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Wheat Disease Update

Wheat Disease Update published on No Comments on Wheat Disease Update

by Boyd Padgett, Ph.D., Plant Pathologist, LSU AgCenter

I have received a few reports of leaf and stripe rust in commercial fields; however, not at high levels. I have not observed any rust in producer fields in Northeast and Central Louisiana. In my tests around the state (Dean Lee, Red River, Ben Hur, and Macon Ridge), I have observed leaf rust at low levels in my tests located at the Macon Ridge Research Station, at moderate levels at Ben Hur, and stripe rust at low levels in tests at Dean Lee.  These tests are intentionally planted to SUSCEPTIBLE varieties, and are not representative of producer fields planted to resistant varieties. I have also observed powdery mildew in tests located at Ben Hur and the Red River Research Station. This disease is not considered to negatively impact wheat produced in Louisiana. However, if the disease is active (high incidence and severity) and present on the flag leaf prior to heading a fungicide may be justified. I HAVE NOT SEEN THIS SENARIO IN THE PAST 15 YEARS.

 Producer fields: If rust incidence and severity is low (no pustules on the flag and confined to the lower canopy not active), most plants are fully headed (not flowering), and the variety is rust resistant, a fungicide is probably not needed.

Fungicides are justified if the wheat is at flag leaf to early heading and rust is active (spores are easily seen on the lower canopy). The following conditions are necessary for leaf and stripe rust development.

 Stripe rust development is most aggressive when nighttime temperatures are 50 to 65oF in the presence of intermittent rain or dews. However, development can occur when temperatures are near freezing up to 70oF.  Initial infections on seedling wheat may not have the characteristic striping pattern that occurs on more mature plants.  Seedling infections often occur in ‘thumb-sized’ clusters on the leaves, as opposed to a random distribution that occurs with leaf rust.    Infections may appear as linear rows of small yellow to light orange pustules (stripes) on the lower leaves during late winter or early spring. Striped patterns are typical of infections in older pants.  If conditions remain favorable for development, pustules may cover the entire upper leaf surface, as well as portions of the head. A lifecycle (infection to reproduction) can be completed in 7 to 10 days when conditions are optimum for development.

 Leaf rust is usually evident later in the season than stripe rust. This is because the leaf rust pathogen requires warmer temperatures for development than stripe rust. Initial symptoms of leaf rust begin as light yellow spots, usually on the lower foliage. As the disease develops, small pin-point pustules form on the upper leaf surface. Pustules are brick or dark red and occur randomly on the leaf. Similar to stripe rust, pustules can cover the entire leaf surface if conditions remain favorable for development. The disease develops optimally when nighttime temperatures are 50 to 70oF and leavers remain wet for 6 to 8 hours. Similar conditions will favor the development of leaf and glume blotch caused by Stagonospora and Septoria, respectively.

 For more information concerning wheat disease management, contact your local LSU AgCenter county agent, LSU AgCenter specialist, or your agricultural consultant.

Preparing for the upcoming season using precision ag equipment

Preparing for the upcoming season using precision ag equipment published on No Comments on Preparing for the upcoming season using precision ag equipment

By Dennis Burns & R.L. Frazier

Now is the time to get fields and crops organized for the upcoming season.  When it comes to field names and numbers, consistency is the key to success.  Analyzing yield data or documenting production practices for multiple years makes it virtually a requirement.  Other information such as crops, variety names, chemicals, fertilizers, equipment, etc. can be entered now in preparation for use.  This information can be entered using desktop programs (e.g. APEX, Farm Works, SMS) and copied to the data cards which go in the equipment on the tractors, sprayers, and harvesters.  Or it can be entered directly into the equipment if one of the desktop programs is not available.  Along with these card entries, make a reference notebook with maps and other information that can stay with each tractor, sprayer, harvester, and other equipment.  Time spent now getting data prepared and organized will help keep field operations moving smoothly with fewer glitches to hinder data analysis after the tasks are finished.  For more information or assistance with this or other precision ag applications please contact Dennis Burns (318-267-6709) or R.L. Frazier (318-267-6714) with the LSU AgCenter.

LSU AgCenter Establishes Blog Site for Row Crops Newsletter and Updates

LSU AgCenter Establishes Blog Site for Row Crops Newsletter and Updates published on No Comments on LSU AgCenter Establishes Blog Site for Row Crops Newsletter and Updates

by John S. Kruse 

LSU AgCenter researchers and specialists have created a new avenue for obtaining the Crops Newsletter. Articles published in the Louisiana Crops Newsletter can now also be found at www.louisianacrops.com. Many constituents have expressed their preference for the easy, article-by-article access provided by a website and it is our goal to make science-based information available in forms that are user-friendly. For those that prefer to continue to receive the Newsletter in the current pdf form, rest assured that we will continue to send it out in this form as well. We look forward to serving your needs and hope you enjoy this additional way of accessing the Newsletter.

