The EPA has granted a section 18 request for the use of Transform (sulfoxaflor) for 2016 Louisiana cotton production season. Please see the link below for information on conditions and restrictions outlined by the section 18 label.
Wheat and Corn Pathology Update (4/15/2016)
Trey Price, Field Crop Pathology, Macon Ridge Research Station
Boyd Padgett, Wheat Pathology, Dean Lee Research Station
At the time of this writing, most wheat in the state is at or past flowering with the exception of some later maturing varieties. We have seen issues with vernalization in a few entries in variety trials throughout the state. Simply, there was not enough cold weather to trigger reproductive development. Fusarium head blight (scab, Figures 1 & 2) has been of utmost concern to the few wheat producers we have this year. Conditions have been favorable for scab during flowering, and applications of Caramba or Prosaro using maximum rates and water volumes are recommended for management. The best control we can expect is 50%, and time will tell if applications were successful or not.
Other concerns this season have been stripe rust (Figure 3) and leaf rust (Figure 4). Conditions are currently favorable for both diseases; however, stripe rust activity is slowly decreasing and leaf rust activity is increasing rapidly. Most varieties are resistant to stripe, leaf, or both rusts, and fungicide applications are usually not necessary. In susceptible varieties, rusts are effectively and economically managed with triazole fungicide applications.
Other diseases of note have been Septoria leaf blotch (Figure 5) and bacterial streak (Figure 6). Septoria usually remains low in the canopy and does not escalate to damaging levels; however, if infections occur on the flag leaf or flag leaf -1, a fungicide application may be warranted. Most fungicides provide adequate control of Septoria leaf blotch. Bacterial streak cannot be reactively managed. Fungicides are not effective, of course, so variety selection in the fall is the primary management technique. LSU AgCenter scientists rate wheat varieties for multiple diseases at multiple locations in the state, and the results are available online (www.lsuagcenter.com), from your county agent, or your nearest research station. Bacterial streak and Septoria leaf blotch can be difficult to diagnose. Older Septoria lesions will have black spots (pycnidia) within lesions, while bacterial streak will not. Younger Septoria lesions may be indistinguishable from bacterial streak lesions; therefore, a quick diagnostic method can be used. First, cut an affected leaf section then submerge in water. Wait 5-10 minutes, and observe for bacterial streaming (Figure 7). This can be accomplished on the turn row with a pocket knife and bottled water.
It is no secret that this has been a tough year for corn so far. Soon after early planting, most producers received copious amounts of rainfall (particularly in NELA) over an extended period. Many fields were replanted because of flooding. On stands that withstood the flooding, the majority of field calls have involved corn plants that had poor nodal root development causing them to fall over (Figures 8 & 9) and stressing or breaking the mesocotyl (first true stem) in the process (Please see Dr. Dan Fromme’s post for more information on rootless corn syndrome (RCS) http://louisianacrops.com/category/crops/corn/). Most producers planted on the higher end of plant populations allowing tolerable losses due to RCS.
Interestingly, damping off (Rhizoctonia solani) was commonly observed in RCS situations where fields had been planted for at least one month (V3-V4). Over time, seed treatment efficacy declined, plants were stressed (particularly at the mesocotyl), and the pathogen took advantage of optimal environmental conditions. Classic damping off lesions were observed on the upper sections of mesocotyl (Figures 10 & 11), and the pathogen was subsequently isolated in the laboratory.
Since we have a significant number of corn acres that will be relatively late, foliar diseases, southern rust (Figures 12 & 13) in particular, will likely be a concern this year. Southern rust (SR) can be devastating if it develops early (tasseling or before) and conditions (warm, wet) are favorable for development. Scouting is key to managing this disease. Typically SR will develop low in the canopy and progress upward. Fungicides are effective on SR (Table 1). If the disease is present at or before tasseling, fungicide applications are warranted. Depending on disease severity and prevailing environmental conditions, applications could occasionally be warranted between tasseling and milk stage. Applications are rarely warranted after this stage, because the crop will usually “out-run” disease progression. Keep in mind that tasseling is the most vulnerable stage to foliar diseases. As plants mature, more defoliation can be tolerated as time goes by.
Northern corn leaf blight (NCLB) is an annual problem in Louisiana. In fact, we can probably drop the “northern” at this point. Scouting also is key to managing this disease. Similar to SR, if NCLB develops during late vegetative stages or near tasseling, a fungicide application may be advisable. Once the disease initiates, it will continue to progress for the remainder of the season. Hot and dry weather may slow NLCB progression somewhat, but with most of our acreage irrigated, temperature and moisture requirements for the pathogen are satisfied until black layer. Specific fungicide efficacy data on NCLB remains elusive; however, pooling of nationwide data indicates that fungicides are effective on NCLB (Table 1). Similar to SR, the further the crop is past tasseling, more defoliation can be tolerated.
