Progress 07/01/03 to 06/30/06
Outputs
A mechanical harvester was evaluated in two phases: El Centro, California and Pasco, Washington. The selective asparagus harvester was operated for a period of 5 consecutive days in El Centro, California and obtained 56% of recovery compared to a hand crew, and additional analysis demonstrated the machine would have achieved 76% had 90% of dropped product been collected. An economic model was used to determine the break-even efficiency of the machine harvester, which was 70.15%. The machine was also operated over a period of 60 days in two fields north of Pasco, Washington. Each time a test was initiated, the harvester recovered more than 70% of hand harvest, however recovery declined I subsequent days. Electronic graders were evaluated further as to their application in Washington. In 2005, almost three-fourths of the fresh packers in the state added technology to their applications. Methods to improve the quality or extend the shelf life of asparagus focused on the
use of edible coatings, nutrient addition to asparagus, and pallet-sized modified atmosphere (MA) covers. Results indicate that asparagus treated with SemperFresh (sucrose ester of fatty acids) or Michem 13025 (carnauba wax) lost only 2-4% fresh weight compared to 10% loss for uncoated asparagus during a 2-week period when stored at 3C. Limited samples were taken of 9 asparagus varieties from the Central Washington growing area and analyses initiated for antioxidant activity and specific compound quantification. Antioxidant activities as measured by the ABTS method were greater at the later sampling dates (May and June) with mean values of 4700-5050 nM Trolox/g fresh weight in contrast to a mean of 2580 in April. Guelph Milennium a Canadian cv. Had a markedly greater antioxidant activity at the April sampling compared to the other varieties.
Impacts
The U. S. asparagus industry, if it is to survive the intensive offshore competition, must substitute technology for labor and shift the workforce to value-added employment. In a specialty crop industry such as asparagus, there are major barriers to developing innovative technologies to substitute for labor because there is a small market for such new technologies. It is imperative that public research universities do and/or foster the research to develop such technologies. At the farm level mechanized means of harvesting asparagus are being explored. This development would change the way asparagus is currently handled, allowing for development of value added products that make use of the whole spear. The outlook of the Washington asparagus industry would be altered because growers could compete with countries that have low wage rates. Significant progress has been made this past year with implementing technology in asparagus fresh packing sheds. Mechanical means to
handle asparagus will be implemented in several fresh sheds next season (2004) for the first time. The entire packing industry could move toward automation of the fresh handling process, based on a successful season by the packers with the new machines. Such technology adoption will benefit asparagus growers since the packer will have lower per unit costs, which can potentially be returned to the growers. In addition to the automation, improving and extending the shelf life of the fresh product will increase fresh handlers competitiveness in the national and international marketplace.
Publications
- Cembali, Tiziano, Raymond J. Folwell, Ray Huffaker, Jill McCluskey, and Philip Wandschneider. Economics of Alternative Simulated Manual Asparagus Harvesting Strategies. Agricultural Systems, 2005.
- Cembali, Marta Mari, Raymond J. Folwell, and Carter D. Clary. Analysis of Technological Advancements in Asparagus Mechanical Harvesters with a Crop Growth Model. Presented at the American Society of Agricultural and Biological Engineers Meeting, Portland, July 2006.
- Cembali, Tiziano, Raymond J. Folwell, Jill McCluskey, Ray Huffaker, and Philip Wandschneider. Economic Analysis of the Inter-year Effect of Alternative Harvesting Strategies for Asparagus. Journal of Vegetable Science, 12, 29-50, 2005.
- Cembali, Tiziano, Raymond J. Folwell, Ray Huffaker, Jill McCluskey, and Philip Wandschneider, 2005. Economic Evaluation of Selective Mechanical Harvesting for Asparagus. Forthcoming, Acta Horticulture (Proceedings for the XIth International Asparagus Symposium, Amsterdam, Netherlands.)
