CULTURAL TIP: APPLYING THE TREE-GROWTH CYCLE IN CULTURAL-MANAGEMENT DECISIONS
Every year, avocado trees grow in a series of consistent stages that avocado growers can reference, when considering what, when and how much cultural-management activity to apply. Therefore, a solid understanding of the tree-growth cycle is useful for growers, when determining whether trees are growing as expected; or, if the tree needs management intervention to achieve optimal productivity. This leads to a general principle that can be applied to grove management: when using the tree-growth cycle, cultural-management decisions are based upon current tree growth – or previous growth – rather than time of year.
When avocado trees are alternate bearing, they annually follow regular growth stages, which vary considerably in strength. When an "off crop" occurs on trees, heavy flowering and fruit set – and inadequate shoot growth for good return bloom the following season – are expected to take place. When an "on crop" exists, the opposite happens, with expectations for a light flowering and fruit set, as well as heavier-than-necessary shoot growth for good return bloom the following season.
At the “PGR Strategies and Avocado Phenology” seminar (second workshop in the five-part California Avocado Grower Seminar Series 2010/11), February 8-10 in San Luis Obispo, Ventura and Temecula, Dr. Jonathan Dixon, California Avocado Commission (CAC) research program director, discussed the two-year growth pattern, including changes that may occur in the regular growth cycle, due to varying circumstances (i.e. – flower buds destroyed by freeze or an extremely heavy crop set). If trees fail to grow as expected, then the required intervention and cultural-management activities can be tailored to the trees’ specific needs.
Seminar discussion also focused on the effect of a much-delayed harvest, when mature fruit is hung considerably longer than the norm, and the damaging and long-term consequences for future productivity. It was further emphasized that avocado growers are confronted with the challenging task of continually forecasting what needs to be done to obtain good production. Using the tree-growth cycle as a basis for decision making can be a valuable tool, when fine tuning cultural-management activities to obtain high yields. To view the handouts and presentations from the PGR Strategies and Avocado Phenology seminar, which featured Dr. Dixon, as well as Dr. Carol Lovatt, University California-Riverside, please visit the Grower website here: http://www.californiaavocadogrowers.com/pgr-strategies-avocado-phenology-february/.
