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Archive for July, 2010

We usually say that fall armyworms can be controlled by a flood and for that reason we don’t expect them to be a problem in flooded fields.  I recently received word from a consultant in Catahoula that they treated a serious infestation of Fall armyworm in rice that had been under flood for 2 to 3 weeks in Central Louisiana. 

This is the message I received: “We had to treat 400 acres last week for armyworms in Catahoula Parish.  They started in some grass, but we also had them in some fields that had little grass in it.  It was severe enough to cause 20 – 25% defoliation and they were not through eating yet. These fields had been to flood for 2 – 3 weeks.  Populations were 20 – 40 per sweep.  Yep, per sweep.”

This has also been observed in Arkansas this year, and as Gus noted they are not restricted to the edges of fields.  In Arkansas they have seen caterpillars in the middles of flooded fields. 

I light of this report from the field, I would encourage you to continue to monitor for fall armyworm even in flooded rice.  As you probably know armyworms can march into a field overnight and cause severe damage in a short period of time.  Let me know if you find any infestations.

You can view pictures of fall armyworms at the following link:

https://louisianariceinsects.wordpress.com/?s=armyworm

The table below is pulled from the Louisiana Insect Pest Management Guide.  Keep in mind that these products cannot be used in a field that is co-cultivated with crawfish.  If you treated with Dermacor X-100 it should provide control of FAW.  If you do see FAW damage in a Dermacor treated field please contact me.

Threshold: treat when there is 1 armyworm per 2 plants; better results are obtained when larvae are small.

Insecticide Rate Preharvest Interval
Methyl parathion 4EC6 0.25 – 0.75 lb A.I./acre 15 days
(1.0 – 1.5 pts/acre)  
Karate Z 0.025 – 0.04 lb A.I./acre 21 days
(1.6 – 2.56 fl oz/acre)  
Mustang Max 0.020 – 0.025 lb A.I./acre 14 days
(3.2 – 4.0 fl oz/acre)  
Declare 0.0125-0.02 lb A.I./acre 21 days
(1.28 – 2.05 fl oz/acre)  
Prolex 0.0125 – 0.02 lb A.I./acre 21 days
(1.28 – 2.05 fl oz/acre)  
Proaxis 0.0125 – 0.02 lb A.I./acre 21 days
(3.20 – 5.12 fl oz/acre)  
Sevin 80S 1.25 – 1.75 14 days
 lb/acre   
Sevin 4F 1.0 – 1.5 qt/acre 14 days

Insecticides are not listed in order of effectiveness and/or preference. 

Cautions about insecticide applications:

  • Karate Z: Do not use treated rice fields for the aquaculture of edible fish and crustaceans. Do not release floodwater within 7 days of application. Do not apply more than 0.12 lb A.I./acre/season. Do not apply as ultra-low volume (ULV) spray. Karate-Z can be safely used when propanil products are being used for weed control. Do not exceed 0.12 lb A.I./acre when Karate is used in addition to Prolex or Proaxis in a single season.  
  • Malathion 57% EC: Do not use malathion within 15 days of applying propanil. Applications may not be made around bodies of water where fish or shellfish are grown or harvested commercially.  
  • Methyl parathion 4EC, Penncap-M: Do not use within 14 days of applying propanil. Do not apply Penncap-M more than 6 pts/acre/year.
  • Mustang Max and Mustang EW: Do not use treated rice fields for the aquaculture of edible fish and crustaceans. Do not release floodwater within 7 days of application. Do not make applications less than 7 days apart. Do not apply more than 0.10 lb A.I. (1.0 pints)/acre/season. Do not apply as ULV spray.  
  • Prolex/Proaxis: Do not use treated rice fields for the aquaculture of edible fish and crustaceans. Do not release floodwater within 7 days of application. It can be used safely when propanil products are being used for weed control. Do not exceed 0.06 lb A.I./acre when Prolex or Proaxis (either product alone) are used in a single season. Do not exceed 0.12 lb A.I./acre when Prolex or Proaxis is used in addition to Karate in a single season.
  • Sevin (carbaryl): May kill shrimp, crabs, and crayfish. Do not use Sevin within 15 days before or after application of propanil; up to 2 applications per crop but not more often than once every 7 days.  

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Today I scouted some rice with County Agents Rob Ferguson and Trent in Avoyelles Parish.  We visited the Big Horn Farm Partnership which is farmed by two brothers Chris and Randy Dauzat.  They have a beautiful operation.  I saw a few interesting things that I thought you might like to see.

