The topic this month is right up my alley – insect pest management. For 2010, Texas rice farmers have more options than ever to control insect pests. CruiserMaxx received a full federal label and can be used as a seed treatment to control rice water weevil and chinch bug. This seed treatment also contains three fungicides to control an array of seedling diseases. In addition, CruiserMaxx will probably control other seedling pests, such as thrips, aphids and leafhoppers. CruiserMaxx also controls grape colaspis, which is not a problem for Texas rice farmers.
I have seen fields in Liberty and Matagorda Counties completely wiped out by chinch bugs. These insects have piercing-sucking mouthparts and suck the juices out of seedling rice plants as soon as rice emerges from the soil. The adults are black with a white “X” pattern on their backs. The nymphs are orange and smaller.
During the heat of the day, adults and nymphs can be found near the base of the plant or underground near the roots of the plant. Inspect the plants above ground and then wiggle the seedlings in the soil and look in the gaps in the soil around the bases of plants. If you find one or more chinch bug adults per two seedlings, it’s time to do something. This is the beauty of seed treatments because control prevents problems later. I know you get very busy during the planting season and often do not have time to check your fields – seed treatments can help ease your mind and take some of the “guesswork” out of your management practices.
Another seed treatment recently was granted a full federal rice label. This seed treatment is Dermacor X-100, which controls fall armyworm, South American rice miner, rice water weevil and stalk borers (Mexican rice borer and sugarcane borer). Therefore, Texas rice farmers can use this insecticide in 2010. Prior to 2009, we knew Dermacor X-100 did a good job controlling stalk borers on the main crop; however, research in Texas in 2009 showed significant carry-over of stalk borer control on the ratoon crop.
Another excellent insecticide, Tenchu 20SG, which controls rice stink bug, is being reviewed by EPA for a Section 18 Emergency Exemption in Texas for the 2010 season. Data from last year revealed that rice farmers who used Tenchu 20SG reduced their number of rice stink bug applications by one-third to one-half.
Just a quick note on a water-related issue: For much of 2009, Texas experienced a severe drought. There was talk of limiting rice water use in Texas for the 2010 season. However, due to a very wet fall and winter (2009/2010), rice farmers along the Colorado River will be able to irrigate both main and ratoon crops in 2010. This is truly good news!
I want to personally thank Dr. Tim Walker and the rest of the Mississippi State University folks for putting on an excellent Rice Technical Working Group meeting at Biloxi last week! Lots of great information was shared among scientists and others in attendance. I was involved in the Plant Protection Sessions, which I think were the best ever. We have many young folks, including graduate students, who are doing excellent, innovative work on behalf of rice farmers.
I also want to congratulate Jack Wendt who has produced more than 60 Texas rice crops over the course of his rice farming career – and, yes, Jack plans to plant another crop this year. For many years, Jack has volunteered his camp house for rice Extension meetings where about one month ago he was awarded Agriculture Man of the Year in Texas – a truly great honor that Jack richly deserves. I had the pleasure of eating dinner with Jack during this meeting. He is passionate about getting the word out about the value of agriculture to society. Jack, I hope you have the best year ever in 2010 – you truly are a fantastic role model for all rice farmers and scientists alike!
When I started working with rice more than a few years ago, the only insect pests we regularly considered were the rice water weevil and rice stink bug. And the only insecticides we used to any large degree were methyl parathion and carbofuran. There were a few other materials labeled for stink bug control, but, for the most part, they were not used very much.
Then the EPA stepped up its re-registration programs targeting organophosphate and carbamate chemistries in particular. We still have malathion and methyl parathion for use in rice. Carbofuran (Furadan) is long gone.
The initial reaction to these proposed changes was resistance. Nothing was in the agrichemical pipeline to fill in the expected gaps in insect control. In the long run, it has been a good thing because it opened the door to companies to develop new materials or at least label existing ones for rice. We now have several insecticides in different chemical families to help us control these and other pests in rice.
Pyrethroids were introduced on other crops many years before they were labeled for use on rice. One of the benefits of our rice research verification program was its exposure of weaknesses in the proposed scouting methods to determine when to use these materials to control rice water weevil. Through trial and error in commercial fields, we learned how to use them effectively.
The pyrethroids have also been the material of choice in many cases to control rice stink bugs. The fact that the same chemistry is being used on two major pests at different times of the year has long had rice scientists concerned about eventual development of resistance to these materials. New chemistry was definitely needed.
