The tomato harvester is a marvel of engineering, science, and years of collaboration between experts of all aspects of the processing tomato industry. Originally developed by engineers working at the University of California at Davis, the first commercial harvester (manufactured by Blackwelder) had to be towed by a farm tractor and was very labor intensive to operate. 1970, 1980 and 1990 saw great strides in technological advancements in tomato harvester design, including self propulsion, increased throughput, and opto-electronic sorters that "kick out" dirt clods and sub-ripe tomatoes and keep only the operator-specified level of ripe tomatoes.
A harvester loading tomatoes.
A tomato harvester works by driving straight over a row of tomatoes (called a bed), and separating the main plant from the roots by means of an oscillating clipper or rotating bar (called a cutting bar). The tomatoes are then brought into the interior of the harvester by a large elevator belt. Once inside the harvester, the tomatoes themselves are separated from the vines by means of a shaker, which works by agitating the tomato-vine clusters with large, flexible, interlocking fingers that shake, hence the name "shaker".
A harvester cutter bar and conveyer belt.
Once separated from the vines by the shaker, the tomatoes are transported, by way of small conveyer belts, to be sorted. One of the greatest advancements in harvester technology has been the development of high-speed opto-electronic sorters. These sorters consist of a long array of photoemitters coupled with photoreceptors. The photoemitters project a continuous stream of light of a known wavelength, this light bounces off individual tomatoes as they pass by. The wavelength of light that is bounced back (interpreted by a photoreceptor) is analyzed to determine the color of a tomato, and hence, its ripeness. These devices, which can be calibrated to accept tomatoes of varying degrees of ripeness, are coupled with pneumatically actuated paddles. Dirt and unacceptable tomatoes are "whacked" onto the ground. Those tomatoes which do not meet specifications fall to the ground, where they will provide fertilizer for future processing tomato crops. The accepted tomatoes continue on their journey to tomato sorting specialists, who pick out any vines, green tomatoes, dirt clods, and moldy tomatoes that slipped past the scanners. Once past this stage, they are elevated onto a loading arm, then delivered into tomato trailers. The modern tomato harvester may have as many as 4 sets of electronic sorters--the more sorters, the fewer people necessary to hand sort--but this increases the cost of the harvester. A brand new harvester, fully outfitted with electronic sorters, costs over $300,000.
A loading arm filling tomato trailers.

 
Front view of a harvester.
California Sun Harvesting Company, a Morning Star partner company, has made great strides in dramatically increasing the efficiency of harvesting processing tomatoes. Traditionally, a contracted grower would have to purchase or lease at least one of these machines in order to transfer the tomatoes from the ground into the bins of tomato trucks. With the advent of California Sun Harvesting, growers are now freed of having to put forth large sums of money for the acquisition, operation, and maintenance of a machine that generates revenue for only 80 to 100 days per year. Because California Sun Harvesting specializes exclusively in the operation of tomato harvesters, both growers and the Morning Star Company have realized dramatically elevated levels of efficiency, which is passed on through the value chain.
Click the "PLAY VIDEO" button below to see a California Sun harvester in action.
The video pans from the harvester to show loaded sets of tomato trailers on what is known in the industry as the "pad", ready for pickup by tomato trucks.
Pay close attention to the width of the tomato beds, and note how the furrows match perfectly with both the width of the harvester's wheel spacing and that of the tomato trailer. The modern processing tomato industry acts as a highly efficient machine, where all aspects of this machine work harmoniously with one another on many different levels (some more obvious than others). This efficiency is constantly pushed ever higher by the work of Morning Star.