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.
Fumiomi Takeda and David Handley
David Handley and Barbara Goulart
Fourteen cooperators representing four universities and the USDA/ARS developed a 5-year program of research and education for small fruit production in the northeastern United States. The objectives were to develop and test alternative production practices for strawberries and raspberries, to analyze the economic feasibility of sustainable production practices, to evaluate grower acceptance of sustainable technology, and to deliver the knowledge based on this research to the farming public. Specific research efforts determined strawberry and raspberry cultivar susceptibility to insects and disease and the influence of various cultural practices on crop susceptibility to disease, insects, and weed competition. Farmers indicated a willingness to adopt new sustainable technologies, even if profits might be reduced. However, they were not willing to commit more management time to such technology. Information delivery channels included a newsletter, more than 150 public presentations, and more than 100 publications.
David T. Handley
A light frost in a field of strawberries (cv. Redchief) resulted in varying degrees of injury to blossom receptacles. Five injury categories were established: 1. No damage; 2. Brown discoloration only at the tip of the receptacle; 3. Brown discoloration over approximately 1/2 of the receptacle; 4. Brown discoloration over the entire receptacle; 5. Black discoloration over the entire receptacle. From each category four blossoms at anthesis were tagged and allowed to develop for 30 days. Blossoms with no visible injury on the receptacle developed normally. When browning was observed on the tip of the receptacle or on approximately 1/2 of the receptacle, various deformities developed, tending to be more pronounced in the latter category. Blossoms with brown or black receptacles generally died. Thus, expression of frost injury on strawberry blossoms in the field can vary greatly.
David T. Handley
Frost injury on strawberry flowers (cv. Redchief) was studied in a field over two seasons. During the first season, a light frost during anthesis caused varying degrees of injury to blossoms. Five grades were assigned to the blossoms according to the degree of injury observed. The resulting fruit malformations correlated to the severity of blossom injury, ranging from no development (blossom death) when flower receptacles were completely black, to slight dimpling when only a portion of the receptacle had been discolored. During the second season, a colder frost occurring at the bud stage caused generally greater injury to the blossoms. The range of injury was less variable, therefore only three grades were assigned to the blossoms. The resulting fruit malformation again related to the intensity of blossom injury. Frost has long been understood to kill unprotected strawberry blossoms. This study has shown that nonfatal frost injury to strawberry blossoms can result in a variety of fruit malformations which previously may have been attributed to other causes.
Mark G. Hutton and David T. Handley
Twenty-seven green bell pepper (Capsicum annuum) cultivars were evaluated over three growing seasons in Maine. Each year, plants started in a greenhouse were transplanted into double rows on raised beds covered with black plastic mulch. Overall yields were low compared with similar experiments in other regions of North America and varied considerably from year to year. ‘Ace’ and ‘New Ace’ consistently produced the largest crops by both weight and number of fruit. However, both of these cultivars had undesirable characteristics of small fruit size (<150 g), few lobes (two-three), and thin fruit walls (<6 mm), limiting their commercial market potential. Other cultivars, including ‘Vivaldi’, ‘Patriot’, and ‘Socrates’, had significantly better fruit quality but very low or inconsistent yield. The results of this study demonstrate the current limitations for growing economically viable crops of bell peppers in regions such as Maine that have short growing seasons and a wide range of seasonal temperatures. Further, the data underline the need for the development of cultivars better adapted to these growing conditions.
Christina S. Howard, Renae Moran, and David Handley
The strawberry bud weevil (Anthonomus signatus), “clipper,” is an invasive pest to northeastern U.S. strawberry and raspberry crops. Strawberry is the primary host of clipper, but it has been observed damaging raspberry crops as well. The first objective for this research is to determine the importance of clipper as a pest on raspberries in the northeastern U.S. Raspberry plantings were scouted weekly on 13 grower-cooperator farms in Maine during the late spring and early Summer 2005 for the adult insects and bud injury (clipped or not). 10 canes from each site were then collected and the number of total buds and clipped buds were taken. This data will be correlated with the bud injury data to determine interrelationships between clipper populations and bud injury levels on different varieties of raspberries. The first year of this research has determined that clipper is a pest of raspberry in the northeastern U.S. Up to 55% clipper damage was found on raspberry plants in 2004 and up to 22% clipper damage was found in 2005. The other objective for this research is to develop integrated pest management (IPM) strategies for clipper on raspberry crops in the northeastern U.S. While scouting the farms this past summer, some different scouting techniques were tested for their efficiency and effectiveness at predicting the population levels of clipper on the crop. The scouting method of white sticky traps were hung in the field and provided the most accurate method of scouting for clipper in the field. In addition to this research, the importance of clipper as a pest of raspberries was tested using greenhouse-grown plants. They were analyzed for the ability of raspberry fruit yield to compensate for the loss of flower buds due to clipper damage. The research showed that plants with any clipped buds yielded significantly lower and the mean number of berries is significantly lower than the control plants with no clipped buds. The results also showed that the mean berry size was highest if there were no primaries clipped and significantly lower if primaries or secondaries were clipped concluding that there is little or no compensation in Killarney red raspberries when buds are clipped. This is a thesis project in progress with one more season of data to collect. Concluding the research, this work should improve grower awareness of clipper as a pest of raspberries and provide an IPM program to manage clipper on raspberries in the Northeast.
