Arkansas Rice Update 4-6-24

by Jarrod Hardke, Rice Extension Agronomist - April 6, 2024

Arkansas Rice Update 2024-02

April 6, 2024

Jarrod Hardke, Trent Roberts, and Camila Nicolli

“Keep your eyes on the road, your hands up on the wheel.”

Up and Away

Reported planting progress for Arkansas this past Monday was a nice little start (Table 1) but expect a big jump in the progress report on 4/8.  I think it’s very possible that we’ve made a jump to north of 30% planted (could be 40%) which would surpass the progress achieved at this point in 2016 and 2017 and trail only 2012 (Fig. 1).  Massive rains this coming week will stall progress (Fig. 2), but we’ll still be way ahead of the game.  And we already have rice emerging (Fig. 3).

While the overall progress looks very good, some individual progress is exceptional with some reporting completed rice planting, and plenty of others reaching a very high percent planted.  As with last year, keep in mind that we can plant faster than we can harvest.  This can contribute to milling issues when rice ends up in the field too long under high temperatures and humidity after reaching maturity.  Having said that, the rainy April expectation may hold true with additional rain chances the following week after this system passes, which means more progress now could pay off in the face of potential delays upcoming.

Since we have a great deal of rice in the ground, hopefully we also have our pre-emergence herbicide applications in place to take advantage of the upcoming rains.  Rice is not the only thing that’s been planted and when the rain moves out, herbicide applications will begin to get more difficult as different crops emerge around each other.

Historically we have had more transitional periods moving from planting one crop then another that allowed for more windows of safe herbicide application.  Now that we are consistently planting multiple crops in the same window, safe and effective herbicide applications will remain difficult.

Table 1. U.S. Rice Planting Progress as of April 1, 2024 (USDA-NASS).

Fig. 1.  2012-2024 Arkansas rice planting progress by week (USDA-NASS).

Fig. 2.  NOAA 7-day precipitation forecast.

Fig. 3.  Rice emerged in Arkansas on April 5, 2024 (h/t Tyler Hydrick).

Zinc Fertilizer and Coatings

Trent Roberts

Zinc (Zn) is a plant essential micronutrient and its proper management is critical for many of our row crops including rice and corn.  Recent research and field monitoring programs have suggested that many rice fields in Arkansas may be suffering from moderate Zn deficiency or hidden hunger that reduces crop yield, but no visual Zn deficiency symptoms are present.  Coating fertilizer with dry or liquid Zn has been an increasing topic this spring.  Here are a few thoughts on these coatings as well as general Zn fertilization.

1. Zinc (Zn) coatings (either liquid or dry) applied to granular fertilizer only supply about 1.1 lb of Zn per acre and they are often in a form (Zinc Oxide) that is not readily water-soluble which results in them being slowly available for plant uptake. They are only useful as a maintenance application (putting back what the crop removes).

2. For these coating products – the claim is that we can get by with lower application rates based on increased distribution of the products, but when the soil test calls for 10 lb Zn/acre these products will NOT supply sufficient Zn to overcome very low or low soil test Zn and high pH conditions (pH>6.0).

3. MESZ is a great product but should only be used as a P fertilizer source. If you apply MESZ to get 90 units of P₂O₅ you will get ~2 lb Zn/acre.  This will need to be supplemented with 3-5 lb Zn/acre as Zinc Sulfate to have adequate Zn when the soil test calls for 10 lb Zn/acre.  MESZ at 100-200 lb product/acre is also a good maintenance approach as it will put back slightly more than what the crop removes.

4. Foliar applications of Zn made post-emergence should only be done with a chelated Zn source such as a Zn EDTA. They are highly effective but should only be used for salvage situations as they do not build soil test Zn.  A foliar application of Zn EDTA and 30 lb of Zn Sulfate (10 lb Zn/acre) cost roughly the same amount – so why not apply the Zn Sulfate preplant incorporated and build your soil test Zn.

5. Our current Zn rate recommendations are based on a combination of soil test Zn concentration and soil pH. These are highly reliable and when less than the soil test recommended Zn rate is applied there is a high likelihood that Zn deficiency or hidden hunger will occur.

Seed and Seedling Diseases

Camila Nicolli

Most rice seeds planted in Arkansas receives commercial treatment.  CruiserMaxx Rice (thiamethoxam + azoxystrobin + fludioxonil + mefenoxam) or equivalent is a common seed treatment package that provides protection against the two main pathogens on seeds and seedlings: Rhizoctonia and Pythium.  These diseases often manifest during germination and early stages of plant growth, but it’s important to remember that the seed treatment provides protection for about two weeks only while the seeds are underground.

If you haven't purchased treated seed, it's crucial to be aware of your field's history.  Identifying seedling diseases can be challenging early in the rice season, especially when temperatures are lower than optimal for seedling emergence and plants are stressed by herbicides or insect damage.  However, if your field has a history of low seedling stands or seedling mortality, it's advisable to consider using fungicide seed treatments.  Consult the 2024 Arkansas Plant Disease Control Products Guide for additional details on rice seedling diseases: https://www.uaex.uada.edu/publications/pdf/mp154/2024%20MP154.pdf

Why Good Drainage Matters Next Week

With the upcoming rains, it's essential to ensure adequate drainage in rice fields to discourage the formation of standing water.  Standing water not only aggravates seedling disease but also creates an ideal environment for stand problems.  Remember, salty fields may have seedling stand problems as well, and fungicide seed treatments do not solve salt problems.  We encourage growers to evaluate their drainage systems and take proactive measures to facilitate water movement away from the seedling area.

Fig. 4.  Seedling disease impacting rice stand.

Use the Arkansas Rice Advisor Internet App!

The Arkansas Rice Advisor site https://riceadvisor.uada.edu functions like an app on your mobile device.  There you can readily access the DD50 program, rice seeding rate calculator, drill calibration, fertilizer and N rate calculators, publications, and more.

Additional Information

Arkansas Rice Updates are published periodically to provide timely information and recommendations for rice production in Arkansas.  If you would like to be added to this email list, please send your request to rice@uada.edu.

This information will also be posted to the Arkansas Row Crops blog (http://www.arkansas-crops.com/) where additional information from Extension specialists can be found.

More information on rice production, including access to all publications and reports, can be found at http://www.uaex.uada.edu/rice.

Acknowledgements

We sincerely appreciate the support for this publication provided by the rice farmers of Arkansas and administered by the Arkansas Rice Research and Promotion Board.

The authors greatly appreciate the feedback and contributions of all growers, county agents, consultants, and rice industry stakeholders.