Timely Info

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June is Cotton 'Sidedress' Time
on 6/15/2017 11:59 AM
Category:Agronomy Series

While cotton planting for the 2017 crop season is winding down, more work is in store for producers.  Sidedress applications will soon need to be applied​.  For more information about nutrient application timing, see the attached article.

cotton sidedress time - W Birdsong 2017 TI.pdf

Fungicides compared for the Control of Southern Rust and Yield Response in Late-Planted Irrigated Corn
on 6/12/2017 1:27 PM
Category:Plant Pathology Series

 Fungicides compared for the Control of Southern Rust and Yield Response in Late-Planted Irrigated Corn

June 12, 2017                                                                                   PP-775

 

 

A. K. Hagan

Extension Plant Pathology and Professor

Department of Entomology and Plant Pathology, Auburn University, AL 36849

 

 

Southern rust (Puccinia polysora) poses a significant threat to corn in the southern third of Alabama, particularly in Baldwin and Mobile Co.  Yield gains from fungicide inputs have exceeded 80 bu/A under severe rust pressure in late-planted irrigated corn in screening trials at the Gulf Coast Research and Extension Center (GCREC) in Fairhope, AL.   Destructive southern rust outbreaks occur every three to four years in Southwest AL, with disease onset typically occurring at tasseling or silking in outbreak years.  The risk of damaging rust outbreaks in corn declines with increasing distance from the Gulf of Mexico.  The later in the corn growth cycle that southern rust appears, particularly at the dough stage, the less likely that this disease will adversely impact yield.  Double crop corn sown behind early corn or wheat in South AL is particularly vulnerable to southern rust as inoculum pressure is often be very high in July and August.  Regardless of the planting date, rapid disease development and subsequent yield losses are also more likely in irrigated than dryland corn.  Frequent showers coupled with weather systems moving from Mexico or Florida over the Gulf of Mexico accelerates disease onset and development.

 

So far, low levels of southern rust have been found in corn at the GCREC but not yet at other Alabama locations.  Frequent showers over the past few weeks along with continued rain showers in the extended 10-day forecast should favor continued rust spread and intensification in SW AL.  In addition to southern rust, noticeable common rust development was noted in the lower and mid-canopy on corn at the GCREC and to a lesser extent at Brewton Agricultural Research Unit (BARU) in Brewton, AL, Wiregrass Research and Extension Center (WGREC)  in Headland, AL and Plant Breeding Unit (PBU), Tallassee, AL.  Also, Northern corn leaf blight and southern leaf spot disease along with gray leaf spot have been diagnosed on in corn variety trials at either BARU, GCREC, and PBU.  While common rust rarely causes sufficient damage to reduce corn yield, Northern and Southern corn leaf blight along with gray leaf spot can negatively impact corn yield. 

 

Should a southern rust outbreak occur, protective fungicides are key to slowing disease progress and protecting kernel yield.  Based on previous Alabama field trials, sizable yield gains from fungicide inputs are realized only when serious damage attributed to either southern rust or Northern corn leaf blight develops on the ear and ear-1 leaves.  When there is little or no disease activity, no yield gains from fungicide inputs will be realized.  All corn fields are not candidates for fungicide treatments. Name-brand fungicides at $20 to $30 per acre are fairly costly and producers are likely to see good returns on their fungicide investment in irrigated or dryland fields with yield potentials exceeding 175 to 200 bu/A, particularly with corn prices near the $4 per bu mark.  Ideally, fungicide treatments should be initiated for rust control based on a scouting report(s) and corn growth stage with a two-application program at growth stage VT-R1 and R2-R3 when disease pressure is high and weather favorable for further disease intensification.

 

The objective of this multi-year study at BARU was to assess the efficacy of registered fungicides for the control of southern rust and yield response of late-planted, irrigated corn.

 

Production Methods

 

