Modern tomato breeding has led to improvements in postharvest attributes including shelf life, but this has come with a noticeable decrease in fruit flavor (Klee, 2010). Educated consumers have begun demanding heirloom tomatoes for their superior flavor and unique appeal (Bland, 2005; Jordan, 2007; Klee, 2010). This increased interest has helped expand a niche market for local organic growers (Jordan, 2007). However, heirloom tomatoes can be difficult to grow in Florida as a result of high pest and disease pressure. One of the major pest management challenges is RKNs (Meloidogyne spp.), which thrive in warm weather and moist, sandy soils (Roberts et al., 2005; Sasser, 1980). RKNs cause root galls that damage the root system and result in stunted plant growth and significant yield loss. RKNs persist in the soil for many years and have a broad host range. These characteristics make RKN difficult to control on organic farms. The small size of many organic farms may prevent use of the long rotation times needed to ameliorate soil conditions between planting of susceptible crops.
Organic growers often face pest and disease challenges with few effective control methods, making organic heirloom tomato production even more difficult and potentially less profitable than conventional production (Rivard and Louws, 2008; Rivard et al., 2010a). With the use of appropriate rootstocks, grafting may be a useful technique for vegetable producers to overcome soilborne pathogens including RKN. Vegetable grafting began in Japan and Korea in the 1920s to manage fusarium wilt (caused by Fusarium oxysporum Smith) in watermelons and is currently widely used in cucurbitaceous and solanaceous crop production in Asian and Mediterranean countries (Lee, 1994; Lee et al., 2010).
Recently, growers and researchers in the United States have begun examining vegetable grafting as an integrated pest management tool for successful vegetable production. Research has focused on grafted seedling production, use, and economics (Kubota et al., 2008; Rivard et al., 2010b); grafting as an alternative to methyl bromide in field production (Freeman et al., 2009); and the use of resistant rootstocks for controlling RKN and soilborne diseases such as bacterial wilt [caused by Ralstonia solanacearum (Smith) Yabuuchi et al.], fusarium wilt, and southern blight (caused by Sclerotium rolfsii Sacc.) (Bausher, 2009; López-Pérez et al., 2006; Rivard and Louws, 2008; Rivard et al., 2010a). With the phase-out of methyl bromide for soil fumigation and the continued rise in demand for organic produce in the United States, the need for alternative disease control methods that do not rely on synthetic biocides has increased (Greene et al., 2009; King et al., 2008; Louws et al., 2010).
Tomato hybrids (Solanum lycopersicum L.) and interspecific tomato hybrids (S. lycopersicum × S. habrochaites S. Knapp & D.M. Spooner) have been used worldwide as disease-resistant rootstocks in grafted tomato production (King et al., 2010). It is unclear how the differences between tomato hybrid rootstocks and interspecific tomato hybrid rootstocks will affect field production of indeterminate heirloom tomatoes. Hence, rootstock evaluations for heirloom tomato production in open-field conditions should involve both types of rootstocks. Field studies conducted in North Carolina demonstrated that southern RKN [M. incognita (Kofoid & White) Chitwood] could be managed by grafting heirloom tomatoes onto interspecific hybrid rootstocks (Rivard et al., 2010a). However, the inconsistent function of the Mi resistance gene in these rootstocks suggested the need for more examinations of rootstock performance in fields infested with RKN to provide recommendations for effective use of rootstocks. Interest in tomato grafting is emerging among small and organic growers in Florida. The results from the North Carolina studies are promising and suggest that grafting may be applicable in Florida heirloom tomato production. However, appropriate rootstocks for Florida conditions need to be determined.
The purpose of this study was to assess heirloom tomato grafting for RKN control under organic production in naturally infested Florida sandy soils. It is hypothesized that grafting onto resistant rootstocks can reduce nematode galling incidence. Tomato hybrid and interspecific tomato hybrid rootstocks were compared with respect to their influence on nematode resistance, crop vigor, and fruit yield.
BausherM.G.2009Commercial tomato rootstock performance when exposed to natural populations of root-knot nematodes in FloridaHortScience441021(abstr.)
