Research highlights benefits of soil and foliar nutrition in almond results

Research highlights benefits of soil and foliar nutrition in almond results

Due to continuing concerns about the use of phosphite based inputs in almonds and other nut crops as a result of European Union regulations, Agro-K, in 2015 began a multi-year trial with independent contractor, Brooks Bauer of Two Bees Agricultural Research & Consulting in Escalon CA, to demonstrate that a comprehensive Agro-K soil and foliar nutrition program without phosphite-based materials could improve nut meat yield and quality while improving tree growth and overall tree health.

This planned multi-year trial was initiated in 2015 with Two Bees Agricultural Research and Consulting (Escalon, California). It was conducted as a randomized complete block. The trial consisted of multiple tree plots of 4-year old, ‘Independence’ trees replicated six times. The foliar materials were applied at 100 GPA. BioMax Dual Action + was applied to the top of the soil and watered-in as directed. Agro-K nutrient materials were applied at key points during the season based on plant physiology and peak nutrient demand timing.

Almonds Trial 1Almonds Trial 2

The Agro-K program resulted in a statistically significant increase in nut meat (486 lb/a) compared to the standard soil program. Not only was there a statistical yield increase, tree growth improved as measured on trunk diameter. Agro-K programs are meant to compliment comprehensive soil nutrient programs which are the foundation to overall plant health and consistent annual yields. The trial will continue in 2016 and possibly 2017 to observed continued long-term benefits of the program.

Maximizing profitability in your almond orchard starts with maximizing nut set every year. Achieving consistency in set and minimizing alternate bearing cycles is the key to consistent above-average yields and higher profits. The secret is ensuring the tree has the right nutrients at the right time in the right forms and right mix.

Agro-K’s carbohydrate based foliar line including:

Vigor-SeaCal (a highly available calcium combined with Agro-K’s proprietary seaweed extract)
Vigor-Cal-Bor-Moly (a Dextro-Lac blend of calcium, boron and moly)
Zinc Plus +4 DL (a Dextro-Lac blend of zinc, magnesium, manganese, iron and copper)

are designed to help growers meet specific peak nutrient timings in the crop cycle.

BioMax Dual Action + is a unique soil applied product that has a dual purpose. The first is to directly feed existing beneficial microbial populations (like Mychorrizae) in the rhizosphere to increase native populations that help to naturally compete against soil borne pathogens. The second purpose is to encourage root growth and increase root mass to improve nutrient foraging and uptake from the soil to support tree health while maximizing long-term tree growth and productivity.

Agro-K nutrient programs are based on a SCIENCE DRIVEN approach with a clear understanding of the almond tree physiology and meeting the tree’s peak nutrient demands throughout the season. With bud break happening in the near future, the focus needs to be on early season nutrient demands and the environmental dynamics of this season.

While more is needed, the almond growing regions have been fortunate to receive much needed rains this winter. Ken Dart, Agro-K’s National Technical and Marketing Manager states – “because of the rains we can expect cool wet spring soils to limit nutrient availability, root activity and nutrient uptake to be minimal. Growers that are interested in maximizing yield (consistently year over year) and quality will work to address spring nutrient needs by managing and meeting peak nutrient demand timings all season long so that the tree has reserves ready at bud-break, but will also supplement with early spring sprays. You never want the tree to lack nutrients at critical physiological timings.”

“In the spring, due to poor nutrient availability in the soil the tree will support its nutritional needs by utilizing nutrients stored in the roots and wood. Foliar applied nutrients early season are needed to fully support the tree’s need and to ensure more uniform bud break and faster early growth with larger leaves that have more photosynthetic capability,” says Dart.

Dart cites these important nutritional facts:

  • The process of breaking dormancy is a very zinc-intensive process.
  • Almond trees have a large early season demand for zinc to support leaf and vascular systems. All these tissues require zinc to function and grow fully and properly.
  • The best nut set and yields won’t happen without molybdenum for pollen production and pollen performance, and boron for pollen tube development and phosphate for cell division for good nut size.
  • The full potential of a good nut set won’t happen with small leaves and poor chlorophyll. Leaf size is dependent on adequate zinc levels while the leaves are forming – early peak nutrient demand. The key to making this work is having zinc in the buds, roots and vascular tissues applied at a time, and in a form that will be taken in, stored in these tissues and ready to go when dormancy breaks in the spring.
  • Chlorophyll production takes place as the leaves expand and requires Manganese, Magnesium, Iron, and Sulfur. If these are deficient as the chlorophyll forms, the leaves will not be effective in capturing the light for photosynthesis (especially in the lower canopy) which leads to smaller nuts, weak lower limbs and terminals that are more vulnerable to the complex of diseases leading to lower limb die back.

For more information on Agro-K’s almond trial research, fertility programs and Agro-K’s products contact your local dealer or Agro-K today. 1-800-328-2418 or email

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