The accompanying photograph is of Command injury to drilled Cheniere. The farmer applied the herbicide himself using a well calibrated ground rig. He was able to associate the injury pattern with the first pass of each of two loads he applied that day. We discussed the situation with Henry Stefanski, the FMC representative in an effort to understand why it happened. The problem likely occurred in the process of loading the spray rig. Command 3ME is heavier than water. If the agitator was not running when the herbicide was added to the tank even though there was water in the tank the herbicide settled to the bottom of the tank where a larger dose was drawn into the sump and boom before it could be mixed thoroughly. Thus the first pass of spray contained a higher than desired dose of herbicide resulting in the injury. It also means the remainder of the area sprayed probably has less than the intended amount applied to it.
Even though there is considerable bleaching, long term consequences are not expected to be severe. We recommended that he keep the field moist, but not establish a flood until the new leaves are coming out green. It also means no other herbicides can be applied until recovery is observed. In this case the direct effects may not be as great as the indirect especially if broadleaf weed pressure becomes heavy before recovery is evident.
Vermilion Rice Grower, Dwight Hardee of Gueydan is taking part in a field demonstration of the N-Sta*R test. His 15-acre field is divided into three nitrogen treatments based on
University of Arkansas nitrogen soil test recommendations.
Treatment 1: 95% relative yield–65 units of Nitrogen
Treatment 2: 100% relative yield–95 units of Nitrogen
Treatment 3: Standard Farmer Practice–95 units of Nitrogen plus an
additional nitrogen application at green ring
–2/9/12: burn down with 1.5 pt 2,4-D, and 1 qt. roundup
–3/7/12: no-til drill planted into bean stubble CL151 at 50 lbs to the acre. Seed was treated with dermacor/cruiser/fungicide/AV1011
-3/26/12: 4.5 qts RiceBeaux, 6 oz command, 9 oz newpath
4/10/12– 6 oz command, 4 oz newpath, 1 oz permit Fertilizer applied
(took 4 days to flood)
Urea was treated with N-fix.
All 3 plots received 150 lbs DAP 18-46-0 and 150 lbs of Potassium
Urea was used to make up the remaining nitrogen required.
(83lbs–95% and 150 lbs–100%)
I will keep you updated on the progress of the plots. We hope to visit
the plots at the Vermilion Rice Field Day scheduled for Thursday, July
5th, 2012. We will keep track of the yields when the plots are
harvested. The plots are just to the west of the Hardee drier on
Burnell Road in Gueydan.
Over the weekend Sebe Brown scouted a field in Concordia parish where the stand was being severely reduced by colaspis larvae feeding on seedlings. Problems with this field started on March 16 when the stand began to decline. The plants were described as yellow and stunted. This was a Dermacor X-100 treated hybrid rice field no-till drill-planted at a 23 lbs/acre seeding rate. Surrounding fields were growing nicely. When Sebe scouted the field on Saturday he confirmed that the injury was being caused by Colaspis larvae feeding on the roots of seedlings. The stand was reduced about 40% by this injury. The recommendation was made to establish a shallow permanent flood to avoid further injury. In a situation like this, where the rice isn’t quite ready for a flood, you may lose some injured plants to the flood. The alternative is to wait to establish flood, during which time the colaspis will continue to injure the seedlings and further reduce the stand. Establishment of a flood on the field will prevent further feeding injury by the colaspis larvae and eventually the larvae will die. Note: according to experts in Arkansas it may take up to a month for colaspis larvae to die in the permanent flood. Click here to read more about colaspis. You can watch a video on how to scout for colaspis here. The Dermacor X-100 should provide about 30% suppression of the colaspis infestation. Next season, they will consider using a CruiserMaxx or NipsitInside seed treatment to target control of colaspis. The use of pyrethroids will not provide control of colaspis because they are injuring the crop below the soil line.
I have been receiving reports of true armyworms and chinch bugs in corn. True armyworms will usually move into corn once grass hosts have been exhausted or a recent burndown application has been made removing their primary host source.
Corn planted in close proximity to wheat is also susceptible to damage by migrating armyworms. Infestations are typically found around field margins where armyworms have migrated from a wheat field or grassy area. True armyworm damage gives corn plants a tattered appearance with frass (insect feces) present on the leafs or in the whorl of the plant during active infestations.
