 2005).…”

Plasma membrane H+‐ATPase activity and graft success of breadfruit (Artocarpus altilis) onto interspecific rootstocks of marang (A. odoratissimus) and pedalai (A. sericicarpus)

“…; Sanabam et al . ; Dabirian & Miles ). The uptake of most nutrients into cambial cells is an energy‐dependent process under the control of PM H + ‐ATPase (Michelet & Boutry ; Palmgren ).…”