Pruning strategies can help regulate avocado yields ByBob Johnson
of 18,000 pounds an acre, according to Gabriel Filipe of Mission Produce, though different areas within the block may produce as little as 5,000 pounds or as much as 30,000. “Within a grove, we try three differ- ent systems,” said Filipe, whose title at Mission Produce is senior director of California sourcing and farming. “In one area, we will remove a limb or quadrant ; in another, we will take out
trees; and in a third, we will just top.” Filipe made his remarks as farmers discussed pruning strategies during a Zooming to Healthier Trees and Soils webinar co-sponsored by the California Avocado Society, California Avocado Commission andUniversity of California Cooperative Extension. Oxnard-based Mission Produce is a leading avocado producer, with or- chards and facilities throughout the
Western Hemisphere, Asia, Europe and NewZealand—and Filipe cautioned that the management strategy that works for themmight not be best for all growers. “A lot of what growers should dowould depend on their tree size, their tree age and their budget,” he said. One part of theMissionpruning strate- gy is to thin the trees, whichover time can produce a dense canopy that becomes unworkable and unproductive. “In older groves, wemight remove half the trees in 10%of the block, and just top in 40%,” Filipe said. Avocado trees generally need to be thinned over time as the canopy spreads out, but he said thequestionof howmany trees to pull out, and how early, depends on the density of the original planting. “Planting high density will get you into high production a few years earlier, but if you’re planting 400 trees an acre, you might start removing trees at five years,” Filipe said. “If youplant 150 trees an acre, you can wait until year 10 or 12.” Another question in developing an avocado pruning strategy is how tall to allow the mature trees to grow, to avoid toomuch shadewithin the canopy and to minimize tall ladder work. “We like to keep our tree height no more than 80% of the row width,” Filipe said. “If the rows are 20 feet apart, our goal is 16 feet, so we top them at 12 feet and let them grow. The trees we top this year will come on heavily in two years.” For around half the trees in a mature orchard, he said, theMission strategy is to remove a few limbs to open the canopy. “We bring light into trees that were shaded out, and we also promote fresh budwood,” said Blake Petrucci, Central Coast regional farmmanager forMission Produce. “We like to have layers of fruit on the sides, so the trees protect them- selves when the winds come.” The Mission Produce representatives said the result of this pruning strategy is that in a particular year, some areas with- in the block have low yields, other areas have extremely high yields, but the aver- age is good yields that can be repeated year after year. “We’ve been able to sustain yields of 18,000 pounds,” Filipe said. “In one area of the grove, we get around 5,000 pounds; in another, it is 10,000 to 12,000; but in a third area, we get 20,000 to 30,000 pounds.” For the first few years after planting, avocado trees need littlepruning, accord- ing to Filipe, until the leaders are chosen around year three. “We dominimal pruning the first three years and by year three start taking out branches,” he said. The Southern Cal i fornia ground Mission uses to grow avocados is gener- ally too hilly to make machine pruning practical, he added. “We use pole saws, or chain saws on poles, hand-held chain saws, and pole
To mitigate the effect of alternate bearing and promote a consistent yield from avocado trees, Mission Produce uses a complex pruning strategy that varies within the same block. The strat- egy also accounts for the need to thin trees as the canopy closes and shades out some areas. The management regime results in average San Luis Obispo County yields
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See AVOCADOS, Page 14
10 Ag Alert May 12, 2021
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