Stumped
BY LAUREN MCEWEN, fourth-year agricultural communication major
Cal Poly’s Oldest Avocado Orchard Provides New Educational Opportunities
The terraced avocado orchard lining Radio Tower Hill along Highway 1 is a familiar Cal Poly agricultural landmark. But things are looking a little different now, as nearly 100 stumped trees, painted white, slowly begin to regrow.
The avocado trees on Radio Tower Hill are some of the oldest and tallest such trees on Cal Poly’s campus. This summer, the orchard’s scaffold branches were removed and the stumps were painted over, preparing the several acres of trees for a multi-year journey of regrowth. “Stumping helps bring down height and increases the productivity of the tree,” said Plant Sciences Professor Lauren Garner. “There will be more fruit and of higher quality. It also increases efficiency of harvest,” she said. Stumping can also extend the life of mature trees and serve as a valuable learning opportunity about alternative production methods for students.
The shade of the massive canopy of the overgrown avocado trees resulted in limited blooms, and prevented fruit from growing well. Stumping the trees allows for the trees to regrow, said Garner. After Johnny Rosecrans, manager of Cal Poly's Bartleson Ranch and Conservatory, worked with a professional crew to remove the branches and mulch the woody remnants of the avocado trees, a crew of students painted over the stumps to ensure that the trees would be protected from sunburn. “Diluted white latex paint prevents damage to the bark and allows for gas exchange,” explained Garner, making the paint a perfect choice for protecting the trees while they grow.
“For the students, it is a really good example of how avocados develop,” she said. Garner looks forward to bringing students enrolled in the Citrus and Avocado Fruit Production course in the spring quarter to the orchard to see how the trees have developed. Garner also said that soil science and plant pathology students could benefit from the project by looking at plant health and the efficacy of the mulch spread throughout the orchard.
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