Another problem, in south Louisiana especially, with the use of pyrethroids is their extreme toxicity to crawfish. With over 100,000 acres of crawfish ponds that are either rice fields flooded up after harvest or very near rice fields, application of pyrethroids has always been difficult in some parts of the state. This is one more reason for having other insecticides.
The rice industry is finally getting different materials. The newest kids on the block in Louisiana are the seed treatment materials Dermacor X-100 and CruiserMaxx. These are seed treatments labeled for use on dry-seeded rice only. Dermacor belongs to a totally new class of insecticides called anthranilic diamides. CruiserMaxx is a neonicotinoid. Both are a welcome addition to the arsenal of materials to combat the rice water weevil and other pests.
Dermacor was available in the 2008 and 2009 seasons as a Section 18 label. A full Section 3 label has been granted recently so it will be available this season. Target pests are the rice water weevil, stalk borers, fall armyworms and leaf miners. Dr. Natalie Hummel, Extension rice entomologist, had an extensive demonstration program last summer where Dermacor performed well when compared to the pyrethroids and Trebon.
CruiserMaxx is actually a combination of an insecticide and fungicides, so it provides some seedling disease control in addition to controlling the rice water weevil, grape colaspis and chinch bugs. It was not available for rice last year although it has been around and used on other crops for some time. A full Section 3 label was granted for its use in 2010.
The discovery of a colaspis beetle, now identified as Colaspis louisiani in Louisiana, last year might influence the choice of materials. Dermacor does not control this insect, but it does have a Section 2ee label for suppression of it. Last year, Cruiser was used in Arkansas and controlled the grape colaspis well, so it will likely control the colaspis we have here. Some research indicates Dermacor may have the edge on the rice water weevil.
Note that pest spectrum could influence your choice of insecticides if you choose to use a seed treatment product.
Both products must be applied by seed processors, and, because they are applied to seed, their rates per acre are influenced by planting rate. This can be compared to a granular insecticide where the seed are the granules. The Dermacor label provides guidelines for the amount of Dermacor to be applied to 100 pounds of seed to achieve the desired product per acre.
The Cruiser label rate is 0.03 milligrams of active ingredient (AI) per seed. To convert that to active ingredient per acre, we developed the chart that follows. It is based on a range of the number of seed per pound of popular varieties and the interaction between seed size and planting rate.
The left hand column of the chart shows the rate of product in ounces applied per 100 pounds of seed. Each column represents a planting rate in pounds per acre. The numbers in the table show the grams of active ingredient per acre. Dr. Stout has looked at the traditional planting rates; however, he has not looked at the very low rates characteristic of hybrids and some seed growers.
It strikes me as interesting that without the introduction of Clearfield technology neither of these products would have much application in south Louisiana where without the ability to control red rice with herbicides, most of our acreage would be water-seeded. One thing often leads to another.
Every year, more and more acres are being grown in a Clearfield cultivar. When this technology was first introduced, rice producers only used this technology on acres that were heavily infested with red rice. As better agronomic and higher yielding cultivars were released, more rice producers began planting more acres of Clearfield cultivars. Also, rice producers found this technology to be more simplistic for weed control than the older traditional herbicide system. As the Roundup Ready system has changed, the Clearfield system will change now and in the years to come.
Many of you have read article after article on herbicide resistance over the last year. Some producers have resistance problems and some do not. If you do not have a resistance problem in your fields, consider yourself lucky. But, you must decide now whether you want to manage resistance before or after it happens to you.
The immediate threat to the technology is barnyardgrass resistance to Newpath. There has already been one documented case of Newpath-resistant barnyardgrass in Arkansas and a few suspected cases in Mississippi. Newpath-resistant barnyardgrass will be the main concern as more and more acres are repeatedly grown in Clearfield rice.
Crop rotation is a critical component in helping prolong the effectiveness of the Clearfield system. Growing Clearfield cultivars in consecutive years puts you on the super highway towards herbicide resistance. Some have said the only crop I can make money on is rice. I am not here to judge everyone’s economic situation, but from a herbicide resistance standpoint, you will be on a fast track for problems. To help curtail resistance problems in the Clearfield system, soybeans need to be grown behind Clearfield rice. Also, the addition of a pre-emergence grass control product (i.e. Dual, Outlook, Prefix) into the Roundup Ready system will help maintain grass control throughout the year.
