Arkansas Rice Update 4-26-24

by Jarrod Hardke, Rice Extension Agronomist - April 26, 2024

Arkansas Rice Update 2024-04

April 26, 2024

Jarrod Hardke, Bob Scott, Nick Bateman, and Ben Thrash

“I was too busy movin’ and hopin’ I didn’t run outta luck.”

Pressing Forward

Last week there was an update written but couldn’t be posted due to a website gremlin – but on we go!

Last weekend’s cooldown turned frost event slapped young rice in the head, to be blunt.  It wasn’t alone though, this really was an environmental dogpile.  Cool temps slowing rice, then a frost for a little insult, then high winds to further dry and desiccate the crop added up to creating sickly rice.  There were plenty of questions about the impact of the frost on rice – the frost alone wasn’t going to be very impactful, but we added multiple issues to where the frost certainly didn’t help.

Rains yesterday and expected into next week should help relieve some of the dry conditions stressing small rice.  Very warm temperatures and some scattered sunshine over the weekend should turn this rice around pretty quickly, especially if the winds begin to settle down next week as forecast.

With the winds creating tough conditions, spray applications have been difficult with a lot of rice emerged along with corn and soybean.  We’re starting to see off-target hits awfully early this year and we’d like to head that off.  In particular, thou shalt keep thy paraquat to thyself.  See the table later in the update for more on crop sensitivity to common herbicides.

Planting progress per USDA-NASS had us at 67% on 4/21 which is close to where I was thinking at around to just over 70%.  At this point in my travels around the state (and unlike Johnny Cash I haven’t been everywhere), we should be stretching on north of 80% planted by the next report.

Temperatures climbing back into the 80s for the foreseeable forecast could see some of the earliest planted fields ready to go to flood in the early part of May this year.  Quick to flood means quick to harvest, and with weather folks starting to talk ‘active hurricane season’ I start getting antsy to keep this crop moving along.

Table 1. U.S. Rice Planting Progress as of April 21, 2024 (USDA-NASS).

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

Fig. 2.  NOAA 7-day precipitation forecast.

Fig. 3.  Poor looking rice from recent weather conditions.

New on Arkansas Row Crops Radio this week:

Weeds AR Wild Series, S4 Ep 2:  Rice Seed Availability and Weed Control Program Updates

Weeds AR Wild Series, S4 Ep 3:  Ryegrass Resistance & Control in Burndown

Sensitivity of Major Arkansas Field Crops to Commonly Used Herbicides

Jarrod Hardke and Bob Scott

With a lot of questions coming in now about what is safe to spray around surrounding crops that are emerged, it’s time to revisit herbicide safety.  The table below can be found on page 28 of the MP44 Arkansas 2024 Recommended Chemicals for Weed and Brush Control.  There are a few additional herbicides added to the table below that will be included in the MP44 next year.

Table 2.  Sensitivity¹ of major Arkansas field crops to commonly used herbicides.

¹ T=Tolerant, M=Moderately Tolerant, M/S=Moderately Sensitive, S=Sensitive, VS=Very Sensitive; T* Some crops are available with herbicide tolerance to these herbicides.  These ratings are based on the best available information to date and on foliar application or drift.

² Some soybeans are available with tolerance to ALS herbicides, STS or BOLT Soybeans; this tolerance varies for rice ALS herbicides, particularly Grasp, Regiment, and Gambit.

³ Smart Stack and Herculex are tolerant to glyphosate and glufosinate.  Tolerance does not imply that this herbicide is labeled for a specific crop.

⁴ Soybean is sensitive to Bolero if a full rate were to be applied prior to soybean emergence.  Once soybean is emerged, it is tolerant to Bolero.

Armyworms in Small Rice

Nick Bateman and Ben Thrash

We started receiving a few calls this week about true armyworms feeding on rice and wheat.  For the most part the numbers observed have been low, with sporadic damage throughout the field in both crops.  Over the next few weeks, there may be more true armyworms show up in rice as they move out of wheat.  Based on the calls we have received it doesn’t sound like there is a large population of true armyworms but enough that we may see some problems in a few fields.

As far as recommendations go, we generally don’t recommend treating small rice for defoliation.  We have done several years of work on this, and just do not see a yield loss from defoliation occurring prior to tillering (Fig. XX).  In a lot of cases, we see a minor yield increase.  With that said, there are always exceptions to thresholds.  If armyworms can feed on the growing point due to soil cracking, then an application should be considered.  This typically will only occur on heavy clay soils.

Remember when scouting, check under dirt clods and any debris (old stubble, etc.) near plants that have been fed on.  These are the most likely places for armyworms to be hiding.  For insecticide options if you are in a situation where you need to spray, we would suggest sticking to lambda-cyhalothrin products (Warrior II, Lambda-Cy, etc.).  It is the most effective foliar option that is labeled.  Everyone may remember the control issues from 2021, but those were fall armyworms.  What we are currently seeing are true armyworms, where we would still expect to achieve 90% or greater control with lambda.  If you have Dermacor or Fortenza as a seed treatment, then they should protect the rice with no issues and not require a foliar application.

Fig. 4.  Rice plants that have been fed on by true armyworms (h/t Craig Brown).

Fig. 5.  Rice field with damage from true armyworms (left), and true armyworm in stubble within a rice field (right) (h/t Craig Brown).

Fig. 6.  Yield compared to the untreated control for multiple defoliation levels and growth stages for April planted rice.

CBOT September Rice Futures, 10-Year Monthly Continuation.

DD50 Rice Management Program is Live

The DD50 Rice Management Program is live and ready for fields to be enrolled for the 2024 season.  All log-in and producer information has been retained from the 2023 season, so if you used the program last year you can log in just as you did last year.  Log in and enroll fields here:  https://dd50.uada.edu.

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.