Exogenous Treatments to Enhance Splice-Grafted Watermelon Survival

Pinki Devi,Carol Miles,Scott Lukas,Lisa Wasko Devetter

doi:10.3390/horticulturae7070197

Pinki Devi, Carol Miles + Show 2 more

Open Access

https://doi.org/10.3390/horticulturae7070197

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Abstract

This study evaluated the use of splice grafting as a propagation strategy for watermelon. In experiment 1, the treatments consisted of sucrose, antitranspirant A, antitranspirant B, auxin (indole-3-butyric acid (IBA)) at two concentrations (10 and 20 mg·L−1), plus a water control. The survival (%) of splice-grafted watermelon plants differed due to the number of days after grafting and treatment (p < 0.0001, for both). At 21 days after grafting, plants treated with sucrose and antitranspirant A, and sucrose and antitranspirant A with 10 mg·L−1 auxin had 90% and 88% survival, respectively, whereas the graft survival was 18% for plants treated with water. Experiment 2 included the three top performing treatments from experiment 1 and a water control treatment, applied to both root-intact and root-excised rootstocks. There was a significant difference in survival (%) of splice-grafted watermelon due to root treatments, exogenous treatments, and the number of days after grafting (p < 0.0001, for all). At 21 days after grafting, survival for root-excised grafted plants was 11% lower compared to root-intact plants. Plants treated with sucrose and antitranspirant A, and sucrose and antitranspirant A with 10 mg·L−1 auxin had 87% and 86% survival, respectively, whereas plants treated with water had 14% survival. The external application of auxin applied to rootstock seedlings does not appear to be cost-effective; however, other products should be evaluated.

Highlights

Grafting in watermelon (Citrullus lanatus) production has emerged as a promising abiotic and biotic stress management strategy
Lewis et al [6] reported that the number of watermelon plants that can be grafted with the one-cotyledon method is about
At 21 days after grafting (DAG), plants treated with sucrose and antitranspirant A, and sucrose and antitranspirant A with 10 mg·L−1 auxin had 90% and

Summary

Introduction

Grafting in watermelon (Citrullus lanatus) production has emerged as a promising abiotic and biotic stress management strategy. The one-cotyledon method requires more labor during and after grafting to scout and remove undesirable rootstock regrowth from the watermelon transplants, both in the greenhouse and in the field [1,2,3]. Lewis et al [6] reported that the number of watermelon plants that can be grafted with the one-cotyledon method is about. There is no rootstock regrowth with splice grafting because meristem tissue lies below the axillary bud at the base of the cotyledon and is completely removed [7,8]. The watermelon grafting process needs to become more efficient and cost effective in order to produce the large number of plants required by growers, especially for medium- and large-scale farms in the U.S that use approximately

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