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

View the project final report

• 2011 annual report

Commodities

• Vegetables: cucurbits, peppers, tomatoes

Practices

• 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

A comparison of four systems of vegetable production indicated that cover and companion crops could promote sustainability in vegetable farmscapes by enhancing biotic resistance. The bidens companion plant attracted non virus-vectoring thrips that often displaced viruliferous thrips species. Under some years and combinations with bidens, the cover crop blue lupine had limited positive effect on yield weights when compared with conventional plastic mulch treatments. Although deployment of these types of cover crop / companion crop would require changes in current cropping practices, they can produce comparable crops to those grown with current higher input methods.

Objectives: 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; i) conventional black plastic mulch utilized as a standard control; ii) conservation tillage cover crop, with spring cash crops transplanted into overwinter leguminous cover crops; iii) transitional cover crop, with the cash crops planted on black plastic overlaid in a cover system; iv) 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.