Learn by doing
San Joaquin growers use trial and error.
Twenty years ago, when apples suddenly became a profitable crop to plant in California's San Joaquin Valley, few had experience in growing the new fruit.
Outside the state's central and northern coast, where Gravenstein and Newtown Pippin varieties were produced in cool, coastal climates, apple production on a commercial scale in the San Joaquin Valley was new. Some growers looked to their neighbors in the Pacific Northwest to learn about rootstocks and training systems; others tried growing the fruit similar to tree fruit crops that they already grew, such as cherries. For those that have stayed with apples, it's been trial and error.
The Colombini family, farming as Lodi Farming Company, in Lodi, California, planted their first Granny Smith orchard about 25 years ago. The Colombinis had grown cherries and walnuts for decades, but never apples. "No one knew what the heck we were doing," said Jeff Colombini, president of the company. After Granny Smith, they planted other varieties, including Gala, Fuji, and Pink Lady. Their first Fuji planting was in 1994.
"First, we tried the central leader orchard system," he said. "Then we learned that it was better to grow them on a V trellis, but we didn't know what angle we should have. In Washington, we saw some at 60° and some at 65°, so we went for the average of the two at 62.5°." They then learned that the 62.5° angle was too open, leaving the insides too exposed and encouraging more sucker growth while not getting enough light to the outside.
Trial and error taught them that a 70° angle was more desirable, especially on their early Fujis. "The tree opening on the top is about equal to the opening between rows," he explained.
Pink Lady apples, which they planted in 1999, were another learning experience. First, they tried growing the variety on the central leader. After visiting Australia, and not seeing any Pink Lady on a central leader, they came home and modified the system, cutting out the central leader and retraining it to a V-trellis system. The modified system has been very productive, producing about 102 bins per acre, peaking on size 88.
Pink Lady is a long-season apple, he commented. Bloom occurs in the middle of March, while the crop is picked in October. "That's why we can hang a large crop."
In a fourth-leaf Fuji planting, Colombini said that he tried out the concept of alternating the trees on either side of the V-trellis, using five leaders to spread across the wires. He thought the system would be easy to prune. "But this is an idea that I wish I didn't have," he said, noting that the space hasn't filled in as quickly as he hoped.
Malling 7 rootstock has worked best for them, though they have some M.9 plantings. "A lot of the dwarfing rootstocks stress too easy under our conditions; they runt off and won't grow," he noted.
Their orchards are planted with 14 feet between rows and 8 feet between trees.
Colombini uses overhead evaporative cooling on all apple varieties, except Granny Smith. Cooling begins in mid- to late June, with cycles of ten minutes on and ten minutes off until temperatures drop to 86°F.
"It's not the temperature of the water that cools down the orchard, but it's the evaporative action that cools the fruit," he explained. "What hits the ground is almost nothing. We irrigate less because of evaporative cooling, but we still have to irrigate."
As harvest draws near, the temperature is adjusted to 91°F. "With the overhead cooling, the orchard never reaches above 94°F," he said, adding that it allows them to crop heavier.
Colombini said that the average number of bins they produce per acre is 60 for Fuji; 70 to 75 for Granny Smith; 80 for Gala; and 80 for Pink Lady. Alternate bearing has not been an issue.
Codling moth, the major pest they are concerned with, can be particularly troublesome because they grow walnut trees in the vicinity. They were concerned that any insecticide used would be washed off by the evaporative cooling, so they now use mating disruption that automatically dispenses pheromone from "puffers." The puffers have timers that dispense the pheromone in the evening when moth activity is greatest.
Fireblight is not an issue unless they have strong winds during conducive conditions, Colombini said. "With the strong winds, the young plant tissue gets beat up," he reported. They use a fireblight model which alerts them when it's time to apply sprays. When conditions are conducive to fireblight, they spray every other row every four days with streptomycin. An emergency-use permit for streptomycin was recently approved for use on Pink Lady, he said.
Colombini hasn't noticed an increase in mildew pressure from using evaporative cooling. Summers are relatively hot and dry. Humidity is only about 20 percent in the summer but around 100 percent in the winter from fog.
Owl boxes are placed in the orchard to encourage gopher predation.
His favorite labor-saving tool is the Prune-Rite, a pruning tower manufactured by Dakota Ag, a division of Jackrabbit, Inc., located in Ripon, California. Lodi Farming just added 10 more self-propelled towers to their fleet of 20, at a cost of $19,500 each.
The towers, which have eliminated almost all ladder use except during harvest, are used for pruning, hanging pheromone puffer dispensers, thinning, hanging bird-scare tape, installing overhead cooling systems, and installing and repairing trellis wire.
"It's the most-used piece of equipment on the ranch," Colombini said. The towers increase efficiency of his workers because they don't have to move ladders around, and he believes they are much safer than ladders.