- Vegetables: tomatoes
- Crop Production: fertigation, irrigation, organic fertilizers
- Education and Training: demonstration, extension, on-farm/ranch research, workshop
- Farm Business Management: budgets/cost and returns, feasibility study
- Pest Management: cultural control, integrated pest management
- Production Systems: organic agriculture, transitioning to organic
This two-year project demonstrated the effectiveness of using grafting with appropriate rootstocks for root-knot nematode control in organic heirloom tomato production. The two commercial rootstocks tested significantly reduced root galling. Under severe root-knot nematode pressure, use of the interspecific rootstock resulted in significantly higher yields than the non- and self-grafted treatments. Grafting did not exhibit any consistent effects on fruit quality attributes. Grafting could be an economically feasible pest control measure to help maintain a profitable production given that the risk of economic crop losses due to root-knot nematodes outweighed the higher cost of grafted transplants.
The purpose of this project was to study the benefits of grafting to improve disease resistance and to determine the effects of grafting on productivity and fruit quality of heirloom tomatoes. In addition, we aimed to investigate the feasibility of implementing grafting as an economically-viable practice on organic farms. Heirloom tomato varieties with superior flavor and outstanding eating quality have been grown increasingly by small growers as a niche product with a high price premium. However, the lack of a good disease resistance package in many varieties has been a great challenge for successful production of heirloom tomatoes. Pest management under organic production may be even more challenging as cultural control measures like crop rotation and cover cropping tend to be less effective due to the long-term survival and wide host range of certain soilborne pathogens such as Fusarium oxysporum and root-knot nematodes.
Grafting has been used in many cropping systems in a number of countries to obtain crop resistance or tolerance to soilborne diseases (Leonardi and Romano 2004). Grafting can create a new “hybrid” plant through a physical union of a rootstock plant and a scion plant. This technique is more rapid than breeding in uniting positive genetic and physiological traits that confer elevated vigor and productivity to the resulting plant (Edelstein 2004; Pogonyi et. al. 2005). Interest in tomato grafting is increasing with growers in Florida. Our recent interview with some heirloom tomato growers revealed their strong interest in innovative and integrated alternative practices for soilborne pest management. In addition to disease management, increased efficiency of nutrient and water absorption and improved tolerance to abiotic stresses have been observed on grafted vegetables (Davis et al., 2008; Lee, 1994). It is expected that using appropriate rootstocks may promote marketable fruit yield by reducing the incidence of fruit cracking and misshapen fruits in heirloom tomato production.
Despite the numerous benefits of employing vegetable grafting technology, the cost of using grafted plants in commercial production is often perceived as a major concern of growers. Compared with traditional heirloom tomato production, additional costs associated with grafted tomato production are reflected mainly in producing grafted transplants, i.e., seeds, space, water, nutrients and labor for growing rootstock seedlings, tools, materials, space and labor for making grafts, and care of grafts during the healing process. Hence, high marketable yield and quality is the key to profitability in production of grafted heirloom tomatoes. In this project, an updated, comprehensive, and objective cost-return analysis will be performed to provide recommendations for innovative and integrated use of grafting to grow heirloom tomatoes in an organic production system.
Objective 1: Examine the effectiveness of using rootstocks in organic production of grafted heirloom tomatoes to provide resistance or tolerance to root-knot nematodes.
Objective 2: Assess growth promotion, yield increase, and fruit quality in grafted heirloom tomato production under organic growing conditions.
Objective 3: Analyze the costs and returns of producing and using grafted heirloom tomato transplants in organic farming systems and provide updated information on the economic feasibility of adopting tomato grafting technology for these systems.
Objective 4: Outreach; Teach growers and extension agents how to graft and about the benefits of grafting and work with growers and extension agents to increase and promote sustainability in agriculture.