The LSU AgCenter Explores Biofuels as an Alternative Crop for Growers

The LSU AgCenter Explores Biofuels as an Alternative Crop for Growers published on No Comments on The LSU AgCenter Explores Biofuels as an Alternative Crop for Growers

Authors:  John Kruse, Michael Blazier, Richard Vlosky, Vadim Kochergin, Glenn Hughes, Dek Terrell, Paul Darby, Roger Smithhart

Research scientists and extension specialists from the LSU AgCenter are participating in federally-funded research and extension efforts to explore the potential that biofuel crops may hold for Louisiana producers.   These efforts have great potential to expand the energy production portfolio of Louisiana.  An ambitious five-year study will involve growing and selecting cultivars of energy cane (sugarcane varieties with characteristics better suited for biofuel production than conventional sugar production) and sweet sorghum well-adapted to Louisiana.  Agronomic practices such as planting rates and dates as well as fertility will be developed for these crops.  Processes for converting these crops into an array of biofuels and biochemicals are being developed in partnership with collaborators in the biofuels industry. Louisiana is particularly well-suited to develop biomass crops due to its climate, well-developed agricultural and energy infrastructure, and central location within the U.S.

In another study, a team of researchers led by Dr. Richard Vlosky submitted a survey to producers in Pointe Coupee, Concordia, Catahoula, Tensas, Madison, Richland, West Carroll and East Carroll Parishes, as well as several counties in Mississippi’s Delta region. The purpose of the survey was to gauge initial interest in producing biofuel crops, as well as find out what factors are important to making it a success. Well over 700 surveys were returned, providing a solid sample to study the responses.  Roughly 60% of the respondents farmed less than 250 acres and 40% farmed more than 250 acres. Thirteen percent of the respondents farmed over 1000 acres, providing a good cross-section of producers. When asked their overall opinion of using biomass for bioenergy, two thirds of the respondents were somewhat or extremely positive. Only 17% were pessimistic that a bioenergy market will be competitive relative to conventional energy markets.

When growers were asked about their perceptions of biofuel crops, 56% felt that economically viable technologies already exist for converting biomass to bioenergy and half of all respondents believed that agricultural biomass transportation can be conducted with existing equipment. When it came to on-farm equipment needs, 43% believed that some sort of specialized equipment would be necessary to get the job done.  A plurality (41%) neither agreed nor disagreed with the statement that converting agricultural biomass to bioenergy is a simple process that can be done at most agricultural processing facilities, and almost a third were not sure if agricultural biomass requires utilizing the entire crop as well as residual feedstock. These responses strongly indicate that growing biofuel crops is a new frontier for most producers, so agronomic education will be critical to its successful adoption by growers.

The majority of producers surveyed were clearly willing to give biofuels the benefit of the doubt when it comes to potential impact on the environment, with roughly three-fourths of respondents believing that raising a biofuel crop would not negatively impact wildlife, air and water quality, or soil quality. The majority of growers surveyed felt that government had a clear role to play in the development of this potential market. Two-thirds of respondents felt that tax credits should be given to landowners, harvesters, and companies that produce and utilize biomass for bioenergy. Well over half believed that subsidies should be provided as an incentive to companies for selling biomass residues from agricultural operations. Over 60% agreed that incentive programs should be provided to defray the costs of establishing biomass crop species and that secured loans should be provided to develop and construct commercial-scale bio-refineries. Almost three quarters of responding growers specifically saw a lead role for research institutions such as theLSU AgCenterwhen they agreed that grants should be awarded for research and development capable of advancing biomass production technologies. When it came down to individual participation, the jury is still out: When asked, “Would you be willing to participate in management activities specifically geared toward biomass production from your agricultural land?” the response was virtually evenly split, with 49% saying “No” and 51% saying “Yes.”

The fact that half of responding growers were willing to participate in bioenergy feedstock production and the high percentage of neutral responses to many of the questions indicates that many producers would benefit from additional information. It was also concluded that a gap exists between the desire to utilize agricultural biomass and the current viability of bio-based markets. The survey seems to reveal that a biofuel-based crop production system in Louisiana is still in its infancy, and that many producers are open to the idea of making it part of their production systems. They just need more information before they can make a decision.

 

 

Fall Fertilizer Applications – Are They Worth It?

Fall Fertilizer Applications – Are They Worth It? published on No Comments on Fall Fertilizer Applications – Are They Worth It?

