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United States Department of Agriculture

Agricultural Research Service


Location: Subtropical Plant Pathology Research

2008 Annual Report

1a. Objectives (from AD-416)
Obj. 1: Identify available germplasm resistant to soilborne diseases and pests currently being controlled by pre-plant soil fumigation with methyl bromide for use as grafting rootstocks for Solanaceous vegetables, primarily tomato and pepper. Obj. 2: For selected rootstock germplasm shown to be effective for management of soilborne pests and pathogens of economic importance in the southeastern United States, describe rootstock-scion interactions that influence plant growth, fruit yield, fruit quality, and other important horticultural traits. Obj. 3: For selected rootstock-scion combinations shown to have an acceptable resistance to soilborne pests and pathogens and produce fruit of acceptable quality, evaluate under field conditions, similar to those used for commercial production, the plant growth, fruit yield, fruit quality, and other important horticultural traits that contribute to the economic feasibility of grafting.

1b. Approach (from AD-416)
Identify rootstock and scion germplasm material which have traits that resist diseases commonly found in the Southeastern U.S. currently controlled by methyl bromide. Screen available rootstock material for compatibility using current and new techniques. Select and evaluate rootstock and scion combinations for initial disease resistance and adaptation to current and new cultural technique. Determine the influence of rootstock/scion combinations on the horticultural characteristics of fruit including fruit appearance pre and post harvest quality, flavor, time to maturity, and yield. Develop techniques to evaluate the growth and development of the plant combinations under biotic and abiotic stress and evaluate grafted plant performance under varying cultural conditions.

3. Progress Report
This project was approved in January, 2008 and replaces 6618-22000-033-00D which was terminated at that time. This project is in support of National Program 302 Plant Biological and Molecular Process - as related to the mechanisms of and chemistry of biologically active products from genes which have an influence on the pest resistance and quality of crop species and NP 308 Methyl Bromide Alternatives - using biological alternatives including resistant plants as a means to protect crops from pathogen infestations.

4. Accomplishments
1. Pepper germplasm resistant to root-knot nematode. Gathered available pepper germplasm resistant to root-knot nematode and tested these under conditions in the southeast as grafted plants. The grafted tops of the plants were a commercial bell pepper variety. It is possible to use grafted peppers as an alternative to fumigation for root-knot nematode protection and possible reduction in use. This project is in support of National Program 308 Methyl Bromide Alternatives - using biological alternatives.

2. Methods to propagate grafted peppers. It has been difficult to get high survival rates under current guidelines. With research achieved near 100% survival for grafted peppers in numbers sufficient to produce statistically valid tests for field and greenhouse studies. These findings are important in that achieving high survivability of plant brings the cost of use of grafting in commercial setting. This project is in support of National Program 308 Methyl Bromide Alternatives - using biological alternatives

5. Significant Activities that Support Special Target Populations

Last Modified: 06/28/2017
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