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by

Eddie McGriff

Alabama Extension Regional Agent

 

The poet Robert Frost penned that good fences make good neighbors. Just as good fences make good neighbors, good sunlight is critical for high corn yields if it is supplemented with adequate moisture.  There's the rub, getting good sunlight when plentiful rainfall is accompanied by cloudy weather.

Many farmers in north Alabama recorded their best corn yields this year. It may be the best overall corn crop for the region and yet some irrigated growers were surprised that their yields weren't higher. They are not complaining and very grateful as the bin-busting dry land yields more than offset the less than anticipated irrigated crop for some growers. Nevertheless, a question asked by some of my irrigated growers, especially those putting the inputs and management in for high yields, was "Why aren't my irrigated yields higher especially considering the ideal rainfall we had this year?"

This year, the limiting factor for most of our high-yielding irrigated growers was sunlight. Full sunlight is needed for maximum photosynthesis. Photosynthesis is the process where the plant converts sunlight into sugars. These sugars are frequently called photosynthates or carbohydrates and are the energy source for the corn plant and grain. The frequent rainfall that blessed our dry land crop limited the sunny days for our irrigated corn. Still, even though some irrigated growers had lower than expected yields, they benefited from lower fuel costs by having to irrigate less.

Sunlight or solar radiation is measured in watts-hour per square meter. This year at Auburn, 22% less solar radiation was measured in June than average. June is when much of our corn was in the most sensitive stage of crop growth, flowering and early grain fill, when it was most susceptible to stresses such as insufficient sunlight, water or nutrients.  

The reduced sunlight during pollination limited yield by decreasing the number of kernels per row and caused poor tip fill if the plant population was too high. The kernel weight also dwindled due to less solar radiation during early grain fill.

Dr. Dewey Lee, former University of Georgia Extension agronomist and one of the leading corn experts in the southeast, agrees, "In south Georgia, we had more cloudy than sunny days when the corn was silking. Twenty out of thirty days were cloudy and overcast during this critical time and really reduced the amount of solar radiation the crop received.  In addition, we had the lowest growing degrees in the last four years at the same time. This resulted in a ten to twenty percent reduction in yield in our irrigated well-managed fields. Poor tip fill was a common problem in these fields due to diminished sunlight."

A common theory on increasing corn yield is to increase nutrients, particularly nitrogen, and plant population. Unfortunately, growers with high plant population experience poor tip fill when solar radiation is limited during silking and early grain fill. So, what is the seeding range growers need to strive for optimum yields?

I worked with Cherokee County farmer Nick McMichen this year on a corn seeding rate study. It showed that higher seeding rates actually decreased yields in a year with less solar radiation than normal. Three varieties (DeKalb 70-27, DeKalb 67-44 and DeKalb 64-35) were planted at 28,000; 32,000; 35,000; 38,000 and 42,000 seeds per acre. The field had subsurface drip irrigation and inputs were for high yields. The field had plentiful rainfall and did not have to be irrigated. The average of the three varieties was 232.01 bushels per acre at 28,000 seeds; 245.03 bushels per acre at 32,000; 248.24 bushels per acre at 35,000 seeds; 240.95 bushels per acre at 38,000 seeds and 235.04 bushels per acre at 42,000.

In our heavier soils of north Alabama, the maximum seeding rate for well-irrigated corn should be 36,000-38,000 seeds per acre. The optimum seeding for dry land growers should be in the 24,000-28,000 range. Farmers planting corn on bottomland close to our rivers with a shallow water table may be able to increase their seeding rate to 30,000. On sandy soils, especially the sandy soils in many areas of south Alabama, the ideal seeding rate would be 18,000-22,000 seeds per acre.

Dr. Lee adds, "There is good evidence that the yield potential for corn is 10 bushels for every 1,000 plants per acre. Unless a grower is striving for over 350 bushels per acre, their maximum seeding rate for irrigated corn should be in the 36,000-38,000 range. I would only recommend growers increase their seeding rate if they have fully developed ears with the kernels are developing to the tips of the ears at their present seeding rate and then only in slow increments, one or two thousand seeds per acre."