Most transgenic corn varieties offer protection against armyworm damage. However, single gene varieties such as Yield Guard and Herculex 1 may be overwhelmed when large populations of armyworms are present. Adverse environmental conditions can influence the expression of Bt genes in corn, and larval size is also a contributing factor for control. Normally large larvae are more difficult to control than small larvae.
As long as the growing point has not been injured, young corn (up to V4) can withstand substantial amounts of defoliation and not see a significant drop in yield. Grass control around fields can help prevent outbreaks of armyworms.
Chinch bugs are small insects 1/5 to 1/6 inch in length, with a black body and white front wings creating a white X when viewed from above. Immature chinch bugs resemble the adults only smaller and lacking wings. Nymphs range in color from reddish brown to black in later instars.
Chinch bugs are typically active on grasses in and around fields and movement to seedling corn is common. Damage by both adults and nymphs causes corn to have a reddish appearance on the stem and leaves.
Continued feeding can cause plants to wilt and eventually die. Corn is most susceptible in the seedling stage when plant growth is slow and conditions are dry. Seed treatments and soil insecticides will typically give an 18 day window of protection after emergence. Once plants have surpassed the most susceptible stage, chinch bug damage becomes less of an issue.
If plant growth is slow and chinch bug numbers have reached 5 or more on 20% of plants 6 inches tall or less, a foliar rescue treatment should be applied to stop injury.
When using ground equipment, a high volume, high pressure sprayer delivering a minimum of 20 gpa should be used. Aerial applications should only be used if ground equipment cannot make it across a field.
If an application is deemed necessary, bifenthrin would be the product of choice for ground and air.
Here are a few of the more prominent broadleaf weeds in the Cameron verification field.
The predominant grass is barnyardgrass. However,
the most troublesome grass is Creeping Rivergrass. I did not bother photographing the grasses this time. The variety planted is Cheniere so weed control is going to be a challenge. We will keep you informed of our progress.
We expected our verification field in Vermilion parish to test us because it has a history of Newpath resistant red rice and volunteer hybrid rice. It was fallow last year and was water seeded this year. The photo at right shows red rice seedlings that are already growing well in spite of having been worked in the water and water seeded.
An overview of the field is portrayed below. Rice was a day or so from emergence. We plan to fertilize and flood as soon as possible. The only other option would have been to try to apply glyphosate and start over.
Nearby rice, the late date, and poor results from trying that in the past eliminated that idea. I am afraid we will have an ugly field before it is over.
I know the field conditions are not the best for fertilizer application, especially nitrogen, but that is one of the limitations of pinpoint flood water management.
Last year I wrote the first edition of Rice Field Notes one month earlier than this year. In spite of the much warmer weather (hottest March since record keeping began in 1895), much of the crop is later than last year.
The photo below was taken in our verification field in Cameron parish and is a good example of why it is late.
The intention here was to drill seed. Each time it got almost dry enough to drill, it rained. In desperation we decided to vibrashank and broadcast seed. As you can see it had gotten pretty hairy with weeds in the interim. Nearby water seeded rice kept us from hitting it with glyphosate.
By the following Monday rice was up or coming up. A lot of emergence is occurring in 5 to 7 days when we normally expect 10 days to call it. By that time we could have drilled, but would have been a week behind. Based on the data generated by Dr. Steve Linscombe last year a week later could mean a significant drop in yield. We’ll just have to see how it goes.
By Dr. John S. Kruse, Cotton and Feedgrain Specialist
Several producers and consultants have contacted me this spring with photographs and reports of yellow-striped corn in the two to three leaf stage. ]
In many instances, these symptoms appear to be zinc deficiency, and what is so interesting is how widespread it was in the corn planting areas of Louisiana. Zinc is a trace element, meaning the corn plant does not require very much of it (compared to nitrogen or potassium), but it is very much needed in small amounts, and the lack of it can result in measurable yield reductions. Zinc is absorbed by the plant as a positively charged ion (cation: Zn2+), and is important in the synthesis of tryptophan – a building block of certain proteins that are needed for the production of auxins (growth hormones). Zinc is generally more available in acid soils and less available in neutral to alkaline soils.