For more information please do not hesitate to contact your local county agent, specialist, or nearest research station. Please visit our websites (www.lsuagcenter.com and www.louisianacrops.com) for the latest in field crop pathology.
Table 1. Fungicide Efficacy for Control of Corn Diseases—April 2016
The Corn Disease Working Group (CDWG), which includes many members from the mid-South including several pathologists from Louisiana, has developed the following information on fungicide efficacy for control of major corn diseases in the United States. Efficacy ratings for each fungicide listed in the table were determined by field testing the materials over multiple years and locations by the members of the committee. Efficacy ratings are based upon level of disease control achieved by product, and are not necessarily reflective of yield increases obtained from product application. Efficacy depends upon proper application timing, rate, and application method to achieve optimum effectiveness of the fungicide as determined by labeled instructions and overall level of disease in the field at the time of application. Differences in efficacy among fungicide products were determined by direct comparisons among products in field tests and are based on a single application of the labeled rate as listed in the table. Table includes systemic fungicides available that have been tested over multiple years and locations. The table is not intended to be a list of all labeled products1. Efficacy categories: NR=Not Recommended; P=Poor; F=Fair; G=Good; VG=Very Good; E=Excellent; NL = Not Labeled for use against this disease; U = Unknown efficacy or insufficient data to rank product
1Additional fungicides are labeled for disease on corn, including contact fungicides such as chlorothalonil. Certain fungicides may be available for diseases not listed in the table, including Gibberella and Fusarium ear rot. Applications of Proline 480 SC for use on ear rots requires a FIFRA Section 2(ee) and is only approved for use in Illinois, Indiana, Iowa, Louisiana, Maryland, Michigan, Mississippi, North Dakota, Ohio, Pennsylvania, and Virginia.
2Harvest restrictions are listed for field corn harvested for grain. Restrictions may vary for other types of corn (sweet, seed or popcorn, etc.), and corn for other uses such as forage or fodder.
Many products have specific use restrictions about the amount of active ingredient that can be applied within a period of time or the amount of sequential applications that can occur. Please read and follow all specific use restrictions prior to fungicide use. This information is provided only as a guide. It is the responsibility of the pesticide applicator by law to read and follow all current label directions. Reference to products in this publication is not intended to be an endorsement to the exclusion of others that may be similar. Persons using such products assume responsibility for their use in accordance with current directions of the manufacturer. Members or participants in the CDWG assume no liability resulting from the use of these products.
One of the most important decisions producers must make when planting soybeans in Louisiana is planting date. Soybeans have the utility to be planted in early March to late June. This wide variation in planting dates exposes seedling soybeans to a multitude of insect pests that affect both above and below ground plant structures.
Optimal seeding dates for each maturity group planted in Louisiana are:
- Group III – April 15–May 10
- Group IV – April 15–May 10
- Group V – March 25–May 5
- Group VI – March 25–April 30
Soybean seedlings possess an exceptional amount of vigor and can tolerate a substantial amount of insect injury during the seedling stage. However, early planted soybeans may also encounter greater amounts of environmental fluctuations that affect air and soil temperature. Cool conditions can negatively affect vigor and under the right conditions stall plant growth and development. The addition of insect injury, to the aforementioned environmental conditions, increases stress the plant encounters resulting in loss of stand and yield potential. Therefore, the inclusion of an insecticide seed treatment (IST) provides growers a risk management tool when soybeans are planted early. The primary insect pests of early planted soybeans are bean leaf beetles, wireworms and grape colaspis.
On the opposite end of the spectrum are soybeans planted late i.e. behind wheat or are late due to unforeseen circumstances such as inadequate or excessive soil moisture. These beans are more at risk for insect injury due to the potential for large insect populations to build in neighboring fields and generally more insects present in the environment. As a general rule with all agronomic crops, the later the crop the more insect pressure that will be encountered throughout the season. This is particularly evident when soybeans are planted into wheat stubble. Wheat stubble is favorable for the development of threecornered alfalfa hoppers and thrips. Thus, an IST is a sound investment when soybeans are planted late.
However, soybeans planted in a timely manner that being within the recommended planting window, under optimal soil conditions and low pest densities will often not benefit from the addition of an IST. Insecticide seed treatments typically produce the most benefits when environmental conditions are sub optimal as outlined in the prior paragraphs. With the current economic climate and many ag professionals looking at areas to cut inputs, justifying the use of an IST on soybeans when planted under optimal conditions becomes harder to support. Saving the cost of an IST can go to making a stink bug application later season that may provide a greater economic return.