 

Eddie McGriff is the Alabama Extension Regional Agent in NE Alabama. He can be contacted at dem0029@auburn.edu or 256-557-2357


McMichen Farm became the first Alabama grower to hurdle the 100-bushel soybean barrier with an eye-popping 102.158 bushels per acre. The Cherokee County farm located near Centre in NE Alabama, which has been in the family since 1842, consists of Nick McMichen and his wife Freida along with father Randall and son Matt. Future son-in-law Tyler Bruce, who is engaged to Nick's daughter Mindy, joined the operation in 2015.

The record yield was entered in Matt's name but Nick says it was a family effort and a blessing from the Lord. Nick quotes his favorite Bible verse Psalm 67:7, "Then the land will yield its harvest, and God, our God will bless us." He humbly adds, "The Lord made the 100 bushels, we are merely his stewards."  

The McMichens will be recognized at the Alabama Farmers Federation Commodity Organizational Meeting in February as the first winners of $10,000 Soybean 100 Bushel Yield Contest. The contest is funded by the Alabama Soybean Producers.

Alabama Farmers Federation's Carla Hornady, who is director of the organization's Soybean Division, said farmers saw growers in other states making 100-bushel yields and wanted to encourage farmers in their own state to reach the goal.

"In 2015, our State Soybean Producers Committee decided to fund Extension specialists Mark Hall and Dennis Delaney's proposal for the $10,000 100 bushel yield challenge so our growers would try different production practices to see if they could make higher yields," Hornady said. "We congratulate the McMichens as our first winner."

Mark Hall was thrilled to have a 100-bushel winner after over 50 entrants in the challenge over the last three years. He noted, "While only one farm made the 100-bushel challenge, many entrants made record farm yields."

Nick also credits the Alabama Cooperative Extension System for helping develop a plan he used to break the 100-bushel mark. "We came close to the 100-bushel mark in the past, but I really worked close with the Alabama Regional Extension agent and specialists to develop a production scheme to get me over the hump," Nick said. "They advised to plant earlier to have pod fill during the longest days of the year to take advantage of extra sunlight."

The McMichens planted Pioneer 47T36 no-till in 30-inch rows at 140,000 seeds per acre on April 14. Ideal weather provided excellent emergence and a final stand count of 125,000 plants per acre.

"We were blessed with rain this year, and the beans didn't suffer for moisture," Nick said. "I only irrigated four times, with .4 inches during each irrigation."

Auburn University Extension Specialist Dr. Dennis Delaney praised the McMichens' efforts. "This goes to show our farmers are just as capable of making as high yields as growers anywhere," Delaney said. "Alabama farmers have invested in research to increase yields and profitability through the Alabama Soybean Producers Committee and soybean check-off fund. Nick has supported our efforts by having cotton and soybean variety trials. I am glad to see his efforts pay dividends. The information we collect from on-farm trials like his are a great asset in helping Alabama growers make better decisions to increase crop profitability."

Fertility and Tissue Sampling Key:  The McMichens applied two and a half tons of chicken litter to the field before planting. ABM Graph-Ex SA inoculant and seed lubricant were applied to the seed to maximize the plant's nitrogen production. Weekly tissue samples were taken from the farm's 2016 soybean crop that made 86 bushels per acre and discovered a shortage of potash — a common deficiency in high-yielding soybeans. Potash (K) levels decline rapidly in the leaf during pod fill as potash is translocated from the leaf to the beans. K levels above 1.75% in the leaf are preferred as long as possible. Last year, the K level in the leaf tissue samples dropped to 1.18% at pod fill and prevented the beans from getting the size needed to make a 100-plus bushels.   

Bean Size Critical in High Yields:  The McMichens' soybeans averaged 2,140 beans per pound, which meant much of the yield came from the bean's huge size. Normally, soybeans average between 2,800-3,100 beans per pound.  Nick said he learned a great deal from taking tissue samples the last two years. For high yields, adequate potash levels are required during pod fill. He applied 100 pounds of 0-0-60 and 40 pounds of ammonium sulfate per acre over-the-top of the beans at R3, when the pods began to fill. This application was key in getting bigger beans and increasing yields.

Controlling Pests a Must:  The McMichens two biggest weed problems are pigweed (Palmer amaranth) and morningglories. Roundup and Sharpen were applied at burndown, then followed up with Roundup and Dual at early postemergence. Two weeks later, an application was made with Roundup and FirstRate, resulting in excellent weed control.

