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Archive for the ‘seed treatments’ Category

This year EPA approved a section 24C approval to use Dermacor X-100 in water-seeded rice in Louisiana. [Click here for a blog post about the registration.] Quite a few producers used this insecticide option in water-seeded rice in Louisiana this season. Mike Stout had extensive research data to support the efficacy of Dermacor in water-seeded rice, but I felt it would be good to verify the activity in commercial fields. Dr. Saichuk used this treatment option at the Vermilion Parish LSU AgCenter rice verification field. According to Johnny, the Dermacor rate was 1.75 oz/A. The variety Cheniere was planted on 4/5/2012 at 120 lbs/A. A true pinpoint flood was applied to the field. Nick Colligan and Stuart Gauthier pulled ten core samples from the field 4 weeks after permanent flood to verify the activity of the insecticide. Nick reported that they did not find any rice water weevil larvae in the core samples gathered.

On another note, one of the field reps reported that they are starting to see armyworms in vegetable gardens in Grand Chenier. I have not received reports of armyworms  in Louisiana rice yet, but it would be good to be on the lookout for this pest. If you treated with Dermacor X-100, the rice should be protected from injury, but CruiserMaxx or NipsitInside will not control army worms. Click here to read about armyworms in rice.

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A portion of the rice water weevil field crew. From left to right: Anna Meszaros, Nick Colligan, Jordan Fryoux, Natalie Hummel, Jimmy Meaux and David Albano.

Rice water weevil (RWW) management demonstrations have been conducted for the past four field seasons. The purpose of these demonstrations is to evaluate currently recommended insecticides on commercial rice farms in Louisiana to control RWW. These trials are a joint effort between county agents, farmers, consultants, seed dealers and chemical distributors. In 2011, we compared three insecticide seed treatments (CruiserMaxx, Dermacor X-100 and NipsIt INSIDE) to an untreated check. Each treatment was planted in two strips at each location. A total of 6 locations were included in the 2011 demonstration test. The commercial farms were located in Acadia, Calcasieu, Evangeline, Jeff Davis, Rapides and St. Landry parishes. We took stand count data 2 weeks after seedling emergence at five locations and RWW core samples (10 cores / plot) 4 weeks after permanent flood to assess the relative efficacy of treatments at all 6 locations.

The on-farm demonstrations were conducted in the parishes indicated in purple.

At five of the six locations we planted the variety XL745. Thus, the seeding rates were low and the results of our study may not translate to field planted at a higher seeding rate (more than 25 pound seeding rates).

We found no significant difference between stand counts. Plant heights were significantly greater in CruiserMaxx and Nipsit INSIDE treatments than in Dermacor X-100. When we analyzed the RWW core sample data we found that all seed treatments had significantly fewer RWW larvae per core than the untreated check (average 12.9 RWW larvae/core). Dermacor X-100 (average of 2.5 rww larvae/core) provided the highest level of control, whereas Nipsit INSIDE (average 7.9 larvae/core) and CruiserMaxx (average 7.9 larvae/core) provided intermediate levels of control.

We conclude from these observations that if you are planting rice at low seeding rates (less than #25) and decide to use a neonicotinoid seed treatment (CruiserMaxx or Nipsit INSIDE) you should scout the field at the time of flood for the presence of rice water weevil adults. If you find a high population of rice water weevil adults, you may want to consider applying a pyrethroid to provide additional protection from rice water weevils. However, if you use Dermacor X-100, be aware that it does not provide protection against other early season pests such as thrips, aphids, and Colaspis.

This project was coordinated by Natalie Hummel, Anna Meszaros and Mike Stout. Thank you to all of our cooperators: LSU AgCenter County Agents: Barrett Courville, Trent Clark, Vince Deshotel, Rob Ferguson, Keith Fontenot, Matt Martin, Jimmy Meaux, Dusty Zaunbrecher; Rice farmers: Chris & Randy Dauzat, Charlie Fontenot, Johnny Hensgens, Kenneth LaHaye, Glen & Wes Simon, Mark Stelly, Bill Wild; Crop Consultants and Company Representatives: Rusty Elston, Dennis Fontenot, Kent Guillory, Rustin Gilder, Cullen Minter, Dean Reed, Randy Verret; our Field Crew: Nick Colligan, David Albano, Jordan Fryoux, Marty Frey and the rice station entomology crew. Finally, we could not have completed this project without the financial support of the Louisiana Rice Research Board, DuPont, Syngenta and Valent.