Outside of early or late planted soybeans are situations where ISTs are justifiable. These include weedy fields with incomplete burn down applications, reduced tillage field arrangements, fields with historically problematic early insect pests (wireworms and/or threecornered alfalfa hoppers) and continuous plantings of one crop. Each field is unique and the use of ISTs as a blanket treatment over every acre may not be justifiable with $8 soybeans.
Trey Price, Field Crop Pathology, Macon Ridge Research Station;
Boyd Padgett, Central Region Director, Dean Lee Research and Extension Center
Last year Louisiana wheat was devastated by Fusarium head blight (scab) because of warm and wet weather conditions during flowering. Weather conditions are currently favorable for wheat scab development statewide. Most of the wheat in the state is at or very near flowering, which is the most susceptible stage to scab infections. Wheat in southernmost production regions is already showing early signs of scab infection.
The disease is mainly caused by the fungus, Fusarium graminearum, which also causes ear, stalk, and root rots in corn. Symptoms of the disease will first appear 10 to 14 days after flowering as bleached heads which will be noticeable from the turn row (Photo 1). This symptom is often mistaken with the appearance of maturing wheat. Upon closer inspection, affected wheat heads will usually have infected kernels showing the characteristic bleached appearance with pinkish/salmon/light orange coloration along the glumes (Photo 2). This coloration is millions of microscopic spores (reproductive structures) of the fungal pathogen. There are usually healthy kernels along with the diseased kernels on the same head (Photo 3). In extreme cases, however, the entire head may be infected. At harvest, affected seed will be shriveled, off color, and much lighter than healthy kernels and are referred to as “tombstones” (Photo 4).
The pathogen over summers on corn, wheat, small grain residue, and other grasses. With that in mind, there are some cultural practices that may aid in management: crop rotation, tillage, mowing/shredding, or staggered planting/varietal maturity. At harvest, combine fan speed may be increased to remove infected seed, which is lighter than healthy seed. Additionally, seed cleaning equipment may help remove affected seed but may not be cost effective. These cultural practices alone will not completely manage FHB. An integrated approach is required to lessen the impact of FHB.
Triazole fungicides may be somewhat effective on FHB. Some earlier research indicated that tebuconazole (Folicur and generics) may reduce incidence and severity of FHB. Later research has shown that Prosaro (prothioconazole + tebuconazole), Proline (prothioconazole), and Caramba (metconazole) are most efficacious on FHB. THESE APPLICATIONS WERE MADE UNDER IDEAL CONDITIONS WITH IDEAL TIMINGS AND THE MAXIMUM CONTROL WAS AROUND 50%. AVERAGE CONTROL WAS ABOUT 40%.
Timing is critical. We have a very short window during flowering to make an effective application for FHB. The biggest problem is that ideal conditions (wet weather) for FHB infection are not ideal for making fungicide applications. Head coverage also is critical. Sprayers should be calibrated to deliver maximum water volume (minimum 15 GPA by ground, 5 GPA by air) and optimal droplet size (300 to 350 microns). For ground sprayers, nozzles angled at 30° to the horizontal will maximize head coverage. Some research has shown that dual nozzles angled in opposite directions will also increase head coverage.
It is common to see 2-3 years of epidemics of FHB followed by years with little to no disease. Judging by the amount of scab we saw last year and current weather conditions, the probability is high for another severe epidemic. An online (www.wheatscab.psu.edu) risk assessment tool that is based on temperature and relative humidity is available online, which has regional commentary that will help you to determine your risk at a given location.
For more information, please see the following resources:
Cover crops can provide producers a variety of benefits from nutrient cycling and soil cover to nitrogen fixation and pollinator food sources. Cover crops come in many varieties including grasses, legumes and brassicas, however; cover crops maintain a “green bridge” throughout the fall and early spring that may facilitate the movement of pest insects into above and below ground plant structures.
Seedling corn, in Louisiana, is often adversely affected by many factors including excess moisture, cold temperatures and a complex of above/below ground insect pests. The complex of underground insects includes southern corn rootworm, wireworms and white grubs, while the above ground complex includes sugarcane beetles, chinch bugs and cutworms. Most of these insects require a food source that is present in fields for them to successfully overwinter and subsequently begin reproduction when temperatures begin to warm in the spring. The inherent benefits of cover crops often include the presence of large volumes of biomass and an abundant root structure that anchors soil or penetrates a hard pan. Yet, these attributes make cover crops an ideal source for the buildup of yield limiting insects.