- Cembali, Tiziano, Raymond J. Folwell, Trent Ball, and Carter D. Clary. 2005. Economic Comparison of Selective and Non- Selective Mechanical Harvesting of Asparagus. Presented at the American Society of Agricultural and Biological Engineers Meeting, Tampa. July 2005. http://asae.frymulti.com/
- Cembali, Tiziano, Raymond J. Folwell, Ray G. Huffaker, Jill McCluskey, and Philip R. Wandschneider. 2005. Economic Evaluation of Selective Mechanical Harvesting for Asparagus. Presented at the 11th International Asparagus Symposium, Amsterdam. The Netherlands, June 2005. http://www.ias2005.com
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Progress 01/01/05 to 12/31/05
Outputs
The selective mechanical asparagus harvester was operated for a period of five consecutive days in El Centro, California at which point it obtained 56% of recovery compared to a hand crew, and additional analysis demonstrated the machine would have achieved 76% had 90% of dropped product been collected. An economic model was used to determine the break-even efficiency of the machine harvester, which was 70.15%. The machine was also operated over a period of 60 days in Pasco, Washington and each time a test was initiated, the harvester recovered more than 70% of hand harvest. Machine reliability was drastically improved from previous years and numerous improvements were made. The two sets of rollers reduced drops, the reinforced cylinders and mounting brackets decreased breakdowns, conveyor systems eliminated damage, and timing of the cut was dramatically improved. Initial test days in a field with the machine would generate a machine versus hand efficiency above the
economically acceptable point. It is possible that asparagus variety has a major impact on the harvesters ability to compete with a manual cutter. Varieties with spears that do not emerge in clusters may be more suitable for machine harvesting. Narrower blades and more sensors may be a practical solution to reduce the amount of collateral damage. Further, having control of the bed height with gauge wheels in combination with sensing systems would alleviate problems.
Impacts
The U.S. asparagus industry is facing increased competition from foreign producers. The actions of the Federal Government such as the North American Free Trade Agreement (NAFTA) and the Andean Trade Pact have placed the Washington/Oregon and Michigan asparagus industries at a competitive disadvantage in international and domestic markets. If the U.S. asparagus industry is to insure a competitive position, it must substitute technology for labor to lower per unit costs and shift the workforce to value-added employment. Instituting new technologies is imperative for the advancement of the industry now that the wage rate is indexed by the CPI-W in Washington.
Publications
- Cembali, T., Folwell, R.J., Ball, T. and C.D. Clary. 2005. Economic Comparison of Selective and Non-Selective Mechanical Harvesting of Asparagus. ASAE Paper Number: 053003. ASAE Annual International Meeting, Tampa, Florida.
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Progress 01/01/04 to 12/31/04
Outputs
A mechanical harvester was evaluated and initial results indicate the selective machine harvester did minimal field damage and could harvest 57% of the weight of the hand crew if all cut and dropped product was collected. The average pay weight grade was 66% and 79% for the harvester and hand crew, respectively. However, the harvester generated as high as 79% useable number one spears. An economic evaluation identified that the necessary efficiency the harvest must obtain to provide a return to the grower compared to hand harvesting is 65% at the current wage rates. It is estimated that after minor modifications the mechanical harvester will achieve a greater efficiency than this by the spring of 2005. Research on selected electronic graders indicated potential labor savings capabilities of up to 30%, and for the first time mechanical means to handle asparagus will be implemented in several fresh sheds next season (2005) due to the WSU project research. Modified
atmosphere (MA) packaging was examined at laboratory and commercial scale to study effects on quality attributes and storage life of fresh packed asparagus. Simulated commercial application of MA packaging of early and mid-season asparagus was successful in slowing deterioration and extending storage life. All small MA packages tested also improved quality of early and mid-season harvested asparagus. However, asparagus from a late season harvest developed severe tiprot in both MA and nonpackaged asparagus. Sensory analysis or taste tests found a preference for MA packaged over nonpackaged asparagus based on a sweeter and more flavorful taste. Commercial application of hot water treatment (HWT) were partially successful in slowing deterioration of quality in asparagus. Storage at high relative humidity provided better results than low relative humidity. Spears and trims from manual harvesting, mechanical harvesting, fresh packs, and pickling operations were used to evaluate if value
could be added through drying or juicing technologies. The pilot drying experiments have demonstrated the potential benefits of using innovative drying techniques such as Refractance Window and microwave vacuum system to gently dry asparagus within a very short time. Refractance Window drying takes very short time (less than 5 minutes) and demonstrates excellent color retention in dried vegetables. An unidentified compound that is likely a flavonoid was observed and presents an opportunity to increase the measurable antioxidant activity of asparagus via careful enzyme selection.
