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Bermudagrass Stem Maggot Control Options

Chemical Control

Many of us county agents are working with Dr. Lisa Baxter who is helping look for new products with BSM efficacy. Still today the use of a pyrethroid labeled for forage use around 10 days after the previous cutting appears to be the best strategy for control. Sometimes a second application 10 days later will be beneficial, especially if the forage is growing slowly. UGA Extension Forage Scientist Dr. Dennis Hancock adds that some formulations add residual control for fall armyworm, but residual insecticides (chlorantraniliprole, dimilin, spinosad, etc.) have proven ineffective at preventing the BSM. They are great for FAW, though. So, consider formulations or tank mixes with them when we start seeing more FAM show up.

Physical Control

With some who missed the first cutting and damage is showing up (6 to 8 inches tall), the best option is to cut or graze the field now and encourage regrowth. It’s better to cut early and accept the loss than have low-yielding, damage crop harboring fly populations. This also prevents shading of any regrowth. The maggot does not remain in cut stems. It exits the stem to the soil and adult flies escape to field margins and other fields. A prompt treatment gives best reduction in damage.

Varieties with smaller stems and leaves seem to be more susceptible to damage. Below is a table from the updated publication Managing Bermudagrass Stem Maggot.

Update on Stored Grain Protectants

News Release (7/16/2018)

For Immediate Dissemination

Contact: Dr. Michael Toews, UGA Extension Specialist on Grain Storage (mtoews@uga.edu)

Update on Stored Grain Protectants:

Empty Bin Treatments

Centynal EC. This is a good product for treating empty bins and elevator boots.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Defense SC (labeled for empty bin use only).  This is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Suspend SC. This is a good product for treating empty bins and elevator boots.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Tempo SC (labeled for empty bin use only). Tempo is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain.

 

Direct Application to Shelled Corn and Grain Sorghum

 

Actellic 5E. This product has long been the standard for use on corn and grain sorghum. A full rate will provide protection from weevils for 9-12 months.  Reducing the rate will decrease the longevity of the protection.  UGA data suggest that Actellic is susceptible to heat degradation in the drier when grain temperatures exceed 120 F.

Centynal EC.  Centynal EC is a new formulation that will provide 3 to 6 months of protection from weevils.  This material is heat stable in the drier (tested up to 150 F).

Diacon IGR.  Diacon IGR is an insect growth regulator that is effective for killing nearly all immature grain moths and beetles, except weevils.  The 4 oz per 1000 bu rate is sufficient for tank mixing.

Diacon IGR PLUS. This product is a premix of Centynal EC and Diacon IGR.

Malathion. Although widely used in the past, this product is no longer recommended due to well documented resistance in many stored grain insect populations. Expect malathion to break down in the drier.

Sensat. This product is new to the market, but has been in our evaluation program for several years.  Test results show excellent weevil control for up to 12 months.  No dryer stability data at this time.

Storcide II. Storcide II is labeled for use on wheat and grain sorghum, but not corn.  Protection will degrade with heat and time.

Suspend SC.  This product is an older formulation that must be completely suspended before measuring and requires frequent agitation.  It provides 3 to 6 months of protection from weevils.

Three-way tankmix (only tested on corn).  UGA tests from 2014-2018 showed that a three- way tank mix of Centynal (8.5 oz) plus Diacon IGR (4 oz) plus PBO-8 Synergist (13.5 oz) per

1000 bu will provide 6-9 months of protection from weevils.  This is a moderately priced option for growers in markets where other products are unavailable or cost is a limiting factor.

Regardless of the product used, be mindful that grain protectants are not a silver bullet.  Shelled corn should be dried to a maximum of 15.5% moisture content before dropping into the storage bin and must be immediately aerated to further reduce moisture content. Chemical applications should only be made to clean grain that will be stored for more than 3 months.  Apply protectants at the bottom of the auger in a course spray to maximize coverage as the kernels are moving up

to the top of the bin.  Long-term grain storage requires moisture content below 14%, proper housekeeping, use of a spreader when filling bins, and managed aeration.

 

Additional information is available in the 2018 Georgia Pest Management Handbook or in a recent Extension Publication (http://www.aces.edu/pubs/docs/I/IPM-0330/IPM-0330.pdf) that was published with colleagues at Auburn University.