We scouted a field that had a pretty heavy infestation of grasshoppers earlier this season.  Rusty Elston reported catching more than 25 grasshoppers per 10 sweeps.  This is the damage that was being attributed to the grasshoppers.  Let me know if you saw any injury like this that you think was caused by grasshoppers in your rice. 

Empty hulls that may have been caused by grasshopper feeding on the developing grain.

A spray was applied to control the grasshoppers and we could not find any in the field.  The application was made about 10 days ago.  The rice is starting to mature and the panicles are turning down.  Some of the grains are still in the milk stage.  We did stumble upon a batch of rice stink bug eggs that were just hatching.

Rice stink bug egg mass just hatching. Notice the egg shells that are like little capsules - these little first instar nymphs are in the process of hatching out through the top hatch.

They are about to drain the rice field in preparation for harvest.

We also observed an abundance of different birds.  This farm has been part of conservation programs for 35 years and you could see the positive environmental impact of these efforts.

Wood duck box in an area set aside for conservation programs.

Large flocks of birds including great white egrets, great blue herons, roseate spoonbills and a number of species of ibis were enjoying the habitat.

These conservation areas will serve as an important alternative habitat for birds that typically rely on the coastal marshes.  NRCS conservation programs have been implimented this year in response to the potential long-term impact of the oil spill in the gulf.  Rice farmers are in a perfect position to provide the habitat desperately needed by a variety of birds and other wildlife.

Finally, we saw crews out roguing red rice from water-seeded fields.  These are planted in conventional varieties.  It’s important to remove the red rice before it has a chance to go to seed.  The red rice is removed by hand to keep the field clean and prevent adding to the seedbank next season.

Clumps of red rice in a field that will be rogued soon.

Crew roguing red rice - this is a tough job, but necessary to control this weed!

Tracks in the field left by the rogue crew.

Sacks of red rice rogued by the crew. These sacks are collected and the red rice is burned.

Hope you have a good weekend.  Next week we’ll start harvesting the demonstration test sites, unless we are delayed by Tropical Storm Bonnie.

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I’ve had a few calls about grasshoppers in rice – particularly in the south-central Louisiana.  I called Mo Way (Texas rice extension entomologist) to discuss this with him.  I know they had some trouble with grasshoppers in Texas earlier this season.  As Mo said this is an odd year, so we are seeing some out of the ordinary insect problems.  Here’s a little information about grasshoppers.     

Possible damage: Grasshoppers can cause defoliation, but unless you exceed 20% defoliation of rice that is actively growing and past the boot stage, then we would not generally recommend a treatment.  Grasshoppers can also feed on grains as they develop in the panicle and this can cause blanking as grains mature – you might see a white, empty hull on a panicle.  The grasshoppers cause this damage by feeding near the bract at the base of the grain.  This damage is usually not severe enough to warrant a treatment.    

Long-horned grasshopper adult - this insect could damage the rice, or actually help out by eating rice stink bugs.

Beneficial insect: Long-horned grasshoppers in particular (bright green with long antennae) are omnivores – they will feed on vegetation and also other insects.  In some cases they can help to manage your rice stink bug infestation by eating the rice stink bugs.     

Recommendation: We do not recommend applying an insecticide for grasshoppers unless you are certain they are causing enough of a reduction in yield to cover the cost of a spray.  It is possible that a pyrethroid application for rice stink bug or stem borer will also control grasshoppers.    

Please contact your local county agent, or me, if you have a severe infestation of grasshoppers and you feel it is causing damage to your rice.

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UPDATE: I didn’t get any guesses about the mowing injury, well here’s the answer – it was caused by (drumroll please) Cows!  They had escaped from some nearby pasture and enjoyed munching on the edge of the rice field. 

Today we learned a good lesson about verifying the cause of crop damage.  Fred Cramer (G&H in Gueydan) had called me about whiteheads in rice.  Tiffany and I drove out to Gueydan early to beat the heat.  We met with Toby McCown and Fred at the G&H store.  We suspected that the whitehead damage was being caused by borers.  When we struck out across the Dermacor X-100 treated field we found a few whiteheads.  As we began to inspect the damaged plants, the symptoms just didn’t look like borer injury.   

Whiteheads in rice - at first we thought these would be caused by borers, but we found that was not the cause.

 

Feeding injury most likely caused by the rice field rat.

 

Rat chewing injury near a node - this resulted in whiteheads.

 

Whitehead that was most likely caused by rat feeding injury.

