Nitrogen Management & NDURE DCD

April 2020, Issue 5

WILBUR-ELLIS UPDATE REGARDING COVID-19

Wilbur-Ellis is closely monitoring the National and Global COVID-19 situation, as we continue to support our operations, facilities, employees, and most importantly, our customers. In this unprecedented situation, we remain committed to our customers as we face this challenge together. Following is the current position of our business operations.

Wilbur-Ellis Agribusiness locations remain open and will continue to serve our customers’ needs. Our operations are currently running without impact.
Wilbur-Ellis Agribusiness is working closely with our suppliers and taking the necessary precautions to ensure continuity of product supply for the current growing season. Currently, our product supply has not been impacted and there is no cause for concern with our ability to service our customers.
Customers wanting to pick up orders at their local branch are encouraged to work with their Wilbur-Ellis sales representative in advance to call-in orders, or they can e-mail their local Wilbur-Ellis order desk in advance; both options will allow orders to be ready upon arrival.
Currently, all counties in California that have implemented "shelter in place" directives have identified agriculture as an "essential business", which exempts them from these rules; ag retail locations are included in this exemption.

COVID-19 Customer Update

Nitrogen Management

As presented in the last issue of the Almond Newsletter, about 30% of the season total should be scheduled for April and again in May. That’s 60% of the season total applied in just a two-month period! Maximizing Nitrogen Uptake Efficiency (NUE), meaning maximizing the percent of applied nitrogen that is actually taken up by the crop, is critical for cost efficiency and tree performance. The Four R’s of Nutrient Stewardship are very important considerations for nitrogen management in almonds

The right nutrient source
Applied at the right rate
Applied at the right time
Applied at the right place

In our last Almond Grower Newsletter, we discussed the right rate and the right time. If you missed this issue, then please get with your Wilbur-Ellis fieldman to receive a copy. Now let’s discuss the right source and the right place.

The primary form of nitrogen that is taken up by almonds and most other crops is nitrate. But this is not by preference. In fact, if soil-applied nitrogen would remain in the ammonium form, then plants would have a physiological preference for ammonium. This is because once nitrate-nitrogen is taken up, it must first be enzymatically converted to the amine form by an enzyme called nitrate reductase, which is an energy-consuming reaction. But, in moist, warm soils, ammonium is rapidly converted to the nitrate form, meaning almonds have no choice but to take up nitrogen in the nitrate form. That is, until Now.

NDURE DCD Nitrification Inhibitor

Introducing NDURE DCD. NDURE DCD is a proven nitrogen stabilizer containing the powerful nitrification inhibitor DCD (dicyandiamide, CAS 461-58-5). NDURE DCD mixed into liquid UAN or urea blends slows the conversion of ammonium to nitrate. This leaves a greater percentage of applied N in the ammonium form that benefits almonds by freeing up energy that would have been required to convert nitrate back to the amine form. This energy can now be used for canopy development, nut fill and formation of spurs for next year’s crop.

By keeping more of the applied N in the ammonium form, which does not leach as does nitrate-nitrogen, we are keeping the soil nitrogen in THE RIGHT PLACE – in the root zone.

The data below is from a study evaluating the effects of DCD on nitrification inhibition. Urea with and without DCD were applied and mixed in soil and incubated at a constant temperature of 82^OF for up to 45 days. Soil samples were collected over the course of the experiment and evaluated for ammonium nitrogen. It is clear from this data that DCD is a powerful nitrification inhibitor. The untreated urea rapidly nitrified and had near non-detectable levels of ammonium after just 10 days. By contrast the treated urea showed high levels of ammonium well into the experiment and detectable levels out to almost 45 days.

Maintaining applied nitrogen in the ammonium form increases NUE and reduces nitrate leaching. Presented below is research data showing the effects of DCD on nitrate leaching when added to UAN. As can be seen, DCD reduced the amount of nitrate that leached below the root by about 50%

So, what do the benefits of the right nitrogen source in the right place mean to almond production?

A two-year study on flood-irrigated almonds in Kern County compared surface-applied UAN alone to surface-applied UAN + NDURE DCD. Seventy-five pounds of nitrogen were applied post-harvest and 125 pounds of N were applied in the spring in each of the test years.

Treated UAN resulted in an average yield gain of 311 pounds of nut meat per acre compared to the UAN alone treatment.

In summary, NDURE DCD provides the following advantages when included in your almond nitrogen program.

Keeps applied nitrogen in the ammonium form longer
Increases nitrogen uptake efficiency
Reduces nitrate leaching potential

All of this leads up to the opportunity to increase almond yields. Apply at 4-6 quart per ton UAN. Use the lower rate for frequent nitrogen applications (spoon-feeding) and the higher rate for intervals between nitrogen applications of two weeks or more

Carl Bruice, Wilbur-Ellis National Nutrition Technical Manager

Early Mite and Mummy Sprays (May Spray)

Don't be an April Fool! Stay Ahead of Damaging Pests

As we head into April and the season gets into full swing, it is time to start monitoring for key pests in your orchard.

Mites
Two Spotted mites showed up early this year with a dry February and early March in the San Joaquin Valley. Brown mites are also being reported in some fields. Recent heavy rains and cooler temperatures have slowed down mites temporarily; however, adult mites are still being found along with juveniles and eggs. It is important to remember hotspots within your fields and monitor them for mite activity. Treatment for mites should occur early before populations can grow to concerning levels. Talk to your Wilbur Ellis representative about different treatment options and optimal treatment timing.

Left: Two Spotted Mites and Damage
Right: Two Spotted Mites and Eggs (magnified)

Navel Orange Worm
Navel Orange Worm (NOW) continues to be one of the most economically damaging pests in almonds. Coming off of a relatively light pressure year in 2019 is no reason to let off the pedal during the 2020 season. It is vital to monitor the orchard for NOW pressure. Do so by cracking open mummy nuts and checking for worms, checking mummy nuts for eggs and deploying pheromone traps.

Left: Adult NOW
Right: NOW inside of a mummy nut

It is equally important to monitor degree days. Research by Joel Siegel with the USDA has indicated that NOW degree days can be calculated from January 1st with good accuracy. It is important to remember that several degree days can accumulate in a single calendar day when conditions are right. The first treatment timing window is between 600 and 750 degree days from January 1^st. The eggs laid during this period will become the adults that will lay eggs at hull split. This time generally arrives between mid-April and early May in the San Joaquin Valley. Below is a table displaying the degree days from January 1^st through April 1^st for 2017, 2018, 2019 and 2020. Use this to gauge when the previous year's sprays occurred and how your damage turned out.

South Valley weather stations are showing degree days somewhere between 2017 and 2018 and are noticeably higher than in 2019. Fresno county weather stations show less of a pattern; however, they highlight the different micro-climates within the county. Check your nearest station on the list to see where your field stacks up to previous years. Merced County is tracking cooler than 2017 and 2018 but warmer than 2019. It is important to remember each field has its own micro-climate and the weather stations should only be used as a general guide. Consult with your Wilbur Ellis representative to discuss degree days for your orchard and treatment timings.

John Flanigan, Wilbur-Ellis Sales Rep & Agronomist

NOW Degree Days 2017 - Present

*All data is compiled from CIMIS Weather stations utilizing the UC IPM Navel Orange Worm degree day calculator. Consult with your Wilbur Ellis representative to discuss treatment timings for NOW.

To learn more about which products are right for you, visit almonds.wilburellis.com, or contact your local Wilbur-Ellis PCA/Agronomist

Stay tuned for next month’s newsletter and remember,
You Can’t Win Them All, But You Can Win Your Almonds

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