Arkansas Rice Update 6-1-24

by Jarrod Hardke, Rice Extension Agronomist - June 1, 2024

Arkansas Rice Update 2024-09

June 1, 2024

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

“And I feel so much depends on the weather.”

Strange Days

I don’t really know what to make of this weather either.  I know we joke about if you don’t like the weather in Arkansas, wait a few minutes and it will change, but this is getting out of hand.

Many of the same problems reported last week have continued into this week, with just enough scattered and unpredictable rains to stifle progress.  Rains yesterday and last night were again more than expected, but overall total amounts expected for the upcoming week are slacking off and may give us some opportunity for quality progress later in the week (Fig. 1).

Overall, the rice crop looks very good up and down the state at the moment.  These mild conditions and rainfall have plants looking happy.  Delays in getting out nitrogen applications and being able to get rice to flood are getting very worrisome both from creating more weed control issues and loss of maximum yield potential by getting too late before applying any nitrogen.

If the summer continues to be relatively mild temperature-wise, that usually sets us up for very good yields, but we need some help right now to drive the crop forward the right way for us to get there.  We’re already at midseason on some of our earliest planted rice, so we’re likely in for an early start to harvest this year but it’s getting more spread out by the day as we’re delayed pushing many more acres to flood.

Let us know if we can help.

Fig. 1.  NOAA 7-day precipitation forecast.

Ricing Around

Jarrod Hardke

• More on nitrogen (N) with wet conditions. If you have fields where you’re unable to flood due to unfinished levees, etc. and it’s getting past the final recommended N timing, we need to consider some “less than optimal” means of feeding the rice.  Once the paddies are free of standing water, we can try applying 100 lb urea/acre ahead of the next rain – if the rain misses then apply the remaining preflood rate, get levees up and flood.  If you do get that rain, repeat the 100 lb urea/acre applications weekly until you’re able to get the field in a position to establish the permanent flood.  This will usually involve 3-4 weekly (7-10 days apart) applications for hybrids and 4-5 applications for varieties.  There are some exceptions so feel free to call to discuss.

• If you have ended up extremely late where the rice should be nearing midseason and still no N applied, if you're going with one of the above less than optimal approaches consider shortening the timing between applications to every 5-7 days so that we can get as much N into the plant as we can before ½” internode elongation. This shortening of the application windows should only be done for larger rice that will take up N more readily.

• While I typically advocate for “get the herbicides sprayed first, then fertilize” we’re going to have to throw that out the window in some cases. The reason for spraying first is that getting the right winds to make herbicide applications is more difficult, and we have greater opportunity of wind speed and direction to get fertilizer flown.  But as late as some of this rice is getting, we’ve got to focus on getting the N applied to drive our yield then hope to clean up our weeds as best we can later – and in some cases live with more weeds than we like.

• Delayed phytotoxicity syndrome (DPS) calls continue to come in. It’s still primarily quinclorac applications that appear mostly responsible.  Given the extended period of mild and wet conditions, we’re seeing an uptick in DPS on rice before it’s actually been put to flood (Fig. 2).  Rice in this situation just needs a little time and drier soil to respond.  For fields that have been flooded 1-2 weeks and are starting to experience DPS, let the flood drop to where it’s a shallow or muddy state and rice usually recovers.  In rare severe instances we may need to begin letting the soil dry to get rice to respond.

• ALS flash from products such as Permit, Permit Plus, etc. is also popping up under these cool and wet conditions (Fig. 3).  Once again, the solution is letting the flood depth back off allowing plants to recover.  They will slowly grow out of it and the discoloration will disappear.

Fig. 2.  Delayed phytotoxicity syndrome (DPS) from quinclorac on rice prior to flood due to extended wet conditions.

Fig. 3.  Bottle brushing of roots and highlighter yellow flashing plants from ALS herbicide.

Bobbing and Weeding

Bob Scott

Scattered thoughts on weed control.

