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
Photo Credit: David Eddy
Nuts
February 10, 2016
Incentives Available For Low-Emission Harvesters 
Almond and walnut growers who use lower-emission harvesting equipment may be eligible for financial incentives. Beginning this year, the USDA Read More
Bayer company logo
Crop Protection
February 10, 2016
Bayer Contests EPA’s Decision On Insecticide  
Company seeks to stop agency’s proposed cancellation of flubendiamide. Read More
AFG state of the industry
Apples & Pears
February 9, 2016
State Of The Fruit Industry 2016 [VIDEO]
According to an national poll of fruit growers, fruit industry suppliers, and researchers, the market is poised for growth in Read More
Almonds
Nuts
February 3, 2016
Avoid Tree Nut Cargo Theft
American Fruit Grower® and Western Fruit Grower® recently reported on a rash of nut thefts, in which truckloads of nuts Read More
honey bee on almond tree
Nuts
February 3, 2016
Tips To Help Secure A Good Beekeeper Agreement
Pollination is one of the most important aspects of almond growing, and this time of year, making sure you have Read More
Varroa mites
Fruits
February 2, 2016
EPA Releases List Of Products Labeled For Use Against Varroa Mites
Agency gives recommendations on products to protect hives against parasites. Read More
Mark Jansen
Photo: Blue Diamond Growers
Nuts
January 27, 2016
Almond Industry 2016 Preview
American and Western Fruit Grower talked with Blue Diamond Growers President and CEO Mark Jansen about the health of the Read More
The Latest
Citrus
February 13, 2016
5 Questions With The New American Farm B…
Zippy Duvall weighs in on priority issues. Read More
Disease Control
February 10, 2016
Broad-Spectrum Fungicide Approved For Sp…
Rhyme controls powdery mildew, brown rot blossom blight, and leaf rusts. Read More
Nuts
February 10, 2016
Almond Board Working Toward Next-Generat…
New sustainability initiatives will bring the almond industry into the 22nd century. Read More
Nuts
February 10, 2016
Incentives Available For Low-Emission Ha…
Almond and walnut growers who use lower-emission harvesting equipment may be eligible for financial incentives. Beginning this year, the USDA Read More
Crop Protection
February 10, 2016
Bayer Contests EPA’s Decision On Insecti…
Company seeks to stop agency’s proposed cancellation of flubendiamide. Read More
Apples & Pears
February 9, 2016
State Of The Fruit Industry 2016 [VIDEO]
According to an national poll of fruit growers, fruit industry suppliers, and researchers, the market is poised for growth in Read More
Nuts
February 3, 2016
Avoid Tree Nut Cargo Theft
American Fruit Grower® and Western Fruit Grower® recently reported on a rash of nut thefts, in which truckloads of nuts Read More
Nuts
February 3, 2016
Tips To Help Secure A Good Beekeeper Agr…
Pollination is one of the most important aspects of almond growing, and this time of year, making sure you have Read More
Fruits
February 2, 2016
EPA Releases List Of Products Labeled Fo…
Agency gives recommendations on products to protect hives against parasites. Read More
Nuts
January 27, 2016
Almond Industry 2016 Preview
American and Western Fruit Grower talked with Blue Diamond Growers President and CEO Mark Jansen about the health of the Read More
Nuts
January 26, 2016
Thefts Plaguing California Tree Nut Indu…
Thieves have been taking off with truckloads of tree nuts valued as much as a half million dollars, and catching Read More
Citrus
January 22, 2016
It’s Official: 2015 Was Earth’s Wa…
NASA, NOAA analyses reveal record-shattering statistics regarding global temperatures this past year. Read More
Citrus
January 21, 2016
Chance Of Profits Up For Growers Tuned I…
UF/IFAS study confirms how paying attention to the 10-day forecast can affect a farmer’s bottom line. Read More
Apples & Pears
January 20, 2016
Herbicide Flood Irrigation Application A…
Crops include stone fruit, pome fruit, grapes, tree nuts, and olives. Read More
Nuts
January 20, 2016
Regional Trials Pinpoint Almond Varietie…
Since the 1970s, the Almond Board of California has been trialing varieties regionally to determine the best and brightest trees Read More
Citrus
January 20, 2016
USDA Report: Pesticide Residues Not A Fo…
Following monthly samplings, survey finds more than 99% of products sampled fall below EPA tolerances for pesticide residues. Read More
Nuts
January 15, 2016
Researchers Crack Walnut Genome
Genetic sequencing paves the way for better breeding. Read More
Citrus
January 13, 2016
American Farm Bureau Elects New Presiden…
Georgia farmer Zippy Duvall to take leadership reins from retiring Bob Stallman. Read More
[gravityform id="62" title="false" description="false"]