Evaluating optimal bed spacing for grafted watermelon production to combat Fusarium Wilt
Applied Research
Hayden Schug
University Of Maryland College Park
Bel Alton
Abstract
Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum, is a destructive soilborne disease that can cause severe yield losses in watermelon production and persist in soil for more than ten years. Grafting seedless watermelon onto resistant rootstocks has emerged as an effective strategy for managing this disease in affected production fields. However, grafted watermelon transplants are substantially more expensive than non-grafted plants, increasing production costs for growers. Previous University of Maryland Extension research demonstrated that grafted watermelon plants exhibit strong resistance to Fusarium wilt and maintain yield even at reduced plant populations. In addition, earlier studies suggested that wider in-row plant spacing may increase fruit size without negatively affecting overall yield. These findings raised an important production question, whether bed spacing between rows could also be increased to reduce input costs while maintaining productivity in grafted watermelon systems. Field trials were conducted during the 2024 and 2025 growing seasons in St. Mary’s County and Upper Marlboro, Maryland, to evaluate the effects of bed spacing on grafted seedless watermelon production. Seedless watermelon scions were grafted onto the rootstock Carolina Strongback, which was selected based on its strong resistance to Fusarium wilt in previous trials. Three bed spacing treatments were evaluated, 6 ft, 9 ft, and 12 ft. Plant population was held constant across treatments. Field trials were established using a randomized complete block design in Upper Marlboro and a block design in St. Mary’s County. Data collected included total yield, fruit number, average fruit weight, harvest distribution, and canopy coverage. Across sites and years, total marketable yield per acre was similar among all bed spacing treatments. Fruit weight and harvest distribution varied by site and year but were not consistently influenced by bed spacing. These results suggest that increasing bed spacing in grafted watermelon production systems may be feasible without reducing overall yield. Wider bed spacing could allow growers to reduce production inputs such as plastic mulch, drip tape, fumigants, and labor while maintaining productivity and disease resistance in fields with Fusarium wilt pressure.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
Click to view Poster
Authors: Hayden Schug, Benjamin Beale , Haley Sater, Alan Leslie
-
Schug, . Extension Educator , University Of Maryland , Maryland, 20611
-
Beale , B. Extension Educator , University of Maryland , Maryland, 20650
-
Sater, H. Extension Educator , University of Maryland , Maryland, 21801
-
Leslie, A. Center Director, University Of Mayland , Maryland, 20742