David Doll5 CommentsJuly 12, 2014Nutrient

Importance of Hull Sampling for Boron

Boron is a micronutrient for almonds. It is required in the process of flower fertilization, being involved in directing the germinating pollen tube. Deficiencies lead to a reduced nut set, and in severe cases, an appearance of a “nonproductive symptom.” Within the tree, boron deficiency can lead to a dieback of small twigs and a “weeping branch” like look.  Boron is also toxic at too high of concentrations.  Often being found in areas with high soil boron or in blocks irrigated with water containing boron, toxicity symptoms appear as gummy nuts that may  form “stick tights” or presence of gum exuding from pruning wounds, bud and leaf scars, and spurs.

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Joe Connell0 commentsJuly 4, 2014Horticulture, Nutrient, Salinity

Leaf analysis and salinity monitoring

Written by Joe Connell, Butte County Farm Advisor Leaf analysis for the full range of nutrients is best done in July when nutrient levels in leaf tissue are stabilized. Published July critical values established for almond by U.C. researchers can help guide you in your fertilization practice.  Analysis can reveal specific nutrient deficiencies or can alert you to developing trends when results are compared from one year to another.  Keeping trees in the adequate zone for nitrogen can save on fertilizer costs by helping to avoid over fertilization. 

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Franz Niederholzer0 commentsApril 11, 2014Nutrient

Potassium Webinar Q&A

At the end of February, David Doll and I presented a webinar on potassium nutrition of almond orchards hosted by Western Farm Press with support from Compass Minerals.  During the webinar, listeners asked questions and we tried to answer them at the end of the webinar.  We could only get through a few.  In this post, we try to answer at least a few of those questions asked (another link to the webinar…click here!).

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David Doll6 CommentsMarch 7, 2014Nutrient

Almond Nitrogen Uptake: Seasonal Perspective

There has been a lot of workshops and seminars discussing nitrogen management in almond. The data and conclusions discussed from these trials has been thought provoking, and has provided information to help better manage almond orchard nitrogen.  One particular slide has caught my attention – and provides the basis of nitrogen timings for almond orchards.

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Franz Niederholzer1 CommentSeptember 9, 2013Nutrient

Sustainable Nutrient Management: a Review.

Almond harvest looks to be progressing well (knock, knock).  Orchard fertility/nutrition planning for the 2014 is beginning.  Now is a good opportunity to review the basics of almond orchard nutrient management.  While some of what follows will be review for many readers, a quick review may be of value. Sustainable nutrient management comes down to the four R’s – the Right Rate, the Right Time, the Right Place, and the Right Material.  A sustainable approach to orchard nutrition is intended to optimize crop production and maximizing net profit while reducing the risk of environmental contamination.

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David Doll8 CommentsAugust 17, 2013Nutrient

Postharvest Fertilization – Q&A

Q. How much nitrogen should be applied in the postharvest period? A. This depends.  This should be based upon the current tissue N levels detected from mid-July sampling. If within the prescribed ranges of leaf N (2.2-2.5%), 20% of the budget should be planned for application. If richer (>2.5%), slightly less can be added. If really high N leaf levels are observed (>3.0% in mid-July), postharvest fertigation may not be needed. 

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Franz Niederholzer0 commentsApril 20, 2013Nutrient

A quick review of UC ESP sampling for accurate almond orchard nitrogen fertilization.

This is the first year that the UC Early Season Protocol (UC ESP) model for predicting July almond leaf nitrogen (N) levels from April leaf samples, has been available for public use.  This model was developed by UC Davis researchers led by Dr. Patrick Brown.  Based on calls to several reputable ag labs and questions from PCAs, there seems to be some uncertainty about availability and use of the new model.  Where is the model?  How does is it used?  Who should use it to develop the July leaf N prediction and what should be done with the results?  Does an analytical lab run it for growers and PCA/CCAs?  If the lab doesn’t do it, should/can the grower or their PCA/CCA to do it, and, if so, where is the model?  This blog post is intended to answer these questions and help interested almond industry members use the UC ESP model.

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Franz Niederholzer1 CommentApril 16, 2013Nutrient

April Leaf Sampling Protocol

To take and utilize an early season leaf sample for estimating of seasonal nitrogen needs, follow the UC Early Season Protocol (UC ESP) for leaf sampling (details below).  So far, this program has only been tested on Nonpareil, but it should work well for other varieties.  (Dr. Brown’s lab is working up the details for a Monterey variety sampling protocol.  For now, here’s how to take leaf samples using the new UC protocol worked up for Nonpareil:

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David Doll0 commentsApril 3, 2013Nutrient

Fertilizing Young Trees – First Year Trial Results

There have been several posts over the past few weeks about fertilizing mature almond trees. This data has been based upon long term studies held primarily in Kern County with some data points from across the state. Not all of this, however, is applicable to determining the rates of fertilization for developing almond orchards. At best, there are “educated guesses” in regards to identifying the proper rate for developing trees. Whole tree assays have found about 480 lbs of N/acre are stored within the woody biomass of mature trees. In order to reach that amount, trees would have to be accumulating nitrogen within the woody tissue at a rate of 20-50 lbs/acre/year until maturity (10-12th leaf). Once the tree begins to bear (~3rd/4th leaf), nutrients must be added to compensate for what is removed by the crop.

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