Nick made a protective ground-applied fungicide application with Quadris at R3. He added Dimilin to give season-long suppression of soybean loopers, beanleaf beetles and other leaf-feeding pests; a pyrethroid for stinkbug and kudzu bug control; and boron with this application. Fields were scouted three weeks later and some minor frogeye leafspot and downy mildew development were noted. To ensure excellent yield potential, a follow-up aerial application of Priaxor was made.

Another key component to the McMichens' high yields was timely harvest. Gramoxone was applied before harvest and the soybeans were harvested September 8.

"The early-season soybeans were more profitable than corn," Nick said. "My corn acreage will be limited next year. Early-season beans will take preference over corn, but commodity prices will eventually dictate what I plant."

Eddie McGriffRegional Extension Agent


Alabama Farmers and Crop Consultants will have the opportunity to get an update on cutting-edge management strategies from several Extension specialists across the Southeast and Midsouth regions. The Alabama Cooperative Extension System is working with Auburn University’s Department of Crop, Soil and Environmental Sciences to bring Alabama farmers the Row Crops Short Course. The short course will be held at the Auburn University Hotel and Dixon Conference Center Dec. 12 and 13. The short course will cover aspects related to the major crops planted in Alabama: Cotton, Corn, Soybean, Peanut, and Wheat. Aspects related to nutrient management, pests and diseases, seeding rates, as well as irrigation will be discussed. Continuing education units and pesticide points will be available for all attendees. Click to register here. There is no registration fee, but registration by Nov. 30 is required.

For more information click on this Extension Daily News article: http://news.aces.edu/blog/2017/10/04/row-crops-short-course-held-dec-12-13/ 


​Ryegrass continues to be a problem in wheat each year due to resistance to more herbicides, timing of applications, and weather conditions. Last year, we looked at several herbicides applied delayed-PRE that were promising for ryegrass control but this year we looked at some additional timings to see if they would control the ryegrass as well as or better than the previous year and timings. We looked at the following herbicides: Anthem Flex, Valor, and Zidua in combinations with metribuzin. After 154 days after treatment, the Zidua plus metribuzin continued to provide over 92% control of ryegrass whereas the Zidua alone provided 70% and Valor at 3 oz alone gave less than 40%.  Anthem Flex plus metribuzin provided over 95% control of ryegrass at 84 days after treatment in another location which was better than any other treatment. Metribuzin is currently not labeled for wheat in Alabama but I am currently working with companies to get a label for it prior to the 2018 spring season. If we are able to do so, it will give us some extremely good opportunities for ryegrass control.

Joyce Ducar, Extension Specialist


During the period 9/6 – 9/12 moth trap catch numbers for cotton bollworm were lower in comparison to the previous week with the highest catch reported in Baldwin county (59 moths). The tobacco budworm moth trap catch was also low.with the highest catch in Autauga county. (31 moths). The soybean looper moth trap catch was significant at 4 of the 5 trapping sites with the highest number recorded in Limestone county (475 moths).

Inspecting soybean fields in extreme western Alabama on September 12 and 13 revealed that the red banded stink bug (=RBSB) has become well established in the region from Baldwin county to Pickens county. Soybeans were sampled in Baldwin, Marengo, Dallas Perry, Sumter, Pickens and Tuscaloosa counties and RBSB's were easily found in all these counties except Tuscaloosa. Fields sampled in Tuscaloosa had been treated with bifenthrin 10 days earlier and this significantly reduced stink bug numbers. The greatest density of  RBSB's was found in unsprayed test plots at the Fairhope Research Station in Baldwin county. The average density per  3 row foot of adults plus immatures  in test plots in which a total of 50 three-row-feet drop cloth samples were taken was 1.4 RBSB's (26% adults), 0.69  southern green stink bugs (15% adults), and 0.4 brown stink bugs (20% adults). Inspection of soybean pods in these 6 counties showed low levels of stink bug- damaged beans within pods in the upper portion of the canopy. All these soybean fields that were surveyed for stink bugs were in the R6 to R7stage.  The southern green stink bug was the most abundant stink bug  in the other counties and it comprised at least 90% of all stink bugs present in these 5 counties. No brown marmorated stink bugs were found in any of the surveyed fields.  If winter temperatures do not significantly reduce numbers of these stink bugs ,which could potentially overwinter, then growers could see worrisome numbers of stink bugs, including RBSB's in next year's crops. Foliage-feeding caterpillars were also abundant in some of the fields. The soybean looper  was the most common worm observed in all counties except Sumter where velvetbean caterpillars were very abundant (greater than 3/sweep) in R2 stage soybeans.