BlandS.E.2005Consumer acceptability of heirloom tomatoes. MS thesis University of Georgia Athens GA
CortadaL.SorribasF.J.OrnatC.KaloshianI.Verdejo-Lucas.S.2008Variability in infection and reproduction of Meloidogyne javanica on tomato rootstocks with the Mi resistance genePlant Pathol.5711251135
DevranZ.SöğütM.A.MutluN.2010Response of tomato rootstocks with the Mi resistance gene to Meloidogyne incognita race 2 at different soil temperaturesPhytopathol. Mediterr.491117
Di GioiaF.SerioF.ButtaroD.AyalaO.SantamariaP.2010Influence of rootstock on vegetative growth, fruit yield and quality in ‘Cuore di Bue’, an heirloom tomatoJ. Hort. Sci. Biotechnol.85477482
DongK.DeanR.A.FortnumB.A.LewisS.A.2001Development of PCR primers to identify species of root-knot nematodes: Meloidogyne arenaria, M. hapla, M. incognita and M. javanicaNematropica31271280
FreemanJ.RideoutS.WimerA.2009Performance of grafted tomato seedlings in open field production. Ann. Int. Res. Conf. Methyl Bromide Alternatives and Emissions Reductions. Methyl Bromide Alternatives Outreach San Diego CA. 22 Nov. 2011. <http://mbao.org/2009/Proceedings/045FreemanJGrafted%20tomato%20MBAO.pdf>
GreeneC.DimitriC.LinB.H.McBrideW.OberholtzerL.SmithT.2009Emerging issues in the U.S. organic industry. EIB-55. U.S. Dept. Agr. Econ. Res. Serv. Washington DC
KhahE.H.KakavaE.MavromatisA.ChachalisD.GoulasC.2006Effect of grafting on growth and yield of tomato (Lycopersicon esculentum Mill.) in greenhouse and open-fieldJ. Appl. Hort.837
KingS.R.DavisA.R.ZhangX.CrosbyK.2010Genetics, breeding and selection of rootstocks for Solanaceae and CucurbitaceaeSci. Hort.127106111
KubotaC.McClureM.A.Kokalis-BurelleN.BausherM.G.RosskopfE.N.2008Vegetable grafting: History, use, and current technology status in North AmericaHortScience4316641669
LeeJ.M.KubotaC.TsaoS.J.BieZ.Hoyos EchevarriaP.MorraL.OdaM.2010Current status of vegetable grafting: Diffusion, grafting techniques, automationSci. Hort.12793105
López-PérezJ.A.Le StrangeM.KaloshianI.PloegA.T.2006Differential response of Mi gene-resistant tomato rootstocks to root-knot nematodes (Meloidogyne incognita)Crop Prot.25382388
LouwsF.J.RivardC.L.KubotaC.2010Grafting fruiting vegetables to manage soilborne pathogens, foliar pathogens, arthropods and weedsSci. Hort.127127146
Medina-FilhoH.P.StevensM.A.1980Tomato breeding for nematode resistance: Survey of resistant varieties for horticultural characteristics and genotype of acid phosphatesActa Hort.100383393
OlsonS.M.StallW.M.ValladG.E.WebbS.E.SmithS.A.SimonneE.H.McAvoyE.J.SantosB.M.Ozores-HamptonM.2011Tomato production in Florida p. 309–332. In: Olson S.M. and B.M. Santos (eds.). Vegetable production handbook for Florida. Vance Publishing Corporation Lincolnshire IL
RivardC.LouwsF.2006Grafting for disease resistance in heirloom tomatoes. North Carolina Coop. Ext. Serv. Bul. Ag-675. North Carolina State University Raleigh NC
RivardC.L.2006Grafting tomato to manage soilborne diseases and improve yield in organic production systems. MS thesis North Carolina State University Raleigh NC
RivardC.L.O’ConnellS.PeetM.M.LouwsF.J.2010aGrafting tomato with interspecific rootstock to manage diseases caused by Sclerotium rolfsii and southern root-knot nematodePlant Dis.9410151021
RivardC.L.SydorovychO.O’ConnellS.PeetM.M.LouwsF.J.2010bAn economic analysis of two grafted tomato transplant production systems in the United StatesHortTechnology20794803
RobertsP.A.MatthewsW.C.JrEhlersJ.D.2005Root-knot nematode resistant cowpea cover crops in tomato production systemsAgron. J.9716261635
U.S. Department of Agriculture Agricultural Marketing Service2002Code of Federal Regulations Title 7 Part 205. National Organic Program. U.S. Dept Agr. Washington DC. 8 Aug. 2011. <http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3004452>
WangK.H.McSorleyR.GallaherR.N.2004Effect of Crotalaria juncea amendment on squash infected with Meloidogyne incognitaJ. Nematol.36290296
ZotarelliL.ScholbergJ.M.DukesM.D.Muñoz-CarpenaR.IcermanJ.2009Tomato yield, biomass accumulation, root distribution and irrigation water use efficiency on a sandy soil, as affected by nitrogen rate and irrigation schedulingAgr. Water Mgt.962334