Welcome to the Ultra Gro Agronomy Letter!
Welcome to the newest issue of the Ultra Gro Agronomy letter. We have decided to put together an issue entirely devoted to pistachios. The timing couldn’t be better…we are fresh on the heels of the American Pistachio Growers Conference and pistachio orchards are starting to come out of dormancy. With that in mind, we are happy to present Rich Kreps’ take on the APG Conference, a thorough agronomy update from UG Agronomist, Robert Smith, and a market update from Jim Zion of Meridian Growers.
Report from the American Pistachio Growers Conferece
by Rich Kreps, CCA
The first week of March is a fabulous time to be a nut grower, especially if you are part of American Pistachio Growers. After a year off, we had our annual conference at the Omni at La Costa in Carlsbad, CA and once again, the team at APG organized the best ag conference of the year.

The line-up of speakers was informative and entertaining. Headliners ranged from Captain Scott Kelly, the astronaut who has spent the most time in space, to Buffalo Bills QB and new pistachio grower, Josh Allen. Both were terrific.

Preceding Josh in the speaker line-up, Executive Director of APG, Richard Matoian, gave us a very informative overview of the world supply and demand situation. With more pistachios being planted and some replacing almond orchards, the whole industry shares concerns about over-supplying the market. This was followed by a grower panel Q&A session of industry leaders, of which, I had the privilege of acting as moderator. The panel spoke to the outlook of the industry for the next 5 years. Clearly, they brought forth the need for all of us to join together in support of the leadership role that APG plays in representing our industry. The grower panel discussion was inter-woven with some impressive analytical work that marketing consultant, Dr. Dennis Tootelian, Ph.D, put together for APG. It was very reassuring to see that Dr Tootelian’s conclusions demonstrated the effectiveness of the marketing efforts of APG in building demand for pistachios and the outlook for our industry is very bright.

Speaking from my perch as a crop advisor, the production sessions were well attended and very informative as well. Topics ranging from sap flow analysis to nutrient timing were tops in my book. All in all, as a board member of American Pistachio Growers, a pistachio farmer in Madera, and a crop advisor to many growers, I can say with great confidence that APG is doing a great job for our industry. If you grow pistachios, please consider joining the Association.

Starting This Year (2022) in Pistachios
by Robert Smith, Agronomist
Another year of California drought…

After record-setting storms in October and then December, the past two months — usually among the wettest months in California — have been the driest January and February in California history. We have seen precipitation totals plateau at roughly half the yearly average in the state’s major watersheds, prompting state officials to warn of dire water conditions ahead and issuing zero to super-low allocation estimates. All this is pointing to, again, some pretty dire conditions statewide for drought. 

With this in mind, now is the time to be planning your irrigations strategies for the upcoming season. The University of California Agricultural and Natural Resources has done extensive research in the water use by pistachio trees. Led by Dr. David Goldhamer, UC Extension Specialist (with an assist from well-known pistachio expert, Bob Beede) studies have been conducted in season-long irrigation at 0, 25, 50, 75, and 100% Crop Water Use (ETc). Importantly, temporary reductions from full ETc at the three main stages of pistachio development have been established. Stage I: bud break to shell hardening, Stage II: (late May to late June), when neither shell or kernel growth is occurring, and Stage III (late June to harvest) when kernel growth and shell splitting takes place. These are carefully managed reductions of water applied. This is commonly called Regulated Deficit Irrigation (RDI).

In reviewing, Goldhamer and Beede’s research, they suggest that 7-10 inches of water can be saved with RDI with no impact on fruit yield or quality; either for this or subsequent seasons. This is accomplished by irrigating at 50% of potential ETc during Stage II (mid-May through late June). This is after the attainment of full shell size and before rapid growth of the kernel.
If you need to reduce water use by more than 7-10 inches, you must stress the trees more severely and during other times of the season. 

Critical periods when pistachio should NOT be under-irrigated are: (1) from nut filling to hull slip (Stage 3: July 1 to Sept. 15 in the San Joaquin Valley), and (2) from bloom to end of shell expansion (Stage 1: Apr. 1 to May 15 in the San Joaquin Valley).

Deficit irrigation of pistachio can be practiced during the following periods: (1) 50% reduction in irrigation during shell hardening (Stage II: May 16 - June 30 in the San Joaquin Valley), and (2) 70 - 75% reduction in irrigation during the postharvest period (Oct. 1 - Nov. 15 in the San Joaquin Valley).

To reduce seasonal ETc by 16-20 inches, irrigate at 50% ETc through mid-May (Stage I), then 25% through early July (Stage II), 100% through harvest, and 25% ETc postharvest. Reductions in shell splitting, increased blank nut production, and greater difficulty in crop removal will be proportional to the percentage of full ETc applied during this critical period. Again, reduction in applied water greater than 7-10 inches does reduce shoot growth and nut size, and above average irrigation skill is required to properly execute this “controlled plant stress”. However, if you do not have enough water, you need to do what you need to do.

The dry winter demands irrigation prior to bud push for early root growth and hydration of the tree. If salinity is an issue, you still have time to apply high quality water for leaching. If you have not done it already, get some water in the ground, even if it means delaying shredding of the brush.

