Grafting for Root-knot Nematode Control and Yield Improvement in Organic Heirloom Tomato Production

Abstract

<jats:p>Organic heirloom tomatoes (<jats:italic>Solanum lycopersicum</jats:italic> L.) are difficult to grow in Florida as a result of root-knot nematodes (<jats:italic>Meloidogyne</jats:italic> spp.) (RKN) and hot, humid growing conditions. Although grafting with resistant rootstocks has been shown effective for RKN management in tomato production, little research has been conducted on grafted heirloom tomatoes under Florida conditions. In this 2-year study, two susceptible heirloom tomato scions, ‘Brandywine’ and ‘Flamme’, were grafted onto two hybrid rootstocks, i.e., interspecific tomato hybrid rootstock ‘Multifort’ (<jats:italic>S. lycopersicum</jats:italic> × <jats:italic>S. habrochaites</jats:italic>) and tomato hybrid rootstock ‘Survivor’ (<jats:italic>S. lycopersicum</jats:italic>). Non-grafted and self-grafted scions were used as controls. Three field trials were conducted including the 2010 and 2011 organic field trials as well as a transitional organic field trial in 2011. There was a lack of RKN pressure in the organic field in 2010. In 2011, the RKN population was higher in the transitional field than the organic field, whereas grafting with hybrid rootstocks significantly reduced root galling (<jats:italic>P</jats:italic> ≤ 0.0001) in both fields. In the organic field, the hybrid rootstocks performed similarly and significantly reduced root galling compared with the non-grafted and self-grafted scions by ≈80.8%. In the transitional field, compared with non-grafted scions, the root galling reduction by ‘Survivor’ (97.1%) was significantly greater than that by ‘Multifort’ (57.6%). In general, tomato plants grafted onto ‘Multifort’ tended to be more vigorous than all other treatments. There was no clear relationship between root galling and tomato yields. Grafting did not significantly affect the total marketable yield for the scion ‘Flamme’ in both years. Total marketable yield was similar among treatments in 2010 but varied in 2011 for the scion ‘Brandywine’. In 2011, the non-grafted ‘Brandywine’ and ‘Brandywine’ grafted to ‘Survivor’ produced significantly higher (<jats:italic>P</jats:italic> &lt; 0.05) yields than other treatments in the organic field. However, in the transitional field, ‘Brandywine’ grafted to ‘Multifort’ resulted in significantly higher (<jats:italic>P</jats:italic> &lt; 0.05) yields than the non- and self-grafted ‘Brandywine’ treatments. Grafting with appropriate rootstocks may play an effective role in RKN management during the transition to organic production when high populations of nematodes are present.</jats:p>

Rootstocks Shape the Rhizobiome: Rhizosphere and Endosphere Bacterial Communities in the Grafted Tomato System

“…Previous studies in our experimental system (53) and other grafted tomato systems (45,78,79) have indicated that tomatoes with effective rootstocks gain greater aboveground biomass and have higher overall photosynthetic activity, a result often attributed to the root system. A particular pairing of scion and rootstock may define the root nutrient and metabolite profile (42) through absorption and shoot feedbacks.…”

Nutritional Quality of Field-grown Tomato Fruit as Affected by Grafting with Interspecific Hybrid Rootstocks

“…It is also noteworthy that previous studies on fruit quality of grafted vegetables were oftentimes focused on protected production systems rather than the open-field systems used in this study. With respect to grafted tomato production in the United States, a number of studies have clearly demonstrated the great potential of using grafted plants for controlling several soil-borne pathogens and increasing plant vigor and fruit yield (Barrett et al, 2012a;King et al, 2008;Louws et al, 2010;McAvoy et al, 2012;Rivard et al, 2012); however, research is lacking as to whether the plant growth modifications as a result of grafting with vigorous rootstocks could also lead to marked changes in fruit quality properties especially with field-grown, large fruit size tomato cultivars. Therefore, it is hypothesized that grafting onto interspecific hybrid rootstocks does not adversely affect the major intrinsic quality measurements of fresh-market tomato fruit.…”

Yield, Water-, and Nitrogen-use Efficiency in Field-grown, Grafted Tomatoes

“…Vegetable grafting has proven to be an innovative and effective technique for controlling soilborne diseases such as fusarium wilt (caused by Fusarium oxysporum), verticillium wilt (caused by Verticillium dahliae), southern blight (caused by Sclerotium rolfsii), and bacterial wilt (caused by Ralstonia solanacearum) (McAvoy et al, 2012;Rivard and Louws, 2008;Rivard et al, 2010Rivard et al, , 2012 as well as root-knot nematodes (Meloidogyne spp.) (Barrett et al, 2012;Bausher, 2009;López-Pérez et al, 2006). Grafting with certain rootstocks has also been shown to improve plant tolerance to abiotic stresses such as high salt and low temperature (Fernández-García et al, 2004;Schwarz et al, 2010).…”