A combination of simple cultural practices, a modified rotatable crossarm (RCA) trellis system, and covering plants with insulation material in winter overcame the lack of cold hardiness in trailing blackberries that have been established at Kearneysville, W.Va. After tying canes to trellis wires and rotating the cross-arms to below horizontal, tied canes were close to the ground, allowing them to be covered with protective materials, such as floating rowcover and polyethylene plastic during winter. Covers were removed in early spring and the canes remained in the horizontal orientation until bloom, which promoted flowering laterals to grow upright. After bloom, the cross-arm was rotated beyond vertical to position the fruit on one side of the row and improve harvest efficiency. In Jan. and Feb. 2005, the daily minimum temperatures under the FRC+PE covers were about 3 °C higher than in the open. The covers also provided protection against the wind. Tissue damage in protected trailing blackberries was significantly less than for unprotected plants. `Siskiyou' plants in covered plots produced 3 to 5 times more fruit than plants in the open. Harvesting of `Siskiyou' fruit occurred during the red raspberry harvest season or 2 to 3 weeks earlier than for eastern blackberries. Our findings suggest that trailing blackberries can grow satisfactorily and produce fruit if the adverse effect of low temperatures and winds is mitigated with our trellis system and winter protection method. If practical cultural techniques for improving their winter survival become available, there is a potential for early-season high-quality blackberry production in the mid-Atlantic coast region.
A 3-year study was carried out on the use of row covers as a substitute to straw for winter protection of five strawberry cultivars. Seven cover treatments were tested: “Agronet” removed on May 2, 12 and 19; “Kimberlay farms” removed May 19; perforated polyethylene removed May 16; conventionnal straw mulch removed in mid-April, and no row cover protection. Row covers advanced first harvest for all cultivars. There was a 10-day gain in earliness with perforated polyethylene followed in decreasing order by “Kimberley farms”, “Agronet”, straw mulch, and no protection. Treatments favoring early yields tended to shorten the period of production and to reduce total yield. Of the “Agronet” treatments, the May 12 removal increased the yield for the first 4 harvests compared to the May 2 and May 19 removals.
Renewed interest in red raspberry production in Colorado has been limited by winter kill of canes. Winter kill in Colorado may be the result of extreme cold temperatures, desiccation, or a combination of the two. We are evaluating winter protection strategies to increase survival and to better understand the winter stress of raspberries. The four (4) cane treatments of red raspberry, Rubus ideaus L. cv. Heritage, used were (1) canes bent and wrapped with plastic; (2) canes bent and mulched with hay and soil; (3) canes upright with anti-desiccant spray; (4) a control of canes upright without protection. Moisture content and electrolyte leakage were evaluated at intervals. Relative moisture loss was greatest in the control as compared to the other treatments. The terminal sections of the canes exhibited greater moisture loss as compared to basal sections in the control with a similar trend in the other treatments. Relative survival as indicated by electrolyte leakage was monitored and will be correlated with moisture loss.
Extensive winterkill of golf greens is a major problem in northern climates. In this study, the efficiency of several protective covering materials used to shelter Poa annua golf greens from winter damages was evaluated over 2 years. The bioclimatological environment under these protective covers was studied at crown level and at 5, 10, and 20 cm under the ground Treatments (permeable and impermeable covers, curled wood Excelsior mat, straw mulch protected by an impermeable cover, geotextile material with an impermeable cover, and air space under an impermeable cover) were compared to a control treatment without protection. Results indicate that temperature profile was strongly influenced by both winter protection covers and snow depth Temperatures at crown level were stable and just below 0C under plots covered with a significant amount of snow. However, temperatures varied considerably, when snow cover was <15 cm. Snow thermal conductivity was increased by periods of rain during the winter. Impermeable covers minimized the negative effect of this change in the insulation properties of the snow cover by limiting temperature fluctuations at the crown level. Temperature profiles under permeable covers were similar to profiles observed on control plots. Temperature profiles were comparable for 5 and 10 cm air space treatments and were not significantly different when compared to impermeable covers spread directly on the turf. Straw with an impermeable cover and Excelsior mats maintained crown level temperatures at >0C and the incidence of disease was higher under these highly insulative materials.
cultivar(s) for production in the northern Great Plains using the RCA trellis system and several types of rowcovers for winter protection. Materials and Methods Design. This experiment was conducted as a randomized complete block design and arranged as a
On average, one year in ten is a true test winter for screening winter hardy plants. Thus, screening of cultural practices under field conditions is often difficult, requiring many years data. In Saskatchewan, the two major winter stresses are low temperature and desiccation. Under controlled lab conditions, a rapid screening method for cultural practices on strawberry (Fragaria × ananassa Duch.) plants was developed. Temperature profiles and survival under various row covers and mulches in this controlled system corresponded well to previous field results. Straw over plastic and snow over plastic row covers conferred the best low temperature protection on these plants.
Although the inland Pacific Northwest has a warm climate during the growing season, grapes grown in this region may be exposed to colder than optimal temperatures at several times during the year. In addition to damage from spring and fall frosts, intermittent winters with little to no snow cover and subzero temperatures can cause vine dieback and death. Temperature patterns in the recent past indicate that both fall and midwinter are times when risk of bud damage from cold events is probable, making proper site selection and cultivar choice critical. Water is not used for frost protection in this climate, but wind machines have proven to be useful. In frost-prone sites, annual sucker growth with cane burying is practiced as an insurance strategy. Modifying pruning strategies has not been shown to be advantageous after fall cold events. If rootstocks are used, research has shown greater scion survival with higher graft positions.
Four methods of overwintering container-grown ornamental nursery stock were evaluated. Canopy temperatures of plants unprotected or covered with a thin layer of ice closely followed air temperatures during subfreezing conditions; minimum ambient air temperature was – 16C. Canopy temperatures under white copolymer film fluctuated widely, while canopy and growth medium temperatures of plants continuously irrigated during subfreezing temperatures did not drop below 0C. Root injury of all species and foliar injury of azalea (Rhododendron × ‘Due de Rohan’), euonymus (Euonymus japonica Thunb. ‘Microphylla’ H. Jaeg.), and pittosporum [Pittosporum tobira (Thunb.) Ait.] were least when plants were continuously irrigated or covered with white copolymer film. Foliage of Japanese holly (Ilex crenata Thunb. ‘Compacta’) and dwarf Burford holly (Ilex cornuta Lindl & Paxt. ‘Burfordii Nana’) was not injured with any treatment. Bark splitting of azaleas was most severe under the thinly iced and white copolymer-covered treatments, less severe in the unprotected treatment, and least with continuous irrigation.
The benefit of applying an antitranspirant for protection of cranberry (Vaccinium macrocarpon Ait.) vines exposed to desiccating conditions was evaluated at four different sites, two sites per year, for a period of 1 year each. Overall, plots receiving one fall application of an antitranspirant produced more berries and greater total fruit mass the following year than did nontreated plots. Overall dry leaf mass was not significantly affected. At one site, treated plots had more flowering uprights and more flowers per upright per unit of ground area than the nontreated plots. For cranberry growers who cannot maintain a winter flood, one fall application of pinolene (Vapor Gard) may offer some protection against winter injury. Further research is needed to document long-term yield effects as well as to clarify the role of the antitranspirant in protecting exposed vines and floral buds against adverse winter conditions. Chemical name used: di-1-p-menthene (pinolene).
that, with the help of rowcovers, strawberry could be successfully produced through winter, although unpredictable low temperatures in winter could cause chilling damage to fruit ( Gu et al., 2017b ). Additional winter protections such as adding low