Update 2013: Managing Pistachio Nutrition Overview
Current Pistachio Industry Problems
At present, growers primarily use leaf tissue analysis to determine tree nutrient status and make fertilizer management decisions. Previous results of a survey of pistachio growers, and consultants in California, suggested that the existing leaf sampling protocol and comparison of the tissue results with the established standards does not provide sufficient guidance for nutrient management.
Concerns with leaf tissue testing include:
- A poor correlation between tissue nutrient concentration and soil nutrient availability
- A high degree of variability in tissue nutrient concentration in adequately fertilized crops within a single tree and within the same field.
- Additionally, the current practice of sampling late in the summer limits the grower’s ability to make in-season fertilizer adjustments.
- Another problem with the leaf sampling results is that these analyses do not provide information on the rate or timing of fertilizer application.
|The overall goal of this research project was to develop integrated nutrient management practices for pistachio trees across different ranges of environments to provide growers with improved leaf sampling protocols and interpretation tools and to develop nutrient budget models for pistachio to better manage their crops.|
Contribution of Current Project in Optimizing Fertilizer Use and Pistachio Yield
Substantial nutritional information was gathered under the pistachio nutrient optimization project entitled “Development of leaf sampling and interpretation methods for pistachio and the development of a nutrient budget approach to fertilizer management in pistachio”. This large scale project was conducted from 2009 to 2012 in four pistachio producing counties in California (Madera, Kern, Fresno and Kings Counties). In this study, we have assessed new and improved ways to assess the nutrient status of the trees to help pistachio growers manage their fertilizer applications with more precision.
Parallel to the development of improved leaf sampling protocols an analysis of the full suite of nutrients in the fruit combine with the yield data were used to develop nutrient budget curves for pistachio. The nutrient budget model as a management tool helps growers to optimize the time and rate of fertilizer application to match with the tree demand. The implementation of the improved leaf sampling strategies combine with the nutrient budget models is expected to help growers to better monitor and manage the nutrient status of their orchards and increase their profitability and environmental stewardship.