In this research, we have modeled the relationships between leaf nutrient concentrations and the yields of avocado trees with the aim of developing decision support tools for improved fertilization and nutrient management to increase avocado fruit yields. Using a data base of ~3500 observations in which nutrient concentration profiles and yields of individual trees were examined over several harvest seasons, we now present in our final report a refined model that predicts nutrient-yield relationships based on all possible combinations for the 11 elements that are monitored by leaf analyses.
Use of Plant Growth Regulators to Increase Fruit Set, Fruit Size and Yield and to Manipulate Vegetative and Floral Shoot Growth
This research addresses the research priority: “The role of endogenous and exogenous growth regulators in avocado and the evaluation of commercial growth regulators on flowering, fruit set, fruit size, yield and vegetative growth.”
The increasing costs of inputs necessary for avocado production dictate that growers of the 'Hass' avocado in California increase profitability per acre. The goal of this research is to increase net income per acre by developing plant growth regulator (PGR) strategies that increase yield of commercially valuable fruit.
California avocado growers must increase yield, including fruit size, and/or reduce production costs to remain competitive in the US market, which now receives fruit from Mexico, Chile, New Zealand, Dominican Republic and an increasing number of other countries (http://www.ers.usda.gov/Data/Fruit VegPhyto/Data/fr-avocados.xls). Despite the popularity, the ‘Hass’ cultivar (Persea americana Mill.) is known to be problematic with regard to fruit retention, fruit size and alternate bearing.
Competition from Mexico, Chile and other countries requires that the California avocado industry not only increase production per acre, but also increase fruit size to remain profitable. The goal of this research is to increase net income per acre for growers of the 'Hass' avocado in California by developing plant growth regulator (PGR) strategies that increase yield of commercially valuable large size fruit.