David Doll4 CommentsDecember 15, 2014Diseases

Recent Storms and Tree Loss

The high wind from this past weeks storm has caused damage to orchards throughout the State. Trees have been blown over, uprooted from the strong winds, which will impact crop yields and orchard stand. This damage usually can be categorized into two categories – trees that have blown over from a failed root system or from heart rot disease. Failed Root Systems. Damage to almond trees from failed root systems tends to occur in younger orchards and is characterized by leaning trees within saturated soils. 

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David Doll2 CommentsOctober 27, 2014Diseases

Fall Sampling for Nematodes: Now is a Good Time

Late fall is a good time to consider nematode sampling. Sampling may be important to perform if lack of vigor or poor growth is observed within an orchard. Samples should be taken once the soil begins to cool in October. For best results, multiple soil samples should be taken, with a minimum of one sample per soil type present in the orchard. If soils are  relatively uniform,  two to three samples should be made for fields smaller than 60 acres. Five or six samples are needed for  for larger uniform fields. A composite of 5-7 different spots within the soil type or field quadrant should be pooled (mixed and combined) as one “sample.” Soil samples should be taken at a depth of 15″-20″ within the rootzone of the tree. Once enough samples have been collected, they should be placed in a properly labeled bag, kept cool and out of the sun, and submitted to a lab to conduct the nematode analysis. 

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David Doll2 CommentsJuly 25, 2014Diseases, Salinity

Salt Burn v/s Leaf Scorch

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. 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.

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Franz Niederholzer0 commentsMay 29, 2014Diseases

Alternaria season starts in the Sacramento Valley

In a Colusa County almond orchard, this past week saw the beginning of summer conditions that can produce alternaria leaf spot.  Based on hourly tracking of leaf wetness and temperature, the treatment threshold may not have been reached, yet, but the conditions that can build up to disease infection have begun.  Note:  For more information on alternaria leaf spot biology and control from the UC IPM program, click HERE.

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David Doll5 CommentsMay 16, 2014Diseases, Horticulture

Lower Limb Dieback of Almond

Lower limb dieback (LLDB) has become an emerging problem within many almond orchards throughout California. Observations of orchards with LLDB occur independent of soil types, irrigation systems, and planting spacings, while typically affecting orchards that are in their 8th leaf or older. Symptoms are predominantly found on Padre and Butte, but are also found on many other varieties including Nonpareil, Fritz, Carmel, Wood Colony, and Mission.

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David Doll0 commentsApril 11, 2014Diseases

Jacket Rot on Almond

I have been receiving a few calls about issues with deformed almonds, particularly with the variety of Monterey. When looking at the nuts, it appears that the damage is associated with the jacket. This appears to be jacket rot. Samples submitted were placed in a humidity chamber and produced the gray/brown “fuzz” that is common to Botrytis, one of the causal agents of jacket rot. Based on the weather, this appears to be an issue with the four day rain event that occurred as the jackets were splitting on the later blooming varieties. I dont suspect a major problem, unless we re-enter a period of rainy, cool weather.

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David Doll6 CommentsApril 3, 2014Diseases

Leaf Spot on Padre, Other Varieties

Odd leaf symptoms on several different varieties have been reported across the valley. Predominantly found on Padre, they are found on the edge or the tip of the leaf. The lesions can be quite large, but tend to have a watersoaked margin and a yellow halo. In other varieties, the lesion has a shot-hole-like appearance, but fruiting bodies are not visible. Farmers have complained that fungicide spray programs have not been effective in controlling this disease.

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Franz Niederholzer3 CommentsFebruary 7, 2014Diseases, Horticulture, Insects

Pollen, Bees, R.U.L.E.S., and Almond Bloom

Almond bloom has begun.  No time of the season is more important to delivering a good crop.  You don’t get a Mulligan at almond bloom.  Good pollinization, delivery of viable pollen grains to the flower stigma of a compatible flower, is the first step of a successful bloom season.  Keeping spray materials off the pollen helps keep the pollen viable for germination (the next step in a good crop) and healthy for bees—the key pollinators from Red Bluff to Bakersfield.

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Roger Duncan7 CommentsJanuary 21, 2014Diseases

Bacterial Spot Management

Almond growers and pest control advisors who attended our July bacterial spot field day in Manteca saw how devastating this new disease can be.  A map passed around at that field day showed two hot spots for the disease in our area.  The most severely affected area was between Highway 120 and the Stanislaus River in the Manteca/Ripon/Escalon area.  The second area was south of Turlock in the Delhi / Ballico area. 

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