Kissing bugs in Georgia

Kissing bugs in Georgia not cause for

Chagas’ disease worry

By Nancy Hinkle, UGA Professor of Entomologist, Jule-Lynne Macie,

UGA ANR Program Development Coordinator, & Heather N. Kolich, UGA Cooperative Extension Agent

November 25, 2015

 

Between media coverage of Texas kissing bugs transmitting

Chagas’ disease to people and a recent news article reporting that a “deadly” kissing bug was found in Georgia, people are worried. Fortunately, here in the Southeast, these insects are not a public health concern.

Kissing bugs are not a public health concern in Georgia.

 

Kissing bugs are in the insect family Reduviidae, which includes several different species, such as beneficial assassin bugs and large, menacing looking wheel bugs (Arilus cristatus). While these insects can deliver a painful bite if handled, they’re not the Genus of insect that carries the Trypanosoma cruzi parasite that causes Chagas’ disease.

Wheel bugs (above) are often mistaken for kissing bugs.

Although kissing bugs have been present in the Southeast for many decades, the Centers for Disease Control and Prevention, located in Atlanta, has never recorded a case of Chagas’ disease caused by the parasite

some of the insects may carry. Blood-feeders, kissing bugs in Georgia tend to live in the nests and burrows of their animal hosts, typically raccoons, opossums, skunks and armadillos. Furthermore, the parasite doesn’t pass from insect to mammal through a bite. Instead, if the trypanosome

parasite is present, it is shed through the feces of infected

 

insects. Humans can become infected by ingesting or inhaling the feces, or by getting it into their eyes or into a cut or break in the skin.

Kissing bugs will bite humans, especially if they are handled; however, in Georgia, we have certain advantages over areas of Central and South America where Chagas’ disease is endemic. First, our homes tend to be well-sealed, which limits opportunities for the nocturnal insects to visit us as we sleep. Second, the kissing bugs present in Georgia behave differently than those in other regions of the world. In Central and South America, kissing bugs tend to defecate immediately after feeding, leaving potentially parasite-infected feces next to the feeding wound, where it may be scratched into the

broken skin. In Georgia, kissing bugs usually move away from the host before defecating. Since the

parasite is transmitted through the insect’s feces, not through the bite, the victim is much less likely to be exposed to it.

Homeowners with concerns about kissing bugs can take measures to keep insects from entering the house. Repair damaged window screens, replace weather-stripping around doors and windows, and install door sweeps to seal small openings. These measures will also keep out cold air, making the home warmer and more energy efficient this winter.

 

 

Peanut Tank-Mix

Peanut Tank-Mix Thoughts (Prostko)

Rain delays and/or late planting have resulted in continual inquiries about peanut herbicide + fungicide tank-mixes and their potential effects on weed control and crop injury. UGA will never be able to adequately address all concerns with 90,000+ potential tank-mixtures in peanuts. Here is a quick review of some of the published data:

1) When 2,4-DB is tank-mixed with a postemergence graminicide, grass control can be reduced by 8% to 15% approximately 45% of the time.

2) When averaged across 5 grass species, Cadre (imazapic) + Select (clethodim) tank-mixtures provided 19% less effective grass control than Select alone.

3)  Abound (azoxystrobin), Absolute (tebuconazole + trifloxystrobin), Bravo (chlorothalonil) and Headline (pyraclostrobin) are 4 fungicides that have caused significant grass antagonism when tank-mixed with Select (~12% to 30% reductions in grass control).

4) Grass efficacy with Poast (sethoxydim) and Select has not been consistently reduced by tebuconazole (various trade names including Folicur, Orius, TriSum, Integral, Ebustar, Muscle, Tebuzol).  However, when reductions have been significant, grass control was reduced by 4% to 13% with tebuconazole mixes.

5) Palmer amaranth (PA) control was not reduced when 2,4-DB was tank-mixed with Bravo, Provost (prothioconazole + tebuconazole), Headline, or Absolute.  But, 2,4-DB is not that great on PA anyway though?

6)  Sicklepod control with 2,4-DB was reduced by 14% when applied with Abound but not with Bravo or tebuconazole

Is your stocking rate correct?

By Steve Morgan

Harris County CEC

There are many important components in a successful livestock production system. One of the most important tasks in grazing management is understanding livestock stocking rate. It is critical in making timely management decisions that affect profits in beef cattle production. The optimum number of animals on a pasture makes efficient use of the forage and still leaves enough forage behind to allow a quick and complete recovery. Therefore, producers must understand how to determine the correct stocking rate for their pastures.

