Critical Tree Nut Nutrition at Bloom

Newsletter - January 2021

Though the final 2020 has not been tallied at the time of writing this article, the expectation is that final crop receipts should not fall far from the 3 billion-pound estimates. This volume, along with other global issues, not to be mentioned here, have contributed to softer pricing through the end of 2020 and into the new year. This constriction led many growers to face some tough decisions late in the 2020 season, and many growers backed off on nutrition inputs to balance their budgets.

Due to relatively uniform increases in production at the field level, many growers had difficulties meeting the nutritional demands of last year’s crop. Additionally, by backing off late in the season, they are now entering the 2021 crop season at disadvantage. These orchards are likely lacking in stored carbohydrates, stored nitrogen, and adequate nutrition to facilitate the physiological processes of bloom, root-flush, and early nut-set.

In the coming months, we can positively influence our crop performance with properly executed bloom sprays and our first application of soil-applied nutrition. The purpose of our bloom sprays should be to provide critical elements that will facilitate floral development, pollen transfer, embryo fertilization, cell division, and cell expansion.

Critical foliar nutrients at bloom

Phosphorus provides energy for all metabolic processes in the forms of ADP and ATP. It is a critical element to support cellular division and growth. Because almonds bloom so early in the spring, soils can often be cool and wet which suppresses the mineralization of phosphorous from soil reserves.

almond bloom.jpg

Potassium is essential for translocation of carbohydrates and enzyme activation. It aids cell division processes and regulates the turgor pressure and transpiration activities of these newly developed cells.

Calcium, as a key component of cell walls, helps to bring structure to plant cells. Additionally, calcium is required for cell elongation and selective permeability through the middle lamella. This permeability encourages the movement of select ions into the cell while maintaining a barrier for those that will have a negative impact. This dual role of providing cell wall strength and permeability also plays a key role in biotic and abiotic stress reduction.

almond pollen tube.jpg

Boron supports cell maturation and the process of differentiation. Along with Calcium, boron plays a role in cellular integrity by promoting cell to cell adhesion. Proper cell to cell adhesion is critical as it facilitates translocation of carbohydrates to support metabolic activities and defend against pathogenic disease development. Boron is also directly implicated in its role to support pollen tube development.

Zinc is an enzyme (auxin) activator. It is required for node, and terminal leaf development. It is one of the nutrients that has the most direct impact on promoting healthy flowering and fruit/nut set. It is also the most common element along with phosphorous and iron that tends to be deficient early in the leaf-out stage of the crop season.

Think beyond nitrogen

Notice in the intro we referenced the “first application of soil-applied nutrition”, and not the first nitrogen application. This was intentional as we need to remove the mental constraints that limit our focus to nitrogen only. Now there is considerable debate on how many nutrients should be considered “essential” though for our immediate purpose let’s use the most commonly reference number of 17 essential plant nutrients. Essential means that limitations of any one of these 17 elements can have a negative impact on plant health and crop performance. As we are doing with the MyAlmonds Program treatment at the Incubator Farm, we encourage you to begin addressing all crop demands and targeting our applications at the appropriate time to derive the maximum benefit and ROI.

nutrient demand jan-apr B.png

Crop nutrition demand from bud swell to nut set for soil-applied nutrients
(check out the entire Nutrient Demand table w/ all crop stages here)


Yara foliar products to support from pink bud through early nut set

Pink bud

YaraVita® POWERBOR™ Ca: Supports cell development and strength

  • 4-0-0-15(Ca)-6(Zn)-3(B)
  • Suspension concentrate
  • Drives proper cell division: high calcium with balanced zinc and boron; promotes string flowering and fruit set; consistent crop performance
  • Rate: 1-2 quarts

Full bloom

YaraVita® PENTAFLO™: Fuel for growth and stress mitigation

  • 4-15-1-12.5(Ca)-3.7(Mg)-2.5(Zn)-1.2(B) with kelp extract
  • Suspension concentrate
  • Improves flowering, fruit set and fruit development: unique high P2O5 and Ca formulation; balanced Mg, Zn and B for leaf and fruit development; kelp component benefit
  • Rate: 2-4 quarts

Petal fall or 2 weeks post petal fall

Leffingwell NUTRA-PHOS Zn-K PLUS: High P2O5 NPK blend fortified to support cell growth and regulation

  • 3-20-10-12(Ca)-20(Zn)
  • Wettable powder
  • Formulated for strong crop growth and establishment: micronized for uptake effective sustained feeding; fully formulated with wetting, spreading, sticking agents
  • Rate: 5-15 lbs


First soil-applied nutrition

YaraLiva® CAN-17™: Key role for 1st and last fertigation events during the growing season

  • 17-0-0
  • Balanced nitrogen forms, increased cation uptake (e.g. Zn, Fe, Mn), source of soluble Ca
  • Rate: 30% of N budget


Reach out to your local Yara Agronomist to build a collaborative crop program today.

Check out the latest article 

Devin Clarke
Devin Clarke
Agronomy Solutions Manager
Allison Gwin
Allison Gwin
Sales Agronomist

South Central Valley, California

tim barrett
Tim Barrett
Senior YaraVita Specialist

North Central Valley, California

Vanessa Vicencio
Vanessa Vicencio
Sales Agronomist

South Central Valley, California

Learn about the Yara Incubator Farm in Modesto, CA

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