Insecticide seed treatments (ISTs) are neonicotinoid based insecticides that coat the outer layer of the seed offering protection from below and above ground early season insect pests. The systemic nature of ISTs make these compounds water soluble and facilitate the vascular movement of the insecticide into the plant tissue. The value of ISTs in Louisiana varies among crops and environmental conditions, most agricultural commodities will usually not benefit from ISTs when planted under optimal environmental conditions (adequate soil temperature, optimal soil moisture and low pest pressure). However, insecticide seed treatments will typically produce an economic benefit when conditions are sub-optimal including very late or early planting, reduced tillage field arrangements, double cropping systems (soybeans behind wheat), pests that are present every year and consecutive plantings (i.e., corn behind corn). In addition to the above mentioned situations, data from the LSU AgCenter’s Macon Ridge Research Station confirmed the need of an IST when corn is planted behind cover crops (Figure 1). A statistically significant increase in yield was observed in corn treated with Poncho 500 IST in Berseen Clover, Crimson Clover and Hairy Vetch while a significantly lower yield was measured in corn planted behind Tillage Radishes treated with the IST (Figure 1). No fungicide seed treatment was used in this study. The measurable difference in yield may be due to the presence of below ground insects that also produced a notable decrease in vigor (Figure 2). Unfortunately for producers, there are no rescue treatments available for below ground insect injury in corn or any other agriculturally managed crop in Louisiana. Therefore, the use of an IST can help safely and effectively control below above and below ground insect pests in corn planted behind cover crops.
Aside from the use of ISTs, there are other management practices that can be done to minimize the effects of pest insects, from cover crops, on corn. Burning down cover crops in a timely fashion (6 weeks before planting) will provide enough time for available biomass above the soil to dessicate and force any harbored insects off of the plants. Yet, this timing may not allow enough time for below ground insects to cycle out or succumb to a lack of forage. Earlier burn down timings and the use of minimum tillage may allow enough time for insects to cycle out or be physically removed or destroyed with implements. If you elect to destroy your cover crops earlier than intended, check with your local NRCS representative or LSU AgCenter county agent to ensure enough time has passed that your preplant intentions are met (ie. Nitrogen fixation, nutrient cycling, etc.).
The use of ISTs is a best management practice recommended by the LSU AgCenter and will help ensure your crop is protected from yield limiting insects. The use of ISTs is highly recommended if you choose to plant corn behind cover crops particularly Berseen Clover, Crimson Clover and Hairy Vetch. If you have any questions or concerns please contact your local LSU AgCenter extension service.
Trey Price, Field Crop Pathology, Macon Ridge Research Station
Boyd Padgett, Small Grain Pathology, Dean Lee Research and Extension Center
Over the past two weeks there have been multiple reports from producers and consultants throughout Louisiana of wheat scab, also known as Fusarium head blight (FHB). Reported incidences have ranged from 10 to 20 percent. The disease is mainly caused by the fungus, Fusarium graminearum, which also causes ear, stalk, and root rots in corn.
Symptoms of the disease will first appear 10 to 14 days after flowering as bleached heads which will be noticeable from the turn row (Photo 1). This symptom is often mistaken with the appearance of maturing wheat. Upon closer inspection, affected wheat heads will usually have infected kernels showing the characteristic bleached appearance with pinkish/salmon/orangish coloration along the glumes (Photo 2). This coloration is millions of microscopic spores (reproductive structures) of the fungal pathogen. There are usually healthy kernels along with the diseased kernels on the same head (Photo 3). In extreme cases, however, the entire head may be infected. At harvest, affected seed will be shriveled, off color, and much lighter than healthy kernels and are referred to as “tombstones” (Photo 4).
Since 1996, outbreaks of FHB have been as variable as the weather. Outbreaks have been reported in the Great Plains, Central U. S., Mid-South, and Southeast with reported losses of up to 20% and up to 80% in isolated fields. Conditions favoring development are wet, warm weather during flowering. The fungus may infect wheat from flowering to harvest with the most devastating infections occurring during flowering. This infection timing creates hurdles for managing the disease.
The pathogen oversummers corn, wheat, small grain residue, and other grasses. With that in mind, there are some cultural practices that may aid in management: crop rotation, tillage, mowing/shredding, or staggered planting/varietal maturity. At harvest, combine fan speed may be increased to remove infected seed, which is lighter than healthy seed. Additionally, seed cleaning equipment may help remove affected seed but may not be cost effective. These cultural practices alone will not completely manage FHB. An integrated approach is required to lessen the impact of FHB.