Stocking rate is defined as the concentration of grazing livestock on a given amount of land over a season, year or period of time. Generally, stocking rate is expressed as “animal units” for a given amount of land. This is to allow stocking rates to universally cover all livestock types since an animal unit is equivalent to 1000 pounds of body weight regardless of the type of livestock. Though stocking rate depends on the intensity of grazing management, most pastures would be approximately 2 acres per animal unit. This would provide a forage allowance of approximately 2.5% of body weight per day. However, not all livestock have the same forage demand as a 1000 pound lactating cow. For this reason, animal unit equivalents (AUE) have been developed to assist with the approximate determination of forage demand based on the kind, class and size of animal.

   Animal                                            AUE  

Cow – dry                                             1.00 – 1.50

Cow with calf                                  1.20 – 1.60

Bull – mature                                   1.25 – 1.75

Calf – weaned                                   0.50 – 0.70

Steer/Heifer – 18 months                  0.80 – 1.00

Sheep – mature ewe or ram             0.20 – .030

Sheep – yearling                              0.15 – 0.20

Goat                                                 0.17 – 0.20

Horse – mature                                  1.25 – 2.00

The usefulness of animal units is especially apparent considering the weight difference among various producers’ livestock and the fluctuation of average weights in a herd over time. For example, the average cow size varies considerably and has increased over the past 50 years. Today’s beef cow averages around 1300 – 1400 pounds. These cows are not equivalent to one animal unit. In addition, forage demand varies within a livestock species based on its growth rate (e.g. heifers and steers vs. mature cow). For example:

If the estimated stocking rate for a 1,000 pound cow is 2 acres, the estimated stocking rate for the 1,150 pound cow (assuming both cows have the same forage intake rate of 2.5 percent of body weight) is found as follows:

1,150 pounds x 2.5% = 29 pounds forage intake per day ÷ 25 pounds forage per animal unit = 1.16 animal units per cow

Therefore, 1.16 animal units per cow x 2 acres per animal unit =

2.3 acres per 1,150-pound cow

Condition of the pasture impacts stocking rate. Factors such as previous grazing management, forage species, age of stand, soil type, texture, fertility level and moisture conditions all impact forage yield and consequently stocking rate.

Livestock need forage year-round, but providing an adequate supply of forage for grazing 12 months out of the year can be challenging. Ideally, forage production should correspond with livestock needs. However, pasture production is variable during the growing season while livestock nutritional requirements are relatively stable or steadily increasing. One way to balance this equation is to make hay from some pastures during periods of rapid forage growth. In addition, calving before rapid growth will allow the period of highest animal need to match the greatest production of quality forage. A second way is to manage for a more uniform pasture growth. Some Best Management Practices to accomplish uniform growth include:

  • Keeping forage healthy and unstressed. These plants begin growth earlier in the spring, produce higher yields through the grazing season and continue growing longer in the fall.
  • Switching from continuous to rotational grazing can extend the grazing season and boost yields, since rotational grazing, by virtue of its rest periods, is less stressful to the forage.
  • Maintaining a good fertility program will extend the season and boost yields.

Many forage problems can be avoided by fertilizing properly. To determine fertilizer requirements, take regular soil tests and follow the recommendations given. Be sure to state the type of pasture being grown when submitting your sample because fertilizer recommendations will be based on the crop stated. Many producers incorporate grass/legume mixtures to meet more of the fertility needs of the pasture. Seeding legumes into poor quality pastures is the most common form of renovation. Legumes reduce dependence on nitrogen fertilizer, complement grasses by balancing forage production throughout the season, and improve pasture quality.

Switching from continuous to rotational grazing increases forage utilization. Forage utilization is a critical component that helps determine stocking rate. Most pastures contain a great deal of forage that is never consumed and eventually decays. Traditional continuous grazing systems may use only 30 to 40% of the available forage. The rest of the forage is either trampled, soiled, or of little nutritional value because it becomes overly mature. Most of this loss occurs with underutilized fall stockpiles and during periods of rapid growth where there is surplus beyond what is needed for livestock. When the appropriate stocking density is used, shortening grazing periods through rotational grazing increases forage utilization to 60-75%.

Good producers strive to achieve the right balance between forage availability, forage utilization, and animal performance. They stock pastures heavily enough to graze available forage down to a target height that will allow rapid and maximum regrowth without compromising nutritional needs of livestock. Good producers will observe pastures frequently for overgrazing and undergrazing and will periodically adjust the stocking rate or movement of cattle as needed. Overstocking and overgrazing leads to a reduction in palatable plant species and an increase in less desirable plants. Overuse also means that livestock must graze for longer periods to meet their needs. Over time, heavy stocking causes the more palatable and productive forage species to disappear. These desirable forages are replaced by less productive, less palatable plants.

