'California and the rest of the pistachio producing nations face the same problems'

For years, the pistachio industry seemed unstoppable: growing consumption, new producing regions, and record-breaking plantations around the world. But are we now entering a more uncertain stage, where climate volatility could call into question the model that drove the sector’s success?

Correct.  If one examines pistachio production in the three major pistachio producing countries, ranked by growth over the last 30 years the USA, primarily California, grew most rapidly with a compounded annual growth rate (CAGR) of ~ 8.6%, Turkey ~ 5.7% and Iran ranged from a decrease of ~ -0.5% to + 1%. 

Iran was the clear leader in the 1990s.  Now California is the leader having produced an average annual 639,000 mt in-shell in 2023-2025 versus Turkey with 227 mt in-shell annually and Iran producing 198,000 (USDA) to 312,000 (FAO) mt in-shell tons annually, depending upon the data source.

However, currently all three countries are experiencing climate related, or water problems, further exacerbated by the pistachio’s characteristic of alternating heavy (on) and light (off) crops. The International Nut Council’s (INC) projects the following for the three major pistachio producing countries, expressed as metric tons in-shell pistachios

California is entering a low crop year.  The INC is forecasting 350 mt inshell in 2026, roughly half of 2025’s 722,700 mt in-shell on-crop. Record heat during an unusually early bloom in March 2026, temperatures rose above 30°C to 38°C in the major growing areas.  Early bloom was destroyed, resulting in flower drop and poor nut set. Currently, some orchards are reporting up to 80% blank (empty) nuts. A normal year is 15–20% blank nuts.

Iran is also entering a low crop year.  The INC is forecasting a 130,000 mt in-shell crop, down roughly 42% of 2025’s 224,100 mt in-shell on crop. Iran is experiencing an ongoing drought, plus electricity shortages that limit the pumping capacity for irrigation. 

Turkey is entering an on crop year.  The INC is forecasting 156,400 mt in-shell crop 2025-2026; 36.5% increase from 2024-2025’s 114,400 mt in-shell crop. Frost and poor seasonal weather in key growing areas, plus drought and limits on irrigation water are harming Turkey’s productivity

California has been the world’s leading benchmark for pistachio production for decades. However, even there, growers are facing water shortages, warmer winters, and rising costs. From your perspective, what uncomfortable realities should the global industry be prepared to confront today?

All the world’s pistachio industries are grown in similar Mediterranean climates and therefore ace the same face the same problems.  These problems are, in order of importance, the climate change that is producing warmer winters, more erratic temperatures throughout the year including early fall and spring freezes and periods of extreme heat and less precipitation.  A secondary result of climate change is less water and increasingly saline water and soils.  And, as traditional and new pests and diseases spread and appear, the lack of effective tools to combat, and increasing regulation of insect and disease chemicals.  California and the rest of the pistachio producing nations face the same problems.

Much of your scientific career has focused on salinity, irrigation, and tree physiology — issues that once seemed purely technical but are now at the center of the global agricultural debate. Do you believe the pistachio sector is reacting quickly enough, or is the scale of the coming change still being underestimated?

The pistachio tree evolved under extreme conditions and developed multiple adaptations to survive extreme conditions.  We are still learning how to take advantage of these adaptations to profitably produce pistachios. The ability of an individual pistachio industry, or grower, to implement the results of this scientific information is not the result of underestimating the data, or being slow to adapt, as it is the availability of solutions.  For example, we now know the limits of pistachio salinity tolerance.  However, if an orchard is planted in saline ground it cannot move; so, within limits, if the soil drains well, and water and amendments are available and economical, salinity can be managed but will never be eliminated.  Similarly, we are learning the effects of climate change on pistachio bloom, pollination and nut set and maturity.  But we have limited tools to mitigate lack of winter chill, early fall or spring freezes, or extremely high spring temperatures, all conditions which decrease successful crop production.

The World Pistachio Congress is taking place at a particularly decisive moment for the sector. Beyond networking and market outlooks, what role should international gatherings like this play in driving real solutions to the industry’s major challenges?

International conferences like this first World Pistachio Conference are a chance to learn how others are approaching our shared problems and cooperate in developing solutions. The California pistachio industry is only 50 years old.  Pistachios have been grown in Iran for 4,000 years and in Turkey for 2000 years.  These older industries have collective information and germplasm resources the California industry does not.  For example, I never would have begun investigating the impact of saline water and soils on pistachio production had I not observed Iranian growers producing economically profitable pistachio crops at 16 dS/m. Hopefully, conferences like this first World Pistachio Conference will facilitate cooperations that will result in more profitable pistachio production for all of us.

The pistachio industry is going through a period of profound transformation, facing challenges ranging from climate and water resources to evolving markets and technology. In such a rapidly changing context, what do you believe should be the top priorities for international discussion within the sector today?

The top priorities for a conference like this is to realize first, we are colleagues with the same goal; more knowledge about how to successfully produce pistachios.  Second, to collectively define our mutual challenges, determine the state of our collective knowledge and develop best cooperative approach to our challenges.  For example, Iranian and Turkish pistachio scientists have access to pistachio germplasm that has evolved and survived under harsh conditions for 4000 years.  California is developing tools to manipulate and evaluate this germplasm.  A combination of our collective resources and skill sets could produce more resilient pistachio trees for each of our unique situations.  A conference like this can facilitate accomplishing this goal.

WPC Newsroom