Triazole fungicides may be somewhat effective on FHB. Some of the earlier research showed that tebuconazole (Folicur and generics) may reduce incidence and severity of FHB. Later research shows that Prosaro (prothioconazole + tebuconazole), Proline (prothioconazole), and Caramba (metconazole) may be efficacious on FHB. THESE APPLICATIONS WERE MADE UNDER IDEAL CONDITIONS WITH IDEAL TIMINGS AND THE MAXIMUM CONTROL WAS AROUND 50%. AVERAGE CONTROL WAS ABOUT 40%.
Timing is critical. Essentially we have a 5 day window during flowering to make an effective application for FHB. The biggest problem is that ideal conditions (wet weather) for FHB infection are not ideal for making fungicide applications. Head coverage is also critical. Sprayers should be calibrated to deliver maximum water volume (minimum 15 GPA by ground, 5 GPA by air) and optimal droplet size (300 to 350 microns). For ground sprayers, nozzles angled at 30° to the horizontal will maximize head coverage. Some research has shown that dual nozzles angled in opposite directions will also increase head coverage.
The vast majority of fields in Louisiana are currently past the application window. Fungicide applications at this point would likely by off label and ineffective.
It is common to see 2-3 years of epidemics of FHB followed by years with little to no disease. Judging by the amount of calls and observations at this point, FHB has been more prevalent this year compared to previous years. If we have similar weather conditions next year during flowering, expect to encounter FHB again in 2016. An online (www.wheatscab.psu.edu) risk assessment tool that is based on temperature and relative humidity is available online, which has regional commentary that will help you to determine your risk at a given location next year.
For more information, please see the following resources:
Acephate found on exported rice
A detectable a level of acephate (an organophosphate insecticide) was identified in a recent shipment of rice by a receiving country’s grain inspection service. This is the third time acephate has been detected in U.S. exported rice the past three months.
In Louisiana, acephate is labeled for use for control of stinkbugs, corn ear worm, salt marsh caterpillar and the threecornered alfalfa hopper in soybeans. It is also labeled for use to control thrips, plant bugs and stinkbugs in cotton. One advantage of acephate has over pyrethroid insecticides for control of stink bugs is its longer residual. However, acephate is not labeled for use in rice to control stink bugs.
The origin of the acephate on the exported rice is unknown. It is very possible that a drift event from a nearby soybean field being sprayed with acephate (Orthene) to control stinkbugs occurred, which contaminated the rice. Although the exact origin of the acephate is unknown, one thing that we do know is that if acephate continues to show up in U.S. exported rice, it will surely undermine our efforts to promote and sell our high quality rice to export markets. So please, make every effort to ensure that acephate does not find its way on U.S. rice in the future. The future of our industry depends on it.
2014 Louisiana rice crop worth over $670 million
Every year the LSU AgCenter tabulates the value of Louisiana agriculture commodities and publishes this information in the Louisiana Agriculture Summary of Agriculture and Natural Resources. This publication serves as a historical record of the Louisiana cropping season and estimates how agriculture industries contribute to our state’s economy. The Agriculture Summary for the 2014 cropping season is still being put together. However, the preliminary rice data has been completed.
Rice acreage in Louisiana increased from 410,902 acres in 2013 to 456,047 acres in 2014. Medium-grain production increased from approximately 4% in 2013 to 14% in 2014. Much of this increase in medium-grain production was due to the decrease in rice acreage in California. The variety Jupiter was the predominant medium-grain grown.
The 2014 rice crop began with a cool and wet March. This delayed much of the drill-seeding and caused a slight increase in water-seeded acreage. The cool March also slowed the early season growth and development. Disease and insect pressure were average to below average in 2014. Daytime and nighttime high temperatures were not excessive during grain fill. Harvest season was again marred with wet conditions, which led to delayed first crop harvest and postponed the onset of the ratoon crop. The wet conditions also slightly decreased the ratooned acres in southwest Louisiana. The mild temperatures coupled with below average disease and insect pressure led to high crop yields with excellent milling and grain quality traits. Average yield in 2014 was 7,539 pounds per acre, slightly lower than the record yield of 7,600 pounds per acre set in 2013.
The 2014 Louisiana rice crop was harvested by 1,040 producers. The gross farm value of the state’s rice crop was $515.7 million for 2014, $21 million (4 percent) more than the year before. The higher acreage, combined with high yields, accounted for the significant increase in overall farm-gate value in 2014. Value added of $154.7 million, when combined with farm-gate value, brought the total value of rice production in Louisiana to $670.4 million.