Some 6- to 10-day-old escaped bollworms were found  in top cotton bolls in one DPL variety in Monroe County on 9/12 providing more evidence that we are seeing reduced effectiveness in the ability of dual-gene cotton to prevent bollworm damage in cotton. During the last 3 years there appears to have been  a gradual loss in efficacy of dual-gene cotton in preventing boll damage by bollworms..Sampling of cotton test plots at the Wiregrass Research station and field reports indicated that the wind and rain from Hurricane Irma reduced the number of silverleaf white fly (SLWF) adults by 90% and washed away much of the honey dew on the leaves. Immatures are still present and could still impact lint quality but the level to which this will occur appears to have been reduced. This may be the only positive effect from Irma which has reduced lint weight and grade index plus has made cotton harder to defoliate and harvest.

For referring to the data table, please click here.

Tim Reed, Extension Entomologist

Ron Smith, Extension Entomologist

Alana Jacobson, Research Entomologist


Sandy Place Crop.jpg

Many cotton fields in North Alabama have very few open bolls and are maturing later this year.  Several have asked where we are for heat accumulation for this year compared to last.  After running the numbers for May through August, it's no surprise that we are 285 DD60s off this year compared to last.  Last year was somewhat of an anomaly with respect to conditions and harvest.  What was surprising is that we are only 86 DD60s off in 2017 from the five year average (2012-2016) for May-August.  A couple of potential reasons for lack of maturity up to that point are:
  1.  Lack of sunlight intensity.  We've had quite a bit of wet weather and cloudy days this year.  Clear sunny days are very important with respect to cotton maturity and something that DD60s do not take into account.
  2. Larger/Taller plants.  With all of the rainfall this year plants have typically been taller with more nodes and will take longer to mature out.

With all of that being said, the above numbers are for May-August.  The first half of this month hasn't done us any favors.  Through the first 14 days of September, we are now 471 DD60s behind for this year compared to 2016 and 233 DD60s off from the five year average (2012-2016) (graphs below). It's not all doom and gloom though.  The 10 day forecast is projected to be mostly sunny with highs in the mid-80s to low 90s.  This should be excellent for cotton maturation and should go a long way in doing so. If the forecast holds true, I would expect things to look very and different in the next two weeks.

 Note: All readings taken from the TN Valley Research & Ext. Center in Belle Mina, AL. 

DD60 Accumulation 16  17.jpg

DD60 Accumulation 5 Year.jpg

Tyler Sandlin, Extension Agronomist 


Since mid-July, I have received several grower inquiries regarding mid-late season weed control in peanut.  Most of them were related to large morningglory, sicklepod, coffeeweed, pigweed, FL pusley, etc.  Growers wanted to know what options they can spray to control those weeds when their peanut is around 90 days old.  I hate to tell them use a bushhog to mow weeds down, but at this point, herbicide options are limited due to pre-harvest interval (PHI) restrictions on herbicide labels.  For example, a PHI of 90 days means that growers cannot apply this herbicide within 90 days before harvest. 

Late season morningglory infestation in Headland, AL peanut fieldIt is understandable that growers may have a few patches of weeds in mid-late season that they want to clean up.  However, if someone is in deep trouble with weeds when his peanut is at 90 days after planting, I believe that he did not use proper postemergence treatments early on in his crop.  Lack of residual herbicides in early postemergence treatments is a major cause for this problem.  Chloroacetamide herbicides such as Dual Magnum, Zidua, Outlook and Warrant applied at full label rate can usually provide 20-30 days of residual weed control and they are critical components to a successful season-long weed control program in peanut.

As a conclusion, for those who struggle with mid-late season weed problems in peanut:

 

  1. Check your postemergence treatments and include chloroacetamide residual herbicides with postemergence herbicides if you have not.
  2. Apply postemergence herbicides with short PHI and make sure you follow label restrictions.
  3. A weed wiper or roller will allow growers to wipe high rates of Gramoxone and other non-selective herbicides on weeds, however, it is a very slow process and may not work on large acreage.
  4. Bring your bushhog to the field. No weeds have developed resistance to a steel blade yet. If you cannot fully control them with herbicides, then at least do not let them set seeds and build up future problems for you.  

