Delta Crop Summit – November 13, 2012, Stoneville, MS
The 2012 Delta Crop Summit will be held on Tuesday, November 13, in Stoneville, MS. Please see the attached schedule.
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Posts From Tom Allen, Extension Plant Pathologist
Strobilurin-resistant Frogeye Leaf Spot Confirmed in Mississippi
For the first time, strobilurin-resistant frogeye leaf spot was confirmed in MS during the 2012 season. Numerous states in our region have previously confirmed the presence of the resistant fungus.
Soilborne Diseases and Disorders of Soybean: Is it Sudden Death Syndrome (SDS) or is Something Else Responsible?
Many diseases of soybean can produce a symptom of interveinal chlorosis. Stem canker, sudden death syndrome, Phytophthora root rot, southern blight, and several other less common diseases in the MS production system can all produce symptoms on the uppermost leaves that appear similar to SDS. However, disorders can also produce the same symptom and are oftentimes readily misdiagnosed at the field level.
The Principles of Plant Pathology: The Disease Triangle and Influence of the Environment
Plant pathogens require a specific set of factors to occur at the same time for disease to begin. More often than not diseases require a prolonged conducive environment before the pathogen can produce observable symptoms.
Impact of Hurricane Isaac on Soybean Rust and Potential Management Decisions
Over the past six weeks soybean rust has been detected in numerous soybean fields throughout Mississippi. Even though it appears that a large number of counties have soybean plants infected with the disease, at present only low levels of soybean
2012 MSU Short List of Suggested Wheat Varieties
This article lists those wheat varieties which have demonstrated superior productivity in the MSU Wheat and Oat Variety Trials and summarizes their characteristics. This impartial information should help you better assess how many variety traits potentially work to affect wheat performance on your farm next season.
Soybean Foliar Disease Update: August 21, 2012
Foliar disease in the soybean crop continue to be observed throughout MS. Presently, soybean rust has been detected in 11 counties, with Lowndes, Noxubee, and Winston being the most current finds (8/21/2012). In addtiion, frogeye leaf spot and Cercospora blight continue to be observed across a greater number of acres.
Cotton Foliar Leaf Spots: Determining the Underlying Cause is Most Important Management Option
Foliar leaf spot diseases continue to be observed throughout the MS cotton production area. Determing the particular leaf spot at the field level can be quite difficult especially if the leaf spots are a result of a foliar potassium deficiency. Bacterial blight, Corynespora leaf spot, and various other fungal diseases are being observed at present within our production system.
Choosing Winter Wheat Varieties with Tolerance to Leaf and Stripe Rust
Six locations of the MS wheat variety trial plots were rated for the presence of leaf and stripe rust. Included is information regarding the reaction of each of the varieties contained to aid in determing the best wheat varieties with rust tolerance to plant for the 2012/2013 season.
Soybean Update and Additional Management Considerations
To date, the majority of Mississippi’s soybean crop is either blooming, setting pods, or turning color in places. Some isolated fields in parts of Bolivar, Issaquena, and Washington counties have been harvested over the past 10 days. Since July 4,
Soybean Rust Update: July 30, 2012
Additional soybean rust has been detected in MS as of last Thursday. At present, 5 counties (George, Issaquena, Jefferson, Pearl River, Pike) contain extremely light soybean rust infections in either commercial soybean fields (George, Jefferson, Pike) or in soybean sentinel plots (Issaquena, Pearl River).
General soybean disease update: July 21, 2012
Numerous foliar diseases in our soybean production system are being observed. Frogeye leaf spot, aerial blight, Cercospora blight, and southern blight have been observed on numerous acres at this time.
Southern Corn Rust: Is a Late Fungicide Application Warranted?
Southern rust continues to be a topic of conversation throughout the MS corn production area. Presently, the disease can be observed at low levels in a patchy distribution throughout the Delta. However, there are likely some fields that contain hot spots of the disease. Scouting continues to be necessary in situations where a fungicide application could be beneficial. But, the necessity to apply a fungicide will be dependent on several important variables.
