New Ag Mechanization

New Technological Innovations Make Field Mechanization Possible

A recent University of Arizona-Yuma study suggests that the tourniquet wrapped around shrinking supplies of available field workers for winter vegetable production in Yuma might grip even tighter in the future. As the Yuma field labor supply faces a continued drought of available field workers, the industry is preparing for the time when some workers are replaced with mechanization and technology. Such machines, now in various stages of development, could become essential for harvesting delicate fruits and vegetables that are still harvested by hand.

Mechanized harvesting wouldn't be new for some California crops such as canning tomatoes, low-grade wine grapes and nuts. But the fresh produce that dominates Yuma’s agricultural output - and that consumers expect to find unblemished in supermarkets - is too fragile to be picked or processed by the machines currently now in use. Highlighted below are four of the latest advances in agricultural technology that could be on the horizon for Yuma area producers.

Automated Transplanter (FIGURE 1)
Able to take vegetable seedlings from trays and plant them in a field at up to 20 per second, a new machine applies factory equipment and automation allowing producers to plant transplants with greater labor efficiency.

The machine was originally conceived by three brothers in a family nursery business but, it has since taken 10 years, thousands of dollars, and a lot of effort by a UK manufacturer of agricultural equipment to bring the device to market.

Missing or weaker plants are automatically detected and not planted resulting in higher planting efficiencies. These machines are already in service in the UK and point the way towards the automated processing of even the most variable and difficult to handle seedlings. The transplanter can plant a 20 acre broccoli field in a few hours, with the help of only three men: one driving the tractor and two on the back, putting trays of seedlings on the input platforms in time for telescoping pneumatic cylinders to push them into the seedling grasping and handling system. With current, semi-automated equipment, planting transplants is a task which takes several workers – mainly to take the seedlings out of the trays. The new machine can do 30-40 acres per day, selecting four plants per second on five heads and running forward at 4 miles per hour.

The automated transplanter is a very sophisticated system, with onboard computer systems capable of controlling every movement of the mechanism – from the speed of the planting heads, the actuators to the servo motors. The seedlings are grown in standard rigid trays with a separate, slightly tapered square aperture for each seedling. The plants are grasped and lifted out a row at time. Four steel fingers go in and pick each one from the germination tray. Computer controlled optical sensors ensure that weaker seedlings are not planted and accurately selects only the strongest plants for transplanting.

The company started construction of its first prototype machine in 2000, and tested it in 2001. A second machine was built and tested in 2002 and was able to plant over 500 acres of different Brassica varieties in a variety of soil conditions. Last year, the machine was shipped to California with keen interest from tomato and Brassica growers.

An onboard modem allows operators to monitor machine performances remotely and to carry out diagnostics and remote programming if required. The main moving parts need no lubrication. Entrapped dust and other material can be removed by blowing down with compressed air.

Improved Lettuce Harvest Aid
A highly motivated individual effort has brought the lettuce harvester to its current stage of development. And, the methods and techniques employed are as spectacular as the breakthrough itself, considered all but impossible as recently as 10 years ago. The latest lettuce-harvester builds on decades of development through individual and group trial-and-error experiments — boosted by durable metals coupled to workhorse driving units. The basic manufacturer credits his "trash eliminator" as a key to making the unit practical.

Manufacturers at Ramsay Highlander Inc. in Salinas, California claim that the trash eliminator allows harvested heads of lettuce to be conveyed upward into the machine with their wrapper leaves attached. By removing them mechanically, the machine paves the way for graders and packers riding the machine to complete their tasks efficiently and comfortably.

Fully Mechanized Lettuce Harvester (FIGURE 2)
With the cost of the machine at nearly $500,000, Ramsay Highlander's newest product launch, the Headraiser Mechanical Harvester, is designed to harvest and pack romaine, green leaf, and iceberg. The company is nearing completion on a model that picks, cleans, cores and packs lettuce and other greens. The harvester’s efficiencies could put the costs in perspective, and getting high-value crops picked when hand labor is at a minimum justifies otherwise unsustainable inputs.

The machine substantially reduces labor and handling of product. A cutting head mechanically cuts, and then helps eliminate trash leaves before reaching the sorting/packing belt. The rear of the machine can be configured for totes or bins to meet packing requirements. The harvester has a field proven band saw cutting mechanism, all stainless steel construction for efficient cleaning and maintenance, slide out walkways and a rear inspection platform is provided to help verify the product quality. For extremely wet conditions the dual track drive offers ample flotation.

New “mini” Spinach/Spring Mix Harvester (FIGURE 3)
The Spinach/Spring Mix mechanical harvester represented a revolution in the harvesting of Baby Leaf, Spinach and other small leaf produce when it was introduced several years ago. Built completely in stainless steel for food safety and longevity, reports from the field indicate that this machine has reduced harvesting cost from .28 cents per pound to less than .01 cent per pound. The next generation of baby leaf harvesters is smaller, more compact and durable and easier to service. Called the “Mini” the machine reconfigures easily for transport to a slim 102” wide so, no permits are required for transport.

Sanitation is a crucial part of every day procedures. Special attention to this was taken by minimizing the electrical components and using water tight connectors on all connections. Washdown is quick and easy because hard to reach areas have been minimized.

The new harvesters rely on advances in computing power and hydraulics that can make robotic limbs and digits operate with near-human sensitivity. Modern imaging technology also enables the machines to recognize and sort the produce of varying qualities.

With authorities promising tighter borders, some farmers who rely on immigrant labor are now eyeing an emerging generation of fruit-picking robots, mechanical harvesters and high-tech tractors to do everything from pluck premium wine grapes to clean and core lettuce, it’s a trend that will certainly continue.

Figure 1. Advances in agricultural technology and a declining labor pool has prompted the development of a computer controlled automated transplanting machine.

Figure 2. The latest development in mechanization is the fully automated lettuce harvester, able to cut and pack Romaine, leaf and iceberg lettuce.

Figure 3. The next generation of baby-leaf harvesters has been developed to be more compact for transport, easier to service and with more efficient sanitation and cleaning.