expensive to purchase, likely less expensive to apply when the drip irrigation system is used and has a relatively rapid N release rate ( Gale et al., 2006 ). Crops grown in organic production systems may require fewer fertilizer inputs and still produce
Javier Fernandez-Salvador, Bernadine C. Strik, and David R. Bryla
Amy Fulcher, Diana R. Cochran, and Andrew K. Koeser
and therefore cannot be planted or composted. This workshop provided an overview of alternatives to petroleum-based plastic containers for greenhouse, aboveground container production and pot-in-pot production systems. In doing so, the participating
Xiuming Hao, Guang Wen, Athanasios P. Papadopoulos, and Shalin Khosla
’, 2005A, and 24–119 grown in 2005; ‘Myrthos’ grown in 2006) were used in the experiments. Fig. 1. Set-up of the conventional single-head high-wire and twin-head “V” high-wire cucumber production systems on the raised troughs. 1 m = 3.2808 ft. Several
Brian Ward, Powell Smith, Susan James, Zachary Stansell, and Mark Farnham
to make broccoli production in that region more competitive with western production systems. Early in this effort, we proposed that it is especially important to test increased population densities combined with the use of contemporary broccoli
Mathieu Ngouajio, Rafael Auras, R. Thomas Fernandez, Maria Rubino, James W. Counts Jr, and Thitisilp Kijchavengkul
Fig. 1 . Laboratory tests with corn starch as a control have confirmed the biodegradability of the films ( Kijchavengkul et al., 2006 , 2008a ). However, field testing of the films is necessary to assess their performance in a production system
Peter J. Zale, Daniel K. Struve, Pablo Jourdan, and David M. Francis
propagated by sexual or asexual means, and amenable to container and field nursery production systems. Extensive phenotypic variation occurs in M. virginiana , and there exists opportunity for selection toward our proposed ideotypes ( McDaniel, 1966 , 1970
Aaron Heinrich, Richard Smith, and Michael Cahn
data). Although this winter-kill strategy to control biomass accumulation of cover crops may not consistently reduce nitrate leaching, it fits the constraints of the production system in the coastal valleys of California and may encourage more
Jennifer Nelkin and Ursula Schuch
Fresh weight production of basil (Ocimum basilicum`Genovese') growing in a retractable roof greenhouse (RRGH) or outdoors was evaluated under different shade environments, cultural production systems, and roof control strategies in a semi-arid climate. Cultural production systems included raised beds and towers consisting of six pots arranged vertically and stacked on edge. The growing substrate in both systems was perlite. The three shade environments included a RRGH with either a clear woven roof (35% shade) or a white woven roof (50% shade), or outdoors in full sun (0% shade). Within the RRGH, three strategies of roof control were tested based on air temperature thresholds, quantum thresholds, and globe thermometer temperature thresholds. After establishment, plants were grown for 4 weeks, each under the three roof control strategies in each environment and in both cultural systems. New shoots were harvested weekly and fresh weights were determined. Overall, fresh weight per plant was significantly affected by cultural production system, and basil grown in raised beds produced twice the biomass compared to plants grown in vertical towers. Productivity of basil grown in raised beds was not affected by the three shade environments, but plants in vertical towers produced about 20% more when grown in full sun or under 35% shade compared to under 50% shade. Within the RRGH, roof control strategy significantly affected basil fresh weight per plant. Roof control, based on either a quantum sensor or globe thermometer, increased production by 31% compared to air temperature control. Greater productivity was related to higher cumulative light exposure of plants. Quality of basil grown in the RRGH was superior to that grown in full sun.
P.A.W. Swain and R.L. Darnell
Two cultivars of southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrid), `Sharpblue' and `Wannabe', were container-grown outside in either a dormant or nondormant production system to determine how the two production systems affected carbohydrate (CH2O) status, growth, and development. Plants were maintained in the nondormant condition by continuous N fertilization throughout winter (average maximum/minimum temperatures of 17/5 °C). Plants in the nondormant system retained their foliage longer into the winter compared with plants in the dormant system. Flower bud number, density, fruit number, and total fruit fresh weight (FW) per plant were greater in the nondormant compared with the dormant system plants for both cultivars. Mean fruit FW was greater in dormant compared with nondormant `Wannabe' plants, while in `Sharpblue', mean fruit FW was similar in both systems. Cane and root CH2O concentrations in nondormant system plants were generally similar to or lower than those measured in dormant system plants. Assuming that longer leaf retention in nondormant system plants increased CH2O synthesis compared with dormant system plants, the patterns of reproductive/vegetative development and root/shoot CH2O concentrations indicate that the increased CH2O in nondormant system plants was allocated to increased reproductive growth in lieu of CH2O reserve accumulation. It is probable that this increased CH2O availability, combined with longer perception of short days due to longer leaf retention, were major factors in increasing flower bud initiation and yield in the nondormant compared with the dormant system plants.
Jens N. Wünsche, Alan N. Lakso, Terence L Robinson, Fritz Lenz, and Steven S. Denning
Although apple (Malus domestica Borkh.) system yield differences are generally related to whole-canopy light interception, this study tested the hypothesis that these orchard yields are related primarily to total light intercepted by the spur canopy. Seasonal leaf area development of different shoot types, exposed bourse shoot leaf net photosynthesis, fruit growth, whole canopy light interception (by image analysis of fisheye photographs) and relative light interception by different shoot types (by a laser assisted canopy scanning device) were estimated within four 14-year-old `Empire' apple production systems (slender spindle/M.9, central leader/M.7, central leader/M.9/MM.111 and Y-trellis/M.26). The final LAI values were CL/M.7 = 1.8, CL/9/111 = 2.3, SS/M.9 = 2.6 and Y/M.26 = 3.6. Exposed leaf net photosynthesis showed few differences and was not dependent upon the production system. Yields of the pyramidal shaped tree forms were 40 to 42 t·ha-1 while Y-trellis produced 59 t·ha-1, with similar fruit sizes. Again, yields were primarily related to the percentage of light intercepted by the whole canopy, 48% to 53% for conic forms versus 62% for the Y-trellis system. Laser analyses showed that the Y-trellis system intercepted about 20% to 30% more light with the spur canopy than the conic tree forms, supporting the hypothesis. Yields were better correlated with spur canopy LAI and spur canopy light interception than with extension shoot canopy LAI and light interception.