Progress 07/01/07 to 06/30/10

Outputs
OUTPUTS: The objectives of this research were to: 1 Evaluate a mechanical asparagus harvester prototype for performance related to yield, quality and reliability. 2 Confer with the leadership of the Washington asparagus industry to determine whether or not to develop a commercial scale machine. 3 Proceed with evaluation of a new harvester configuration in 2009. Since 2006, 5 harvester prototypes were evaluated with limited positive results. A multi-row prototype manufactured by Kim Haws of Agri-Trac Inc, Mesa, WA was selected for evaluation in 2009. The goal is the development of a multi-row harvester capable of harvesting 50 acres per day of pack-out grade fresh asparagus. Although the harvester was not ready at the start of harvest, there was the opportunity to test it later in the season. Performance was very good meaning the harvester recovered 80% of asparagus compared to hand harvesting operating over 3 rows at 5 mph. Full season evaluation is planned for 2010. Full reports will be available upon request. PARTICIPANTS: USDA Special Grants, Ag Research Center, Washington Asparagus Commission, Cooperating growers and packers TARGET AUDIENCES: Asparagus industry, Growers, Processors, Refereed journals PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Developing and adopting harvesting technology for asparagus and other fruits and vegetables provides an important means for the food production system to address increasingly urgent concerns including global competition and ensures maintaining Washington State's position in national and international markets. Past research has indicated that mechanical harvesting of asparagus is not economical, based on high capital cost and low labor costs (Hopper and Folwell, 1998, Folwell and others, 2000). Our work indicates that due to global competition and the cost of labor particularly in the State of Washington, mechanical asparagus harvesting is a practical solution if the harvester can meet the performance specification noted above (Clary and others, 2007).

Publications

• No publications reported this period. A manuscript will be prepared pending second year evaluation in 2010

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The objectives of this research were to: 1) Evaluate a mechanical asparagus harvester prototype for performance related to yield, quality and reliability. 2) Confer with the leadership of the Washington asparagus industry to determine whether or not to develop a commercial scale machine. 3) Proceed with evaluation of a new harvester configuration in 2009. Since 2006, 5 harvester prototypes were evaluated with limited positive results. A multi-row prototype manufactured by Kim Haws of Agri-Trac Inc, Mesa, WA was selected for evaluation in 2009. The goal is the development of a multi-row harvester capable of harvesting 50 acres per day of pack-out grade fresh asparagus. Although the harvester was not ready at the start of harvest, there was the opportunity to test it later in the season. Performance was very good, meaning the harvester recovered 80% of asparagus compared to hand harvesting. Full season evaluation is planned for 2010. PARTICIPANTS: USDA Special Grants, Washington State University's Ag Research Center, Washington Asparagus Commission TARGET AUDIENCES: US asparagus industry, refereed journals PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Developing and adopting harvesting technology for asparagus and other fruits and vegetables provides an important means for the food production system to address increasingly urgent concerns including global competition and ensures maintaining Washington State's position in national and international markets. Past research has indicated that mechanical harvesting of asparagus is not economical, based on high capital cost and low labor costs (Hopper and Folwell, 1998, Folwell and others, 2000). Our work indicates that due to global competition and the cost of labor particularly in the State of Washington, mechanical asparagus harvesting is a practical solution if the harvester can meet the performance specification noted above (Clary and others, 2007).

Publications

• No publications reported this period

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: The objectives of this research were to: 1 Evaluate mechanical asparagus harvester prototypes for performance related to yield, quality and reliability. 2 Confer with the leadership of the Washington asparagus industry to determine whether or not to develop a commercial scale machine. 3 Complete a commercial three-head harvester by 2006. Four harvester prototypes were evaluated in 2006. It was recommended to continue evaluation of two of the prototypes in 2007 and one prototype in 2008. Complications in development will defer testing until the spring of 2009. This unit is made by Oraka Harvesters, New Zealand. The other harvester that did not perform sufficiently for continued evaluation was built by Geiger Lund, Stockton, CA. The goal is the development of a multi-row harvester capable of harvesting 50 acres per day of pack-out grade fresh asparagus. PARTICIPANTS: USDA Special Grants, Ag Research Center, Washington Asparagus Commission TARGET AUDIENCES: US Asparagus industry, Refereed journals PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Developing and adopting harvesting technology for asparagus and other fruits and vegetables provides an important means for the food production system to address increasingly urgent concerns including global competition and ensures maintaining Washington State's position in national and international markets. Past research has indicated that mechanical harvesting of asparagus is not economical, based on high capital cost and low labor costs (Hopper and Folwell, 1998, Folwell and others, 2000). Our work indicates that due to global competition and the cost of labor particularly in the State of Washington, mechanical asparagus harvesting is a practical solution if the harvester can meet the performance specification noted above (Clary and others, 2007).

