How We Grow

2020 Jan/Feb How We Grow

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A L M O N D O R C H A R D 2 0 2 5 G O A L S HARVEST DUST 3 spectrum of options depending on what resources are available to the grower." Scenario 1 imagines off-ground harvesters that deposit almonds into an adjacent windrow immediately after they are caught. This would eliminate the blowing and sweeping that would otherwise be required, reducing the dust that would occur from those practices and delivering minor cost savings. Still, the nuts would have to be picked up off the orchard floor after they had finished drying, creating the likelihood of some dust generation. Scenario 2 is the option Simmons projects to have the greatest cost savings potential for growers. This scenario also uses off-ground harvesters but moves drying from the orchard itself to open lots on or near the farm. Based on the space within orchards used to dry nuts, Simmons calculates that his hypothetical 100-acre orchard with multiple almond varieties maturing at different times would need five to seven acres of drying area. He also assumes that nuts would dry more quickly without the orchard's shady canopy. In this scenario, growers could spread tarps across the drying area or use stabilizing amendments to reduce dust when picking up the nuts. Simmons speculates that in addition to eliminating blowing and sweeping and reducing the area used for pickup, this scenario would allow for the reduction or elimination of certain in-orchard practices aimed at soil pest control that together could result in substantial savings for growers. "For instance," said Simmons, "ants in the orchard would no longer threaten almond quality and weeds would no longer factor into the pickup stage of harvest." Based on input from University of California Cooperative Extension farm advisors, Simmons hypothesizes that pesticide and herbicide applications for ant and weed control could potentially be eliminated while weed mowing could be reduced from six to two times a year. Scenario 3 involves harvesting off-ground and then quickly transporting almonds to facilities with mechanical drying capabilities. There, the nuts' moisture content would be reduced from 21% to 9% (the goal for air drying). This scenario faces hurdles, however, the greatest of which is the lack of adequate mechanical drying facilities within the industry and the cost of hauling nuts with higher moisture content to those operations. Simmons said most mechanical drying facilities that exist today are in the Sacramento Valley, which not only experiences a higher chance of rainfall during harvest, but also represents a smaller growing region among all those in California. Though this scenario virtually eliminates dust during harvest because the nuts never touch the ground, it also requires growers to pay for drying instead of using the free resource of sunlight. For this reason, excessive hauling and drying costs may negate the operating cost savings gained during the harvesting process. Simmons said if off-ground harvesting were to be widely adopted, spurring installation of more mechanical dryers, an economy of scale may be realized that decreases drying costs and elevates net returns for the grower by allowing them to eliminate various pest management and harvest operations in the orchard. From calculating returns to an orchard trial Almond grower Brian Wahlbrink farms more than 1,100 acres of almonds on three family-owned ranches in Stanislaus and Merced counties. A member of ABC's Board of Directors, Wahlbrink also chairs the Almond Board's Harvest Workgroup, which is composed of growers, processors and equipment manufacturers committed to exploring all possibilities to improve harvest techniques. Wahlbrink joined other ABC officials on a four-day visit in August 2019 to Israel, where off-ground harvesting is standard practice for the country's 15,000 acres of almonds. "They're small in acreage, but they have been doing off-ground harvest for a long time," Wahlbrink said. "They're leaders in innovation and even use drying fields, an option that isn't always feasible in California." (see Scenario 2) This past harvest, Wahlbrink tried off-ground harvesting on 30 acres primarily to experiment in dust reduction. "We're trying to think out of the box," he explained. "We know sweepers are a key contributor to dust, so we tried shaking the trees, catching the nuts immediately and then redirecting them in the windrows to dry." (see Scenario 1) Though Wahlbrink experienced promising dust reduction with off-ground harvesting, he said there are still technological challenges to overcome. "We do need to make some advances with the machinery before we see widespread adoption in California," Wahlbrink said. "The biggest issue we had is the height of the tree scaffold – some of our trees are too low for this to work effectively." In many orchards, trunks are only 15 to 18 inches off the ground before branches Continued from page 2 "We do need to make some advances with the machinery before we see widespread adoption in California." – Brian Wahlbrink

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