 

The edges of the damaged area were clean, there was no feeding lesion in the sheath or frass (insect waste), and we did not find any insects except for a few chinch bugs.  It seemed like something had chewed on the rice.  My instinct was to attribute the damage to either an animal or a chewing insect (maybe grasshoppers).  I could not confirm what had caused this damage while I was in the field.  After we wrapped up for the day, I stopped by the rice station in Crowley and showed the pictures to Johnny Saichuk – he told me the damage was probably caused by the rice field rat.  He had seen this damage about 5 years ago in Acadia Parish.  Apparently it is a fairly common problem in some parts of Texas.   

Whiteheads and some cropped rice - any guesses about what mowed the rice?

 

We continued up the road to a nearby untreated field.  Along the way, Fred pointed out a cluster of whiteheads on the edge of a field.  In addition to the whiteheads, quite a bit of the rice had been clipped.  Any idea what caused this damage?  First clue is that it was not an insect, but something else that likes grass.   

The untreated field (no insecticide seed treatment) we scouted next had just started to head.  We were able to locate a few whiteheads, and upon closer inspection found some borers injuring the rice plants.  The rice is heading unevenly, and so this makes pest management more difficult – especially the timing of sprays for rice stinkbugs and borers.   

In one plant that had a whitehead we found a feeding lesion on the leaf sheath, and under that a tiny sugarcane borer larvae.  When I cut into the stem I was surprised to find about 10 more larvae.  It’s rare to find this many borers in a single stem.  It was also discouraging because they were tiny larvae that had already bored into the stem.  An insecticide application will not control the borers once they enter the stem.  About 15% of the rice was fully headed and the rest was around split boot.  We found more borers in a few other plants, and so decided that a pyrethroid spray would be wise to attempt to prevent more whitehead injury from the borer infestation.  The farmer plans to apply 2.0 oz of Karate per acre.  Hopefully this will prevent further borer injury and control the early stink bug infestation.   

First or second instar sugarcane borer that we located behind a damaged sheath. When I cut open the stem there was a surprise...

 

I found about 10 sugarcane borer larvae had already bored inside the stem. Pyrethroid sprays will not control borers that have entered the stem.

 

In this picture you can see just how tiny these borer larvae were - they were just about 1/4 inch long and had already bored into the stem.

 

So where did the borers come from?  A neighboring field of tall weedy grass had been plowed under recently, and it is possible that the borers had moved out of that neighboring field into the rice.  

Rice Stalk borer on the tip of my finger - this larva was also small in size and had bored into the stalk. You can identify rice stalk borers by the dark head in combination with a pair of continuous stripes running the length of the body.

 

We found some classic examples of frass bring pushed out of the stalk.  

Frass forced out of the stem due to sugarcane borer feeding inside the stalk.

 

 When  I pulled back the leaf sheath, the exit hole was apparent.  

Sugarcane borer emergence hole and frass.

 

 We also found some rice stinkbugs on the heading rice that was starting to bloom.   

Rice stink bug on flowering rice - these seed suckers attack rice as soon as they can.

 

This field is also maturing unevenly, and late-season insect management will be a challenge.  Remember that in most cases once you see the injury caused by borers (whiteheads) it is too late to treat.  In this case the crop is maturing unevenly, so a treatment may still do some good.  It is best to scout for borers when you are scouting for sheath blight injury.  In Texas, the first pyrethroid application for borers is recommended from 1 to 2 inch panicle, followed by a second application at boot.   

The final field we scouted had been treated by CruiserMaxx.  This seed treatment will not control borers, and we did find a few whiteheads in this field as well.  In this case we had a combination of sugarcane borers and rice stalk borers infesting the rice.  The field had already been drained in preparation for harvest, and so a borer treatment is not advised.  The infestation of borers was very light.  

Mike Stout and I are co-advising a graduate student who is focusing her studies on borers.  We hope to know more about borer management, thresholds, insecticide control options, and variety susceptibility in the next couple of years.

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County Agent Donna Lee (East Carrol Parish) hosted a field meeting at the farm of Mr. Garrett Marsh in Madison Parish in cooperation with County Agents RL Frazier (Madison Parish) and Dennis Burns (Tensas Parish).  We started bright in the morning and the rice was busy shedding water in the heat.  Dr. Johnny Saichuk described this in a field note a few weeks back.  (in case you didn’t already know this – you can click on the pictures to enlarge the image size on your computer screen)  

These droplets of water are called guttation - the rice is releasing excess water in the morning. This is what causes high humidity around rice fields in the early morning hours.