Zinc can also react with phosphate to the point that it is bound up and less available to the plant. Many soils in the Red River Valley, with high pH and sometimes high phosphorus, often need supplemental applications of zinc to optimize yields.
However, apparent zinc deficiency has been observed on the Macon Ridge (generally acid soils) and in the Delta (generally slightly acidic soils) this year, as well. The causes can be varied, but certainly repeated corn production can result in less than ideal soil levels of zinc. Also, if a producer has historically planted cotton and/or soybeans for a number of years and has not had to pay close attention to zinc levels, a switch to corn may reveal the need for supplemental zinc. If soil test zinc is less than 1 ppm, supplemental zinc should be applied.
If soil test zinc is between 1 and 3 ppm, it may be needed, and if it is above 3 ppm it should not need to be applied under most circumstances. An ideal time to apply zinc is at planting in a band across the surface of the planting zone.
Recent research suggests between 2.5 to 5 pounds of actual zinc per acre is a good rate. If it is too late for a zinc application at planting, a second choice would be to include the zinc in the nitrogen sidedress application at 2.5 lbs per acre actual zinc. If a foliar application is desired, apply 0.1 to 0.25 pounds of actual zinc per acre in 20 gallons of solution.
The high volume of water is needed to prevent foliar burn. Repeat this application 10 to 14 days later, if possible. Mixing zinc with phosphorus fertilizer is not recommended due to the potential for nutrient binding. Chelated zinc, particularly EDTA-chelated zinc is a very good source of zinc. Zinc sulfate granules can also be dissolved in solution and applied as a spray.
Spreading granular zinc is not an ideal method due to the fact that such a small amount is spread over such a large area that many corn plants will not come into contact with it. Zinc oxides are relatively insoluble and slow to break down and become available, and are not recommended sources of zinc.
A consultant recently asked if grain sorghum needs supplemental zinc. It turns out little research has been done in this area, but several University-authored sorghum production manuals did not emphasize sensitivity to zinc as a major issue. Texas producers are cautioned to maintain optimal levels of iron (Fe) in grain sorghum due to the nature of their soils.
Figure 1. Apparent zinc deficiency in young corn. Note interveinal striping. As the condition worsens, striping may appear white and become broader.
By Sebe Brown, Dr. David Kerns, Dr. Rogers Leonard – LSU AgCenter Entomologists
Thrips are annual pests of cotton in Louisiana. Damage by these insects cause stunted growth, delayed plant maturity and plant death under heavy infestations. Cotton is most susceptible to thrips from emergence to the 4 true leaf stage. Once cotton has reached the 4 true leaf stage, root differentiation has increased, terminal bud growth is accelerated and plants become less susceptible to injury.
The most common thrips found in Louisiana cotton are tobacco thrips, eastern flower thrips, onion thrips and western flower thrips. These insects overwinter on a variety of weed hosts. Planting seasons with windy conditions can have considerable influence on the severity of thrips populations in early cotton. Thrips are typically weak flyers and wind helps to distribute infestations across fields.
Cotton seedlings that experience cool, wet soils develop very slowly and remain susceptible to thrips injury much longer than cotton planted in a warmer, more optimum, environment. This year has been very warm and wet with considerable alternate hosts around cotton fields to produce sources of thrips infestations. With the loss of Temik for the 2012 growing season, insecticide seed treatments (ISTs) and over-sprays will be critically important for controlling thrips on seedling cotton.
Cotton seed comes with a variety of seed treatment options that may either be purchased through a seed company or applied by a dealer downstream. Outlined below are a few of my thoughts with regards to insecticide seed treatment packages on cotton seed.
Dow’s Phytogen seed comes with a base package of thiamethoxam (Cruiser), with Avicta Complete Cotton available upon request. Avicta Complete Cotton includes Cruiser for the IST, multiple fungicides and abamectin for nematode control. Information on Phytogen seed treatment options can be found here.