UGA Cotton Team Newsletter July, 2018

Considerations for Cotton PGR Programs (Mark Freeman)

 

Due to the extended rainfall that most of the state saw during the planting window, Georgia’s cotton crop is extremely variable. Within close proximity or adjacent fields we can find blooming cotton next to 1 and 2 leaf cotton. Because of this variability, making any “one size fits all” PGR recommendation is impossible and any PGR decisions must be made on a field by field basis.

 

So what do PGRs do? Contrary to what many may think, mepiquat does not cause the plant to produce more flowers or bolls. What is can do is limit the amount of vegetative growth which may enhance fruit retention in lower nodes. This early node fruit retention will help with “earliness” or a quicker maturation of the crop, which tends to benefit later planted cotton more so than early planted cotton. Excessive vegetative growth can also decrease harvest efficiency, decrease coverage of insecticides and fungicides below the canopy, decrease below canopy airflow (which may increase risk of foliar diseases and boll rot), and excessive shading of the lower canopy which can impact the fiber quality of bolls of the lower portion of the plant.

 

When making decisions on a PGR management program careful consideration should be made on several key factors. The first and most important factor is current crop condition. Is the crop growing rapidly or is the crop stressed in any way (usually drought stress)? One way to determine the crop’s growing condition and growth potential is to look at the top five nodes and internodes of the plant. This is the region of the plant were current growth is happening, and any application of mepiquat will have an effect on. If internode lengths between the 4th and 5th nodes from the terminal are longer than 3” then this is a sign that the plant is growing vigorously and a mepiquat application is likely required.

 

Other factors that should be considered are current soil moisture and future rainfall predictions (mepiquat should not be applied to cotton under any drought stress), a particular field’s history for producing cotton with rank growth, fertility program and available nutrients in the field, and cotton variety. As we know, not all cotton varieties are the same. Some varieties may exhibit strong vegetative growth potential where as others may not need aggressive PGR programs. UGA Extension Agronomists work each year to classify new varieties based on their growth potential and how they respond to PGRs. This classification chart can be used as a guide for growers who may not have experience with a particular variety and how to manage it correctly. The 2018 version of this chart can be found on the ugacotton.com webpage here: http://www.ugacotton.com/2018/01/relative-plant-growth-regulator-requirements-for-cotton-varieties-updated-for-2018/

Rate and Timings:

The rate of mepiquat needed is directly related to plant size and rate of growth. If pre-bloom applications are needed (usually only with an aggressive variety and under optimal conditions for vegetative growth) rates should most likely be between 4-8oz/ac. Early-bloom application rates may range from as low as 8 oz/ac up to 24 oz/ac if rapid plant growth is occurring and internode lengths are exceeding 3”.  One often over looked aspect of the PGR program is the timing of the sequential application following the early-bloom application. It is important to continue to monitor the growth of the plant after application and initiate the follow-up application around 14 days after early-bloom.

 

Remember that there is no “one size fits all” program and that these recommendations should only be used as a guideline. Every field has a unique variable and growers must look at the “whole program” and all of the “other factors” to determine what PGR program is best for their crop.

 

 

Fertility (Glen Harris)

 

Sidedressing N (and K?) and  Boron

 

What is the best source of nitrogen to sidedress cotton with? And are liquids better than solids?  I get these questions all the time and there is not a real clear answer.  It reminds me of cotton varieties, i.e. we have a lot of good ones but overall some may be better than others. Also, what works the best in one area or operation may not work the best in another.  If you are using solid or granular N sidedress fertilizer your choice is basically between ammonium nitrate or urea. Neither of these contain sulfur so ammonium sulfate is often blended with them.  Ammonium nitrate is less concentrated and usually more expensive. However, in research trial it out yielded urea and was the more consistent performer. Ammonium nitrate also has more burn potential than urea.  Urea plus ammonium sulfate blends don’t always spread evenly and can “streak up” a cotton field.  A relatively new fertilizer material, called Amidas (by Yara) is urea and ammonium sulfate homogenized and spreads very evenly. It is a 40-0-0-5.5(S) and is a little more expensive than the blend but performs very well.

 

I have heard that some folks think that solids are not as good as liquids because they have to dissolve first. I don’t think this is true. However, there are some advantages to liquids over solids, namely that you can dribble them by the row and reduce the burn potential compared to spreading a solid over the top.  One of the disadvantages of liquids is that you cannot cover as many acres as quickly as you can with solids.  The two most common liquids are 28-0-0-5(S) and 18-0-0-3(S).  Both outperformed their counterparts with no sulfur (32% and 19 %) in recent field trials.