Final Word on Chill
I have written about this in previous newsletters, so, for a quick update suggests that 58-60 chill portions are needed to completely satisfy the Kerman pistachio rest requirement, using the dynamic model which considers negating warm daytime temperatures. Depending upon your location, the automated weather stations suggest that 47-61 chill portions have been received. In general, the chill requirement has been met at most pistachio-growing locations in California. Looking closely at the numbers, however, it’s not hard to notice that several sites fall slightly short of the target and are below the long-term average of cumulative chilling hours in a season this season. The remaining question is what percent of the state’s pistachio acreage is affected by these regional pockets that may not have met the chilling requirement. Additionally, chill accumulation is only one factor contributing to bloom. Other climatological factors, such as heat unit accumulation, contribute to time and uniformity of bloom.

What should I be doing in my pistachios in March and April? 

Most importantly, you must finish pruning, and then get the brush shredded, so you can access the orchard and treat the weeds which escaped your pre-emergent treatment, or for some, apply your pre-emergent.

Now is also an excellent time to perform some bud monitoring for Botryosphaeria. Cutting the collected buds in half with a razor blade will help you determine how much BOT is present in the orchard. Buds that are black inside are often BOT infected, so if you find several in your first sample, you might want to do a more extensive sample. If you do not get control of it in drier years, it will cause you major economic loss in wet years!

Be on the lookout for cotton-like masses on the main trunks and under the bark scale to be aware of Gills mealybug activity. Continue to assess the presence of Gill’s pistachio mealybug at green tip.

You should also keep an eye out for soft scale adults on the one and two-year-old wood. Go to the UCIPM Pistachio Web site and read up on your options.

Bloom is most import to have adequate levels of Zinc (Zn) and Boron (B). If your levels in the previous season were low it may not be too late for a delayed dormant zinc application. Zinc can be applied up to the early green tip stage (1/4-inch terminal growth). Do not apply if flower buds are expanding. Zinc is so immobile that early season sprays may prevent deficiency in young shoots for only a month. Zn and B micronutrients are critical to shoot growth and flower bud differentiation. Once deficient, it can be difficult to get enough zinc taken up into the pistachio tree to resume normal growth. This is especially true of young orchards! You can lose a year of growth trying to recover from a bad zinc deficiency.

If it rains a quarter inch or more during bloom, it may be necessary to apply a fungicide to control Botrytis and Botryosphaeria. The potential for these diseases depends upon past infection levels and repeated rain events. It has been determined 0.2 inches of rain and temperatures at or above 55o F constitutes a Botryosphaeria infection event.

Botrytis attacks the male bloom more than the female, because the tufts of pollen are high in sugar and proteins, both good for growth of this fungus. Kerman female trees show Botrytis infection in young, tender shoots. Diseased shoots wilt, and their tips curl like a shepherd’s hook. They turn dark and dull green. The base of the shoot also develops a cluster of buff-colored spores. Botryosphaeria shoot infections do not occur until later in the summer when it gets hot.
Beat tray monitoring and sweep net sampling of true bugs should be initiated. The native vegetation surrounding pistachios is still green for now, so the migratory plant bugs have no reason to move…yet! That will quickly change as we move into April and early May! Navel Orangeworm (NOW) traps should be in place. Research suggests pistachios compensate for nuts lost to Phytocoris and Lygus feeding, so early chemical treatment specifically for these pests may not be needed and Calacoris is your predominant plant bug present prior to shell hardening. 

Avoid heavy nitrogen (N) applications before fruit set. Remember that early shoot growth and fruit development is all from stored nitrogen. A good N management program includes soil, plant, and irrigation water N assessment. This should be part of your Irrigated Lands Regulatory Program (ILRP) and part of your implementation of the 4 R’s.

This means you should have samples taken of each, so you can make a better assessment as to how much synthetic N needs to be applied to the soil to meet the plant/crop requirement. I would assess my potential crop shortly after fruit set, check past soil analyses and then begin N fertilization at 30 to 50 pounds depending upon irrigation method and estimated crop load. Keep in mind that it takes about 14 days for ammonia-based fertilizers to convert to nitrate for uptake.
Adding high levels of N to the soil early in the season does result in greater plant uptake unless the tree is deficient. Available data indicates pistachio growth and yield is not improved with July tissue levels above 2.5 percent. 

Research shows good zinc uptake at 50% leaf expansion (late April). It is also beneficial to add Copper (Cu) EDTA to B the foliar zinc sulfate rate. Buffering this mixture to a pH of about 5 improves zinc uptake by increasing the amount in solution. Do not use a phosphate containing Buffer-Spreader to prevent Zinc Phosphate precipitation. Check with your Ultra Gro Crop Advisor for suggestions, but be sure you have adequate amounts of copper, boron, and zinc. This is especially true for young trees. Deficiencies severely limit canopy development and reduce early bearing potential. They are also very common, suggesting growers are not taking young pistachio plant nutrition sufficiently seriously, and suffer loss in orchard development because of it. Second leaf orchards are especially susceptible to micronutrient deficiency, partly because of all tipping performed to create branching.
Pistachio Market Update
by Jim Zion, Managing Partner of Meridian Growers
Shipments continue to stay ahead of last year despite the ongoing logistical issues.  Shipments are almost 5% ahead of last year at this same time.  While we have seen a general slow down on the export side, domestic shipments showed a 15% increase in January over last January. The domestic market continues to have good demand which helps offset any slowdown we have seen in the export marketplace.

Demand for kernels continues to be strong and that market looks to keep growing. We have seen a plethora of new product introductions which is bringing new consumers to pistachios.
We still expect prices to remain fairly stable for the remainder of the 1st quarter. The next big event that will influence prices will be the bloom which will take place in the later part of March. In the meantime, compared to other nuts, pistachios will be pretty flat in terms of pricing going forward. However, multiple headwinds, including; inflation, shipping issues and now, a war in Ukraine, could make the rest of this year very challenging.