ARS | Publication request: Is Grafting Useful for Managing Root-Knot Nematodes in Watermelon?

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: February 11, 2008
Publication Date: June 1, 2008
Citation: Thies, J.A., Ariss, J., Kousik, C.S., Hassell, R. 2008. Is Grafting Useful for Managing Root-Knot Nematodes in Watermelon?. HortScience. 43(3):623.

Technical Abstract: Five Citrullus lanatus var. citroides germplasm lines, four Lagenaria siceraria cultivars, one Cucurbita moschata x C. maxima hybrid, and one commercial wild watermelon (Citrullus lanatus spp.) cultivar were evaluated as rootstocks for watermelon in a field infested with the southern root-knot nematode, Meloidogyne incognita, in Charleston, SC. ‘Fiesta’, a diploid watermelon (C. lanatus var. lanatus) grafted on the rootstocks, was transplanted to the field on 30 July 2007. On 8 Oct 2007, roots of all plants were dug and evaluated for percentage of root system galled by M. incognita. Root galling was severe in rootstocks of Lagenaria siceraria (80 to 96 percent) and Cucurbita moschata x C. maxima hybrid (98 percent), and was moderately severe (40 percent) for non-grafted ‘Fiesta’ watermelon. Root galling of germplasm lines derived from Citrullus lanatus var. citroides ranged from 11 to 34 percent and galling of the commercial wild watermelon rootstock was 24 percent. Four of the C. lanatus var. citroides germplasm lines and the commercial wild watermelon rootstock had significantly less (P less than 0.05) root galling than ‘Fiesta’, the four L. siceraria rootstocks, and the C. moschata x C. maxima hybrid rootstock. Selected germplasm lines of C. lanatus var. citroides may provide a source of resistance that will be useful in development of root-knot nematode resistant rootstocks for watermelon.