Mar 4, 2008

Mechanical Harvest Cuts Costs and Need for Labor

Mechanically harvested fresh-market sweet cherries have already debuted, but the fact they haven’t made headline news testifies that some problems remain.

Nobody’s complaining about quality. In fact, these cherries – harvested without stems – have brought approving letters from consumers wondering why anybody thought having cherries with stems was a good idea, anyway. Still, the cherries aren’t available in high volume, and they’re having trouble cracking into the marketing system.

Meanwhile, a few growers are doing what they need to do to convert from high-priced, increasingly scarce labor to the lower-cost machine harvesting system. They are planting the right varieties on the right rootstocks and pruning the trees to the right shape. But right now, fewer than 5 percent of the cherry trees could be machine-harvested.

The incentive seems huge. Machine harvesting can cut picking costs from 18 to 25 cents a pound for hand harvest down to 2 cents.

The system for producing mechanically harvested sweet cherries for fresh market has been coming together for six or seven years. That’s assuming you don’t count the 20 years before that during which a few dogged agricultural engineers struggled with inadequate funding after a federal government mandate cut off funding for projects that deprived seasonal farm workers of their jobs.

Despite bad odds, however, a good machine has been developed and a couple of manufacturers have expressed interest. Growers know what orchard design they have to use and could easily plant trees properly sized and shaped and of the right varieties. Marketers and distributors are willing to push these cherries into the marketing system; there is a PLU number for stemfree cherries. Consumers like them.

What else is needed? Perhaps a full-blown disaster in labor supply would start a major transition to mechanical harvested sweet cherries. That happened in tart cherries in the 1960s, when the bracero labor program folded.

Key players

There are several major players on the mechanical sweet cherry harvesting stage.

There is Donald Peterson, the USDA Agricultural Research Service ag engineer from the Appalachian Fruit Research Station in Kearneysville, W. Va. He retired just over a year ago, leaving behind two machines. One, a rotating, vibrating spiked drum, is making inroads as a citrus harvester and is being tested in Michigan for harvesting tart cherries. The other is a shaker and catching frame system being used at the Washington State University Irrigated Agriculture Research and Extension Center in Prosser, Wash. Growers see this machine when they attend field days there – the machine that successfully harvests stemfree sweet cherries.

There is Matt Whiting, the Washington State University researcher who, with graduate student Erick Smith and others on his team, is putting together the horticulture – evaluating varieties and rootstocks and tree structures that work with the Washington machine. They also have developed an Ethephon treatment regimen that makes sweet cherries drop from the trees without forceful shaking.

There are Washington growers Lowell Lancaster, Denny Hayden and Bob Harris, who are running tests in their orchards and who started a joint venture to pack and market mechanically harvested sweet cherries. They have gotten them into the Costco distribution system and into a few supermarkets, but they need more volume to make a major impact.

The horticultural tale

From Whiting’s point of view, the impetus behind machine harvest of sweet cherries comes from the grass roots, from growers who are facing increasing labor shortages. There are lots of orchard tasks that can’t be mechanized, but growers are realizing they need to mechanize those that can. They need to shift scarce labor to other tasks.

Sweet cherries, it turns out, can be removed from trees by machines with minimal loss of quality – something not true of apples or peaches, at least right now.

A few years back, innovative growers and fruit industry leaders in the Northwest began work on what is now called the Tree Fruit Technology Roadmap. The map outlines the direction American fruit growers must go if they are to remain competitive. In a world overflowing with cheap labor, the map says growers must do what Americans do best – innovate and mechanize – because cheap labor is not going to remain available in this country.

In the last few years, Whiting’s work has demonstrated these things:

For one, trees can be shaped to harvesters more easily than harvesters can be shaped to trees. The existing large, upright sweet cherry tree can’t be harvested with shakers that drop fruit through multiple layers of canopy.

“Fruit will have to be grown on compact, angled fruiting walls,” Whiting said. “We can’t have cherries bouncing through layers of limbs. The tart cherry is very different because it is harvested for processing.”

Sweet cherries grown in a Y shape present their fruit with no underlying limbs. Peterson’s harvester doesn’t grab the limb, Whiting said. Placed against a limb, it bumps or snaps it so swiftly the cherries stand still and the limb and stems pull away from them.

“It removes the tree from the fruit,” he said. “Fruit falls onto a padded catching frame.”

Besides the shape, the new Gisela and Krymsk dwarfing rootstocks keep the trees short enough so fruit doesn’t fall from a great height.

Another component is varieties.

“With some varieties, cherries don’t separate well from the stem and are just not well suited to mechanized harvest,” he said.

In screening varieties, he has categorized them into (1) those that don’t respond no matter what, (2) those that will respond when treated with Ethephon and (3) those that respond without treatment.

Bing is in the second category. Treated with Ethephon 10 to 14 days before harvest, Bings loosen nicely from the stem and can be harvested with minimal force.

Skeena is in the third category.

“Skeena was being abandoned because of that trait,” he said.

It was a candidate for rejection because it wouldn’t keep its stems on during harvest. Breeders used to breed for stem retention, and now the situation has reversed.

Grad student Erick Smith’s Ph.D. work is focusing on abscission zone biology – understanding what makes cherries come loose – and on post-harvest quality. He has found that cherries without stems have a longer shelf life because there is no pitting and fruit damage from stems.