The study site at the Brewton Agricultural Research Unit (BARU) was prepared for planting with a disk harrow and finished with a ripper bedder.  A broadcast pre-plant application of 25 to 51 lb actual nitrogen/A fertilizer supplemented with 10% sulfur was followed with two or three topdress applications of a total of 200 lb actual nitrogen/A.  Pioneer 2023YHR, Pioneer 1637YHR, and DeKalb 62-08 Smart Stax field corn was sown at a rate of 2 seed/row-ft (29,120 seed/A) during the first week of May in 2014, 2015, and 2016, respectively.  Weed control was provided by an at-plant application of 1.33 pt/A Dual Magnum II followed by a post emergent application of 0.5 gal/A Atrazine + 1 pt/A Dual Magnum II.  Plots were irrigated as needed to maintain optimum crop development with a lateral irrigation system. A factorial design with study year as the whole plot and fungicide program was used.  Individual experimental units consisted of four, 25-foot rows on 3-foot centers in four replications.  A non-fungicide treated control was included.  Fungicides were broadcast with a 'high-boy' sprayer with TX-12 nozzles spaced 19 inches apart mounted on a four row boom in 15 gal/A of spray volume at 40 psi at growth stage (GS) VT (tasseling) – R1 (silking) on July 8 and GS R2 (kernel blister) –  R3 (milk).  Induce non-ionic surfactant at 0.125% v/v was added to all fungicide tank mixtures.  Southern rust was assessed at GS R6 (black layer) on a scale of 1 to 11 where 1 = no disease, 2 = 1 to 10%, 3 = 11 to 20%, 4 = 21 to 30%, 5 = 31 to 40%, etc. of leaf area diseased on 5 ear leaves in each plot just prior to black layer.  Plots were combined on September 12.  Yields are reported at 15.5% moisture.  Statistical analyses for southern rust intensity were done on rank transformations of data.  For presentation, data are back transformed.  Means for all variables were separated using Fisher's least significant difference (LSD) test (P<0.05).

 

Results

 

Southern rust severity significantly differed by study year and fungicide program (Table 1).  For all fungicide programs, southern rust intensity ratings were higher in 2014 than either of the following study years (Fig. 1).  With the exception of the non-fungicide treated control, Quilt Xcel and Aproach fb Aproach Prima programs, lower rust ratings were observed in 2016 than 2015.  Noticeable better southern rust control was provided by Stratego YLD and Fortix in 2015 and 2016 as compared with 2014 when both products proved less efficacious against this disease than Aproach fb Aproach Prima, Priaxor, and Quilt Xcel.  The latter three fungicide programs consistently gave effective disease control, particularly Quilt Xcel under severe disease pressure in 2014.  The two least effective fungicides for controlling southern rust in corn were Tilt 3.6E and Muscle 3.6F.  While the Muscle 3.6F-treated corn reduced rust severity compared with the non-fungicide treated control in two of three years, this fungicide failed to match the efficacy of Aproach fb Aproach Prima, Priaxor, and Quilt Xcel.  When compared with the non-fungicide treated control, Tilt 3.6F failed to reduce southern rust severity in two of three study years and was the least efficacious fungicide program in 2015. 

 

Table 1. P values for generalized linear mixed models for effects of year and fungicide treatment on southern rust severity, test weights, and yield of corn. 

 

Source of VariationSouthern rustTest weightYield
Year80.51*** Z220.24***107.13***
Fungicide program76.23***  11.11***  53.47***
Year × Fungicide program  6.20***    5.67***    6.75***

Z Significance of F values at the 0.05, 0.01, and 0.001 levels is indicated by *, **, or ***, respectively.

  

Figure 1. Southern rust severity as influenced by fungicide program. Means followed by the same letter are not significantly difference according to Fisher's protected least significance (LSD) test (P<0.05).   

 Pooled Corn Fungicide Summary Slide 1.jpg

Yield significantly differed for all fungicide programs by study year (Table 1).  The greatest yield differentials between the non-treated control and the superior fungicide program(s) was noted in 2014 and 2015 when a 50 and 65 bu/A yield gain, respectively, was obtained with Quilt Xcel (Fig. 2).  Yield gains from fungicide inputs was lower in 2016 due to reduced disease severity compared with the previous two study years.  When compared with the non-fungicide treated control, significant yield gains were obtained in all study years with Aproach/Aproach Prima, Fortix, Priaxor, and Quilt Xcel, as compared with two of three years with Stratego YLD and one of three years with Tilt 3.6E and Muscle 3.6E.  In all study years, greater yields were recorded for Quilt Xcel than for Muscle 3.6E, Stratego YLD, and Tilt 3.6E.  Priaxor-treated corn also produced greater yields than Muscle 3.6E and Tilt 3.6E in all study years and Stratego YLD in one of three study years.  Aproach/Aproach Prima and Fortix programs matched the yields obtained with Quilt Xcel in 2016 but not 2014 or 2015 under elevated disease pressure.  Overall, the poorest yield response was recorded for Tilt 3.6E and Muscle 3.6E as neither of these fungicides were able to match the performance of the above fungicides in at least two of three study years.    

