Alternatives to methyl bromide soil fumigation for vegetable and floriculture production
Location: Subtropical Plant Pathology Research
Title: GRAFTING FOR CONTROL OF MELOIDOGYNE INCOGNITA ON BELL PEPPER, TOMATO, AND MELONS
Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: September 30, 2010
Publication Date: October 15, 2010
Citation: Burelle, N.K., Rosskopf, E.N., Bausher, M.G. 2010. GRAFTING FOR CONTROL OF MELOIDOGYNE INCOGNITA ON BELL PEPPER, TOMATO, AND MELONS. Proceedings of Methyl Bromide Alternatives Conference. 76:1-2.
Greenhouse, microplot, and field trials were conducted over three-years to evaluate rootstocks for root-knot nematode (Meloidogyne incognita) resistance. Rootstocks were evaluated for bell pepper (Capsicum annuum), tomato (Solanum esculentum), cantaloupe (Cucumis melo), and watermelon (Citrullus lanatus) scions. Nine pepper rootstocks were grafted to the commercial bell pepper variety ‘Aristotle’ as a scion and evaluated in greenhouse experiments. ‘Charleston Hot’, ‘Carolina Wonder’, ‘Charleston Belle’, ‘Mississippi Nemaheart’ and ‘Carolina Cayenne’ rootstocks were consistently resistant to galling by M. incognita, while Aristotle ungrafted, Aristotle self-grafted, ‘PA-136’, and ‘Caribbean Red Habanero’ were consistently susceptible to galling. Cultivars ‘Yolo Wonder’ and ‘Keystone Resistant Giant’ varied in their response. Caribbean Red Habanero had the highest number of M. incognita isolated from both roots and soil. Four seasons of microplot experiments were conducted to evaluate M. incognita resistance in rootstocks for tomato, muskmelon, and watermelon. Three tomato rootstocks; ‘TX301’, ‘Multifort’, and ‘Aloha’, were tested in addition to the ungrafted scion, ‘FL-47’. Two muskmelon rootstocks, Cucumis metuliferus and ‘Tetsukabuto’ (Cucurbita maxima x Cucurbita moschata), were evaluated with the ungrafted scion ‘Athena’. Two watermelon rootstocks, ‘Emphasis’ and ‘StrongTosa’ were grafted to the scion 'TriX Palomar'. In both years, M. incognita J2 in soil were similar among all tomato rootstocks, but J2 in roots were higher in the ungrafted FL-47 than in all grafted rootstocks. In muskmelon only C. metuliferus rootstock reduced galling. Tetsukabuto did not reduce numbers of M. incognita J2 in either soil or roots. There were no differences in nematode numbers, galling, or plant growth among watermelon rootstocks tested. Field trials were conducted in an area infested with M. incognita. Split plot experiments with four replications were used to evaluate rootstocks in fumigated and herbicide-only treated soil. Four soil treatments were applied under Canslit metalized film; methyl bromide (200 lbs/A, 67:33 mebr:chloropicrin), Midas (100 lbs/A, 50:50 iodomethane:chloropicrin), Paladin (50 gal/a, 79:21 DMDS:chloropicrin), and an herbicide-only control. Subplot treatments in tomato were three rootstocks; TX301, Multifort, and Aloha, and the ungrafted scion, FL-47. A double-crop of muskmelon was planted into existing beds. Two muskmelon rootstocks, C. metulifer and Tetsukabuto, were evaluated with the ungrafted scion Athena. Melon plants of each rootstock were planted into subplots previously occupied by each of the four tomato rootstocks. Although M. incognita populations in soil were highest in herbicide-only plots and in ungrafted tomato rootstocks, fumigant treatments did not differ statistically. All fumigants produced similar tomato plant growth, which was greater than the herbicide-only control, as were numbers of M. incognita isolated from roots. Multifort rootstock produced the largest and healthiest roots, however, M. incognita isolated from roots did not differ among the rootstocks. Galling was highest in plots with herbicide-only soil and ungrafted roots. M. incognita J2 in soil did not differ among soil treatments. M. incognita J2 in soil also did not differ among melon rootstocks but numbers isolated from melon roots were higher in Tetsukabuto than C. metuliferus. C. metuliferus rootstock reduced galling when planted following all tomato rootstocks. Root condition ratings were generally better with C. metuliferus compared with either the ungrafted melon or Tetsukabuto following all tomato rootstocks. All fumigants tested provided protection for all melon rootstocks against galling by root-knot nematodes when compared to the herbicide-only control. Galling on C. metuliferus rootstocks was less in all fumigant treatments compared with the ungrafted Athena and Tetsukabuto. Grafting commercial variety scions onto nematode resistant rootstocks has good potential for nematode management in combination with alternative soil fumigants or as a component in more sustainable crop production systems.