North Carolina is experiencing a revitalization of the strawberry industry due to the adoption of plasticulture technologies and the California cultivar Chandler, which produces excellent yields and fruit quality on black plastic mulch. With this system, berries can be harvested in just 7 to 8 months after planting. The spring harvest season can last up to 6 weeks in most years. Strawberry plasticulture growers in North Carolina typically experience yields of 17,000 to 18,000 lb/acre (19,054 to 20,174 kg·ha-1). Cash expenses for the system are about $4345/acre ($10,736/ha). The system requires both an overhead sprinkler system for blossom and bud frost/freeze protection, and drip irrigation for supplying water and fertilizer in the prebloom, bloom, and fruiting periods. Sandy loam and clay loam soils are ideal for forming the lo-inch-high (25.4-cm) beds with bedding machines. Usually, 33% of the N, 50% of the K, and all of the P is applied preplant, with the remaining N and K applied through the drip-irrigation system. Problems associated with the plasticulture system include higher initial investment relative to matted-row production, and only one fruiting season is possible with the anthracnose-susceptible `Chandler' in the southeastern United States.
The U.S. land-grant university system has been coming under increasing criticism by a number of extension professionals, as well as senior horticulturists, for its primary emphasis on basic research at the expense of applied research and service to horticultural industries. Once-strong extension/research/producer ties have been weakened, and this could result in further declines in general public support for land-grant universities. New approaches, including a “participatory model,” have been proposed as a mechanism to provide public feedback to land-grant scientists on relevant areas of basic science and encourage implementation of new technologies. However, our present expert/student relationship between research scientists and grower would be altered if the participatory model were to be adopted. Recognizing the limitations of existing horticultural production systems and visualizing new purposes for technology is the work of “experts,” not committees. The experience in North Carolina has been that a commodity specialist with a split research/extension appointment (20/80) is capable of providing leadership and guidance `to the scientific community on the problems and research needs of industry. In the case of introducing North Carolina farmers to “strawberry plasticulture,” the split appointment specialist had a role in: 1) identifying useful technological innovations from outside the university community (“reverse technology”); 2) conducting localized testing on promising new “hybrid growing systems”; and 3) extending new research findings to industry.
Working on the basic idea that the small fruit industries in Virginia, South Carolina, Georgia, Arkansas, and other states in the south have a great deal of growth potential, especially in strawberries, the Southern Region Small Fruit Center is now becoming a very focused collaboration between several land-grant institutions to develop a virtual small fruit center web site that will serve to keep specialists, agents, growers, and students well informed on the latest small fruit research and technical findings. It would also give instant access to a variety of small fruit extension publications, budgets, and crop advisories. The site, www.smallfruits.org, opened on 17 Sept. 1999, and was immediately utilized after Hurricane Floyd “hit” to post a series of berry info advisories on specific postplant management strategies to minimize further yield losses due to the extra week of delayed planting caused by Floyd's flooding. The main benefit of regional or multistate institutional approach is that it gives us the “extra horsepower” for tackling some fairly ambitious projects, like the creation of a virtual small fruit center. Recently, the center has begun to offer more in-depth regional training courses for agents and growers, such as the “Extension Strawberry Plasticulture” short course that was conducted on North Carolina State Centennial Campus, 1-5 Nov. 1999. We currently have a “critical mass” of some of the best small fruit research and extension workers you will find anywhere across the whole southern region, and by working together we can develop stronger, more economically viable small fruit industries.
E. B. Poling
One of many forms of Distance Learning is “Interactive Video Teleconferencing” (IVT). I was an early user of interactive video for both course teaching and delivery of extension programs in small fruit production. But after 3 years of trying interactive video for delivery of an extension program, “Preplant Considerations for Strawberry Plasticulture Producers,” agents and growers have indicated a strong desire to discontinue the use of this medium in favor of truly “live” regional meetings for the 1996 season. Growers and many agents may have some anxiety about appearing “on TV,” and this leads to fewer questions and reduced audience participation levels when this extension meeting format is used. There is also the additional problem of finding funds to defray the costs associated with IVT programs. An evening broadcast of 2 hours to six university sites on the MCNC network in July 1994 led to charges of more than $700 to the program sponsor, the North Carolina Strawberry Association. Quality interactive video programs require considerable advance planning and program preparation. In cases where this medium is being used only infrequently by the specialist (one or two meetings each year), the audience is basically uncomfortable with the idea of “being on TV” and network costs are high. The advantages of a more traditional extension meeting format will likely outweigh the benefits of distance education via interactive video.
E.B. Poling, H. Pat Fuller, and K.B. Perry
Floating rowcovers composed of extruded polypropylene, spunbonded polypropylene, and polyester were used in 1987-88 in eastern North Carolina for cold protection of strawberries (Fragaria × ananassa Duch.) growing in annual hill culture on black plastic mulch. Treatments consisted of floating rowcovers in either winter, spring, or both with and without overhead irrigation for spring frost/freeze protection, in addition to irrigated and nonirrigated unprotected plots. Winter rowcovers increased air temperatures by 1 to 2C without advancing bloom or harvest date. Significant blossom temperature differences relative to rowcover materials (≈ 1.5C) and irrigation use (≈ 1.5 to 3.0C) were detected over the course of six spring frosts. Time of application of covers (winter or spring) and irrigation in spring interacted in their effects on early yields (25 Apr.-5 May). However, rowcover and irrigation treatments did not have a significant effect on total marketable yield, yield per plant, or berry mass. In the absence of higher prices for early than late-season fruit or of more severe environmental extremes than experienced in the current study, it would be difficult to justify the added expense of rowcovers.
E.B. Poling, J.G. Richardson, and G.A. Benson
G.S. Miner, E.B. Poling, D.E. Carroll, L.A. Nelson, and C.R. Campbell
Annual-hill strawberry (Fragaria ×ananassa Duch.) production with black plastic mulch and drip irrigation is gaining popularity in North Carolina. Two experiments (E1 and E2) were conducted on a Wagram loamy sand (Arenic Kandiudult) in 1992 and on a Norfolk sandy loam (Typic Kandiudult) in 1993 to investigate the effects of fall-applied N and spring-applied N and K on `Chandler' strawberry yield and fruit quality. E1 treatments included factorial combinations of banded fall-applied N (0, 34, and 67 kg·ha-1) and drip spring-applied N (0, 0.19, 0.37, 0.56, and 0.75 kg·ha-1·d-1 and 0, 0.37, 0.75, and 1.12 kg·ha-1·d-1 in 1992 and 1993, respectively). E2 treatments included combinations of drip spring-applied N (0.56, 1.12, 1.68, and 2.24 kg·ha-1·d-1) and K (0.46, 1.39, and 2.32 kg·ha-1·d-1 and 0, 0.75, 1.49, and 2.24 kg·ha-1·d-1 in 1992 and 1993, respectively). There were no significant interactions among main effects for any of the measured variables. Market yield maximized with total N at ≈120 kg·ha-1 with one-half banded in the fall and the remainder drip-applied in the spring. Fruit firmness decreased with increasing N rate. Fruit pH and concentrations of total acids and soluble solids were not affected by N treatments, but soluble solids increased as the harvest season progressed. Plant crown number was not affected by N treatment but crown yield increased with N rate similar to market yield. There was no response to drip-applied K for any variable in either year. Based on soil test, fall-applied K (broadcast-soil incorporated) met the K requirements both years.