 

These high humidity conditions pose a bit of a challenge when taking pictures, but there were way too many critters to miss the chance.  The rice is just starting to head and the rice stink bugs were poised and ready to strike.  

Rice stinkbugs are light tan in color with points on the corners of the pronotum.

 

Remember that the threshold for treatment in the first two weeks of heading is 30 per 100 sweeps, and after the first two weeks of heading to hard dough is 100/100 sweeps.  Be sure to observe preharvest interval restrictions.  Mike Stout and I are co-advising a graduate student who is studying rice stink bugs.  We may be revising thresholds in the future.  

We had walked out in the field to look at some suspect red rice – this is easy to spot because it usually has a light yellow color, pubescent (hairy) leaves, and awns when the panicle emerges.  Johnny recommended rouging the weedy red rice out of the field before it has the chance to go to seed.  A big problem can grow from a small patch of plants.  

Patch of red rice in a conventional rice variety.

 

As we were examining the red rice I couldn’t help but notice an abundance of long-horned grasshoppers in the field.  This included adults and immatures.  In most cases, even if the grasshoppers feed on rice they won’t do enough damage to warrant a spray, but sometimes they can be severe.  This is a good thing to be on the look-out for as your are scouting your rice.  

Longhorned grasshopper adult in heading rice. You can tell it is an adult because of the wings.

 

Longhorned grasshopper nymph - notice the long antennae.

 

Before we had even driven to the field, the farmer – Mr. Garrett Marsh had mentioned some small black and white insects on the Johnsongrass at the edge of the field.  As I had suspected, these were chinch bugs.  Chinch bugs can be sneaky pests that prefer to hide down inside the sheath of plants.  As we examined the weeds, we found a variety of life stages from nymphs to adults.  

Notice the difference in coloration from the nymph to adult stages. Nymphs molt (shed their skin) to go from orange, to orange with tan band, dark brown with tan band, to finally the black adult with a white hourglass.

 

This is what chinch bugs often look like when you are scouting for them in grasses - this is the rear view of an adult hiding out in the leaf sheath to avoid the heat.

 

Notice the distinct hour glass that you can just barely make out from the rear view of the chinch bug adult.  At this stage of the game, there is no need to treat for chinch bugs even if they were in the field.  Although, I have had some reports of chinch bugs causing damage to panicles in headed rice – Johnny Saichuk featured this damage in his field notes.  It is good to remember that insects do not follow rules and will many times surprise us with what and when they decide to damage the crop.  

This week we have field meetings in Vermilion Parish (Tuesday afternoon) and Richland Parish (Wednesday morning).  Please contact county agents Stuart Gauthier or Keith Collins for more information.

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We have finally concluded all of the core sampling for our demonstration test this production season.  We have gathered all the data and Anna conducted a statistical analysis.  In this analysis each location is treated as a replicate.  

Our demonstration test was conducted in all the Louisiana parishes highlighted in purple.

 

We had a total of 15 sites included in our test this year.  We started this season with 5 locations designed to evaluate rww management tactics.  An additional 5 sites were set up to evaluate colaspis management.  We did not have any colaspis infestations in the test sites.  We gained three more weevil test sites that had been planted out either by seed companies or a cooperator, who requested we take samples.  We wound up with a total of 10 locations that were included in the overall data analysis.  More than 500 core samples were processed to generate this dataset – that’s a lot of backbreaking work to pull all the cores and then to wash all that mud from the  roots!  Thanks to our cheerful, hardworking crew for completing this task without complaint.  

We collected weevil cores from all sites 4 weeks post flood.  Our standard method is to take 10 cores per treatment, in a zig-zag pattern across the field, making sure to pull cores from the edge and middle of the cut.  

   

A few trends broke out in the dataset.  In Acadia and Jeff Davis Parishes, we had a relatively light infestation with weevils, except at one location (Lawson Farm) where we had about 10 larvae per core in the untreated check.  In Vermilion Parish we had low to moderate infestations.  In Concordia Parish we had an average of 10 larvae per core in the untreated check.  In Evangeline Parish we had a relatively severe infestation with untreated counts averaging from 10.8 rww larvae per core at the LaHaye farm to 15 larvae per core at the Morein farm site. Our highest population was in St. Landry Parish where we had an average of 21.9 larvae per core in the untreated check.  While, in Tensas Parish (our most northern location) we had an extremely light infestation with zero larvae per core in the untreated check and the highest count of 0.15 larvae per core in the Dermacor X-100 treated cut.  Interestingly at this location, we had a fairly severe infestation in the 2008 production season.  The  graph that follows summarizes the average number of rww larvae per core when we analyzed the entire dataset.  

