Increasing Fresh Virginia-Grown Edamame Supply through Season Extension Techniques

Project Overview

Project Type: Graduate Student
Funds awarded in 2012: $10,731.00
Projected End Date: 12/31/2014
Grant Recipient: Virginia State University
Region: Southern
State: Virginia
Graduate Student:
Major Professor:
Dr. Maru Kering
Virginia State University
Major Professor:
Dr. Bo Zhang
Virginia State University

Annual Reports


  • Agronomic: soybeans
  • Additional Plants: tobacco


  • Crop Production: multiple cropping
  • Production Systems: general crop production


    Profitability of tobacco production has dropped since the withdrawal of the federal price support program and soybean (Edamame) as a cash crop is an ideal substitute when marketed as a high value vegetable. This project addressed the need for improved supply to meet increased US demand for fresh edamame. This research found that harvest window for fresh edamame can be increased with combination of different production systems and appropriate selection of cultivars to grow. Growth season extension techniques that combine high tunnel, plasti-culture, and selection cultivars of appropriate maturity groups allowed for extended period of fresh edamame availability.


    Edamame, a vegetable soybean, is harvested at R6 to R7 growth stage when seeds are still green (Fehr et al., 1971). Edamame contains high protein, monounsaturated fatty acids, and multiple minerals such as iron, zinc and phosphorus as well as vitamins such as B1 and B2 (Miles et al., 2000; Kelley and Sanchez, 2005). Edamame has been rapidly incorporated in American diet due to ethnic population growth and people's awareness of edamame nutritional qualities. Edamame appears in grocery stores, farmers' markets, and even Ruby Tuesday's salad. The demand of edamame in the U.S. was estimated 14,877 tons annually (Johnson, 2000; Zhang and Kyei-Boahen, 2007).
    Edamame is a promising opportunity in the specialty crop market. Over 70% of the edamame sold in supermarkets across the U.S. is imported from China and Taiwan, and is mainly marketed frozen. However, the quality of frozen edamame drops quickly in storage. Commercial frozen edamame may contain harmful bacteria such as Escherichia coli and Listeria monocytogenes (Pao et al., 2008). In addition, consumers raise the concern of edamame source of safety and start to seek locally grown fresh edamame (Montri et al., 2006).
    Lack of long-term, local supply has become a barrier for successfully marketing of edamame in the U.S. because it has a very narrow field harvest window of only a few days. There is very limited information available of extending edamame harvest window though season extension production techniques in Virginia. Park et al. (2001) cultivated two Japanese edamame cultivars in Korea in plastic film house culture, plastic film tunnel. By planting from February 15 to September 25, they were able to harvest crop from May 25 to December 3. In the U.S., an intensive research was conducted to extend edamame harvest window in 2003 and 2004 at University of Kentucky (Bec et al., 2005). Four Gardensoy series edamame cultivars from MG I to IV were planted in greenhouses and transplanted into the field either covered by plastic film or no protection on April 1, 15, and 29 in Kentucky (Bec et al., 2005). The crop was harvested for fresh pods from June 17 (GardenSoy 11, MG I) to August 10 (GardenSoy 41, MG IV). In addition, GardenSoy 11 had lower marketable yield than other cultivars at all transplanting dates, which means that MG I cultivars may not be feasible for early production by transplanting in Kentucky.
    Because of lack of sufficient research data on extending fresh edamame harvest window in Mid-Atlantic region, growers are looking after superior edamame cultivars with high stability and adaptability. The findings from this project will provide information on potential approaches to increase Virginia growers' on-farm income through off-season supply and marketing of edamame. Compared to current situation, the viability and adoption of these production techniques may benefit edamame related business in future by supplying fresh edamame over a longer period.

    Project objectives:

    The objectives of this project were; 1) To extend the edamame harvest window through season extension techniques; and 2) To identify edamame cultivars that can be grown in combination at each growing season to optimize yield.

    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.