I’ll discuss these results in the rice winter meetings. How did the seed treatments look at your farm?

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We had an excellent crowd at the final stop of the LSU AgCenter south farm tour in Crowley, La this morning. For those of you that could not attend, here is what was discussed:

The RWW is the most important insect pest of rice in Louisiana. Adults enter fields either before or after permanent flood. Injury begins when adults feed on plant leaves, making longitudinal scars. If scarring is excessive the field will sometimes have the appearance of being “painted” with white paint. In some instances adult feeding can be severe enough to merit an insecticide spray before application of permanent flood. Mating commences soon after adults enter the field, but oviposition of eggs occurs after application of permanent flood. Larvae hatch from eggs, feed briefly within the leaf sheath, and then swim through the flood water to burrow into the mud and begin feeding on the roots of the rice plant. This larval feeding on the roots is the primary source of damage caused by rice water weevils when they attack the rice plant. In some cases, root pruning can be so severe that plants will fall over in the field. In other cases, root pruning in not severe enough to cause lodging but can still significantly reduce yield.

Acadia Parish – Simon Farm

Location: South of Crowley, LA – at the intersection of Leger and Nelson Roads.

You can find a map of the field site by clicking here. The purpose of this demonstration test is to compare currently recommended insecticides on commercial farms in Louisiana. This year are comparing three insecticide seed treatments (CruiserMaxx, Dermacor X-100 and NipsIt INSIDE) to an untreated check.

Cooperator County Agent Consultant Variety Seeding Rate
Glen & Wes Simon Barrett Courville Rustin Gilder XL745 22 lbs/ac
Date Activity Date Activity
3/16/2011 Planting 5/18/2011 Permanent flood
4/03/2011 Stand count 6/14/2011 RWW Core sampling

04/03/2011 – Stand counts – 2 weeks after seedling emergence

Method of data collection: Counting the number of plants and taking plant heights on ten randomly selected plants at five random locations in each strip.

We did not notice any obvious visual differences between seed treatments.

06/14/2011 – Core sampling- 4 weeks after application of permanent flood

Method of data collection: Core samples gathered by walking through the field pulling cores at equally spaced intervals across the field. 10 samples were taken in each cut (20 cores/treatment).

RWW core data is an average of 20 cores/treatment.

Treatment Average # rww
CruiserMaxx

1.5

Dermacor X-100

0.5

NipsIt INSIDE

1.15

Untreated

2.4

The infestation at this field site did not turn out to be severe enough to justify the cost of a seed treatment, but at some of our other test sites the infestations have been severe. We have collected up to 40 larvae in a single core. Once we are finished with all the core samples and can compare to the small plot trials Mike Stout is conducting at the LSU AgCenter rice research station, we will let you know how all the seed treatments have performed this season.

For Further Information:

If you have any questions about RWW management or this demonstration please contact your local County Agent Barrett Courville or LSU AgCenter Extension Entomologist Natalie Hummel at nhummel@agcenter.lsu.edu.

Acknowledgements:

We would like to thank all the cooperators, consultants, sales reps, and dealers participating in this trial. Generous support for this demonstration test has been provided by the Louisiana Rice Research Board, DuPont Crop Protection, Valent, Syngenta, FMC, G&H, and Landis International

A lunch was served that was sponsored by Dupont (Toby McCown), Syngenta (Josh Zaunbrecher), and Valent (John Bordlee). Rustin Gilder also provided a tent and tables for the lunch area. You can’t put a price on the value of shade in the middle of the summer (oh, wait, we are only two days in… guess it will be a long one). We appreciate their on-going support of the LSU AgCenter rice extension entomology program.

Rice stink bugs are starting to show up in some of the fields that are heading. I’ll post a blog about this pest tomorrow.

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On Friday, Nick and I made the trek to West Carroll Parish in north Louisiana to scout a rice field that Richard Costello had called me about on Thursday. The field was initially thought to be suffering from herbicide drift injury.

Field infested with thrips.

LSU AgCenter County Agent Myrl Sistrunk had called Weed Scientist Bill Williams out to investigate. Upon a detailed inspection they found a damaging infestation of thrips.

The thrips could easily be found on virtually every plant we inspected. The best scouting method for thrips is to visually inspect plants. The thrips were often found on the leaf sheath near the collar or inside the leaf sheath.

