Taking advantage of pest thrips ecology to increase sustainability of vegetable crop production

Project Overview

Project Type: Research and Education
Funds awarded in 2011: $235,000.00
Projected End Date: 12/31/2015
Region: Southern
State: Florida
Principal Investigator:

Annual Reports


  • Vegetables: cucurbits, peppers, tomatoes


  • Crop Production: cover crops, intercropping, application rate management
  • Education and Training: on-farm/ranch research, workshop
  • Farm Business Management: agricultural finance, whole farm planning
  • Pest Management: biological control, cultural control, integrated pest management, mulches - living, trap crops, mulching - vegetative
  • Production Systems: holistic management
  • Soil Management: organic matter, soil quality/health

    Proposal abstract:

    The western flower thrips (Frankliniella occidentalis) and tobacco thrips (Frankliniella fusca) are key pest of crops such as tomato, peppers, cucurbits, and other horticultural crops in the southern USA. Growers have historically responded with intense insecticide use (Bauske 1998) fearing that if left unmanaged, direct feeding damage and Tomato spotted wilt virus (TSWV) transmission by these thrips could result in complete crop failure. However, inappropriate insecticide use can exacerbate damage by increasing pest thrips populations and populations of other secondary pests. Our labs have made considerable progress in management programs for thrips in vegetable crops, which have been widely adopted throughout the southern USA (Funderburk 2009). Although effective, not all of these IPM tactics are inherently sustainable, nor are they amenable to small scale and resource-limited growers because of costs. Further, they tend to rely on a traditional pest management paradigm that addresses pest problems individually rather than as a part of a holistic cropping system. One key sustainable strategy that we have developed to manage pest thrips is to maintain the biotic resistance of agroecosystems by fostering populations of natural enemies (Orius insidiosus) and competitor species of non-pest thrips (e.g., Frankliniella tritici, F. bispinosa) in the farmscape. In part, this can be accomplished by maintaining refuge crops for these species adjacent to cash crop fields. A number of these beneficial companion plants are also useful winter and summer cover crops. Therefore, we propose to integrate pest management into cover crop systems, and develop this strategy in a holistic, sustainable practice by developing an augmented system of cover crops which integrate the traditional uses of cover crops (soil fertility, erosion prevention, weed suppression) with biological control by providing harborages for natural enemies and non-pest competitor thrips over time. The objectives of this proposal are to: 1) evaluate four different cover crop systems for their effects for their effects on biotic resistance against pest thrips and the spread of TSWV in vegetable crop systems; 2) determine the effect of cover crops on soil fertility and vegetable crop vigor and yield; 3) assess the economic value and practicality of cover cropping systems to growers through collaborative on-farm research; and 4) foster adoption of effective practices by providing readily accessible information to growers, commodity groups and other stakeholders. We anticipate that this cover crop system will lead to: 1) successful management of two key pest thrips - western flower thrips and tobacco thrips – and TSWV; 2) reduce costly pesticide inputs; 3) reduce secondary pest outbreaks; and 4) improve soil health and increase soil fertility, thus reducing fertilizer and herbicide applications. This proposal integrates the strengths of a multidisciplinary team that includes growers, and researchers and extension personnel from the USDA, University of Florida, University of Georgia and Florida A&M University to better understand the risks and benefits of cover crop integration in vegetable systems and the feasibility of covers crops to manage thrips pests in the Southern USA.

    Project objectives from proposal:

    Evaluation of multi-functional cover crops requires the systems approach to research adopted by SARE. Each component (e.g. type of cover crop, mulching system, etc.) has multiple functionalities. Conversely, each measureable outcome (yield, pest populations, soil fertility) is the result of the interaction of multiple cultural practices. These interrelationships obscure analysis by reductionist techniques and statistics designed to measure independent causes and effects. We will examine four systems of vegetable production based on conventional practices, current cover cropping systems, transitioning from plastic mulch with inclusion of traditional cover crops, and a cover crop system designed to maximize integration of thrips pest suppression with the traditional roles of cover crops. Specifically, we will:
    1) Design, implement and demonstrate the following four cropping systems; 1) conventional black plastic mulch utilized as a standard control; 2) conservation tillage cover crop, with spring cash crops transplanted into overwinter leguminous cover crops; 3) transitional cover crop, with the cash crops planted on black plastic overlaid in a cover system; 4) beneficial insect cover crop system, designed for spatial/temporal enhancement of beneficial insects and biotic resistance against pest thrips and the spread of TSWV in vegetable crop systems.

    2) Determine the effectiveness of these four systems in terms of plant vigor, yield, vegetable quality, the traditional advantages of cover crops (including soil fertility and weed suppression), and pest pressures (thrips abundance, disease incidence, and secondary pest populations) on tomatoes, peppers and cucumbers.

    3) Assess the economic value and practicality of cover cropping systems to growers through regional, collaborative on-farm research.

    4) Foster adoption of effective practices by providing readily accessible information to growers, commodity groups and other stakeholders.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.