Monsanto’s Deltapine cotton seed comes with a combination of products that fall within the Acceleron treatment umbrella. The base package in cotton includes imidacloprid (Gaucho) and several fungicides. However there are several options within the Accereleron brand. Be sure that your seed is treated with what was ordered. These options are upgrades to Avicta Duo Cotton with Cruiser for insect control, several fungicides for disease control and abamectin for nematodes. Beware: the Acceleron seed treatment label in other crops may contain other products. More information on Acceleron seed treatment options can be found here.
Bayer’s Stoneville/Fibermax cotton seed comes with a base package that includes Gaucho for insect control and thiodicarb for nematodes that falls under the Aeris treatment umbrella. Producers also have the option to upgrade to Poncho/Votivo with clothianidin (Poncho) for insects and Bacillus firmus (Votivo) for nematodes. More information on Aeris seed treatment options can be found here.
Another option is to buy the minimum insecticide treatment available, and have a dealer apply additional insecticides downstream after the seed is purchased.
IST’s offer limited early season protection from thrips. Effective residual efficacy usually offers 10-14 days of control after plants emerge. Unsatisfactory residual control can occur with these treatments and cotton should be frequently scouted for thrips until the four leaf stage and when cotton plants are actively growing.
During 2011, western flower thrips were a problem in many Louisiana cotton fields. Western flower thrips can be difficult to control with standard applications of acephate, dimethoate, bidrin, etc. Producers also risk flaring spider mites and cotton aphids with repeated applications of broad-spectrum insecticides. Recent research conducted by the LSU AgCenter demonstrated satisfactory control of a complex of species including western flower thrips with Tracer and Radiant at 2 and 7 days after treatment.
The use of a nonionic surfactant with these insecticides can help increase efficacy against thrips. Rescue applications of foliar insecticides should be applied early in cotton development with applications at the 1-2 true leaf stage yielding significantly greater lint per acre than treatments applied at the 3-4 true leaf stage. Do not wait for thrips treatment in an attempt to time an overtop herbicide application.
Insecticide seed treatment options get producers off to a good start when it comes to insect pest management in cotton. However, these treatments should not be relied upon for sole control of all early season pests. IST’s are one of the best management practices (BMP’s) recommended by the LSU AgCenter for cotton IPM.
For more information concerning insect pest management, contact your local LSU AgCenter parish agent, LSU AgCenter specialist, or Louisiana independent agricultural consultant.
All, I have been seeing more instances of true armyworms infesting wheat in the North Louisiana. These include wheat plots at St. Joe and Winnsboro at various stages of growth. Our threshold for armyworms is 5 worms per square foot with foliage loss occurring. If armyworms reach the flag leaf and the wheat has not headed an application should be made. I have also encountered varying levels of stink bugs (primarily rice stink bug) in wheat. Populations of stink bugs have to be high for damage to occur and our threshold is 10% infested wheat heads in the milk stage and 25% infested heads in the soft dough stage. Stink bug numbers will usually be higher around the edges of a field with numbers falling off as you walk further toward the middle. This means you may reach threshold around the edges of a field, but may also be well below threshold 100 feet in. Applications of pyrethroids can control both of these pests.
Rice stink bug photo courtesy of Gus Lorenz
Armyworm larvae on wheat heads photo courtesy of Robert Bellm, University of Illinois Extension
This article was originally published in Louisiana Farm and Ranch, February 2012. I’m reposting it here for your information. This is an important article to read as growers are making their decision about insecticide seed treatments in rice for the 2012 season.
Authors: Natalie Hummel, Associate Professor and Assistant to the Director & Mike Stout, Professor
We have had quite a few inquiries about using a combination of seed treatments, neonicotinoid and Dermacor X-100, in rice. While this practice is legal, using more than one seed treatment is not a practice that we encourage in most circumstances because it results in more insecticide use in rice production than may be necessary.
The rice industry is considering one of these combinations of seed treatments: 1) Dermacor X-100 and CruiserMaxx or 2) Dermacor X-100 and NipsitINSIDE. Typically, a combination of seed treatments is only being considered when planting rice at low seeding rates, primarily because of concerns about the lack of efficacy of CruiserMaxx and NipsitINSIDE at hybrid seeding rates (25 lbs/acre or less) that we have observed in our rice water weevil demonstration trials and small plot trials. The second scenario is where Dermacor X-100 is being used for rice water weevil management and there is a history of stand reduction because of a sporadic pest infestation, usually chinch bugs or armyworms. Combining seed treatments provides a benefit of protecting the crop from injury by some primary and sporadic crop pests.
