ARS | Publication request: Utility of Grafting for Managing Southern Root-knot Nematode, Meloidogyne Incognita, in Watermelon

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: July 12, 2009
Publication Date: December 23, 2009
Citation: Thies, J.A., Ariss, J., Hassell, R., Olson, S. Utility of Grafting for Managing Southern Root-knot Nematode, Meloidogyne Incognita, in Watermelon. Journal of Nematology. 41:385

Technical Abstract: Four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, four wild watermelon (Citrullus lanatus var. citroides) germplasm lines, and one commercial wild watermelon (C. lanatus var. citroides) cultivar were evaluated as rootstocks for cultivated watermelon (C. lanatus var. lanatus) in a field infested with the southern root-knot nematode (Meloidogyne incognita) in Charleston, SC in 2007 and 2008. Commercial watermelon ‘Fiesta’ (diploid seeded) and ‘Tri-X 313’ (triploid seedless) scions were grafted onto the rootstocks in 2007 and 2008, respectively. In 2007, the plants with rootstocks of the wild watermelon germplasm lines and the commercial wild watermelon had significantly less (P<0.05) root galling than non-grafted ‘Fiesta’ watermelon, and plants with the squash hybrid and bottleneck gourd rootstocks. In 2008, plants with rootstocks of three wild watermelon germplasm lines had significantly less (P<0.05) root galling than non-grafted ‘Tri-X 313’ watermelon, and plants with the squash hybrid and bottleneck gourd rootstocks. Root galling of the squash hybrid and bottleneck gourd rootstocks was severe (80 to 96%) in both years. Root galling was moderately severe for non-grafted ‘Fiesta’ (40%) and non-grafted ‘Tri-X 313’ watermelon (56%). Root galling for the wild watermelon germplasm lines ranged from 11 to 34% and 32 to 42% in 2007 and 2008, respectively. Root galling of the commercial wild watermelon rootstock was 24% and 39% in 2007 and 2008, respectively. Wild watermelon germplasm lines derived from C. lanatus var. citroides may be useful as resistant rootstocks for managing root-knot nematodes in watermelon.