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- Author or Editor: Peter Nitzsche x
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Growers in Northern New Jersey are slowly adopting strawberry plasticulture as an improved production system. One advantage of the system is early fruit production. Early fruit usually brings high prices in the marketplace. With early production, however, there is an increased risk of a late frost damaging flowers and fruit. Removing floating rowcover winter protection earlier than flowering may cause strawberries to bloom later, reducing the risk of frost damage. Supporting the rowcovers above the crop with wire hoops may also provide better winter protection and improve fruit production. In 2 years of field trials, removing floating rowcovers 2 weeks before anticipated bloom reduced early yield and delayed the first harvest by 2 to 3 days. Total marketable yield and average fruit weight were not significantly influenced by early removal. Plants with rowcovers supported with wire hoops did not produce significantly greater total yields or average fruit weights than plants protected by unsupported rowcovers. The wire hoops caused damage to the rowcovers, which may make their use in commercial production impractical.
A 3-year study was established to evaluate a large number of heirloom tomato cultivars for horticultural characteristics and yield. The initial 2001 screening included 110 cultivars with fruit types from currant to beefsteak. The 110 cultivars were reduced to 12 (`Arkansas Traveler', `Box Car Willie', `Brandywine Red', `Carmello', `Cherokee Purple', `Costoluto Genovese', `Eva Purple Ball', `Hawaiian Pineapple', `Mortgage Lifter', `Prudens Purple', `Ramapo', and `Santa Clara Canner') based on yield, consumer preference and fruit characteristics and evaluated in 2004. The cultivars were arranged in a complete-block design with plots of eight plants replicated four times. Fruits were harvested 10 times from 15 July to 16 Sept., graded into marketable and cull, counted, and weighed. Internal and external fruit characteristics were evaluated at the seventh harvest from 10 randomly selected marketable fruit from three replications. Days to harvest from transplanting ranged from 61 to 82 days. For the early harvest (1–4), `Mortgage Lifter' (20.18 t·ha-1) and `Cherokee Purple' (19.23 t·ha-1) had significantly more marketable fruit than the other cultivars. By mid-season harvests (5–7), the cultivar Carmello (43.38 t·ha-1) yielded statistically more marketable fruit than all other cultivars. There were few differences among the cultivars for the late harvest (8-10) period. When all harvests were combined, `Carmello' (76.59 t·ha-1) had significantly higher yields than the other cultivars except `Mortgage Lifter' (74.72 t·ha-1). External and internal fruit characteristics varied among the various cultivars. All 12 cultivars would be acceptable in different market segments.
Three tomato varieties were evaluated for early and total yield using row covers. Tomatoes were planted three weeks earlier than the normal planting date and row cover treatments included; 1) slitted, clear polyethylene 2) floating, spunbonded, polypropylene and 3) bare, no row cover. `Pilgrim', `Celebrity' and' Mountain Pride' were selected as early, mid-season and late varieties, respectively. Row covers were removed after three weeks at which time a second planting was made, representing the normal planting time. Slitted, clear, polyethylene row covers significantly increased early yields in all varieties as compared to the bare treatment. In addition, clear row covers resulted in higher early yields in `Pilgrim' and `Mountain Pride' than floating row covers. Despite row covers over `Celebrity' and `Mountain Pride', early yields were still not as great as the `Pilgrim' cultivar without any row cover.
Sweet corn (Zea mays L.) growers evaluating new practices for N management, such as the presidedress soil nitrate test (PSNT), are interested in relating observations about crop performance at time of harvest to their N fertility program. For this purpose, the concentration of nitrogen (N) in the lower portion of sweet corn stalks was examined on the day of harvest as a basis for evaluating the crop N status. Sweet corn stalk tissue was collected from N-rate experiments by cutting a stalk section at 15 and 35 cm aboveground and removing leaf material from the resulting 20-cm segment. Samples were dried and analyzed for total Kjeldahl N. Relationships between crop yield and stalk N concentration indicated that concentrations <11 g·kg-1 are N deficient and underfertilized; N concentrations between 11 and 16.5 g·kg-1 are marginally deficient; and between 16.5 and 21 g·kg-1 the N status is optimum. Concentrations of N >21 g·kg-1 are above optimum and indicate that sweet corn was overfertilized with N. When soil nitrate concentrations (PSNT >25 mg NO3-N per kilogram) indicated sufficient N at time of sidedressing, stalk N concentrations generally indicated N sufficiency at harvest.