 

Cotton Yield (lb lint/a)            4 “Site Year” Average (2013-2014)

 

What about sidedressing with Potassium? If the full amount of potassium as recommended by soil testing is applied preplant or even soon after planting, then sidedressing K with N should not be necessary.  With the heavy rains in late May and on deep sandy soils you may consider replacing some K that may have leached.  Even then, it is difficult to sidedress with liquid forms of K in order to get enough. There are some liquid K formulations being recommended to add to liquid N sidedress but you are only getting very low amounts of K, in the neighborhood of 3 lb K2O per acre.  Instead, on fields where you may have lost some K due to leaching I would recommend waiting until the cotton starts blooming and foliar feeding K with something like potassium nitrate.

 

Boron – Our official UGA recommendation is to apply 0.5 lb B/a as foliar between first square and first bloom (the same window for sidedressing N). There are a number of products that recommend a lot less boron than this. For example, 6 oz/a of a 5 % B material only gives you 0.025 lb B/a.  This would be fine if it was 10 or 20 times better than other products. But it is not. In recent field trials it’s effectiveness is very close to the untreated check.  There are also many things added to boron fertilizers with claims they make the B get in the plant faster.  Actually this may be true in some cases. However, boron by itself gets into the plant very well on its own, thank you.

Economics (Serinna Liu)

 

Generic Base/Seed Cotton Program Timeline

By Yangxuan Liu, Don Shurley and Adam N. Rabinowitz

 

The Bipartisan Budget Act of 2018 authorized Seed Cotton as a covered commodity under Title 1 of the 2014 farm bill and created eligibility for ARC/PLC effective with the 2018 crop year. The legislation provides owners of a farm with generic base a one-time opportunity to convert the generic base to seed cotton base (option 1-A or 1-B) or base of seed cotton and other covered commodities (option 2) based on the 2009-2012 planting history[1].  Landowners also have a one-time opportunity to update the payment yield used for seed cotton PLC.  Producers on the farm must also select the ARC or PLC program for seed cotton.  A lack of action to select the conversion option for the generic base by the appropriate deadline will result in default selections of option 1-A or 1-B, depending on which one results in a higher seed cotton base. Additionally, PLC is the default selection if no decision is made to select ARC/PLC. On April 18, USDA-FSA released Notice ARCPLC-50.  This Notice provided the approximate timeline for the generic base allocation (conversion), yield updates, and ARC or PLC program election and enrollment.  The table below summarizes the timeline.

 

May 2018 All owners and operators receive their Notification of Covered Commodity Acreage History letter that includes all farms in all counties. Owners and operators are provided an opportunity to correct acreage history for years 2008 through 2016.
Late Summer 2018 Owners make final base allocation and yield update decision for the farm.
Late Summer 2018 Official 2018 Notice of Base Acre, Yield, and Election report mailed to all owners and operators on the farm, with appeal rights.
Fall 2018 All owners and operators on the farm make

PLC, ARC-CO, or ARC-IC program election for the farm.

Ends September 2018 Annual enrollment into PLC, ARC-CO, or ARC-IC program for seed cotton base acre farms.

 

 

 

 

 

China’s Potential Cotton Tariffs and U.S. Cotton Exports

By Yangxuan Liu, John R. C. Robinson, and Don Shurley

 

On April 4th, 2018, China announced a potential 25 percent increase on import tariffs on major U.S. origin agricultural commodities in retaliation to a series of tariffs proposed by the United States. United States upland cotton is one of the commodities affected by this proposed increase in import tariffs. The export market is an important source of demand for the U.S. cotton industry. The United States is the largest cotton exporting country with around 71.3% of cotton produced in the U.S. exported last year. China is the second largest trading partner with the U.S. for cotton in 2017 and buys 16.7% of the U.S. cotton exports. The total value of cotton exported to China was worth approximately $976 million last year, which is the second highest value among all the other row crops after soybean.

 

If Chinese tariffs are imposed on U.S. cotton, global cotton suppliers like India, Australia, and Brazil may experience a near-term opportunity to supply more cotton to China. In the short run, the market disruption could be a shock to the U.S. cotton futures market, particularly if hedge fund speculators sell off their long positions. However, the longer-term situation could see more U.S. exports rerouted to other cotton importing countries. This recent history of the change in China’s internal cotton policy suggests a similar reshuffling effect from a bilateral Chinese tariff on imported U.S. cotton. Chinese raw cotton import tariffs would continue to stimulate imports of duty-free yarn from Vietnam, Indonesia, and the Indian subcontinent.