Steve Li

Extension Weed Scientist, Assistant Professor

 


 SEPTEMBER 1, 2017

During the period August 22-28 the cotton bollworm (CBW) trap catch numbers were steady to higher in comparison to the previous week at 3 of the 6 trapping sites with the highest number captured in Baldwin county.(See Table on page 2) The tobacco budworm (TBW) moth trap catch was significantly lower at 3 of the 4 trapping sites with Henry county having the highest number of TBW moths. Soybean looper (SBL) moth trap catch numbers were down by 24% to 49% at 3 sites but increased significantly in Elmore and Limestone counties.

Soybean Looper from BugWood

There are still scattered fields of late-planted cotton that are at risk to losses caused by CBW, but most of the cotton is now at cut-out and is no longer being checked for insects.  We have had one report this week of pod worms (=CBW) exceeding the economic threshold in double-cropped soybeans in Colbert county. Last year we had a few scattered soybean fields in Lawrence county with pod worms that required treatment during the first week of August.  Populations of pod worms that exceed the economic threshold in soybeans tend to be very spotty. Soybean loopers are the main insect of concern this week for double-cropped soybeans in parts of North Alabama. The need to get the corn crop harvested and rains since August 30 have hindered  looper applications. The velvetbean caterpillar (VBC) is now the predominant caterpillar pest of soybeans in central and south Alabama. The density of extremely small VBC larvae ranged from 50 to 70 per 3 row feet on untreated soybeans in test plots at the Fairhope research station in  Baldwin county on 8/29.  Up until this week a mixed population of  SBL's and VBC 's have consumed 40% of the foliage in non-sprayed plots but now the looper numbers have declined significantly  and VBC's are increasing.  If these small VBC larvae survive the result could be complete defoliation.  Based on our test plot results last year, if soybeans were sprayed with bifenthrin, Dimilin, Intrepid/Intrepid edge or Prevathon/Besiege on August 15th  the VBC population probably will not cause much defoliation through mid-September.

The stink bug complex on soybeans is a major concern for late-planted soybeans in central and south Alabama. This week at the Prattville station when 8 unsprayed  R7 stage soybean plots were sampled taking 10 sweepnet sweeps per plot (swept low and hard across 2 rows) the mean number of stink bugs collected per sweep was 1.65. The population consisted of brown marmorated stink bugs (70%, mostly immatures), red banded stink bugs (16.7% mostly adults) and southern green stink bugs (13.6% mostly immatures). Near this soybean test cotton bolls in unsprayed plots on the edge of the station and bordering a road had 93% punctured bolls. The brown marmorated stink bug was commonly observed in these cotton plots. The red banded stink bug is spreading across central and south Alabama. This pest has been reported this year in Pickens, Greene, Monroe, Escambia, Baldwin and Henry counties.  It may be present in most counties from Tuscaloosa to the coast. Another mild winter could set the stage for serious problems with red banded stink bugs in 2018.  The silverleaf whitefly is the major concern for cotton growers in the southeast portion of the state. One practice that has been shown to improve whitefly control is to add an oil or soap product to the insecticide and use higher volumes of water per acre to improve coverage.

Tim Reed, Extension Specialist, Entomology & Plant Pathology

Ron Smith, Visiting Professor (retired), ACES

Alana Jacobson, Assistant Professor,Entomology and Plant Pathology

Barry Freeman, ACES


This report is based on continuous insect monitoring information (May to August) using sticky wing pheromone traps. In this article we have also compared insect counts from 2016 (a drought year) and 2017 (a wet year) to provide some interesting trends to readers.