As the rice industry moves toward a more sustainable crop production profile, the LSU AgCenter strongly encourages rice producers to be good stewards of these insecticide seed treatments. Stewardship of these seed treatments means avoiding the use of insecticides not needed in the crop. For this reason, we discourage the widespread use of a combination of insecticide seed treatments in rice. We instead encourage the person making the seed treatment decision to consider the spectrum of pests that each insecticide can control, the seeding rate, and the history of crop pests in that field.
It is important to remember that each of the seed treatments controls a different group of insects. Dermacor X-100 belongs to a class of insecticides called anthranilic diamides, which target a specific receptor in the muscle of the insect. Dermacor X-100 is registered to control rice water weevil larvae, borers (Mexican rice borer, Rice stalk borer, Sugarcane borer), armyworms and colaspis (2ee registration for suppression). CruiserMaxx and NipsitINSIDE are both neonicotinoid insecticides that affect the nervous system of target insects. CruiserMaxx is labeled to control rice water weevils (larvae and adults), chinch bugs, colaspis and thrips. NipsitINSIDE is labeled to control rice water weevils and colaspis. We do not have data to support the ability of CruiserMaxx or NipsitINSIDE to control chinch bugs, colaspis or thrips in Louisiana, but we anticipate that they will control these pests based on observations from other crops and from rice in other parts of the world. As you study these seed treatments, you can see how a combination of these products can control most of the insects that attack rice in Louisiana. This is part of the reason why there is an inclination toward using a combination of treatments.
Here are criteria for you to consider as you make your seed treatment decision. The first is the seeding rate. This needs to be considered because neonicotinoids don’t always provide good control of rice water weevils at low seeding rates. Dermacor X-100 does provide control of rice water weevils at all seeding rates, but it will not control chinch bugs or thrips. According to the chemical manufacturers, neonicotinoids do control other early season pests including chinch bugs, thrips and colaspis. Another challenge at low seeding rates is that the plant stand is thin and is less tolerant to any insects that reduce the stand by killing seedlings. Insects that can reduce the plant stand count include armyworms, chinch bugs, colaspis and thrips. Borers can infest fields after the plant is at the green ring growth stage and reduce yields by causing deadhearts and whiteheads. Remember that if you put out a combination of seed treatments for a sporadic pest and that pest doesn’t infest your field, then you didn’t need to use a combination of seed treatments. We have data that indicate that rice water weevils infest more than 90% of rice fields in Louisiana. This justifies the use of a seed treatment to control rice water weevils as part of a good IPM program. That is not the case for many of our sporadic pests (armyworms, chinch bugs, colaspis, borers, etc.), which rarely occur at levels that justify treatment. Also, keep in mind that we rarely recommend an insecticide treatment for thrips in rice; usually the damage is not severe enough to require an insecticide.
Here are a couple of situations where a combination of seed treatments may be a good management decision. If you are planting rice at a low seeding rate and you anticipate that you will have an infestation of chinch bugs that would justify a pyrethroid treatment, then a combination of seed treatments would be a good option. In this situation, you would be using Dermacor X-100 to control rice water weevils, borers and armyworms and adding a neonicotinoid to control chinch bugs or thrips. Also, if you are planting rice at conventional seeding rates and you are using a neonicotinoid seed treatment to control rice water weevils and colaspis, but you typically have problems with armyworms or borers, then you may want to apply Dermacor X-100 to your seed.
There is one more thing to consider as you make your seed treatment decisions for the 2012 season. The EPA recently approved a Section 24C (special local need) registration for use of Dermacor X-100 in water-seeded rice. If you are interested in this option, a certified seed treater can provide more information. Remember that you CANNOT use the other seed treatments (CruiserMaxx or NipsitINSIDE) in water-seeded rice. The use of CruiserMaxx and NipsitINSIDE in water-seeded rice is illegal and will not provide control of the target pests.
If you have any questions about the seed treatment options registered for use in rice, please contact your local County Agent, or Natalie Hummel (email@example.com) for more information.