David T. Handley and James E. Pollard
Greenhouse experiments were designed to study conditions affecting strawberry malformation caused by the tarnished plant bug (TPB). Duration of blossom exposure to TPB affected the type of malformation. Exposure at anthesis for 8 hours caused visible deformity. Exposure for 48 hours caused some apical seediness, the malformation most commonly associated with TPB. Continuous exposure to TPB usually caused blossom death. Increased exposure to TPB caused a higher percentage of nonviable achenes per strawberry. Some effects appeared to be cultivar-dependent. Honeoye strawberries were less likely to show apical seediness than Redchief strawberries, but were more likely to experience blossom death. Malformation was also affected by strawberry development stage at the time of TPB feeding. Feeding at prebloom caused blossom death. Feeding at petal fall or achene seperation resulted in fruit malformation, about half of which was apical seediness. Feeding at pink receptacle stage caused little visible damage.
Mark G. Hutton and David T. Handley
Bell peppers (Capsicum annuum) are an economically important yet difficult to grow crop in northern New England. Yields of bell peppers can be increased through the use of plastic mulches; however, refinements are needed to make bell peppers a more viable crop in regions with short, variable growing seasons. The objectives of this study were to (1) compare the effects of black mulch with white inter-row much, reflective silver mulch, and standard black plastic mulched beds on bell pepper yield and quality and (2) compare the effects of two in-row plant arrangements [single rows at 12-inch within-row spacing (7260 plants/acre) and double rows spaced 18 inches apart with 18-inch in-row spacing (9680 plants/acre)] on pepper yield and quality. Treatments were factorial combinations of three mulch treatments and two within-row planting arrangements. Double rows produced more fruit by number and weight than single rows; however, fruit harvested from the double-row plots tended to be smaller than fruit harvested from the single-row plots. Mulch treatments significantly influenced total marketable yield and yield of cull bell peppers grown in Maine. The plots receiving the inter-row white mulch or reflective silver mulch treatment produced significantly greater yield than standard black plastic mulch treatment. The reflective mulch treatment produced significantly more cull fruit per acre compared with the white inter-row mulch and black plastic.
David T. Handley and James E. Pollard
The tarnished plant bug (Lvgus lineolaris) is a serious pest of strawberries in North America, causing a severe malformation of the receptacle known as “apical seediness” or “buttoning”. Light and scanning electron microscopy were used to assess tarnished plant bug feeding on strawberries and to determine the nature of the injury. During early fruit development stages (anthesis to petal fall) the primary feeding sites were developing achenes. Feeding sites on more developed fruit changed to receptacle tissue, usually close to an achene. The “buttoning” malformation of strawberries associated with tarnished plant bug is most likely a result of the destruction of achenes during early fruit development stages. Feeding on receptacle tissue later in fruit development causes more localized damage, such as creases and indentations.
Tori Lee Jackson, Mark G. Hutton, and David T. Handley
Corn earworm [CEW (Helicoverpa zea)] is one of the most important pests of sweet corn (Zea mays) in New England. Conventional management of this pest is achieved through repeated applications of chemical insecticides through the silking period. Organic growers, however, have few alternatives to prevent CEW infestation. Technology first developed in the 1930s and 1940s, using applications of mineral oil directly into the silk channel with an eyedropper, has been further researched in recent years using vegetable oils with and without pesticides, but pollination problems associated with these treatments have been observed. Several materials were evaluated for efficacy in controlling CEW populations and for phytotoxicity to the developing ear. Materials evaluated were corn oil, soy oil, carrageenan, corn oil mixed with Bacillus thuringiensis ssp. kurstaki (Bt), soy oil mixed with Bt, and carrageenan mixed with Bt. All treatments were compared with an untreated control. Treatments provided a range of 33% to 50% control of CEW infestation. The oil and Bt combinations provided some reduction in infestation compared with the untreated controls (33% vs. 100% infestation), but this level of control was inadequate for all wholesale markets and most direct markets. Additionally, oil-based treatments also caused significant injury to developing ears by reducing pollination quality, impacting the development of the kernels at the ear tip. This condition referred to as “cone-tip” is of concern since it may decrease marketability. The percent unmarketable ears due to cone-tips ranged from 0% to 13% for the untreated and carrageenan-based treatments. From 12% to 42% of ears were unmarketable due to the soy oil treatments. Corn oil treatments caused 10% to 50% cone-tips.