2017 ASHS Annual Conference

Grafting fruiting vegetables has been a well adopted practice in some Asian and European countries to combat soil born disease and abiotic stress, and to enhance plant growth and yield in protected cultivation systems including high tunnels. This technique has not been well accepted in the United States. There have been some research projects on tomato, eggplant, watermelon and melon grafting but very limited information is available on cucumber grafting. The objective of this project was to test the performance (vigor, disease resistance and yield) of grafted English cucumbers in high tunnels in North Carolina. Two scion cultivars (Socrates and Tyria) were grafted onto five rootstocks (Clause, Flexifort, Marvel, Sentinel and Titan) with the tongue approach method. Resulting healthy grafted seedlings were transplanted in raised beds covered with white-on-black plastic much in April 2016, in a conventional high tunnel located in Greensboro, NC. The high tunnel was 30’ W x 96’ L and covered with a single-layer, greenhouse grade polyplastic film. A completely randomized design was used with four replications. There were four vines (trellised with the Tomato Rollerhook^® system) in each replication. No grafting incompatibility was observed. Results indicated that grafting did not alter the node of the first female flower, but did influence the blooming date (when 50% first female flower bloomed). For example, non-grafted vines bloomed 19 days after transplanting (DAT), and grafted vines bloomed from 19 DAT for rootstock Marvel to 26 DAT for rootstock Flexifort. However, grafting did not significantly affect the first harvesting date, which ranged from 44 to 48 DAT. The number of marketable and total fruit, and marketable and total yield were not affected by grafting. The grafted vines had an average marketable and total yield of 2.0 and 3.1 kg/vine, and the non-grafted vines 2.1 and 3.2 kg/vine, respectively. Disease incidence, especially the bacterial wilt was not affected by grafting. This trial was conducted relatively late in the season so the effect of cold hardiness could not be assessed. In addition, it was conducted in soil with poor fertility resulted from field grading for high tunnel construction. Therefore, a second year study is needed to fully assess the grafting effects on English cucumbers.