California Crop Fertilization Guidelines

UC Davis
A collaboration between CDFA, FREP and UC Davis
 

Avocado Nitrogen Uptake and Partitioning

The Fertilization guidelines can also be found on the UC Davis Nutrient Management website .

Seasonal N Uptake

Nitrogen uptake of avocado trees on an alternate bearing cycle. These values are from a 'Hass' orchard near Moorpark, CA which blooms in February and is harvested in July. For both "on" and "off" trees, very little N is taken up during the dormant period. The time of greatest uptake is around March through May, when exponential growth of the maturing crop, fruit set of the new crop and the spring flush all occur. In "on" years, more of the spring N uptake is allocated to the fruit, while in "off" years, more is allocated to the new shoots. In "on" years, uptake is also high from July through October as the new crop has its first stage of rapid growth; however, uptake at this stage is slower in "off" years [2,4].


Nitrogen Partitioning

Nitrogen partitioning pie chart

Nitrogen distribution in 20-year old 'Hass' avocado trees. Measurements were taken in August of an 'on' year [3].


Nitrogen Removed at Harvest

Avocado N removed at harvest from a 'Hass' avocado orchards in California. Values include the flesh, peel and seed.

Study location Years Yield (tons fresh fruit/acre) N removed at harvest (lbs N/ton fruit) Source
Ventura County 2001-2002 4.46 4.4 [5]
Southern California 1999   5.6 [1]

Links

 

References

  1. Arpaia, M.L., 1999. Total Fruit Nutrient Removal Calculator for Hass Avocado in California. (Accessed 9/2016)
  2. Rosecrance, R., Lovatt, C.J., 2003. Seasonal patterns of nutrient uptake and partitioning as a function of crop load of 'Hass' avocado. FREP progress report.
  3. Rosecrance, R., Lovatt, C.J., 2004. Seasonal patterns of nutrient uptake and partitioning as a function of crop load of 'Hass' avocado. FREP final report.
  4. Rosecrance, R., Lovatt, C.J., 2005. Seasonal patterns of nutrient uptake and partitioning as a function of crop load of 'Hass' avocado. FREP progress report.
  5. Rosecrance, R., Faber, B., Lovatt, C.J., 2012.Patterns of Nutrient Accumulation in 'Hass' Avocado Fruit. Better Crops 96, 12-13.