- Vegetables: tomatoes
- Education and Training: demonstration, extension, on-farm/ranch research, workshop
- Farm Business Management: budgets/cost and returns
- Pest Management: biological control, biorational pesticides, botanical pesticides, chemical control, cultural control, integrated pest management, mulching - plastic
- Sustainable Communities: sustainability measures
Tomato is the most significant vegetable crop in the southern U.S. totaling more than one billion U.S. dollars in farm gate value with Florida accounting for close to 65% of the fresh market production. In Florida, bacterial wilt and bacterial spot are responsible for many of the losses in fresh market tomato production. Bacterial wilt caused by Ralstonia solanacearum is one of the most important plant diseases caused by phytopathogenic bacteria in the tropical, subtropical and warm temperate zones of the world. According to a needs-based assessment survey for tomato IPM carried out by multidisciplinary IPM teams from seven states in the southeastern U.S., bacterial spot of tomato was identified as a major problem by more than 66.7 % of the respondents from Florida and South Carolina. Bacterial spot, incited by several species, will be referred to in this proposal for convenience as Xanthomonas campestris pv. vesicatoria. For many years control strategies were ineffective for both of these diseases. However, more recently inducers of systemic acquired resistance (SAR) and bacteriophages have been shown to significantly reduce bacterial diseases in tomato. The inducers have been used quite extensively, but using current application practices, yield reductions have been observed. In this research project, we will use several strategies to develop biorational approaches for integrated management of these two important bacterial diseases. The objectives of this proposal are: (1) to develop strategies in management of bacterial wilt by: (a) evaluating the efficacy and application methods of new biofumigants and reduced risk compounds in controlling R. solanacearum on tomato under greenhouse and field conditions; (b) determining efficacy of an SAR inducer (Actigard) in reducing bacterial wilt on susceptible tomato cultivars under field conditions at different inoculum levels, and evaluating integrated effectiveness and economics of field application of Actigard, biofumigant, and commercially available moderately resistant tomato genotype in management of bacterial wilt; and (c) using the data obtained in objectives 1a and 1b to develop and implement best management strategies for bacterial wilt in naturally infested commercial tomato farms; (2) to optimize integrated management of bacterial spot with SAR inducers which have limited effects on plant yield by: (a) identifying resistant lines to determine if reduced rates of Actigard can be applied to enhance disease control without affecting yield; (b) determining the effects of modified application strategies of Actigard in combination with bacteriophages; and (c) combining the best management strategies in 2a and 2b for bacterial spot in field experiments; and (3) to conduct a Cost Benefit Analysis on each bacterial wilt and bacterial spot management strategy selected for field trials and compare with current standard grower practice. Net returns over variable cost and total cost will be used to quantify the expected economic benefits. On-farm demonstrations will be conducted in collaboration with growers and extension agents in north Florida and southern Georgia. Results derived from this study will be used to design more sustainable tomato production for controlling two important bacterial diseases of tomato in the southeastern United States.
Project objectives from proposal:
1. To develop strategies in integrated management of bacterial wilt:
a. Evaluate the efficacy and application methods of new biofumigants and reduced risk compounds in control of R. solanacearum on tomato under greenhouse and field conditions.
b. Determine efficacy of the SAR inducer, Actigard, in reducing bacterial wilt on susceptible tomato cultivars under field conditions at different inoculum levels, and evaluate integrated effectiveness and economics of field application of Actigard, biofumigant (thymol), and commercial tolerant or resistant tomato genotype (FL 7514, BHN 669) in the management of bacterial wilt.
c. Using the data obtained in objectives 1a and 1b to develop and implement best management strategies for bacterial wilt on tomato in naturally infested commercial tomato fields. On-farm research and demonstrations will be conducted in collaboration with growers and extension agents in north Florida and southern Georgia.
2. To optimize integrated management of bacterial spot with the SAR inducer Actigard, PGPRs and bacteriophages.
a. Determine if lower rates of Actigard can be applied to enhance disease control without affecting tomato yield and identify resistant lines to determine if they respond to PGPRs.
b. Determine the effects of modified application strategies of the SAR inducer (Actigard) and PGPRs in combination with bacteriophages.
c. Combine the best strategies in 2a and 2b for management of bacterial spot in field experiments to achieve maximum reduction of the disease and copper bactericide application. On-farm research and demonstration will be conducted in north Florida and southern Georgia and economic benefits will be analyzed.
3. To determine, through Cost Benefit Analysis of each field trial, the management strategies yielding the greatest financial returns to the grower.