 

Diseases (Bob Kemerait)

 

There was a time not too long ago when the most important disease we expected to find in Georgia’s cotton fields was “soreshin” or Rhizoctonia seedling blight.  That disease is still important and we had a significant amount of it this year with the very wet conditions at planting.  However, there are a number of other important diseases that cotton growers must deal with and NOW is the time that there diseases will become apparent.  Weather conditions remain perfect for development and spread of disease; excessive wet weather in some areas, and our cotton crop is developing to a point where the foliage of the inner canopy is remaining wetter longer with high humidity, rainfall and irrigation.  Also, as the crop begins to flower and as bolls develop, we are likely to find spread of diseases as well.  Below are four of the most important diseases cotton growers in the state should be prepared for now.  Unfortunately, there is little-to-nothing that can be done for three of the four.  But recognizing damage and loss this season can help growers to make improved management decisions (variety selection, crop rotation, use of in-furrow nematicides, etc.) next season.

 

Disease watch:  STEMPHYLIUM LEAF SPOT on cotton is associated with a potassium deficiency in the cotton crop and CANNOT be controlled with a fungicide.  I expect to see more Stemphylium leaf spot this year (characterized by red-yellow foliage and numerous spots with papery/gray centers with premature defoliation) because of leaching of fertilizer with heavy rains.  My experience is that once symptoms begin to appear in the field, there is no opportunity for correcting the problem by foliar-feeding potassium, but this is a question better answered by Dr. Glen Harris.  Stemphylium leaf spot typically occurs in the same fields and sandier fields on a regular basis.

 

Disease watch:  TARGET SPOT in cotton is expected because the season is shaping up to be perfect conditions with extended periods of high humidity with wet foliage and good growing conditions.  Growers should begin scouting their cotton prior to first bloom and to consider fungicide applications as early as sometime between 1st and 3rd weeks of bloom if disease is detected or has been a chronic problem in the past.  The disease is difficult to control because coverage is problematic in the interior of the canopy where the disease is first found.  However, fungicide applications early in the development of the disease are critical if there is any hope to slow its progress where occurs.  Not every cotton grower needs to treat for target spot; however every grower should be aware of the opportunity to protect their crop.  The earlier target spot occurs in a cotton crop, the more likely significant yield loss will occur.

 

Disease watch:  Bacterial blight appeared early in 2018 and continues to be an issue; however reports are slowing of new finds.  I expect with recent rains we will see a resurgence of this disease in the field.  There is nothing to be done now to control it, but if bacterial blight is an issue in your cotton fields then you should consider other varieties in the future.

 

Disease watch:  Fusarium wilt of cotton is affecting younger and younger plants and seems to be spreading in the state, or at least our growers are becoming more aware of it.  Fusarium wilt is characterized by smaller stunted plants showing foliage with clear striping and interveinal chlorosis.  The vascular tissue of the plants is stained brown or dark.  This disease is a “one-two” punch brought on by the Fusarium fungus and parasitic nematodes.  Once the seed is planted, there is nothing to be done’ however recognizing the disease this season can help tp make aggressive, effective management decisions for next year.

As a final comment, “vigilance” and “timeliness” are critical components for disease and nematode management in our cotton fields.  Be observant and prepared to make aggressive decisions, either now or in the next season.

 

Important Dates:

Field Days:

Watkinsville – Cotton Field Day – J Phil Campbell Research and Education Center – July 19th

Midville – Southeast Research and Education Center – August 15th

Tifton – Cotton and Peanut Field Day – September 5th

Scout Schools:

Northwest Georgia Crop Scout School – Cartersville, Ga – July 25th – Contact Paul Pugliese for more information: 770-387-5142

 

For more information on any of the discussed topics please contact your local UGA Extension Agent.

[1] For more information about the conversion options for generic base, please refer to the factsheet Ag Policy Update within the Bipartisan Budget Act of 2018, available on UGA Georgia Agricultural Policy webpage.

Replacing Fertilizer in Cotton

  1. The most common question after these large rain events is have I lost all of my cotton fertilizer, and will I have to start over? UGA Extension Soil Scientist Dr. Glen Harris has provided some information on this topic:

May planted cotton could have lost some pre-plant Nitrogen and Sulfur. What should we do? Consider early sidedress AND add 10 to 20 pounds of Nitrogen per acre if rain fall was enough to leach fertilizer. Also, add sulfur to sidedress nitrogen.