ByDonna S. Morgan, Associate Area Agent, Louisiana Master Farmer Program

Traditional methods of applying fertilizer to cropland primarily include fall applications of Phosphorus (P) and Potassium (K), which are usually broadcast, and then may be incorporated if conditions permit. Nutrients are then left on the soil surface, or slightly beneath, for 6-7 months prior to planting of the crop. Soybeans, for example, are categorized as legumes and therefore fix their own nitrogen, but do require adequate amounts of P and K, if soil tests results recommend it (this is based on soil type and texture, soil pH, previous crops, and other variables). A medium soil type (such as a silt loam or clay loam) would normally require the application of 200#/acre of 0-18-36. If these nutrients are applied this far in advance of planting, is it really beneficial to the crop and to the environment to do so? What happens to the nutrients during typical, heavy winter rainfall events? What if the soil has a high pH (such as those found in the Red River Alluvial soil class) and the Phosphorus becomes bound to the soil particles, thereby becoming unavailable to the plant when it needs it the most? Do you apply the nutrients anyway? Or is a spring application more beneficial? These are some of the questions that prompted a study at the Dean Lee Research Station to determine if fall and spring fertilizer applications, as well as the application methods, had any impact on agronomic traits, yield, and water quality.

 The Louisiana Soybean and Grain Research and Promotion Board funded a project titled “The Effect of Phosphorus and Potassium Application and Timing Methods in Soybeans on Yield and Water Quality”. This project was funded in 2011 and will continue through harvest in 2012.  Dr. Brooks Blanche, (former LSU AgCenter cotton and soybean agronomist), and J Stevens, LSU AgCenter state soil specialist, cooperated with me on this project to ensure accurate agronomic data would be collected and nutrient recommendations would be applicable to this project. This study was implemented in November, 2010 and included a fall broadcast treatment (FBT) of P and K, a spring broadcast treatment (SPT), a spring liquid injected treatment (SLI), as well as an untreated check (UTR). Included in these 12 plots were automatic water sample collectors, also known as ISCO samplers, which were programmed to collect 200 ml of runoff every 5 minutes for four hours. The fall and winter months produced fairly significant rainfall events, where several collections were able to be made. After spring treatments were applied and a Maturity Group V soybean (Pioneer 95Y01) was planted, a lengthy drought ensued, which severely limited the water quality data that was able to be collected and analyzed. Growing conditions were fair to good for most of the growing season, with the exception of the summer months. Stand counts, plant heights, tissue samples, and soil samples were collected throughout the growing season to determine if any differences were seen in high pH conditions with each treatment. The plot was harvested on September 21, 2011 with average grain yields ranging from 32-34 bushels per acre.

 Data collected was analyzed and results showed no statistical differences in yield, plant heights, plant stand populations, and soil and plant tissue P and K levels. Plants heights and stands all fell within acceptable ranges to maximize yields. Soil samples (regardless of timing of sample collection) showed higher levels of Phosphorus across all treatments and adequate levels for Potassium. Phosphorus levels in many of the fields at the Dean Lee Research Station have continued to increase because of the limiting crop removal rate with these nutrients being applied annually. Tissue samples collected at the R3 growth stage showed the plants had sufficient levels of P and K during that growing period. And even though the soybeans visually appeared healthy, yields were compressed across all treatments with the onset of lengthy dry conditions.

 Field variability, equipment failure, and lack of field runoff limited the water sample collections and make comparisons for each treatment difficult, to say the least. Analysis showed no differences in the amount of total Solids, total Phosphorus, and Phosphates that left the field during rainfall events. Even though 31 inches of rain fell from November, 2010 to September, 2011, the majority of events were not sufficient to cause high volumes of runoff from plots. Total Solid levels were high in every treatment, primarily because the field had been sub-soiled after the previous crop harvest, and was bare during the winter months. This was due to lack of residue, cover crop, and even natural vegetation during this time period.

 One statistical difference that was noted was the level of Potassium that left the field in water sample collections. The fall broadcast treatment levels were significantly higher than those of the untreated and spring broadcast. No differences were seen in fall broadcast and spring injected. At this point, conclusions cannot be drawn from one year of data collection, but it is a possibility that Potassium levels were higher in fall treatments due to the high volume of rainfall that occurred during that time period. Potassium is also very water-soluble and this may have affected the levels found in the sample collections. Additional replications of this trial would be needed in order to determine any trends in application timings or methods.

 Though this particular study, under these specific field and environmental conditions, proved no differences in most of the parameters, does not mean the information can’t be useful. If multiple years of data are collected, and no statistical differences are determined, wouldn’t that prove useful to a producer in his nutrient management plans? Variables such as post-harvest field conditions, fertilizer prices, cropping systems, and application equipment all affect when and how nutrients are applied. This also has an effect on how many nutrients enter the surrounding water bodies and contribute to water quality issues related to production agriculture. So answering the question, “Are they worth it?” is more complicated than a simple yes or no. Conducting studies such as this will not only help producers answer these questions to maximize their nutrients, but minimizing water quality and environmental impacts as well.

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