Thrip on leaf blade near collar - this is a typical location to find them on the plant.

They will quickly run/hop when disturbed. You can also tap plants onto a white sheet of paper and look for the thrips on the paper.

Thrip on rice leaf blade.

I learned first-hand that they will in fact “bite” you with their rasping mouthparts. They annoyed us for most of the ride home. Thrips injure plants by using a scraping mouthpart to macerate (tear) the leaf tissue. They then extract the plant liquids. This causes desiccation and would typically not be a problem, except for the dry, windy conditions we are experiencing this season.

Thrip feeding injury on a rice leaf. In many cases there were streaks of white near the leaf tip.

I have not had the chance to confirm the species yet, but it looks like they may be tobacco thrips. The infestation and plant damage in this particular field is disconcerting because the field is CruiserMaxx treated hybrid planted at a 25 pound seeding rate. The situation is complicated by the fact that the field has received about 10 inches of rain since planting. This was received in five separate rain events.

 The field started to head south after a flush was applied about a week ago. At this point the field is very dry and plants appear to be desiccating and stressed from the thrips feeding on the leaves. The field isn’t ready to hold a flood yet. We could not find any natural enemies in the field, and due to the ongoing injury caused by the thrips feeding I recommended a pyrethroid application to knock back the thrips population and buy some time before flood.

Also, the lack of apparent activity against the thrips caused some concern about the ability of the CruiserMaxx to provide effective control of rice water weevil larvae after application of permanent flood.  They may consider a second application of pyrethroid at permanent flood if weevil adults are present in the field. Overall the field still has a good stand of rice, which appears to be thicker than many hybrid rice fields I have scouted this season.

On our way back to Baton Rouge we took the levee road and witnessed the Morganza Spillway flooded with water.

You can see in this picture how close the water came to the top of the levee - just south of Vidalia, north of Blackhawk Farm.

We also saw some deer grazing in a soybean field that was mostly flooded. If you’ve read Johnny Saichuk’s field note for this week you’ll notice that we observed the same herd of deer. Apparently they are well-settled in this field. It looks like whatever the water doesn’t take, the deer will finish off.  

I have more pictures to share, but I don’t have the files with me at the moment.

Also, this week I had reports of sugarcane beetles, armyworms, chinch bugs, and colaspis in Louisiana rice. Many of these early-season insect pests should go away as we approach permanent flood. Then we’ll need to make sure good plans are in place for rice water weevil management.

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This morning I admired the moon setting over University Lakes on my way into campus. Wait a minute, I was biking into campus by moonlight? Yep, a sure sign of field season – early mornings and long (but exciting) days. Today we headed down to Jefferson-Davis Parish to scout a couple of fields that were suffering from stand loss due to an unknown cause. In one location we are still trying to determine the cause. In the second field we scouted we confirmed a fairly severe colaspis infestation. We met with Farmer Kyle Fontenot, Consultant Ron Smith and Nicky Miller at the field which is located between Hathaway and Elton.
 

Kyle Fontenot, Anna, Nicky Miller, and Ron Smith. Note that Kyle and Nicky were both on their iPhones connecting with me on the blog and facebook.

 
Within a few minutes of digging we had no trouble finding many plants with colaspis larvae feeding on the roots, causing the plants to decline and eventually die.

Stand reduction in a hybrid rice field that was caused by colaspis larvae feeding on the roots of the plants.

 

We typically found the larvae on dying plants approximately 2 inches below the soil line.
A colaspis larva.
A colaspis pupa near the tip of a knife blade to give you an idea of the size.
 

 

It is worth noting the history of this particular field. In 2010 it was used as cattle pasture. To prepare the field for rice, the farmer plowed in the fall, burned the vegetation (with fire) in December/January, then plowed again, and finally plowed, shanked, and fertilized before planting. Rice was broadcast and then packed. The planting method made it even harder to determine the cause of injury because we did not observe the typical loss of plants along a drill row that we have seen in the past with colaspis infestations.