Another equally critical component to prevent resistance is using other herbicides than just Newpath in the Clearfield system. Preemergence herbicides can sometimes be a miss in a dry spring, especially on heavy clay soils in the Mississippi Delta. But over the long haul, pre-emergence herbicides have more than paid for themselves in terms of grass control and resistance management. Adding preemergence herbicides like Command, Prowl, Bolero and Facet, which all have different modes of action, into a program will help prevent or slow the progression of Newpath-resistant barnyardgrass.
It is highly important to consider resistance management because the herbicide development pipeline is essentially empty with no new developments. Therefore, the herbicides that we have today in rice could potentially be the same herbicides that we will have 10 years from now. Preserving herbicides and herbicide technologies will be key in being successful now and in the future.
Cruiser Seed Treatment Rate In Grams AI Per Acre At Selected Treatment And Planting Rates
Plan, but be flexible
One of my father’s favorite sayings was “Hurry up and wait.” John Wooden, successful college basketball coach, said to his team, “Be quick, but don’t hurry.” These sayings may appear to contain contradictions, but describe the case in terms of rice pest management.
The occurrence of many invertebrate (insects and related organisms) pest populations in rice can be predicted and anticipated based on conditions. Cool, early season conditions that delay rice germination and stand establishment are ideal for seed midge populations in water-seeded rice. Rice fields near weedy field borders, riparian areas and other heavily vegetated areas are ideal for rice water weevil infestations. Fields that had an infestation of tadpole shrimp the previous year will likely have an infestation this year (and often times an increasingly serious infestation). These predictions can be helpful, but as a grower or consultant, you still need to observe your field and make real-time observations.
In the California water-seeded system, look for muddy water that is not caused by wind or some other obvious factor. This can be a sure sign of pest (midge or shrimp) infestation. If you think the stand is exceptionally slow to emerge, uncover some seeds/seedlings to see why, i.e., look for damage. If this is done in a timely manner, field draining or an appropriate insecticide treatment can be used to likely save the stand. By waiting a few days too long, the damage may be too severe to rescue the stand.
Look for signs of pest feeding and/or plant stress. In 2009, rice water weevil populations were very high in California (the highest for the last 10 years). I heard of several cases where plant stress was noted but attributed to some other factor (nitrogen management, stress from herbicides, etc.). A quick sampling of a few rice plants could have revealed water weevil larvae. Finally, utilize the available resources. The color images, up-to-date information on pesticide registrations and other management approaches, real-time observations from the field and other useful information that is available today on the Internet can be a great help in rice production.
The University of California pest management information for rice can be found at http://www.ipm.ucdavis.edu/PMG/selectnewpest.rice.html. “Absorb” the information, modify it to apply to your farm and make use of it. But, remember to plan ahead, get to the field to observe present conditions and be ready to respond.
Check need & cost
After several years of depending on foliar applications of pyrethroid insecticides for control of rice water weevils, we finally have other options. It has taken time, but two new insecticide seed treatments are now fully labeled for use in dry-seeded rice production that have activity very similar to Icon.
Dr. Gus Lorenz, Extension entomologist with the University of Arkansas, has done a lot work assessing the new insecticide seed treatment technology over the past three years. The recommendations I am describing in this article are based primarily on his work.
Cruiser is an insecticide seed treatment sold by Syngenta that has shown good control of grape colaspis (lespedeza worm) and rice water weevil. Dermacor X-100 is an insecticide seed treatment that has excellent rice water weevil control.
Both insecticide seed treatments have demonstrated enhanced seedling vigor, even in the absence of high insect populations. The yield advantages from these seed treatments averages about 14 bushels/acre in both small and large block trials that Gus has conducted. There is no question that these seed treatments will be a valuable tool for rice farmers in the Mid-South.
The recommendations where use of these seed treatments are recommended include fields that have a history of grape colaspis injury or heavy rice water weevil infestations, early seeding dates, high value seed (i.e., hybrids, Clearfield), no-till, or when using reduced seeding rates. However, reduced rates are not recommended for either of these new products. While reduced rates of Icon were normal for most producers, these products are already recommended at the low end of their effective rate range. Reducing rates will likely result in less than desirable control.
The decision concerning which insecticide seed treatment to use is based on your primary need and cost. Cruiser has shown better control of grape colaspis, while Dermacor has shown better control of rice water weevils. Cruiser is being marketed as CruiserMaxx, which includes fungicides in addition to the insecticide.
I encourage every producer to carefully evaluate field and insect history. An insecticide seed treatment can save a lot of anxiety that comes after insect injury has been discovered.