Every field will have a different soil type. A lot of fields have long rows with many different soil types in the same row.

Listed below are some general time tested truths about leachable soil fertilizer nutrients:

  • Most leachable nutrients are Nitrogen, Sulfur and Boron.
  • Potassium is not as mobile as Nitrogen.
  • Phosphorus is immobile.

2. What is the official timing window for sidedressing cotton ? First Square to First Bloom. We want ¼ to 1/3 N at planting and remainder at Side-dress.

Foliar Feeding

Follow recommendations from Petiole analysis:

Emphasis = Nitrogen, Potassium and Boron – During “Peak Bloom” (1st to 4TH  week of Bloom)

What is best foliar products to use:

  • Feed Grade Urea for nitrogen,
  • Potassium Nitrate for Potassium,
  • Solubor or “10% Liquid” for Boron.

Stop Petiole Analysis after 8th week of bloom!

Is Cottonseed Going To Make My Bulls Infertile?

Lawton Stewart, Extension Animal Scientist

As we’re getting into summer, many producers with fall calving herds have picked out calves to keep as bulls and considering a developing ration to feed their bulls.  OR, for winter/spring-calving herds, producers are pulling out bulls and considering supplement to put weight back on them.  Sooo, every year, about this time, I get the phone call or email asking if their bulls are going to be sterile because there is whole cottonseed in the ration they are using.  My answer is always, absolutely not IF you stay within the recommended feeding levels.  That brings up three questions to discuss:

  1. What is it about whole cottonseed that causes concern?
  2. Can whole cottonseed cause infertility in bulls?
  3. What is the recommended feeding rate of whole cottonseed?

What is it about whole cottonseed that causes concern?  The answer is gossypol.  Gossypol is a yellow pigment produced in the roots, leaves, stems, and seeds of the cotton plant, with the greatest concentration occurring in the seeds.  This compound acts as a natural defense, aiding in resistance to pests.  Gossypol has been studied for years and has shown to be toxic to monogastric animals (i.e. pigs, mice, humans, etc.) and pre-ruminants (i.e. cows, sheep, goats, etc. who’s rumen has not developed yet).  For reference, monogastrics and pre-ruminants should not consume a diet more than 100 ppm gossypol.  This is why we recommend not feeding whole cottonseed to calves under 400 lb.  In fact, gossypol has been studied extensively as a birth control method for males!  However, the results have been extremely variable.

Can whole cottonseed cause infertility in bulls?  As indicated earlier, no.  The question then becomes, why is it such a hot topic?  Early research in smaller mammals, in combination with cottonseed products growing in popularity in the 1960’s, 70’s and 80’s, led researchers at Texas A&M University to look at the effects of gossypol on developing bulls.  These researchers mostly found no differences in reproductive development of bulls fed diets containing gossypol.  When the researchers did find differences, whole cottonseed was fed at or above 40% of the diet, or from Pima cotton.  Pima cotton contains a different isomer of gossypol compared to Upland cotton.  Most cotton grown in the Southeast is Upland cotton.  The 40% in the diet is an extremely high amount of whole cottonseed and would not be recommended.  However, these results have been interpreted as affecting fertility.

What is the recommended feeding rate of whole cottonseed? From a nutritional standpoint, whole cottonseed is an excellent feedstuff when utilized correctly.  Nutritionally, it is high in energy (95% TDN), protein (24% CP), and fat (approximately 20%).  Although the fat content does contribute to the high level of energy, if the fat content in the ration is too high (over 5%), it will negatively affect fiber digestion in the rumen, decreasing animal performance.  For this reason, we recommend that whole cottonseed be limited to 20% of total intake, or no more than 6 pounds per day.  Notice that this is half of what was fed in the previously mentioned research.

When the price of whole cottonseed allows it to be used, it can be an excellent feedstuff.  If you are having issues with fertility in your bulls, make sure all the other aspects of bull management are in place (e.g. breeding soundness exam, injuries, etc.).  Very rarely, if ever, will whole cottonseed cause infertility in bulls.  As one of my mentors from Virginia Tech, Dr. Terry Swecker, would say, “If you hear hoofbeats, don’t go looking for a zebra… Look for the horse first!”.  If you have any questions on whole cottonseed, or would like help incorporating it into your nutritional program, contact your local Cooperative Extension office

June Cotton Newsletter

Current Crop Condition (Whitaker and Freeman)

According to the June 4th 2018 USDA NASS Crop Progress Report, 72% of the estimated cotton acreage in Georgia has been planted. This is up slightly from lasts weeks 62% estimate and well below the five year average for this date of 84%.