 

Figure 2. Yield response to fungicide inputs by study year. Means followed by the same letter are not significantly difference according to Fisher's protected least significance (LSD) test (P<0.05).  

 Pooled Corn Fungicide Summary Slide 2.jpg

Summary

 

As the results of this study demonstrate, southern rust, particularly under favor weather patterns for disease development, can drastically reduce corn yields.  When compared with Quilt Xcel, yield for the non-fungicide treated control was reduced up to 60 bu/A for a farm gate income loss of $240 per acre at current contract prices.  Yield losses up to 80 bu/A have previously been recorded in previous fungicide screening trials in Alabama.  

 

The fungicides screened are among many but not all of the products currently recommended for the control of Southern rust and other foliar diseases in corn.  Of the fungicides screened, Quilt Xcel followed by Priaxor, Fortix, and Aproach/Aproach Prime provided the most consistently effective southern rust control.  That high level of disease control was reflected in the sizable yield gains obtained with the two former and to a lesser extent the latter two fungicides in all study years.  The generic fungicides Tilt 3.6E (propiconazole) and Muscle 3.6E (tebuconazole) are considerably less expensive than the above name- brand fungicides but proved to have limited activity against southern rust and often failed to boost yields as compared with Quilt Xcel, Priaxor, Fortix, and Aproach/Aproach Prima. As a result of this and previous Alabama fungicide screening trials, the use of Tilt 3.6E and Muscle 3.6F for southern control in corn should be avoided.  In contrast, the name-brand fungicides in general and Quilt Xcel and Priaxor in particular gave effective rust control over the three-year study period that was backed up with consistently high yields.    

 2017 Corn Fungicide TI.rev.pdf

Culling strategies for beef cattle operations
on 5/22/2017 4:00 PM
Category:Animal Sciences Series

Currently, much of Alabama is either abnormally dry, in a moderate drought, or in a severe drought. As we have had to deal with drought conditions way too often in recent years, longer-term forecasts predict dry to droughty conditions will persist for much of Alabama throughout 2017. Hopefully that will not be the case, but if it is, making plans now to deal with potentially limited feed, forage, and water conditions could pay dividends down the road. In an effort to provide adequate supplies of feed, forage, and/or water, some options to consider include: 

  1. Culling unproductive animals now, thus preserving limited feed and water resources for productive cattle.
  2. Begin rationing feed and hay now, in anticipation of greater than normal use over a potentially dry summer.
  3. Transporting adequate feed to the farm.
  4. If ponds and wells that are normally used for watering cattle are at risk of running dry, consider alternative sources of water.
  5. Transporting cattle to a farm with adequate feed and water.
For more information about general culling strategies for beef cattle, please see the attached Timely Information Bulletin.

Timely Information - Culling strategies for beef cattle operations.pdf 

Weed of the Month: Verbena, Vervain
on 5/8/2017 9:10 AM
Category:Animal Sciences Series; Weed Science Series

Approximately 80 species of Verbena or Vervain occur in the world, and most species are found in the South.  Many of these species occur as weeds in Alabama pastures and hayfields.  This timely information sheet provides information on this group of weeds and explains how to control them.

Timely Information-011 - Verbena.pdf


Where can I get additional information? Contact Joyce A. Tredaway at  Tredaway@auburn.edu.


Grazing Management Strategies During Drought in Tall Fescue Systems
on 5/4/2017 4:08 PM
Category:Animal Sciences Series

​This Timely Information Sheet provides recommendations on grazing management practices for tall fescue stands that were weakened during the 2016 drought. 

Grazing Management During Drought in Tall Fescue Systems - May 2017 - TI Sheet.pdf

Pre-Conditioning Beef Calves with High-Moisture Forages and Co-Product Feeds
on 5/1/2017 10:12 AM
Category:Animal Sciences Series

​There has been an increasing interest in the use of baleage in beef operations in Alabama. This information sheet summarizes the results of a 45-day preconditioning trial evaluating the use of baleage and co-product feeds for pre-conditioning beef calves.


ACES TI Baleage.pdf

Preventing ruminal acidosis when using supplemental feeds for beef cattle
on 4/22/2017 10:46 AM
Category:Animal Sciences Series

Ruminal acidosis is a digestive disorder characterized by low rumen pH (more acidic than normal). Cattle are at greatest risk for acidosis when consuming feed that is high in rapidly fermentable carbohydrates, particularly when they have not had adequate time to adapt to a high-energy supplemental feed. Cattle that go off feed for an extended period are also at risk when they resume feed intake. Ruminal acidosis can result from errors in ration formulation and/or feeding strategies.

