Salt Burn v/s Leaf Scorch

Posted by David Doll  /   July 25, 2014  /   Posted in Almond  /   2 Comments

I have been receiving a few questions regarding the symptoms of salt burn versus almond leaf scorch. Below are a few pictures to help with the differentiation.

Leaf Scorch whole tree

Figure 1: From a distance, an almond tree affected by sodium/chloride toxicity or almond leaf scorch can look similar. Key differences: salt burn will be uniform across the field while almond leaf scorch generally tends to be random across the field. Read More

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Importance of Hull Sampling for Boron

Posted by David Doll  /   July 12, 2014  /   Posted in Almond  /   No Comments
Boron toxicity of a young almond tree. Photo by Franz Niederholzer

Boron toxicity of a young almond tree. Photo by Franz Niederholzer

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. Read More

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Leaf analysis and salinity monitoring

Posted by Joe Connell  /   July 04, 2014  /   Posted in Almond  /   No Comments

Written by Joe Connell, Butte County Farm Advisor2014-04-29 10.34.34

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.  Read More

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Speed Doesn’t Kill Part 3: Economics

Posted by David Doll  /   June 26, 2014  /   Posted in Almond  /   4 Comments

spray rig pictureThere has been a lot of research focusing on spray rig speed and spray coverage. Work by Jack Dibble back in the 70s-90s indicated that the best coverage is achieved at 1.5 MPH, and was the basis of the compromised recommendation of 2.0 MPH. This work has since been repeated by Dr. Joel Siegel (along with several collaborators) and Dr. Ken Giles and colleagues at Arbuckle, CA, and has indicated that at higher speeds, control of navel orangeworm (NOW) is lost in the upper canopy of the tree (>15′ high). This, interestingly enough, is where the majority of the crop is located. A few articles have been posted on this in the past (Speed Doesn’t Kill, Speed Doesn’t Kill, part 2). Read More

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