Project Overview
Commodities
- Vegetables: cucurbits, peppers
Practices
- Pest Management: cultural control
- Production Systems: organic agriculture
Proposal abstract:
Consumer preference is growing in organic field production of vegetables, especially tomato, peppers, and cucurbits. In Florida, organic production of peppers involves crop rotation with squash and soil amendment with compost. These practices are critical for various aspects of sustainability that address soil management and soil-borne plant parasitic nematodes. Optimization of management practices can reduce limitations of crop productivity by plant parasitic root-knot nematodes (RKNs; Meloidogyne spp.). Although studies demonstrate that compost can suppress RKN, many aspects of how compost does this lack experimental verification. The use of RKN resistant vegetable varieties provides an alternative method to chemical nematicides and is suitable for organic production. Therefore, the benefits of using RKN resistant varieties include increasing yield of the respective crop and reducing RKN population densities. RKN resistant pepper varieties are available for commercial production, but there is a scarce genetic diversity regarding resistance conferred against this pathogen. The objective of this work is to test RKN resistant pepper cultivars with value for improving productivity of organic operations. We propose to test the impacts of integrating an advanced inbred variety of pepper (‘UFRJ107(6)A3’, named ‘Ruby’) into production involving crop rotation with squash in which compost application is used as a tool to both suppress RKNs and improve soil fertility. Gaining insight into the range of pepper host resistance as a supplement to cultural management practices involving organic amendments will be valuable for providing research-based recommendations to vegetable growers in the Southern United States.
Project objectives from proposal:
1) Evaluate productivity of pepper cultivars differing in RKN resistance when integrated with soil organic amendment treatments in RKN-infested plots to measure effectiveness of genetic resistance under field conditions.
Field trials will be conducted at the University of Florida Plant Science and Research Education Unit (PSREU) located in Citra, Florida. They will be maintained in areas reserved for organic production research. Soil samples will be collected at the beginning and end of field trials to determine rate of change in RKN population density. The efficacy of organic amendments, with or without RKN resistant pepper varieties, for the control of RKN will be tested and measured through plant productivity and susceptibility to RKN. Pepper plant productivity will be measured by analysis of early and total fruit yield, fruit quality parameters, and plant nutrition during early vegetative and 50% flowering stages. Pepper plant roots will be evaluated for levels of RKN galling at the time of harvest to measure effectiveness of resistance. Organic amendment’s nutrient content, water holding capacity and culturable bacterial counts will be determined before application.
2) To test for potential nematicidal natural compounds in pepper plant roots induced by compost.
Water-soluble compounds such as phenolics have been suggested to be induced as part of systemic acquired resistance response promoted by compost (4), but the chemical properties of roots of different pepper genotypes affected by this remains unclear. Susceptible and resistant pepper plants will be evaluated for induced resistance after application of compost in a growth chamber experiment.
3) Integrate RKN-resistant pepper into crop rotations to determine effectiveness of RKN-resistance in improving yields of subsequently planted RKN susceptible vegetable crop.
Root infection by RKNs, soil RKN population, and productivity of susceptible squash planted after ‘Ruby’ will be measured. Root infection will be measured through determining galling severity for both susceptible and resistant plants at the time of harvest. Soil RKN population densities will be determined at the beginning and end of each trial with appropriate controls. Productivity of susceptible squash planted after ‘Ruby’ will be measured through evaluation of fruit yield, fruit quality parameters, and plant nutrition during early vegetative and 50% flowering stages. Rate of change in RKN soil population and galling severity will be measured for the squash plants at the time of harvest to test for suppressive effects conferred by the different sources of pepper resistance.
4) Report the results of this research to inform BMPs and plant breeders involved in production systems dealing with RKN.
The work is intended to address issues of pepper cultivar selection with relevance to economic loss due to RKN infection. Also, it will address the effect of organic amendment on both pepper plant productivity and level of RKN disease in susceptible pepper cultivars. This objective includes dissemination of information through extension outreach, conference presentations and research publications in refereed journals.