1a. Objectives (from AD-416)
1. Enhance productivity in strawberry. 2. Enhance blackberry yield and survival.
1b. Approach (from AD-416)
Small fruits require high labor and chemical inputs. Improvements in cropping efficiency and out-of-season fruit production of strawberries and blackberries are needed to foster commercial expansion of these small fruits and help mitigate production factors limiting profit potential. In the current global economic market, it is difficult for the small fruit industry in the United States to maintain a profitable operation with ever-increasing competition and market share by fruits being imported from countries to the south. Studies will be conducted to: 1) determine the efficacy of novel cultural and chemical treatments to mitigate low temperature damage, and effects of primocane and environmental manipulations to accelerate and intensify floral bud initiation and subsequent reproductive development, 2) improve the understanding of mechanisms controlling flower development in strawberry and blackberry, and growth processes involved in regulating the flower size and inflorescence development, and 3) analyze the effects of plant material source and environmental conditions during transplant propagation to devise management strategies aimed at producing high quality, superior yielding strawberry transplants. Research into alternative production systems and evaluation of novel germplasm materials is expected to provide new technology and to create new opportunities to produce blackberries for fresh market. Research on season extension techniques for strawberries will provide new technology for the management of strawberries without the need for pre-plant soil fumigation and also opportunities to produce strawberries from October to December in the mid-Atlantic coast region. Technology transfer efforts proposed in this project are expected to improve viability of small fruit farming and rural vitality in several regions of the United States.
3. Progress Report
Progress was made on both objectives and their subobjectives. This research addresses NP 305, Component 1 – Integrated Sustainable Crop Production Systems. Progress on this project focuses on Problem 1B.3: Develop integrated strategies for the management of pests and environmental factors that impact yield, quality, and profitability of perennial crops; and Develop perennial crop production systems that are productive, profitable, and environmentally acceptable; and Problem 1C.4: Develop improved crop production systems for high quality greenhouses, high tunnel, and nursery crops. Under Objective 1, we made significant progress in developing production strategies to accelerate the flowering time in strawberry transplants to enhance productivity from fall to winter months. Also, a technique was developed to prevent flower bud development without affecting the plant’s ability to produce runners. This information will be of benefit to the California strawberry nurserymen who spend as much as $500 per acre each year to remove flowers by hand. Under Objective 2, we made significant progress in enhancing blackberry productivity and developing a new propagation method for blackberries. We used the rotating cross-arm trellis and cane training system to increase the number of five-foot-long canes that can be rooted at their tips in pots and potentially produce as many as 100,000 new plants per acre. Research showed that these potted plants have the capacity to flower quickly and can be transferred for fruit production in southern United States, where winters are too mild to induce flowering to be used for outdoor blackberry production. The commercialization of this technology will benefit a large number of small acreage farmers developing niche market for specialty crops and expand blackberry production into a sub-tropical region, as well as offer new ways to produce blackberries in out-of-season. The products and technology developed has been submitted as part of an invention titled, "New and improved vegetative propagation process for quick flowering blackberry plants". We made significant progress in developing new strawberry selections with high potential to produce fruit in fall and spring, and perform better under mid-Atlantic growing conditions than varieties developed in Florida or California. These results are useful for growers to have new varieties to choose from for the extended fruit production season. Also, we evaluated an additional 1,000 strawberry seedlings for disease tolerance, high fruit firmness, large fruit size, and high plant vigor, from which 16 were selected for further propagation and field evaluation.
1. New technology to grow trailing blackberries without low-temperature injury. Trailing blackberries developed by ARS researchers in Corvallis, Oregon, are susceptible to low temperature injury and are not grown commercially in the central or eastern United States. A variety of techniques, such as rowcovers, cold frames, greenhouses, and high tunnels, have been used to modify the growing environment for berry crops, but none has been shown to reduce winter injury in trailing blackberries. Researchers at Kearneysville, West Virginia, used a novel trellis system with a long rotating cross-arm (RCA) trellis system to position canes close to the ground. Laying canes close to the ground together with rowcover application is a cost-effective method for protecting trailing blackberries from cold temperatures and dessicating winds. This research enables trailing blackberries to be grown in the eastern United States. Trailing blackberries ripen earlier than other blackberries, thus will be a useful variety for growers in this region interested in an early season blackberry. This research was awarded a technology transfer award from the Federal Laboratory Consortium, and the RCA trellis is currently being commercialized by Trellis Growing System, Inc., Ft. Wayne, Indiana, which was awarded a Phase II USDA Small Business Innovation Research grant to expand blackberry production in the Midwest.
5. Significant Activities that Support Special Target Populations
Target populations, including small farms and underserved farms, were addressed through presentations at national and regional grower conferences in Georgia, Virginia, and New York.
Takeda, F., Glenn, D.M., Callahan, A.M., Slovin, J.P. 2010. Delaying flowering in short-day strawberry transplants with photoselective nets. International Journal of Fruit Science. 10:134-142.