Publications

• No publications reported this period

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: In the spring of 2007, two selective mechanical asparagus harvesters were evaluated. A single-row tractor drawn asparagus harvester prototype developed by Geiger Lund Harvesters, Stockton, CA was evaluated in the Stockton area (phase I) as well as in Pasco, WA (phase II). The harvester head employs parallel pairs of counter-rotating "rollers" that engage asparagus spears that have reached a specified height. As the machine moves down the row, the optical system senses a spear of the selected minimum height and actuates a cutting system that drives the closest blade into the soil at the base of the spear. The spear is pulled through counter-rotating rollers onto a backstop and conveyer that transports spears to the rear of the machine. Economic analysis indicates that a three-row harvester must recover 70% of hand-harvested yield to be viable. The other three harvesters were evaluated only during phase II in Pasco, WA. Oraka Developments LTD from New Zealand tested a pull-behind selective mechanical harvester that utilized a horizontal and vertical moving cutter and pickup system cutting one spear at a time and delivering the spear to a conveyor for collection. The Geiger Lund machine was evaluated based on how many spears were detected by the harvester and cut the verses the number of spears unsuccessfully captured by the machine. Uncaptured spears included side cut spears that were not fully cut and spears that were dropped, or not captured in the rollers. The reason this analysis is included is it may be necessary to include a worker following the machine to maintain the beds and pick up dropped and side cut spears. The results of this analysis indicated the harvester did not meet the required 70% recovery and in fact did not perform as well as in 2006. Economic projections require that the harvester recover at least 70% of the total yield to be profitable. When compared to the plots harvested by hand, the Oraka machine met or exceeded the required 70% efficiency. However, ground speed was very slow and the tractor pulling the unit routinely had to stop so the harvester could keep up with the harvest operation. An attempt was made to speed up operation by modifying the machine in time for harvest in New Zealand in December, 2007. PARTICIPANTS: Clary, C.D., T. Ball, E. Ward, S. Fuchs, J. E. Durfey, R. P. Cavalieri, R. J. Folwell and C. M. Read TARGET AUDIENCES: Washington Asparagus Commission

Impacts
Developing and adopting harvesting systems for asparagus provides an important means to address increasingly urgent concerns including the rising cost of labor and global competition. These systems will help to maintain Washington State's position in national and international markets. In addition to increases in the minimum wage to over $7/hr, changes in international trade policies have presented significant challenges to the asparagus industry in Washington State. The asparagus industry has been impacted by imports from Peru. Which now account for 80% of fresh asparagus consumed in the US. In addition to foreign competition, labor for hand harvesting asparagus has become scarce, particularly at the end of the season. It is common for fields to be abandoned prematurely due to lack of labor. This has prompted the industry to evaluate mechanical harvesting in order to reduce production costs associated with hand labor and extend the harvest window when hand labor is not available.

Publications

• Clary, C., T.Ball, E.Ward, S.Fuchs, J.E.Durfey, R.P.Cavalieri, and R.J.Folwell. 2007. Performance and Economic Analysis of a Selective Asparagus Harvester.. Applied Engineering in Agriculture. 23(5):571-577.
• Cembali, T., M.Mari, R.J.Folwell, and C.Clary. 2007. Economic Analysis of improvements in asparagus harvesters with a simulation model. Transactions of the ASAE. 50(3):789-794.