The Louisiana Agriculture Summary of Agriculture and Natural Resources publication from 2000 to 2013 can be found online on the LSU AgCenter’s website at: http://www.lsuagcenter.com/agsummary/.
Do you know which parishes grew the most rice in 2014?
Twenty-nine Louisiana parishes grew rice in 2014.Table 1 below indicates the total estimated acres per parish.
Rice Base Program Survey 2014
We will wrap up the rice extension base program summary this Friday. So if you have not responded and you want your voice heard, be sure to fill out a survey. Remember, the purpose of the survey is to determine your thoughts and get your input on the Louisiana Rice Extension Program. Do you enjoy reading Louisiana Rice Notes? Do you attend field days? Do you use the DD50 program? Do you use the RiceScout mobile application? Should we make more mobile applications? Do you like the Rice Verification Program? All in all, what can the statewide rice extension program do to improve our service to you in the future? Let us know your thoughts. If you misplaced your original e-mail you can use this link ( 2014 Rice Program Survey) to take the survey. Thank you in advance for your participation.
Feb. 10 Louisiana Rice Council & Louisiana Rice Growers Association Annual Joint Membership Meeting, Jennings
Feb. 11-13 Louisiana Agricultural Technology & Management Conference, Marksville
Feb. 12 Northeast Louisiana Rice Forum, Delhi
Feb. 25 Stored Rice Insect Management Workshop. Crowley.
July 1 Rice Research Station Field Day, Crowley.
Random Rice Facts
Did you know that the Rice Research Station was established in 1909 in Crowley, LA? Well, did you know that Crowley was not the only town in Louisiana that wanted to be the home of the Rice Experiment Station? It is true. When the announcement was made in 1908 that a rice Louisiana Agriculture Experiment Station was to be established in southwest Louisiana, most of the citizens in the area were thrilled about the project. Formal proposals were made from three southwest Louisiana towns for the honor to be selected as the home of the experiment station. The proposals contained generous donations of land, resources and money to begin the experiment station. Special committees from each town pitched the advantages of selecting one of the locations in their district as the home of the station. Eleven potential tracts of land were offered in all. In the end, it was a 60-acre tract of land located one mile west of Crowley that got the final nod. Several attributes made Crowley the selected destination: 1) the soil was representative of the rice belt, 2) the land was well-drained, 3) the town was readily accessible because it had “a public wagon road that could be traveled by many people, on two sides, and can be observed from trains on two railroads, and one railroad having a spur already located on the property,” and 4) because the site was favorable for studying rice rotational crops. The Police Jury of Acadia Parish appropriated $3,000 toward the purchase of the land, and the citizens of Crowley and the surrounding vicinity donated another $3,500, in cash, for construction of necessary buildings and infrastructure…Can you name the other towns who gave formal proposals?
The Section 24 (c) for AV-1011 (the bird repellent seed treatment) application was officially withdrawn on Friday morning. A section 18 application was submitted to EPA on Friday afternoon. As you know, part of this application required documentation of economic loss from the 2014 season to establish need. It would be very unlikely that the Section 18 would be granted without this information. Thank you all who contributed testimonials and examples of economic loss to include the application. EPA has assured LDAF officials they will expedite processing the application since we are rapidly approaching the season. I will let you know as soon as we hear something new.
Jennings and Lake Charles. A canal company offered to donate all the land needed if the experiment station was located on its land. State Senator H.C. Drew of Lake Charles offered land he owned near Edgerly and financial support for the establishment of the Rice Experiment Station.
Louisiana Rice Notes is published biweekly to provide timely information and recommendations for rice production in Louisiana. If you would like to be added to this email list, please send your request to firstname.lastname@example.org.
This information will also be posted to the LSU AgCenter website, where additional rice information can be found. Please visit www.LSUAgCenter.com.
The Louisiana Pollinator Cooperative Conservation Program (LPCCP) has been established to foster cooperation among bee keepers, pesticide applicators and agricultural producers for the purpose of preventing honey bees and pollinators from the unreasonable exposure to pesticides through education and stewardship recommendations in the state of Louisiana.
Cooperative Stewardship Recommendations Adopted by the Louisiana Pollinator Cooperative Conservation Program
Active and Open Communication Between Farmers, Applicators and Beekeepers:
Beekeepers, farmers and applicators are encouraged to cultivate and maintain open communication between all parties involved in cooperative activities concerning farming and beekeeping. Farmers, beekeepers and applicators should exchange contact information with one another to facilitate a strong level of communication that should be present in any partnership. Basic information should include: name, telephone number (cell and home), hive locations on the property, agricultural and non-agricultural commodities grown in fields adjacent to hive locations, and information regarding the pesticides applied on these commodities or areas and application timings throughout the growing season.