VBC in peanuts2.JPG
Current pest activity in peanuts:  In recent weeks, caterpillar populations in peanuts have shown a dramatic shift among different pest species. In early August, we reported unusually high cabbage looper and soybean looper activity along with armyworms in the majority of fields scouted (blog post on Aug 11, 2017). However, this week we observed a dramatic increase in the number of velvetbean caterpillar (VBC, in picture) moths flying inside the peanut foliage. VBC is a highly migratory pest that builds up suddenly and rapidly in peanut fields. In the large research plots at Headland, VBC moth numbers have suddenly reached 1 to 2 moths per foot of row (average); at this population level, moths were flying with every step taken in the peanut plots. This high moth activity will eventually result in an outbreak of VBC caterpillars that will graze the peanut foliage in coming days. Together with loopers and armyworms, we expect VBC to raise the caterpillar numbers to over 4 per foot of row that may trigger some insecticide applications. Therefore, we recommend commercial peanut producers to immediately scout their peanut fields and note the caterpillar numbers/species diversity before initiating insecticide treatments. Insecticide efficacy depends on the pest species, so pest identification is critical. Please refer to the earlier blog post regarding caterpillar treatment recommendations and use a combination of chemicals to prevent spider mite outbreaks.

 

comparison chart 9-2-17.jpg
Comparison of 2016 and 2017 production years:  In the table alongside we have compared pheromone trap catches across the two years. It is clear that many moth species like the dry weather; the difference in armyworm, looper, and lesser cornstalk borer numbers show the strongest trends. Data comparison also indicates that in a wet year like 2017, peak insect activity can shift 2 to 3 weeks into the growing season due to a variety of factors. Pheromone trap catches clearly showed a drop in armyworm counts in June and July during the periods of excessive rainfall. Fluctuating temperatures and high natural enemy numbers could be some of the factors that delayed moth/caterpillar activity this year. The good thing is that peanut plants grow fast and compensate for insect feeding in wet years, although early onset of diseases can be devastating to the crop. The whole point is that every production year is different and IPM plans have to suit the weather fluctuations. 



For more help with IPM plan for peanut insect pests, please call an agronomic crops regional extension agent, the authors, or go online for downloading the 2017 Peanut IPM Guide. The Alabama Peanut IPM program also has a mobile-friendly website and a dedicated social media channel on Facebook for sending pest alerts rapidly.


Ayanava Majumdar, Extension Entomologist 

Kris Balkcom, Extension Agronomist


Cotton bollworm moth numbers increased significantly during the second week of August at the Limestone and Elmore county sites. Tobacco budworm moth numbers nearly doubled at the Henry county site, but held fairly steady at the Elmore, Autauga and Limestone county sites. There was a noticeable increase in soybean looper moths trapped during the second week of August at the Autauga and Elmore county sites while numbers remained significant at the Escambia and Limestone county sites. Infestation levels of cotton bollworms in Bollgard 2 and regular Widestrike varieties triggered treatments this week in some cotton fields in the Huntsville area. There have been few reports of  bollworms reaching treatable infestation levels in the rest of the state this week. Clouded plant bugs were reported to be the predominant plant bug pest in some Blackbelt cotton fields. Tarnished plant bugs , stink bugs and leaf-footed bugs were the most common pests of cotton fields in Mobile county.  Bollworms (=pod worms) have been reported to be present in soybeans but the numbers we have heard about this week are relatively low. Soybean looper (SBL) numbers are increasing in some areas of the state.  Loopers numbered 6 per row foot with 5%  defoliation in soybeans planted the last week of July at the Gulf Coast station at Fairhope on 8/15 with 60% of the loopers still small. Ground cloth samples yielded just above 4 SBL's per row foot in an insecticide trial at Brewton on 8/15 and today (8/18) the defoliation level has reached 15% in untreated plots. Similar looper numbers and defoliation levels were observed at the Headland station today. SBL numbers are also increasing at the Prattville Ag Research unit and defoliation is starting to increase toward 5% in some later-planted soybeans.  A report from the Blackbelt region stated that there were mixed populations of caterpillars in soybeans in the Dallas/Marengo county area that included SBL, green cloverworms and velvetbean caterpillars. Fungal disease has significantly reduced the kudzu bug population at Brewton and Prattville.

The silverleaf white fly continues to move westward in the Wiregrass region infesting both cotton and soybeans. Later-planted cotton is especially at risk and the chemicals recommended to control this pest are in very short supply. Cotton that is cutting out now may not be damaged if no immatures are present. A Timely Information newsletter with detailed information about this pest will be provided next week.

Click here for a table showing moth trap catches. 

Timothy Reed

Extension Specialist, Agronomic Crops


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