Impacts
The U. S. asparagus industry, if it is to survive the intensive offshore competition, must substitute technology for labor and shift the workforce to value-added employment. In a specialty crop industry such as asparagus, there are major barriers to developing innovative technologies to substitute for labor because there is a small market for such new technologies. It is imperative that public research universities do and/or foster the research to develop such technologies. At the farm level mechanized means of harvesting asparagus are being explored. This development would change the way asparagus is currently handled, allowing for development of value added products that make use of the whole spear. The outlook of the Washington asparagus industry would be altered because growers could compete with countries that have low wage rates. Significant progress has been made this past year with implementing technology in asparagus fresh packing sheds. Mechanical means to
handle asparagus will be implemented in several fresh sheds next season (2004) for the first time. The entire packing industry could move toward automation of the fresh handling process, based on a successful season by the packers with the new machines. Such technology adoption will benefit asparagus growers since the packer will have lower per unit costs, which can potentially be returned to the growers. In addition to the automation, improving and extending the shelf life of the fresh product will increase fresh handlers competitiveness in the national and international marketplace.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
A field research trial during the 2003 asparagus harvest season evaluated a selective harvester for feasible use as a commercial machine. Initial results indicate the selective machine harvester did minimal field damage and harvested 55-60 percent of the weight harvested by a hand crew. The harvester generated as high as 77 percent useable number one spears based on fresh market standards. Results suggest that the machine has potential application as a commercial harvester. A financial evaluation of the harvester indicates the machine can harvest at approximately 70-80 percent of a hand crew and still generate an economic benefit to the grower. Recent research on selected electronic graders in the grading and sorting process of fresh asparagus packing firms demonstrated potential labor savings capabilities. For the first time in several decades Washington will adopt technology in the fresh packing sheds. Experiments were conducted to investigate the effects of heating
or enzyme treatments on the phenolic composition and antioxidant activity of asparagus juice. Several commercial pectolytic enzymes were used to produce asparagus juice. Eight commercial pectolytic enzymes were incubated with asparagus juice at 37 percent C. Six of the eight enzyme preparations showed various abilities to hydrolyze rutin to quercetin. For most enzymes, although phenolic composition was changed, the total phenols were not apparently different from the control. Further research examined different methods of drying techniques for use in dehydrated soups. High quality dried asparagus can be made using Refractance Window (RW) methods.Hot water (HW) treatments to asparagus demonstrated beneficial quality attributes. Research focused on HW treatments followed by cold water, in depth modified atmosphere (MA) studies and treatment with an experimental growth regulator AVG to interfere with ethylene physiology of the spear. The combination of HW and AVG influenced asparagus MA
by lowering oxygen and increasing carbon dioxide in bags. Ethylene, a gaseous stress hormone, was decreased by HW treatment. The vitamin C and total antioxidant activity (TAA) experienced increases with MA-HW-AVG treatments. There is a demonstrated shelf life extension using these treatments, and they tend to have positive TAA effects. Fresh asparagus spears were heated at various times and temperatures to find optimal treatment to improve visual quality and to prevent geotropism. Color, texture, phenolics, and antioxidant capacity were also measured. Heating at 47.5 degrees C for 1 minute was optimal to improve visual quality, but unexpectedly, heat treatment increased geotropism. Phenolics appear to show no significant change with heating. Antioxidant capacity is still being measured. Data analysis is still under way.
Impacts
The U. S. asparagus industry, if it is to survive the intensive offshore competition, must substitute technology for labor and shift the workforce to value-added employment. In a specialty crop industry such as asparagus, there are major barriers to developing innovative technologies to substitute for labor because there is a small market for such new technologies. It is imperative that public research universities do and/or foster the research to develop such technologies. At the farm level mechanized means of harvesting asparagus are being explored. This development would change the way asparagus is currently handled, allowing for development of value added products that make use of the whole spear. The outlook of the Washington asparagus industry would be altered because growers could compete with countries that have low wage rates. Significant progress has been made this past year with implementing technology in asparagus fresh packing sheds. Mechanical means to
handle asparagus will be implemented in several fresh sheds next season (2004) for the first time. The entire packing industry could move toward automation of the fresh handling process, based on a successful season by the packers with the new machines. Such technology adoption will benefit asparagus growers since the packer will have lower per unit costs, which can potentially be returned to the growers. In addition to the automation, improving and extending the shelf life of the fresh product will increase fresh handlers competitiveness in the national and international marketplace.
Publications
- Ball, T. and R. J. Folwell. 2003. Alternatives to Manual Sorting Using Selected Electronic Graders in Asparagus Fresh Packing: A Cost-Benefit Analysis. EB 1958.
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