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Crop Diversification Complexity and Pest and Beneficial Organism Communities in Humid Tropical and Sub-Tropical Climatic Regimes

Objective

The objectives of the project are to: <ol> <LI>evaluate the impact of selected crop rotations, cover crops, and intercrop systems on growth and yield of organically produced vegetables; <LI>evaluate the effects of the selected systems on the population dynamics of insect pests, beneficial insects, weeds, plant pathogenic nematodes, and to conduct simulation modeling of the dynamics of selected populations to explore how the experimental treatments may be affecting demographic parameters of the populations; <LI>assess soil and crop nutrient status in order to minimize the occurrence of crop macronutrient deficiencies and to correlate pest density and diversity with changes in crop and soil nutrient status; <LI> disseminate the research findings to local service providers, especially extension personnel, who work with organic farmers and farmers interested in transition to organic production, and to organic and transitional farmers; and <LI> enhance the ability of our graduates to manage organic farms and serve as advisors for organic and transitional producers.

More information

Non-Technical Summary: Because tropical and subtropical climates do not have the benefit of a true winter weeds, pests, and pathogens can occur throughout the year and many persist year round. Therefore, alternative ways of breaking pest cycles and preventing species from achieving pest status are critically needed. The purpose of this study is to compare the impact of simple, intermediate, and complex systems that utilize crop rotation, off-season cover crops, in-season living mulches, and intercropping with the longterm goal of reducing pest pressure in organic vegetable cropping systems for regions with humid tropical and subtropical climates. <P> Approach: The effects of crop diversification complexity on pest populations and community dynamics will be evaluated in organic vegetable cropping systems under humid sub-tropical conditions in north central Florida and humid tropical conditions on St. Croix in the Virgin Islands. Mild or no winter results in the year round persistence of many pests, so alternative ways of breaking pest cycles and preventing species from achieving pest status are critically needed. Summer cover crops in monoculture or mixtures will be grown in sequence with several vegetable crops in monoculture or intercropped in a biannual rotation system. The impact of increasing plant biodiversity on growth and yield of organically produced vegetables, on the population dynamics of key insect pests and beneficial insects, weeds, plant pathogenic nematodes, and soil borne plant pathogens will be assessed. Multiple cultural management strategies will be used to address pest and pest-related problems using an integrated or systems approach and correlations between crop nutritional status and pest incidence will be evaluated. A strong training component for professionals who are service providers for organic and transitional farmers is included. The project will also be used to enhance the ability of our graduates to manage organic farms and serve as advisors for organic and transitional producers.

Investigators
Chase, Carlene
Institution
University of Florida
Start date
2007
End date
2010
Project number
FLA-HOS-004655
Accession number
210705