Ruminal acidosis can occur in beef cattle of all ages. Risk for ruminal acidosis increases when calves are weaned onto rations high in rapidly fermentable carbohydrates, especially when they have not had time to adapt to the new ration. Calves are also at risk when creep-fed supplements high in rapidly fermentable carbohydrates. Mature cows and bulls are at greatest risk of ruminal acidosis when provided new or irregular access to supplemental feeds high in rapidly fermentable carbohydrates, as may occur during drought conditions.

Timely Information - Preventing Ruminal Acidosis When Using Supplemental Feeds for Beef Cattle.pdf

Interaction of Planting Date and Seeding Rate on Seedling Populations, TSW and White Mold Incidence, Leaf Spot Defoliation, and Yield of Three Peanut Cultivars in a Dryland Production System
on 4/12/2017 2:14 PM
Category:Plant Pathology Series

​Seed account for up to 20% of the total variable production costs for peanut.  The impact of seeding rate of 3, 4, 6, and 8 seed per row foot as influenced by planting date on the incidence of TSW and white mold, leaf spot defoliation, and yield of commercial peanut varieties Georgia-06G, Georgia-09B, and Georgia-12Y in a dryland production system at the Wiregrass Research and Extension Center in 2014, 2015, and 2016.  Planting date but not seeding rate had the greatest impact on yield of peanut.  Yields were greater in two of three study years for the mid-April (1st Date of Planting [DOP]) than mid-May (2nd DOP)-planted peanuts, regardless of the variety.  Georgia-06G, Georgia-09B, and Georgia-12Y has similar yields except in 2016 for the latter variety when a sharp yield decline was noted at the 2nd DOP.  No yield gains were seen by increasing seeding rates.  The lack of a variety × seeding rate interaction showed that the absence of a seeding rate response was consistent across all varieties.  In a previous Alabama study, seeding rate had a limited impact on the yield of commercial peanut varieties in an irrigated production system.  Year (i.e. rainfall) had a sizable impact on yield.  With good rainfall through much of September, yields were averaged 5660 lb/A in 2016 as compared with drier late summer and early fall weather patterns in 2014 and 2015 when the mean yield was 2454 lb/A and 3217, respectively.

Despite low TSW, leaf spot, and white mold pressure, planting date, variety, and seeding rate alone or in combination significantly impacted disease activity.  While TSW incidence was often similar across planting dates and varieties, greater disease was seen in the April than May planting of Georgia-09B in 2016.  Previously, incidence of this disease was also greater in April than May-planted peanuts.  Elevated TSW levels recorded at the lowest seeding rate is also consistent with the results of previous studies.  Leaf spot defoliation, which was greater in two of three years the May than April planted Georgia-06G, Georgia-09B and Georgia-12Y, also intensified slightly but significantly with increasing seeding rates in the May but not the April-planted peanuts.  When noticeable white mold development was seen in 2015, disease incidence was greater in April than May-planted Georgia-06G, Georgia-09B, and to a lesser extent Georgia-12Y varieties. Otherwise, white mold damage regardless of planting date was low in 2014 and 2016.  Overall, white mold incidence was lower in Georgia-12Y than the other two varieties.

Results of this and a previous Alabama study suggest that growers have some flexibility with seeding rates in dryland and irrigated production settings.  Even under drier conditions in 2014 and 2015, yield was similar across all seeding rates for all three peanut varieties.  None of the varieties screened showed a significant yield advantage, despite differences in disease damage. 

 

The full report can be found in this file.Dryland Seeding Rate Summary Timely Information 2017.pdf

Cotton Planting Situation – 2017
on 4/12/2017 9:56 AM
Category:Agronomy Series

Farmers all over Alabama are filled with excitement and anticipation to get the 2017 Cotton Planting season off to a good start whereas, we are just at that time to begin the Cotton Planting season.  Farmers usually wait until the month of April to consider planting with optimal planting dates being from April 1st through May 20th.   This is the optimal planting window.  Early in this planting window, farmers look to the weather conditions and soil conditions to determine when to begin planting.  The first indicator is soil temperature.  Generally it is recommended to observe the 4 inch soil temperature and for it to be at 65 degrees Fahrenheit for 3 consecutive days with the longer range forecast to be warming and conductive to maintaining and improving these soil warmth conditions.  The reason would be to enhance seed germination and plant establishment. Diseases such as Rhizoctonia are soil borne diseases which can diminish the plant stands of cotton if cool, wet conditions prevail after cotton planting.   Seed and technology is expensive and replanting cost lots of time and money therefore, it is desirable to plant to get the optimal stand of Cotton once without having to replant.