Progress 01/01/06 to 12/31/06

Outputs
In the spring of 2006, four selective mechanical asparagus harvesters were evaluated. A single row asparagus harvester prototype developed by Geiger Lund Harvesters, Stockton, CA was evaluated in the Stockton area (phase I) as well as in Pasco, WA (phase II). The harvester head employs parallel pairs of counter-rotating "rollers" that engage asparagus spears that have reached a specified height. As the machine moves down the row, the optical system senses a spear of the selected minimum height and actuates a cutting system that drives the closest blade into the soil at the base of the spear. The spear is pulled through counter-rotating rollers onto a backstop and conveyer that transports spears to the rear of the machine. Economic analysis indicates that a three-row harvester must recover 70% of hand-harvested yield to be viable. The other three harvesters were evaluated only during phase II in Pasco, WA. Larsen Manufacturing of Pasco, WA designed a pull-behind pickup mechanism that incorporated rotating foam diamonds for grasping spears. If successful, Larsen would proceed with the development of detection and cutting systems for 2007. Oraka Developments LTD from New Zealand tested a pull-behind selective mechanical harvester that utilized a horizontal and vertical moving cutter and pickup system cutting one spear at a time and delivering the spear to a conveyor for collection. HiTek Services, Inc. (Owens Cross Roads, AL), had a harvester with a stop and go system allowing it to detect, cut, and pick up asparagus. Spears enter the unit via channels that guide them into the capture area where a set of soft rubber grippers rotates into place to stabilize and hold the spear while a 1.5 inch cutting blade descends to cut them one at a time. The spear is lifted vertically and transported into a tray located on the side of the harvester. The Geiger Lund machine was evaluated by collecting the spears that were detected by the harvester and cut, but were not successfully captured by the machine. This included side cut spears that were not fully cut and spears that were dropped, or not captured in the rollers. The reason this analysis is included is it may be necessary to include a worker following the machine to maintain the beds and pick up dropped and side cut spears. The results of this analysis indicated the harvester successfully detected and cut an average of 66.4% and 68.5% in two varieties compared to hand harvesting. Economic projections require that the harvester recover at least 70% of the total yield to be profitable. When compared to the plots harvested by hand, the Oraka machine ranged 90 to 50% in one variety and 70 to 25% in the other variety. The Oraka machine experienced a number of electrical problems including problems with servo motors and the lasers failing to detect spears in the center of the row, missed spears and damage to spears being harvested. Ground speed was very slow and the tractor pulling the unit routinely stopped so the harvester could keep up with the harvest operation. Data for the Larsen pickup mechanism was based on the number of spears cut successfully and captured in the pickup mechanism.

Impacts
Developing and adopting harvesting systems for asparagus provides an important means to address increasingly urgent concerns including the rising cost of labor and global competition. These systems will help to maintain Washington State's position in national and international markets. In addition to increases in the minimum wage to over $7/hr, changes in international trade policies have presented significant challenges to the asparagus industry in Washington State. The asparagus industry has been impacted by imports from Peru. Peru now accounts for 80% of fresh asparagus consumed in the US. In addition to foreign competition, labor for hand harvesting asparagus has become scarce, particularly at the end of the season. It is common for fields to be abandoned prematurely due to lack of labor. This has prompted the industry to evaluate mechanical harvesting in order to reduce production costs associated with hand labor and extend the harvest window when hand labor is not available.

Publications

• No publications reported this period

Progress 01/01/05 to 12/31/05

Outputs
Based on 60% level of field efficiency a mechanical asparagus harvester could economically harvest 2.45ac/h. The harvester modified for 2005 was tested in El Centro CA in a randomized trial consisting of ten replicated plots each for hand- and machine-harvesting. The replicated plots were harvested on five separate days over an eight day period. Based on the composite data from all five days, the average harvester yield for the five days of testing was 56%, which is still significantly lower than the 60% requirement. It was noted that a large portion of what the harvester cut successfully was dropped. Based on the assumption dropped spears can be recovered after the machine was modified again, an analysis was conducted including the dropped spears. Average recovery was 78% which was significantly higher than the target of 70% (5% level). This recovery is greater than the recovery achieved by the previous version of the Geiger Lund prototype evaluated in 2004. The machine was operated over a 60 day period in two fields north of Pasco, WA in 2005. Numerous improvements were made including addition of two sets of rollers to reduced drops, the reinforcement of cylinders and mounting brackets decreased breakdowns, conveyor systems eliminated damage and timing of the cut was improved. Initial startup days with the machine would generate a machine versus hand efficiency above the economically acceptable level of 70%. However, in subsequent days the efficiency would decline. Collateral damage was likely the primary reason. Narrower blades (width) and more sensors are a practical solution to reduce the amount of collateral damage. The harvester's mechanical systems have been significantly improved and are now functional and reliable during long term operation. However, the declining efficiency is of concern. Future evaluation of this machine is contingent on narrower blades, in addition to the effect of field conditions and asparagus varieties. It is as important to modify the field conditions to optimize machine performance based on a complete production system, such as has occurred in the grape industry with harvesters. Although the Geiger Lund harvester efficiency is not at the economically acceptable level over the multiple harvest days, there was significant progress made in the Pasco, 2005 trials. Harvester reliability has improved to the extent daily operation was possible without breakdowns. This is the result of three re-models of the machine in a one year period. We recommend continuing the development of the Geiger Lund harvester and appropriate consideration and testing should also be done on any other available selective harvester technologies throughout the world in 2006.