“Bee Aware” Flag:
The LPCCP has elected to adopt Mississippi’s “bee aware” flag to clearly identify hive locations adjacent to an agriculturally managed crop or area. The “bee aware” flag was developed by the Mississippi Farm Bureau to increase awareness of hive locations to farmers, applicators and beekeepers. The use of Mississippi’s “bee aware” flag creates a unified recognition system that is highly visible to pesticide applicators and farmers that manage commodities across state lines. The flags should be placed in an area that is easily visible to aerial and ground applicators and serve as a reminder that bees are in the vicinity and consideration should be taken when making pesticide applications. Farmers and beekeepers should work together in deciding on flag locations so it is visible to both aerial and ground applicators. Flag ordering information can be found here: http://www.mississippi-crops.com/wp-content/uploads/2014/03/Bee-Aware-Order-Information.pdf
Hive Locations and Placement:
Hive location is an important consideration that should be discussed between farmers and beekeepers. Farmers are very familiar with their property, equipment and areas that may offer a natural refuge from accidental exposure to pesticides, while beekeepers know the best habitats for bee yards, appropriate orientation of hives so the opening is not directly facing an agricultural field and areas that are easily accessible to beekeepers to facilitate honey collection and hive transportation. Farmers and beekeepers should discuss apiary locations and bee yards that are acceptable for both parties.
Hive GPS Locations:
Beekeepers should make every effort to establish GPS coordinates of their hives and provide this information to the farmer and his applicator to establish precise hive locations on farm property.
Hive Identification and Bee Flag Placement:
Beekeepers are strongly encouraged to place visible placards on at least one hive that provides contact information in case of an emergency or if an issue arises. The placard should clearly indicate the owner of the hives and should be visible from a distance. Farmers should work with beekeepers in selecting the best location for placement of the bee flag so it is visible to ground and aerial applicators. The LPCCP strongly encourages all beekeepers commercial and hobby to register their hives with the LDAF.
Applicator Awareness of Hive Locations:
The farmer should make every effort to notify his employees of apiary locations and related bee flags on farm property. Farmers should also notify contractual parties and aerial applicators of apiary locations and related bee flags as well.
Annual Apiary Location Review:
Farmers and beekeepers should annually review hive locations on farm property. This is especially important if an accustomed apiary location is moved to a new location on farm. Physical locations on a map or pinned locations on a smart phone may help facilitate this process.
Pesticide Application Timing
Farmers and applicators should consider applying pesticides to areas immediately adjacent to hives as late in the afternoon as possible. Most honey bees have ceased foraging by late afternoon (3 pm) and late applications will help reduce many risks of bee injury. Pesticide applications should only be made when wind conditions are blowing away from colonies and bee yards. Label guidelines should always be followed and applications should only be made when an economic threshold is met.
Assistant Professor, Field Crop Pathology, Macon Ridge Research Station
Over the past two weeks, I have received many phone calls and conducted numerous field visits concerning black root rot of soybean. The suspected causal agent is Thielaviopsis basicola, which has primarily been described as a seedling disease of cotton. In 2009, the disease was described as a disease of vegetative soybean in Arkansas (http://www.apsnet.org/publications/plantdisease/2010/September/Pages/94_9_1168.1.aspx) and has been mentioned as an issue in Mississippi over the past several years (http://www.mississippi-crops.com/2014/08/01/soybean-disease-update-august-1-2014/). Information concerning late-season (R5-R6) symptoms and epidemiology of black root rot is limited.
During pod fill foliar symptoms of black root rot become obvious in soybean fields (below, Plate 1).
These symptoms are easily noticed from the turnrow, and upon closer inspection, interveinal chlorosis is evident with leaf veins remaining green (Plates 2 & 3). Inspection below the canopy in the center of the affected area will usually reveal one or several plants that died earlier in the season (Plate 4).
Apparently, these dead plants go unnoticed because the death occurred during vegetative or early reproductive stages, and adjacent plants quickly covered them. Surviving, infected plants adjacent to the dead plants will be stunted and displaying these foliar symptoms (Plate 5).
Affected plants may snap-off at the soil line when pulled. When plants are excised, roots are black in color (below, Plate 6).
Splitting stems near the crown will reveal white fungal growth in the center of the stem (below, Plate 7). Additionally, infected black plant stems from the previous season are often observed near infected roots.
