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.
Wesley Kline and Peter Nitzsche
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.
Stephen Reiners and Peter J. Nitzsche
`Pilgrim' tomatoes (Lycopersicon esculentum) grown under slitted clear polyethylene or spunbonded polypropylene rowcovers were compared to those with no protection for the effect on yield. Both covers significantly increased early yield in terms of fruit numbers and weight, but no differences were observed in total yields. In addition, no difference was observed in yield between two tomato transplant sizes- 4- to 5-leaf stage and 6- to 7-leaf stage---grown in the same-sized containers. The results from this study indicate that early tomato yield may be enhanced with the use of rowcovers.
Stephen Reiners and Peter J. Nitzsche
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.
Joseph R. Heckman, Ray Samulis, and Peter Nitzsche
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.
Peter J. Nitzsche, Jack Rabin, and Bruce Barbour
Fax-on-demand is a new system of communications that combines computer, fax, and telephone technologies. Corporate use of fax-on-demand has shown it to be a rapid, user-friendly, economical way to disseminate technical support information. A project was initiated to evaluate the usefulness of fax-on-demand for disseminating “time-sensitive” crop management information to growers. The system, named the “RCE FaxInfo Line,” has made extension newsletters, pesticide label updates, market price summaries, IPM insect counts and treatment thresholds, etc. available to callers 24 hours a day. While most of the producers surveyed felt the system fit their needs, there has not been widespread use. A limiting factor has been the lack of producers with fax machines. A recent survey revealed that only 8% of New Jersey farmers own fax machines. If this technology is to be effective for extension, the percentage of growers utilizing fax machines must increase.
Peter Nitzsche, Gerald A. Berkowitz', and Jack Rabin
The objective of this research was to develop an effective antitranspirant formulation for reducing transplant shock (transitory water stress) in bell pepper (Capsicm annuum L.) seedlings. A formulation with a paraffin wax emulsion (Folicote at 5%) and a spreader/sticker type surfactant (Biofilm at 0.5%) was effective as an antitranspirant. This formulation was less phytotoxic than other formulations tested. Application of the formulation led to increased leaf water potential (Ψ w) i in transplanted seedlings for several days as compared with untreated transplants. When this, (relatively) nonphytotoxic formulation was used in a field study for 1 year, increased seedling Ψ w during a period of imposed water stress led to less leaf abscission and increased plant growth throughout the growing season. Chemical names used: alkylarylpolyethoxyethanol (Biofilm).
Stephen Reiners, Peter J. Nitzsche, and William H. Tietjen
Spring-planted `Pilgrim' tomatoes (Lycopersicon esculentum) were grown under slitted clear polyethylene rowcovers on beds prepared in the fall with black plastic mulch and trickle irrigation. Fall beds allowed for earlier planting and a corresponding earlier harvest. Plastic mulch and trickle irrigation remained intact during the winter. There was no significant advantage to leaving covers on past the time of the traditional planting date for the area. It was estimated that the additional cost for this system would be about $1000 per acre. The profitability of this system will be determined by the price growers receive for their earliest fruit. An early season price of $0.60/1b is the approximate break-even figure. Higher early season prices will lead to much greater profits. For heatsensitive crops like tomatoes, using rowcovers on fall beds may effectively maximize early yield and profitability.
Stephen Reiners, James Nichnadowicz, Peter J. Nitzsche, and Stephen Bachelder
Peter J. Nitzsche, C.A. Storlie, W.P. Cowgill Jr., and W. Tietjen
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.