Visit this website for more information on the biology and scouting for colaspis in rice: http://www.lsuagcenter.com/en/crops_livestock/crops/rice/Insects/LSU+AgCenter+Rice+Training+Session+How+to+Scout+for+Grape+Colaspis+in+Rice.htm

This field was planted with hybrid rice seed that was treated with Apron, Maxim, Dynasty and Dermacor X-100. Dermacor has a registration for suppression of colaspis and previous research has indicated it will provide about 40% control. It is possible the injury would have been worse without the Dermacor X-100 treatment. If CruiserMaxx or NipsitInside would have been used, then we probably would not have experienced this much stand reduction. Dermacor was selected because of the history of rice water weevil pressure at the field site. It was determined that a replant was not necessary. At this point, the only option is to bring a light pin-point flood to hopefully stop the feeding of the colaspis larvae and prevent further injury of the rice.

I suspect that the colaspis problems may be more widespread. After they left this field Ron Smith called to say that they also found colaspis in another nearby field. I’ll be back down that way next week to further investigate the situation.

 

 

 
 

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I knew my phone was too quiet last week…

Today I’ve have four calls about insect problems in rice. Yesterday I ran the battery down on my phone between phone calls, e-mails and tweeting field observations. Which reminds me, if you are using twitter, you are welcome to follow me @NatHummel for field updates.

These dry conditions are exacerbating problems in drilled rice, which in many cases is dry, dry, dry. We need some rain. The wind is not helping the situation. One consultant, who has decades of experience in rice, called today to tell me he would appreciate more training in identification of uncommon insect problems – namely aphids, thrips and chinch bugs. As we shift away from water-seeded to drill-seeded rice these insects have the potential to become more common pest problems. It looks like that might be happening this year.

This blog posting will focus on many of those “secondary pests” which we happened to observe in Evangeline Parish yesterday. Before I get to that, just a quick update on what is becoming the chinch bug situation.

In Jeff-Davis Parish I have now heard of four additional locations which suffered from infestations of chinch bugs. This brings the count to about 8 to 10 sites with chinch bugs infestations. Some had been treated with Dermacor X-100, but remember Dermacor will not control chinch bugs. CruiserMaxx and NipsitInside should provide control (refer to previous postings about difference in seed treatments for more details). It has been noted that drilled hybrid rice, planted at low seeding rates, needs to be carefully scouted for chinch bugs. This is true primarily because in a field with a low seeding rate, the number of plants per acre is substantially lower than in field planted at a conventional seeding rate. When an insect (such as chinch bugs) infests a field with few plants to begin with, they can cause substantially more injury more quickly than in a field with a thicker stand.

Chinch bugs can be difficult to scout because they have a habit of hiding in cracks during the heat of the day and also because they often feed at the soil line near the base of the plant. This injury caused by feeding on the heart of the rice plant is what causes the rice to throw a red or orange leaf and eventually die from injury. To treat an infestation it is best to apply a flood or flush water across the field and then follow with a pyrethroid insecticide – this strategy drives the insects up onto the plant allowing them to be exposed to the insecticide.

You can click on the pictures to make them larger.

In Evangeline Parish we found a few chinch bugs feeding on the plants.

Chinch bug near base of rice plant.

 We also found a mating pair of chinch bugs on the soil surface between the rows.  Just to illustrate how difficult these can be to scout, can you find the chinch bugs in this picture?

Chinch bug mating pair on the soil surface.

 As I was taking pictures, they shifted position – here is a close-up.

Chinch bug mating pair.

After mating, chinch bugs will deposit eggs, from which first instar nymphs will hatch. We did see some first-instar chinch bugs near the base of the plant.  The first instars look very different from older stages – are very small and bright orange in color.  Here is a composite picture from my files for your reference – these pictures were taken in Jeff-Davis Parish a couple of years back.

 

Yesterday, Anna and I took stand data at the Evangeline Parish Demo test site.  Here is the field map. (I’m in the process of building LSU AgCenter websites for each of the test sites, but suddenly time at my desk is precious and rare). The field is located between Ville Platte and Vidrine at these GPS coordinates: 30°41’42.66″N, 92°24’23.80″W. The plots are flagged with colored flagging according to treatment.

The variety XL745 was planted at a 25 pound/acre seeding rate on March 21, 2011.  First emergence was noted on April 5, 2011. Yesterday, we visited the site two weeks after emergence to take observations on the stand. At this location we are comparing the three seed treatments (CruiserMaxx, Dermacor X-100 and NipsitInside) to an untreated check.

In general, there does not appear to be a significant difference between treatments, but the untreated cuts do not look quite as vigorous.  We will wait to summarize all the stand count data from all sites before making definitive statements about any effect of seed treatments on the stand vigor. Following is a series of field shots comparing the treated strips.