Average number of rice water weevil larvae per core (calculated from 10 cores per field or cut). Different letters indicate a significant difference in the treatment effectiveness.

 

Overall, Dermacor X-100 provided the best level of weevil control, followed by pyrethroid (either Karate pre,Karate pre + mustangMax on fertilizer post, or Karate post) and CruiserMaxx.  Dermacor X-100 provided significantly better control than the other two treatments.  There was no signficant difference in the core sample average between the pyrethroid and the CruiserMaxx seed treatment. 

Unfortunately, the results from the Hybrid test plots (25 pound or less seeding rate) did not provide any more clarity about the ability of CruiserMaxx to provide effective weevil control at the low seeding rates.  We plan to repeat the demonstration test again next season, particularly focusing on the low seeding rate question.  Mike Stout has some small plot replicated research that may also clarify the question of effectiveness of CruiserMaxx at low seeding rates as currently labeled.  

This was certainly an interesting weevil season, and we learned a lot about weevil management, and just how difficult it can be to scout for adults and properly time insecticide applications.    

We greatly appreciate the support and cooperation of all who are involved with the demonstration test.  Please contact your local county agent, or me, if you have any questions about our observations this season. 

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I had the pleasure of attending the annual Louisiana Farm Bureau Federation Convention in New Orleans, La the weekend before July 4th.  During the rice commodity session, a number of speakers provided some very interesting comments.  To begin we heard from Watts & Associates, a consulting firm that that USA rice federation hired to explore new crop insurance plan for rice.  Mr. Alex Offerdahl (aofferdahl@wattsandassociates.com) presented a summary of the current crop insurance situation , with a preview of some ideas they have for proposing a new structure.  If you want to learn more about this, I recommend you contact Randy Jamison (USA Rice Federation). Mr. Offerdahl did a great job presenting on a highly technical subject.

Next Tara Smith – director of Congressional Relations for American Farm Bureau Federation (AFBF) in Washington, D.C. gave us an update on activities on the Hill.  Her comments primarily focused on “growing our future – the 2012 farm bill”.  Yes, they are already debating the next version of the farm bill. 

The House Agricultural Committee, chaired by Congressman Peterson, has already conducted 10 field meetings and 3 D.C. hearings on the 2012 farm bill.  Additional hearings may be conducted in the future.  They plan to have a first draft of the 2012 farm bill  for mark-ups by May to June 2011.  In the Senate Agricultural Committee – chaired by Senator Blanche Lincoln, the first hearings on the farm bill were held on June 30, 2010.  You may have read about these hearings in the news.  Secretary Vilsack, AFBF President Bob Stallman, and others were scheduled to testify to the committee.  Four more hearings are planned for this year. 

Tara described many constraints on the 2012 farm bill.  The budget for the farm bill is currently facing a triple threat:

  1. Standard Reinsurance Agreements – total of $6 billion
  2. Child nutrition, which could be increased to $10 billion
  3. Budget reconciliation from the 2011 to 2012 budgets could be required of all committees.  This would demand that each committee cut a portion of their budget to balance the budget and reduce the deficit.

There are also a growing number of interests to appease – nutrition and specialty crops are now in the mix for farm bill funds. According to Tara, despite the heavy tilt towards nutrition spending, there is little chance of farm interests laying claim to any of that money in the current political environment.  The goal of AFBF is to ensure that no additional farm or conservation program dollars are lost. 

The Farm Bureau has 5 principles as the 2012 farm bill is written:

  1. The options AFBFputs forward or supports will be fiscally responsible
  2. The basic funding structure of the 2008 farm bill should not be altered
    • 79% nutrition ( this has increased from 66% in previous bill)
    • 1% export
    • 6% conservation
    • 7% crop insurance
    • 7% farm programs
  3. The proposals AFBF puts forward will aim to benefit all ag sectors
  4. World trade rulings will be considered
  5. Consideration will be given to the stable business environment critical to success in Agriculture (slow change is better)

Tara then went on to discuss how farmers have received the 2008 farm bill.  She said it is a little like “Goldilocks and the three bears”.  Is this farm bill too much, too little or just right?  It depends on where you live and what you grow. 

If you’d like to learn more, you can contact Tara at 202.406.3675 or taras@fb.org

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