We have isolated what appears to be Thielaviopsis basicola from diseased roots using a selective medium, and are currently working to confirm identity and pathogenicity. The effects of fungicide seed treatments and in-furrow sprays are unknown. Varietal susceptibilities are currently unknown; however, the official variety trial at Dean Lee Research Station is significantly affected by black root rot and will be rated in an attempt to identify sources of resistance. Additionally, greenhouse screenings may be conducted this winter to corroborate rating information.
This fungus has a broad host range and survives in the soil for long periods of time. Apparently, conditions have been optimal for disease development this year. Incidence in most fields has been <1%; however, in some fields that have been planted to soybean continuously for several years and in a minimum/no till program, incidence has been as high as 10%. This does not necessarily translate to a 10% loss, as affected plants will have the ability to produce some seed depending on disease severity. Anecdotal evidence indicates that rotation to corn will lessen disease incidence. Other diseases/conditions that we have seen this year that may be confused with black root rot include: red crown rot, sudden death syndrome, and triazole burn (Plates 8, 9, 10, and 11).
Plate 9. Red crown rot fruiting structures on soybean.
Primary Author: Clayton Hollier, Plant Pathologist, Department of Plant Pathology and Crop Physiology
Boyd Padgett, Regional Director and Plant Pathologist, Central Region
Trey Price, Plant Pathologist, Macon Ridge Research Station
We have scouted several corn fields concerning reports of southern corn rust (SCR). These reports and field visits reveal an epidemic of southern rust across the state but in particular in the south central and central corn growing regions. Field surveys indicate that SCR has been reported in 25 of 64 parishes and might be in more that have yet to be surveyed. The LSU AgCenter does not recommend an automatic fungicide application to corn. However, when disease epidemics are progressing up to and including the soft dough stage, an application of a labeled fungicide can protect yield and quality and still be economically viable.
Ideally, fungicides should be applied prior to disease onset, but realistically, fungicides are usually applied at or just after onset. Therefore, individuals should make efforts to detect and treat diseases as early as possible to prevent losses to yield and quality. When it is determined an application is needed, a premix fungicide will offer wide spectrum activity (examples are: Headline AMP, Stratego YLD, Quilt, and Quilt Xcel). Follow label instructions for application timings, rates, etc. In most cases, a single application at tassel is justified when disease is present and active. The decision to apply a fungicide should be made on a field-by-field basis. The remainder of this newsletter will address disease identification and management considerations.
Southern corn rust can be found in Louisiana corn fields every year, but its impact on grain quality and yield is dependent on several variables. Although there is some level of resistance, it seems very low. The hybrids considered resistant to SCR in the past are no longer considered resistant, due to new race development found in Georgia four years ago. Therefore, the decision to manage SCR with fungicides should be based on a solid understanding of disease initiation and development. While this disease rarely develops to statewide damaging levels in most years, disease incidence and severity in individual fields may warrant a fungicide application. However, before applying a fungicide, several factors need to be considered. These include disease identification, environmental conditions favoring disease development, and the relationship between disease severity and yield loss.
Southern corn rust is caused by the fungus Puccinia polysora. Initial infections are caused by wind-blown spores. This is a warmer-season rust and, therefore, usually occurs late season and does not always have adequate time to affect yield. However, this rust is very aggressive and if disease epidemics initiate early (prior to or at tasseling), yields could be reduced.
Conditions favoring development include temperatures between 80 degreesF and 90 degrees F with high relative humidity or abundant rainfall. Once established, the spores can survive, spread and germinate at temperatures up to 104 degrees F.
Southern rust produces small circular to oval pustules and contains orange to light brown spores (Figure 1). Pustules are usually more abundant on the upper leaf surface and may also be found on the leaf sheath and husks when disease is severe.
Risk and Management
Risk to disease is influenced by several factors including genetic resistance, tillage practices, planting date, and environmental conditions. Later planted corn can also heighten risk to SCR.
The first line of defense for managing any corn disease should be selecting a disease-resistant hybrid. Since commercially available resistance is not an option, a fungicide may be needed. However, when SCR is not present a fungicide is not necessary. Another factor to consider is when SCR epidemics initiate relative to crop growth stage. The potential for yield loss is high when SCR develops prior to tasseling and conditions remain favorable for development during the growing season. When the rust initiates after tasseling, the potential for disease loss decreases.
The relationship of yield and defoliation can be found in Table 1 adapted from the National Crop Insurance Service’s Corn Loss Instruction.
Table 1. Estimated % corn grain yield loss due to defoliation at various growth stages.
Adapted from the National Crop Insurance Service’s Corn Loss Instruction to represent the leaf collar growth staging method. Included in the Mississippi State University, Grain Crops Update June 4, 2010, Erick Larson.