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November 2, 2015

Is 2015 Growing Hollow for Pistachio Growers?


In water-conscious California, many farmers are finding ways to maintain high yields and quality crops despite limited water supplies. But 2015 is presenting painful challenges for the state’s pistachio growers. Pistachio growers, who produce 99 percent of the nation’s pistachios, are bracing themselves for an expected smaller crop this year due to a significant number of hollow nuts.

Why are shells shooting blanks in bulk?

Hollow nuts – commonly referred to as “blanks” – are pistachios with shells but no meat inside, and are predicted to make up 50 to 70 percent of this year’s yield[1] – compared with the usual 20 percent average. Pistachio blanks are the result of the West Coast’s abnormally warm temperatures and shortage of chilling time. To properly pollinate, pistachios need plenty of exposure to coldness, also known as “chilling hours.” This year’s drawn-out warm weather is causing male trees to bloom and release pollen at a separate time from female pistachio trees – ultimately resulting in malfunction.

What does this mean for pistachio growers?

This year's harvest could be 300 million pounds or less — down from 520 million pounds in 2014.[2]  While nothing can be done to change California’s drought or heat, pistachio growers can combat the challenges caused by the state’s abnormal weather conditions. According to a University of California study,  supplying pistachio orchards with an adequate amount of potassium not only reduces percentages of blank and stained nuts, but also increases nut weight and the percentage of split nuts.[3]  In order for growers to decrease their percentage of blank nuts and optimize their pistachio yields, it is essential that leaf K concentration should be at 1.7% or higher.

Protassium+ – a pistachio’s best friend.

Pistachio and other tree nuts are sensitive to soil salinity caused by dry conditions. Therefore, provide your orchards with a K source like Protassium+®, a premium sulfate of potash, which delivers high potassium and sulfate sulfur without contributing to salt build up. Compared among other potassium fertilizers, Protassium+ has virtually no chloride, making it a very safe input. With a low salinity index, Protassium+ is ideal especially in areas undergoing drought challenges or laden with poor quality water. California growers looking to protect crop performance and profits during dry and warm conditions should consider Protassium+ sulfate of potash as a fit for their potassium needs.

[1] http://www.npr.org/sections/thesalt/2015/09/11/439509278/oh-nuts-why-california-s-pistachio-trees-are-shooting-blanks

[2] http://www.npr.org/sections/thesalt/2015/09/11/439509278/oh-nuts-why-california-s-pistachio-trees-are-shooting-blanks

[3] http://apps.cdfa.ca.gov/frep/docs/Pistachio.html#Potassium