There are fewer freshness issues with stemfree cherries. Stems aren’t there to dehydrate and turn brown. In fact, there is some concern that this freshness signal may not be there for consumers to use, Whiting said.

Several studies were done at the early stages of the research project to investigate fruit quality and consumer attitudes. It was discovered early on that consumers weren’t the ones demanding stems on cherries, and would prefer them without stems. When researchers found that consumers would be on their side, it greatly helped push the project forward.

So does funding. Whiting’s work is supported by IMPACT, WSU’s International Marketing Program for Agricultural Commodities and Trade, and by the Washington Tree Fruit Research Commission.

The growers’ tale

Whiting gives lots of credit to Washington growers Lowell Lancaster of Lancaster Co. in Yakima, Denny Hayden of Hayden Farms and Bob Harris of Harris Farms in Moxee. Early on, they experimented with picking cherries with machines and packing them for sale. In 2002, they started the Western Sweet Cherry Group, a company formed to pack and market stemfree cherries.

Lancaster manages the packing and selling, crediting his partners as “the driving force” on the production side.

“Consumers love them,” he said of the stemfree cherries.

There’s no pitting on the surface from stems, so they keep better—and they’re sweeter, he said. That’s because they’re harvested riper.

“Six or seven years ago, we got together and wanted to press the stemfree thing,” he said. “We found right off that consumers liked those cherries better. We actually got letters and phone calls from consumers saying how much they liked them.”

Still, Lancaster said, “there are a lot of people looking at it but no real movement. Everybody’s watching. The handwriting is on the wall (about labor), and it’s the largest single expense we have.”

Denny Hayden believes they must amass a “critical mass” of stemfree cherries, or the marketers won’t be interested. Growers, on the other hand, want to see demand first. Manufacturers won’t build machines unless they think growers will buy them. It’s a vicious circle.

To get more stemfree cherries, Hayden is using “machine-augmented harvest.” He is using a hand-held chainsaw-like limb shaker, adapted from olive harvest, and a simple, easily moved catching surface covered with bubble wrap. It cuts labor needs by a third, he said, and it allows harvesting on some branches of larger trees. But it’s not the vision of the future.

The most important thing now, he believes, is getting enough stemfree cherries together to build demand. Right now, one Costco distributor is channeling them to a few stores.

The engineer’s tale

Don Peterson doesn’t sound bitter. He’s retired and enjoying it, after spending a career during the worst of times for agricultural engineers working in fruit and vegetable harvest mechanization – the time of the “anti-mechanization movement.”

In 1971, he said, when he was hired by the Agricultural Research Service, he was one of 10 engineers working on six projects related to fruit harvesting. Eleven land-grant universities added 16 more.

In 1979, he got a mixed message. After completing his Ph.D. at Michigan State University, he was assigned by ARS to the West Virginia research station and given the task of developing “mechanized harvest systems for fruit crops while maintaining fruit quality, improving labor productivity and reducing costs.”

That same year, however, Secretary of Agriculture Bob Bergland, speaking at a press conference, said USDA was no longer going to put money into research that deprived farm workers of work. President Jimmy Carter’s administration had been stung by labor leaders who accused the government of deliberately favoring machines over people. The University of California had been sued for the same reasons.

Within a few years, “all the projects were shut down but mine,” Peterson said.

“ARS is a funny animal,” Peterson said. “It is affected by politics but also by the needs of industry. I was not ‘under cover,’ but I wasn’t at the forefront, either.”

Such dualism is not just true of engineering. A horticulturist at the Appalachian station where Peterson worked, Ralph Scorza, worked on a genetically engineered plum, even while the government was officially not supportive of genetic engineering.

“He was essentially told not to do that work,” Peterson said. “Yet when plum pox erupted in Pennsylvania, he became an ARS hero.”

That was because he had developed a plum pox-resistant plum.

Similarly, about five years ago, federal government support for mechanizing fruit harvests began to revive – and Peterson was on the scene as the only USDA engineer with a machine that could work.

“My last year or two with ARS was amazing,” he said.

Peterson is pleased that the new Farm Bill may, once again, include major funding for mechanization research.

But it’s coming years late.

“In 1971, we knew we had a labor problem and that we needed to mechanize harvest,” he said.

Now, nearly 40 years later, movement is resuming.

“If it were not for illegal aliens, we would not have a fruit and vegetable industry in this country,” Peterson said.

So, where do we go from here?

“Somebody has to take the bull by the horns,” Peterson said.

Growers have to plant the right trees.

“You can’t make magic in traditional sweet cherry trees,” he said. “You have to breed for mechanization.”

Sweet cherries can be harvested mechanically and have the quality consumers want, he said. It will be much more difficult with apples, which will need robotic harvesters, he said, because “you can’t shake apples.”

Luckily, apple trees are very malleable, more so than cherries. He says apples will have to be grown in narrow fruiting walls 6 to 12 inches thick, where fruit is visible to camera eyes so it can be picked by robots. Cherry trees have been less malleable, but new rootstocks and new planting schemes – pruning to a Y shape or developing concepts like Matt Whiting’s Upright Fruiting Offshoots – can make sweet cherry orchards mechanically harvestable.

For sweet cherries, all the elements are there. All that’s needed is a final push to get them moving together.