Leaf analysis is a useful tool for developing a strategy for fertilizing an avocado orchard.  Ideally, a relationship between the nutrient concentration in the leaves and the yield is established, and from this the critical concentration (or range) can be determined for each essential nutrient.

Standardizing leaf age and season for leaf analysis samples is recommended due to the diverse stages avocado trees experience throughout the year.  

Autumn sampling of spring-grown leaves is the most appropriate time and leaf stage for nutritional analysis because the concentration of most nutrients is relatively stable at that time.  

Consult with you farm advisor, PCA, or diagnostic laboratory for specific recommendations on fertilizer use and how to collect leaf samples for the laboratory.  

Keep in mind that nutrient deficiency symptoms frequently are not due to inadequate nutrient levels in the soil.  Routine application of nutrients simply because the foliage exhibits deficiency symptoms may actually make things worse by delaying you from finding the true cause of the unhealthy trees.  You can increase the trees’ ability to absorb minerals by improving soil conditions and promoting root health.

Regards, 

Dan & Daniel