Soybean Rust Detected in a Sentinel Plot and Commercial Soybean Fields in George County
Soybean rust has been detected for the first time during the 2012 season in George County in southeastern, MS. Additional information regarding the specific find as well as management scenarios are included in the blog update. Stay tuned for additional information regarding the presence of soybean rust in the MS soybean crop on the blog, at www.sbrusa.net, and through the free telephone hotline (1-866-641-1847) that provides information regarding the presence of soybean rust in AR, LA, and MS and is sponsored by the Mississippi Soybean Promotion Board.
Bacterial Blight of Cotton Update: July 13, 2012
For the second year in a row bacterial blight of cotton has been observed on numerous acres in the MS production system. Compared to 2011, twice as many counties have been observed to contain infected plant material.
Response of Cotton Varieties to Inoculation with Xanthomonas axonopodis pv. malvacearum in Mississippi
Inoculation trials were conducted during the 2011 season to determine the response of several popular cotton varieties to the bacterial blight organism. The attached blog post is a poster that was presented at the 2012 Beltwide Cotton Conferences that were held in Orlando, FL in January 2012.
Root-knot Nematode Observed in Some Delta Cotton Fields
Root-knot nematode damaged cotton fields have been observed in at least two fields this season. With the loss of Temik, farmers have had to rely on alternative methods to manage high nematode populations.
Scouting Cotton for Bacterial Blight
Bacterial blight of cotton has once again been observed in the MS cotton production area. Angular lesions associated with the disease can easily be confused with many other foliar diseases as well as other important issues in cotton. Observe the photos for help in scouting for the disease that until the past two seasons has been a fairly rare occurrence in MS.
Corn Disease Update for June 22, 2012: Southern Rust Detected in Localized Areas
Numerous diseases and disease-like issues are being detected throughout the corn crop in this stage of the season. Nutrient burn, sun scald, northern corn leaf blight, gray leaf spot, and southern corn leaf rust can all be observed throughout localized areas of the Delta at this stage in the season.
Preventive Soybean Fungicide Applications: Products, Rate Selection, Timing
Over the past several weeks several phone calls have inquired about the specifics on timing of fungicide application in soybean. Over the past decade, the majority of the fungicide trials conducted in MS have suggested that an R3/R4 fungicide applied in the absence of disease provides not only excellent yield-loss prevention but in some cases an economic return.
Delta Research and Extension Center’s Corn/Soybean (July 19) and Rice (July 31) Agronomic Crop Field Days
The DREC will be holding two separate field days, one for corn and soybean on July 19 and one for rice on July 31.
Corn Disease Update: June 7, 2012
Over the past few days reports of northern corn leaf blight and gray leaf spot have increased in the MS corn crop. However, common rust is still the only rust that has been observed in MS. Keep in mind that in some cases common rust, on the lowest leaves in the corn canopy, can take on the appearance of southern rust.
Corn Fields Having Sustained Hail Injury May not Benefit from a Foliar Fungicide
Over the past several weeks we’ve encountered tremendous hail damage in corn fields. Leaf shredding is one of the more common symptoms associated with hail injury and the greatest source of yield loss as a result of hail injury (see:
Don’t Sweat the Small Stuff: Disregard those Purple to Black Spots Against the Corn Stalk at the Base of the Leaf Collar
Over the past few weeks numerous maladies have been observed in corn that don’t require a management decision. One of our more common issues, purple leaf sheath, is simply present under the right environmental conditions and when nutrients become available for the organisms that produce the minor staining on the corn plant.
Corn Diseases to Watch for While Scouting Corn
Scouting corn can be especially challenging. Looking for disease within the corn canopy can take a tremendous amount of time and should be done a little different depending on the particular crop stage encountered. Once an ear has set (post-tassel) focusing on the ear leaf and above is generally the best scouting method since protecting the ear leaf is important. I’ve included several descriptions and pertinenent information regarding some of the more commonly encountered diseases in our corn production system.