Unfortunately, it is that time of year again when we occasionally have to deal with herbicide drift.  On rice two of the most common drift occurrences are Newpath/Preface etc. on non-Clearfield/FullPage rice or Roundup (glyphosate) on rice.

Newpath and Roundup damage to rice can look very similar – Fig. 4 is Roundup drift on rice; however, when I first looked at it, I thought it might be Newpath.  One way to tell the difference may be the occurrence of Clearfield or FullPage off-types out in the field, which are unaffected by either an accidental application of Newpath or by Newpath drift (Fig. 5).

In addition to that, we now have Provisia/MaxAce rice out there as well.  Damage from this chemistry to non-tolerant rice and other grass crops creates a mild bleaching or yellowing effect as well as dead center tillers or a symptomology often referred to as rotten neck (deadheart).

So, it is very important to know what field to spray and what type of rice is in neighboring fields.

If you have a field of rice that is damaged by herbicide drift and the flood is on that rice, it will probably be necessary to pull the water off.  If it doesn’t have a flood on it yet it may be necessary to delay flooding until there is some rice recovery from the injury.

University research has shown that nothing beats time in allowing the rice to recover.  For example, the addition of foliar feed fertilizers as well as flushing in other fertility treatments (AMS, DAP) have been shown to have little impact on recovery and ultimately on yield.

Fig. 4.  Roundup (glyphosate) drift on rice.

Fig. 5.  Newpath / Preface (imazethapyr) drift on susceptible rice with a tolerant off-type present.

Time to Scout for Rice Water Weevils

Nick Bateman and Ben Thrash

Over the past two weeks we have received several calls about rice water weevils (RWW).  Some of these have been in the traditional areas where we would expect to find higher populations (near tree lines and low lying / swampy areas) but not all of them.  Many of these calls have been from folks that rarely notice high RWW pressure.  Phone calls about RWW are definitely higher overall than it has been the past few years.  Several questions have been asked about should I make a foliar application or the drain the field, etc.  Right now, we should be focused on adult control.  It will take a few weeks to determine what level of larvae are present in the field, and whether draining is needed.

The bulk of rice planted in Arkansas is either treated with NipsIt or CruiserMaxx seed treatment, which are excellent on grape colaspis.  However, efficacy of these products on RWW decreases 28-35 days after planting.  Although RWW pressure is higher for later planted rice, these plantings typically experience rapid growth allowing us to flood within 3-4 weeks of planting.  In these situations, we still get sufficient control of RWW with NipsIt or CruiserMaxx.  If rice has been treated with Dermacor or Fortenza, it will still have protection from RWW at least 60 days after planting.  Also, it is important to note that NipsIt and Cruiser within the 28-35 days after planting will reduce leaf scarring observed.  However, Dermacor and Fortenza will not affect scarring but will maintain better control of larvae.

For rice that is going to flood past the 28-35 day window with CruiserMaxx Rice or NipsIt, a foliar application of a pyrethroid like Mustang Maxx, Lambda-Cy, or Declare might be called for.  However, Dermacor and Fortenza treated fields will NOT need a foliar application.  While scarring from adult weevil feeding is usually superficial and doesn’t cause yield loss, this is a sign that adults are present and active in the field.  Scarring can be used to determine if a foliar application is warranted.  In general, an application is warranted if over 50% of new leaves have scarring present and adults are present.  Using a sweep net is a good way to determine if adults are still present.

Timing is critical on foliar applications for RWW.  Applications must be made within 5-7 days of permanent flood establishment, as long as adults are present.  If it is later than that, our studies indicate you may as well keep the insecticide in the jug.  Your only option then is to drain the field until the soil cracks to prevent weevil damage.  Most growers aren’t crazy about doing that as it is costly and may impact weed control and fertility.  Remember, late rice will have higher populations of rice water weevil and staying vigilant with scouting and timely applications will be critical.

Fig. 6.  Rice water weevil adult feeding on rice.

Fig. 7.  Leaf scarring from rice water weevil adult feeding.

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.