            Below is the Alabama weather Station Data from Belle Mina, Tallassee, Prattville, Fairhope and Headland as a means of evaluating the soil conditions and the tentative 5 day forecast. The locations of Belle Mina, Headland and Prattville have all passed the 65 degree Fahrenheit rule for three consecutive days and the accompanying longer range forecast indicates that it is acceptable to begin Cotton planting.  The locations of Tallassee and Fairhope indicate that soil conditions are still a little on the cool side to begin planting Cotton seed.  However, the 5 day forecast indicates that it will continue to warm and be dry therefore it is not expected to be much longer before these areas will reach the acceptable soil conditions temperature wise.

            Once the soil Temperature reaches the acceptable level, the soil moisture must be closely monitored to evaluate if there is adequate soil moisture in the top .5 to 1.5 inch depth.   The reason being is that these depths are the recommended depths to plant cotton.  I recommend that Cotton seed be planted into at least .5 inch of moist soil at the time of planting.  The reason being is that the upper .3 to .5 inch of the soil, after being disturbed by the planter unit, will dry out and we want the seeds to germinate and peg down with the radicle before the moisture moves past the seed.  Also, remember the later in the planting season, the faster this soil will dry out due to the increasing air temperatures.  That is the reason for dryland producers to plant early when moisture is available. 

            Please review the chart to help you monitor the soil temperature conditions in conjunction with the 5 day forecast to determine when it will be appropriate for you to begin your 2017 Cotton Planting season.  If I can be of service please call 334-723-6299 or 334-693-3800 to reach me.

The full article and table can be viewed by clicking the link below.

cotton planting date 2017.pdf

Target spot-incited defoliation and yields of selected cotton varieties over a three-year period in Southwest Alabama
on 4/11/2017 2:00 PM
Category:Plant Pathology Series

​The yield response and reaction of selected mid- and full-season commercial cotton varieties to target spot, incited by Corynespora cassiicola, as influenced by fungicide inputs was conducted at the Brewton Agriculture Research Unit (BARU) in 2014, 2015, and 2016.  The experimental design was a factorial set of treatments arranged in a split plot, with the varieties Phytogen 499 WRF, Phytogen 575 WRF, Deltapine 1137 B2RF, Deltapine 1252 B2RF, Fibermax 1944 GLB2, and Stoneville 6448 GLB2 as whole plots and an umbrella fungicide program consisting of four or five applications of Headline SC at 9 fl oz/A + Bravo Ultrex at 1.5 pt/A to minimize disease activity and yield loss.  The site was irrigated as needed and managed for maximum yield.  Final % defoliation and relative area under the disease progress curve (rAUC) for defoliation differed by variety and fungicide program.  While final % defoliation and rAUC for all the above varieties were lower for the fungicide- than non-fungicide treated controls, lower values for the above variables were obtained for the fungicide-treated Phytogen 575 WRF, Deltapine 1252 B2RF, Stoneville 6448 GLB2, and Fibermax 1944 GLB2 than Phytogen 499 WRF, which suffered the greatest disease-related defoliation.  For the non-fungicide treated controls, higher defoliation and rAUC values were obtained for the latter than for the other five remaining varieties, which had similarly lower values for both target spot variables.  Over the study period, equally higher yields were noted in 2014 and 2015 than 2016, when elevated hard lock counts were linked with sharply lower yields.  In addition, Fibermax 1944 GLB2 and Deltapine 1252 B2RF had higher lint yields than Phytogen 575 WRF, Deltapine 1137 B2RF, and Stoneville 6448 GLB2 but not Phytogen 499 WRF with all of the latter varieties having similar yields.  Finally, greater lint yields were noted for the fungicide- than non-fungicide treated controls.  While higher open boll counts were recorded in 2014 than either of the following two study years, hardlock boll counts progressively increased each study year from a low of 2.4 in 2014 to 11.7 in 2016.  Rotted boll counts were higher in 2015 and 2016 than in 2014.  For 2015, counts of rotted bolls was higher for the fungicide-treated than non-fungicide treated control with the latter treatment having similar rotted boll counts as the fungicide-treated and non-fungicide treated control in 2016. 

 

The full report summarizing this study is attached.

2017 Cotton Target Spot Varieties Timely Information.rev.pdf 

 

 

 

 

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