Beating BOT Blight In Pistachios

Many of California’s pistachio growers were taken by surprise when an outbreak of Botryosphaeria blight, or BOT blight, struck their orchards this past season. Boytryosphaeria is spread primarily through moving water in orchards, and late rains in the state last year helped spread Botryosphaeria dothidea spores, initiating multiple infections, says Themis Michailides, a plant pathologist at the University of California’s Kearney Agricultural Center.

Researchers have discovered that more species of Botryosphaeriaceae fungi are involved in BOT blight than were initially thought. According to Michailides, these species are abundant among nut crops and other hosts in California, and they accumulate in the bark of older trees, even healthy branches. When dead clusters, cankers, buds, and shoots accumulate on the trees, pathogens can survive and produce spores in these cankers for six years or longer. If present, the disease can be spread via insect transmission, pollen, and pruning equipment, too.

Monitoring And Management

Michailides says growers should do a bud monitoring (BUDMON) test to determine how much Botryosphaeria, if any, is present in orchards before pistachio shoots and blooms emerge, usually in February or March. “And watch the weather carefully,” he adds. “If the prognosis is for rains that coincide with full bloom, growers will need to apply a bloom spray before the rains.” Michailides recommends monitoring leaf wetness and temperature to determine the best times and how much to spray.

Another option is overnight freezing incubation (ONFIT), which is usually done in June.

Growers should remain vigilant and look out for symptoms like blighted shoots and clusters. Blackening of the main shoot and rachis of clusters is reason for concern. “Learn how to distinguish Botryosphaeria from Botrytis shoot and blossom blight,” Michailides says. “Beige or buff color powdery spores are present at the base of shoots in the case of Botrytis infections, while Botryosphaeria will have pycnidia inside the plant tissues.”

Topics:

Leave a Reply

One comment on “Beating BOT Blight In Pistachios

  1. […] Beating BOT Blight In Pistachios | Growing Produce – How To Manage Tomato Yellow Leaf Curl … 4 New Citrus Rootstocks To Grow On; … Many of California’s pistachio growers were taken by surprise when an outbreak of Botryosphaeria blight, or BOT blight, struck their orchards this past season. […]

Nuts Stories
Fruits
January 16, 2017
Pollination Experts Host Webinar Series
Fruit and vegetable growers can prepare for spring by hearing about recent pollination research. Read More
Example of how farmers can use iPads to track data around his operation
Citrus
January 16, 2017
Precision Agriculture and Big Data Gaining Traction Fast
Specialty crop adoption of hort tech to usher in new efficiencies and transparency. Read More
Tom Vilsack entering stage for a speech
Citrus
January 13, 2017
Vilsack Bids Fond Farewell in Early Exit From Top Office
With no clear-cut replacement in sight, U.S. agriculture secretary leaves one week before his term officially ends. Read More
Washed out veggie field in NE Florida from Hurricane Matthew
Citrus
January 10, 2017
Was 2016 the Worst Weather Year Ever?
Near all-time records in average temperature and costly climate-related disasters make a strong case for dubious distinction. Read More
Nuts
January 3, 2017
Despite Some Pricing Concerns, Nut Growers See Rosy Future
Despite some unsettling prices in recent years, most growers see a relatively smooth ride ahead. Read More
Citrus
December 29, 2016
Are Today’s Agriculture Regulations Ripe for Reform? [Opinion]
Donald Trump has been clear that he is no fan of burdensome rules that stifle productivity. Read More
Nuts
December 27, 2016
Almond Grower Assessments Increased 33%
Almond Board of California recommended the penny-per-pound raise in the face of monster crops in the next few years. Read More
The Latest
Citrus
January 19, 2017
Trump Taps Sonny Perdue for Secretary of…
Ag leaders applaud pick to head up USDA. Read More
Citrus
January 18, 2017
NASA, NOAA Concur 2016 Was World’s Warme…
For the third time in three years, the heat gets turned up on surface temperature statistics. Read More
Citrus
January 17, 2017
The Future of Agriculture is in Your Han…
Can farmers actually reach the point of having too much information? Read More
Fruits
January 16, 2017
Pollination Experts Host Webinar Series
Fruit and vegetable growers can prepare for spring by hearing about recent pollination research. Read More
Citrus
January 16, 2017
Precision Agriculture and Big Data Gaini…
Specialty crop adoption of hort tech to usher in new efficiencies and transparency. Read More
Citrus
January 13, 2017
Vilsack Bids Fond Farewell in Early Exit…
With no clear-cut replacement in sight, U.S. agriculture secretary leaves one week before his term officially ends. Read More
Citrus
January 10, 2017
Was 2016 the Worst Weather Year Ever?
Near all-time records in average temperature and costly climate-related disasters make a strong case for dubious distinction. Read More
Nuts
January 3, 2017
Despite Some Pricing Concerns, Nut Growe…
Despite some unsettling prices in recent years, most growers see a relatively smooth ride ahead. Read More
Citrus
December 29, 2016
Are Today’s Agriculture Regulation…
Donald Trump has been clear that he is no fan of burdensome rules that stifle productivity. Read More
Nuts
December 27, 2016
Almond Grower Assessments Increased 33%
Almond Board of California recommended the penny-per-pound raise in the face of monster crops in the next few years. Read More
Nuts
December 26, 2016
Almond Board of California Announces 201…
Ten positions are open on the Board of Directors. Read More
Fruits
December 2, 2016
The Burchell Nursery 2017 Variety Showca…
The Burchell Nursery, Inc., in Oakdale, CA, offers a new self-fertile almond, an early-season nectarine, and a late-season peach. Read More
Fruits
November 29, 2016
Orchard Spray Oil Now OMRI Listed
Orchex 796 Orchard Spray Oil can be used on number of tree and nut crops. Read More
Citrus
November 29, 2016
Review Shows Low Risk To Aquatic Inverte…
Peer-reviewed evaluation of more than 100 studies finds uses of imidacloprid are unlikely to harm aquatic invertebrate communities, or the birds and fish that rely on them. Read More
Nuts
November 23, 2016
Nation’s Largest Nut Grower Wins Prestig…
The Wonderful Company is honored with the 2016 Corporate Citizenship Award, in the category of Best Community Improvement Program. Read More
Citrus
November 22, 2016
Arysta Partners With Beem Biologics To L…
Agreement to expand Arysta’s portfolio with new biocontrol releases. Read More
Citrus
November 21, 2016
Bacterial Imbalances Can Be Troublesome …
A recent study reports that bees given fresh pollen or fresh supplements fared better than bees given pollen or supplements that had first been aged for 21 days. Read More
Citrus
November 19, 2016
USDA Gives $200 Million To Expand Ag Exp…
USDA Secretary Tom Vilsack has announced the USDA’s Foreign Agricultural Service (FAS) is awarding $200 million to more than 70 Read More