 

Plants grown from Dermacor X-100 treated seed to the left and CruiserMaxx treated seed to the right.

Plants grown from NipsitInside treated seed to the left and Dermacor X-100 treated seed to the right.Plants grown from untreated seed (fungicide only) to the left and NipsitInside treated seed to the right.

Plants grown from Dermacor X-100 treated seed to the left and untreated seed to the right.

Plants grown from NipsitInside treated seed to the right and Dermacor X-100 treated seed to the left.

Plants grown from CruiserMaxx treated seed to the left and NipsitInside treated seed to the left.

Plants grown from untreated seed to the left and CruiserMaxx treated seed to the right.

As we walked across the field site we noticed many fire ants and also parasitoid wasps, which led us to believe there must have been some insects in the field that these predators/parasitoids were consuming.  Sure enough, after some searching we started to find aphids, thrips and chinch bugs.  None are present at levels that are causing noticeable injury in the plots, but we will certainly keep an eye on the populations.

 

Fire ants foraging in the Evangeline Parish test site field.

In this situation, the fire ants are helping us by eating some of the insects that are attacking the rice – including aphids, thrips, and possibly chinch bugs. Of course, they also took a couple of bites out of me  as I was attempting to take picture in the windy conditions at the field. 

Fire ant foraging for insects infesting a rice plant - in this case, it looked like it was searching for thrips.

 

Thrip on a datasheet after it hopped off a rice plant. The datasheet is printed in 10 pt font, so you can see the miniscule size of the thrip adult.

Thrip adult on a rice plant leaf blade - we commonly found them on the blade or in the leaf sheath area. It appeared that feeding injury was causing discoloration on the sheath, but this was not confirmed.

 

We found a few aphids on some of the plants. It is likely that populations would be higher if they were not being attacked by ladybugs.

Ladybugs were also present in the field eating the aphids.

 The herbicides had not gone out yet, they will probably go out today, and so we took a few moments to enjoy a sweet gift of nature – wild blackberries on the edge of the field.

Anna picking blackberries during lunch break – ah the sweet rewards of field work…

Tomorrow we will make some site visits in Jeff-Davis where possible colaspis injury has been reported. In the afternoon, we will head to St. Landry Parish to take stand counts at our demonstration site.

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This morning I received another call about chinch bugs infesting seedling rice – this is the fourth call I’ve had this season, so I want to remind field scouts to be on the look-out for this pest. So far they have been reported in Jeff-Davis, Evangeline and St. Landry Parishes. Chinch bugs can quickly move in and reduce a stand of rice. Click here to read more about chinch bugs and the damage they can cause to a rice field. Rapid identification and a prompt response are key to minimize the impact of a chinch bug infestation.

In one case, there was a minsconception that Dermacor X-100 would control chinch bugs. While these new chemistries provide excellent control of rice water weevil larvae, they are often limited in their ability to control other insects. Keep in mind that each of the seed treatments controls a specific group of pests. 

Below is a list of the available seed treatments registered for use in Louisiana rice production and which pests they can control (or at least suppress):

CruiserMaxx & NipsitInside should control infestations by the following:

  • Rice water weevil larvae
  • Rice water weevil adults – suppression
  • Chinch bugs
  • Colaspis larvae
  • Thrips
  • Aphids

CruiserMaxx and NipsitInside will not control infestations by the following:

  • Fall armyworms
  • Stem borers
  • Seed midge
  • Rice leafminer
  • South American rice miner
  • Stink bugs attacking late-season 
  • Spider mites

Dermacor X-100 should control infestations by the following:

  • Rice water weevil larvae
  • Rice water weevil adult – minimal suppression
  • Colaspis larvae – suppression
  • Fall armyworms
  • Stem borers
  • Rice leafminer
  • South American Rice Miner
  • Seed midge (although this should not be a problem in drill-seeded rice)

Dermacor X-100 will not control infestations by the following:

  • Chinch bugs
  • Thrips
  • Aphids
  • Late-season stink bugs
  • Spider mites

To learn more about identification of the different insects that attack rice, please visit the LSU AgCenter Rice Insect Identification guide by clicking here.

You can read more about the seed treatment options by viewing the presentation I gave at the Louisiana Agricultural Consultants Association Meeting in Feb 2011.  It is can be downloaded by clicking here.

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