Impacts
Developing and adopting harvesting systems for asparagus provides an important means to address increasingly urgent concerns including the rising cost of labor and global competition. These systems will help to maintain Washington State's position in national and international markets. In addition to increases in the minimum wage to over $7/hr, changes in international trade policies have presented significant challenges to the asparagus industry in Washington State. The asparagus industry has been impacted by imports from Peru. Peru now accounts for 80% of fresh asparagus consumed in the US. In addition to foreign competition, labor for hand harvesting asparagus has become scarce, particularly at the end of the season. It is common for fields to be abandoned prematurely due to lack of labor. This has prompted the industry to evaluate mechanical harvesting in order to reduce production costs associated with hand labor and extend the harvest window when hand labor is not available.

Publications

• No publications reported this period

Progress 01/01/04 to 12/31/04

Outputs
During the 2004 asparagus harvest a single row asparagus harvester was evaluated in the Pasco/Mesa, Washington area. The harvester head employs parallel pairs of counter-rotating "brushes" that engage asparagus spears that have reach a specified height as the machine moves down the row. At the same time, optical detectors actuate pneumatic cylinders that drive the closest blade into the soil at the base of the asparagus shoot at a 40-degree angle. The spear is pulled through counter-rotating brushes onto a conveyer that transports the spears to the rear of the machine. Subsequent to minor modifications to the original machine in 2004, the single row harvester performance was recovery of 56 - 63% of what the hand crew picked of equal quality. Harvester efficiency was impacted by mechanical problems including malfunctioning cylinders and optical system problems. These systems have been improved by: upgrading the electronics, changing the number and angle of the knives, using faster cylinders, and increasing the number of harvester heads per machine. Based on 54-in rows and use of 3 harvester heads operating at 2.5mph, this machine theoretical harvest 4.09ac/h. Based on 60% level of field efficiency the machine could potentially harvest 2.45ac/h. Night harvesting would extend harvest operations and may improve quality based on lower temperature. OBJECTIVES: 1. Complete modifications on an existing asparagus harvester for immediate evaluation by August 15, 2004. 2. Design and construct a 3-row asparagus harvester for evaluation by March 1, 2005. PROCEDURES: Field evaluation. The August 15, 2004 tests were postponed until September. At that time, it was determined that the field was not going to produce asparagus of adequate grade to test the machine. A test is planned in El Centro, California, February 7-18, 2005. In the meantime, we had the opportunity to make more modifications to the harvester based on the preliminary evaluation made in September. Modifications of the 2004 machine include: Spear sensing - Simplify alignment; Pick up system - Reconfigure the impellers; Cutting System -Replace cylinders with 18 in. units, refine piston position detection system, change cylinder mounts to steel foot mounts and reconfigure valve-mounting plate; Bed height system - Replace mechanical sensor with optical sensor; and, Conveyor System - Functional. Experimental Design - El Centro, California. Two rows will be used in the field test. The 1/4-mile rows will be divided into 10 - 100ft plots, which will be randomly assigned machine or hand harvesting treatments (10 replications/treatment). The asparagus will be harvested daily and graded for quality and damage. Following harvest, missed and damaged spears will be counted within each 100-ft plot and the row yield will be measured by weight and grade. Deliverables: 1. Asparagus harvester with updated refinements. 2. Statistically based assessment of harvester performance and effect on quality compared to hand harvesting. 3. Recommendations for harvest in Washington State in Spring 2005.

Impacts
Changes in international trade policies have presented significant challenges to agriculture in Washington State. The asparagus industry has been impacted by imports of asparagus from Peru. Peru now accounts for 80% of fresh asparagus consumed in the US. This has prompted the industry to re-evaluate mechanical harvesting in order reduce harvest costs. Asparagus harvest is very labor intensive, consisting of daily harvesting over a 60-90 day period. A 3-head harvester operating at 2 mph over a 16-hour day will harvest 50 acres per day. It is anticipated that mechanical harvesting will not recover 100% of the crop, however economic analysis indicates the cost savings of the harvester would offset the un-harvested or dropped asparagus.

Publications

• No publications reported this period