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, H. Pat Fuller and K.B. Perry
Daniel Rowley, Brent L. Black, Dan Drost and Dillon Feuz
system are particularly efficient for maximizing early-season yields ( Sjulin, 2003 ). This annual system has since been adapted to colder climates ( Black et al., 2002 ; Poling, 1993 ). Optimum fruit production in the fall-planted annual hill system
Daniel Rowley, Brent L. Black, Dan Drost and Dillon Feuz
as a spring-planted annual hill system patterned after the day-neutral production methods used in Ontario, Canada ( Pritts and Dale, 1989 ). The cultivars selected for evaluation were Albion, Seascape, Evie 2, and Tribute ( Galletta, 1997 ; Shaw and
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.
S.J. Locascio, J.P. Gilreath, S. Olson, C.M. Hutchinson and C.A. Chase
Strawberries (Fragaria ×ananassa, Duch) were grown in the annual hill system at four locations in Florida to compare the effects of standard black low density polyethylene (LDPE) mulch and red reflective mulch (SMR-red) on fruit size and production. Marketable fruit size was not affected by mulch color. Early and total marketable fruit yields were not affected by mulch color at Bradenton, but yields were significantly higher at Gainesville with red than black mulch, and were significantly higher with black than red mulch at Quincy and Hastings. Soil temperatures under the black mulch were significantly higher than red mulch at Hastings but significantly higher under red than black mulch at Gainesville. Mean soil temperatures at soil depths of 5 to 25 cm ranged from 0.2 to 0.4 °C Reflected photosynthetically active radiation values at 25 and 50 cm above the mulch were higher earlier in the season and decreased as the season progressed. Within a month after transplanting when foliage covered about 10% of the mulch, reflections were lower and similar at both heights with black mulch than red and were higher at 25 than 50 cm with red mulch. Data indicate that there was not a consistent advantage of the use of this red mulch over black mulch at four locations in Florida.
Brent L. Black, Harry J. Swartz, Gerald F. Deitzer, Bryan Butler and Craig K. Chandler
The effect of altered red/far-red light environment on subsequent field performance of strawberry plug plants was tested. Two wavelength-selective plastic films were compared to neutral shade and full-sun control for conditioning `Chandler' strawberry plug plants before transplanting to a winter production system. The following year, plug plants of `Chandler', `Sweet Charlie', and `Allstar' were conditioned under the same treatments, with the addition of a continuous incandescent light and a short-day photoperiod, and plant performance was followed in the winter production system in Florida, a cold-climate annual hill system in Maryland, and in a low-input greenhouse production system. During the first year, the red light-filtering film slightly advanced fruiting in Florida. However, during the second year, the effect of the red light-filtering film was not significant, and a short-day treatment resulted in a greater reduction in runnering and increased early crown and flower development. For June-bearing strawberry plants maintained above 20 °C, altering the red/far-red environment did not consistently advance flowering.
Matthew D. Stevens, Judith A. Abbott, John D. Lea-Cox and Brent L. Black
Three cold-climate strawberry production systems, conventional matted row, advanced matted row, and cold-climate annual hill plasticulture, were compared for consumer preference in a pick-your-own (PYO) setting. Replicated 6 × 15 m plots were established in 2002 in Maryland and cropped in 2003 and 2004. To simulate PYO marketing, volunteers were recruited to harvest 3.6-m plots in each of the three production systems and to complete a five-part questionnaire. The questionnaire collected demographic information and allowed volunteers to compare the three systems both prior to and after their harvesting experience. Harvests were carried out twice weekly, with 75 participants in 2003 and 45 participants in 2004. The 2003 season was cool and wet, with frequent rainfall and a high incidence of fruit rot. Spring 2004 was unseasonably hot, resulting in an unusually short harvest season. Consumer preference differed between years and among harvests within a season. The annual hill system was favored early in the 2003 season, with preference shifting to the other systems as the season progressed. The advanced matted row was favored early in the 2004 season. Many of the participants' comments, both positive and negative, were directed at the plastic mulch and raised beds. In several cases, participants indicated that their preferences after picking from each system did not match their initial impressions. Implications of this research to the social components of sustainability will be discussed.
Joel L. Shuman* and Anthony D. Bratsch
Anthracnose fruit rot (AFR) and crown rot can cause severe economic losses on susceptible `Chandler' and `Camarosa' strawberry in Virginia: `Sweet Charlie' and `Bish' are moderately resistant to resistant. Actigard (acibenzolar-S-methyl), an inducer of systemic acquired resistance, has been effective at reducing black spot and speck on tomato, blue mold on tobacco, and fire blight on apple. The objective of this study was to determine if Actigard, when spray-applied to field-grown strawberry, can reduce AFR better than or equal to several registered fungicides. Four varieties (VAR) (Chandler, Camarosa, Sweet Charlie, and Bish) were treated with four fungicides (FUNG) (water control, azoxystrobin, chlorothalonil, and actigard). Experimental design was a split plot with FUNG as the main plot and VAR as the split plot with four replicates. Standard annual hill system practices were used throughout. Plots were inoculated three times throughout the harvest season with a conidia: water solution of 1 × 106 conidia per mL. Plots were treated with FUNG on a 14-day schedule from bloom to end of season. Plots were visually assessed for anthracnose and fruit were harvested 2× weekly and weighed into four categories: marketable, cull, fruit with anthracnose, and fruit with other diseases. Environmental conditions were conducive for anthracnose development: extended periods of rain and high relative humidity. Plots treated with water control had more AFR, other fruit rots, and higher overall disease ratings than those treated with a compound. Plots treated with actigard had the same level of AFR as did those treated with azoxystrobin. `Chandler' and `Camarosa' had considerably more AFR than `Sweet Charlie' and `Bish' had the least amount over all FUNG.
Jessica R. Goldberger, Lisa W. DeVetter and Katherine E. Dentzman
biodegradable plastic mulch is likely due to California growers’ current use of PE mulch and the annual hill system of strawberry production. Because adoption is more likely when innovations are compatible with existing practices ( Rogers, 2003 ), California
James P. Gilreath, Bielinski M. Santos and Timothy N. Motis
initially show localized and uneven growth with chlorotic plants, eventually extending the damage to the whole planted area ( Jardine and Todd, 1990 ). Florida strawberries are grown using the annual hill system, where beds are pressed and fumigated before