Fruit cracking in tomatoes is a serious problem, particularly when trellis culture is used. Past studies indicate that fruit cracking is associated with fluctuating soil moisture levels. Soil moisture variations are influenced by irrigation practices, and an irrigation regime employing frequent applications of water will lessen variations in soil moisture. A field study was initiated to study the effect of trickle irrigation regime on fruit cracking in `Celebrity' tomatoes (Lycopersicon esculentum Mill). In the three treatments used, soil was allowed to dry to 10-20, 50-60, and 100-110 centibars of tension, respectively, between watering and then was irrigated to field capacity. These tension levels corresponded with soil moisture levels of field capacity (10-20 cb), 20% of available water depleted (50-60 cb), and 40% of available water depleted (100-110 cb). Yield measurements indicated that the driest treatment (100-110 cb) significantly reduced the percent of radially cracked fruit. This treatment also significantly lowered the total yield, in terms of both fruit number and weight. There was no significant effect, however, on marketable fruit yield due to irrigation treatments. Further field studies are required to determine the optimum irrigation program to reduce fruit cracking.
The pre-sidedress soil nitrate test (PSNT) was evaluated in 27 fields in New Jersey, 6 in Connecticut, 5 in Delaware, and 2 on Long Island in New York for its ability to predict whether sidedress N is needed to grow fall cabbage (Brassica oleracea var. capitata) as a double crop. Soil NO3-N concentrations measured on 20 field sites on the day of transplanting and 14 days after transplanting indicated that NO3-N concentrations over this time period increased, and that residues from the previous crop were not causing immobilization of soil mineral N. The relationship between soil NO3-N concentration measured 14 days after transplanting and relative yield of marketable cabbage heads was examined using Cate-Nelson analysis to define the PSNT critical level. Soil NO3-N concentrations ≥24 mg·kg-1 were associated with relative yields >92%. The success rate for the PSNT critical concentration was 84% for predicting whether sidedress N was needed. Soil NO3-N concentrations below the PSNT critical level are useful for inversely adjusting sidedress N fertilizer recommendations. The PSNT can reliably determine whether fall cabbage needs sidedress N fertilizer and the practice of soil NO3-N testing may be extendable to other cole crops with similar N requirements.
The rapid expansion of Asian populations in the United States presents significant opportunities and challenges for the eastern U.S. produce sector to take advantage of their close proximity to densely populated areas. Initial crop studies followed by ethnic consumer and crop surveys were conducted to examine vegetable, leafy green, and herb consumption and expenditures among Chinese, Asian Indians, and other Asian groups. Consumer choices were used to prioritize subsequent production trials. Family expenditures were determined for specific Asian produce types and total produce purchases. This market data were extrapolated to the east coast Asian populations to assess potential market size (90% confidence interval, error margin 5.6%). Chinese consumer values ranged from $245 to $296 million per annum and Asian Indians ranged from $190 to $230 million per annum. The average annual fresh fruit and vegetable expenditures by both Asian groups were 2 to 3.5 times respective national averages. Leading Chinese vegetables determined by average expenditures were baby bok choy, pak choy, oriental eggplant, snow pea, oriental spinach, and napa cabbage. Highest expenditure of leafy greens and herbs for Chinese consumers were chives and garland chrysanthemum. This market-driven survey reported consumption of over 100 Asian crops and 42 cultivars were ranked “feasible” to grow in the eastern section of the United States. Horticultural matrices of selection criteria narrowed the list to the most promising candidates for production. As a result, 28 cultivars were then grown in University research and demonstration plots at Massachusetts, New Jersey, and Florida in determining growth characteristics and yield to focus horticultural crop producers. Leading vegetable cultivars for Asian Indian consumers were bitter gourd, eggplant, fenugreek leaves, cluster beans, and bottle gourd. Leading leafy greens and herbs for Asian Indians were turmeric, fenugreek, sorrel spinach, and radish greens. Most of these Asian cultivars were demonstrated to grow well in the three main growing zones of 5, 7, and 9. Phytochemical attributes such as antioxidant activity, polyphenols, and mineral contents were analyzed for several of the leading crop candidates. This initial field and laboratory data shows that many of these ethnic crops can be grown in the eastern United States to direct production opportunities and are nutrient rich to help drive consumer demand.