School of Economic Sciences

Agribusiness Management

Selective Machine Harvester

by Trent Ball*

In October 2002, a selective asparagus machine harvester was analyzed. The selective harvester was developed in the 1980’s, but market conditions were not permissive for introduction, as labor at that time was inexpensive. With producers now experiencing high wage rates, more interest is in mechanical harvesting. Consequently, the selective harvester was reinstated, with brief trials done in the spring of 2002 in California.

The selective harvester is powered by a diesel engine; in addition, it contains an air compressor for the pneumatic cutting blades, both of which are located at the back of the machine. The harvester consists of a header cutting system in the front, along with belts that carry cut product to the rear of the machine. The cutting system uses eight knives to cover the span of a row. A sensor system is used to detect the height of individual spears. Similar to the cutting system, eight sensors are used to monitor a full asparagus row width. When the sensor’s are tripped, the high-speed pneumatic knives are activated and cut the spear. The cut spears are picked up by rollers in the front that grab all spears above approximately a six-inch height. The soft rollers release the spear if it is not cut by the knives.

A tentative agreement has been established to have the selective harvester running in Washington sometime during the 2003 harvest season. The purpose of running the harvester is to establish the efficiency and feasibility of application for Washington asparagus producers. The selective harvester will use only one header for the harvesting trials. However, the machine has the capabilities to have a three-row cutting system.

*Trent Ball was an Associate in Research, who worked with Dr. Ray Folwell, on the asparagus project. In October 2002, he traveled to Stockton, California to study the Selective Machine Harvester and its affects on the asparagus industry.

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Full-air brussed harvester machine

Selective harvester from the front

Selective harvester showing the blades


Heading using the h3 tag

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