 

Considerations for the Remainder of the Planting Season (Freeman) This spring has been especially challenging for cotton planting in many parts of the state. Dry weather early in the planting window followed by continual rainfall in the second half of May have delayed planting of over one third of the 2018 crop into June. Although yields tend to decreases as we move into June, there is still potential for strong, profitable yields. Listed below are some tips for managing a late planted crop.

  1. Consider increasing seeding rates. In late planting situations we want to shoot for a final plant stand of at least 2 plants/ft, so adjust seeding rates to aim for this desired plant population.
  2. Decrease any stresses. If irrigation is available, irrigate to promote stand establishment, enhance fruit retention, and eliminate stress during periods of dry weather.
  3. PGR’s. Mepiquat products should be applied to prevent excessive vegetative growth, decrease boll rot, and enhance fruit retention of lower position bolls which promotes crop earliness.
  4. Varieties. Varieties should be chosen on overall yield potential not maturity characteristics.
  5. Fertility. Decrease N rates by 25%-30% to limit excessive vegetative growth. This should be done with at-plant N and sidedress N.

 

For additional information regarding management of late planted cotton, please refer to the following article: http://www.ugacotton.com/2018/05/when-it-rains-it-pours-managing-late-planting-dates-in-georgia-during-2018/

 

Cotton weed control (Culpepper)

Weather has certainly challenged the management program. The intense and often overwhelming rainfall in recent weeks has greatly limited our ability to be timely with weed management programs throughout Georgia.  Below are a few discussion points to address common questions/concerns.

  1. Preemergence (PRE) herbicides in 2018 have been priceless providing excellent early-season control. Even after Palmer amaranth eventually emergences through the PRE herbicides, its growth has been slowed providing a more timely first POST application.  For growers who removed the PRE from their system…………..horrible decision.  As we move into June, the PRE herbicide is just as important as ever because weeds emerge and grow more quickly in June and July than in April or May.  As always, apply two active ingredients that are effective on Palmer amaranth and get the rates right for your soil type and production practice thereby avoiding cotton injury.

 

  1. Postemergence (POST) herbicides are currently preforming exceptionally well in controlling emerged weeds; including Roundup and our labeled dicamba and 2,4-D products. It is worth mentioning that the performance of Liberty was hampered in late May because of consistently cloudy weather but since the sun has returned to South Georgia the herbicide is back to performing as expected and occasionally a little better than expected.

 

  1. Pigweed is big in many fields so keep in mind a systems approach including sequential POST applications and a layby containing products like diuron offer the best opportunity for success. CRITICAL to success is the time interval between your two POST applications; intervals vary within a given technology.  Go to gaweed.com to view cotton weed management programs and intervals between POST applications (or call your extension agent)……….if you are off a few days between sequential POST applications it could have dramatic consequences.

 

  1. As mentioned above, herbicides are currently performing exceptionally well. Of course, that is good for weed control but it is not so great for cotton injury.  UGA research has consistently shown most cotton postemergence herbicide mixtures can cause twice as much injury when applied in saturated soil conditions as compared to ideal soil conditions.  Don’t forget that research suggests that it is best to avoid herbicide damage to cotton past the 8-leaf stage if any way possible……yes, use the layby rig!!

 

Cotton Insects (Roberts)

The question has been asked if we should manage insects differently in late planted cotton.  The answer is no, however we cannot afford to make any mistakes as mistakes will be costly.  A late planted crop will have limited time to effectively bloom and set harvestable bolls.  Cotton with a more extended effective bloom period may compensate and recover from some management mistakes (i.e. delays in maturity and/or lost fruiting positions).  Scout closely, use thresholds, and make good decisions with insecticide selection and timeliness of application.  It is likely that we will need to scout and manage June planted cotton until the end of September.  A few specific points to consider for insect pest you will likely encounter:

  1. Thrips are the most consistent and predictable insect pest of cotton. We are all familiar with the stunted growth and crinkled leaves associated with thrips feeding.  Excessive thrips damage will delay maturity up to 7-10 days which is unacceptable on late planted cotton.  Historically thrips infestations are low on June planted cotton.  Cotton planted in June also has rapid seedling growth which allows the plant to better tolerate feeding.  Don’t assume thrips injury will be low in your fields as delays in maturity could have significant impact on yield potential.
  2. Aphids will infest most cotton fields during June each year. Populations vary from year to year and even field to field.  We normally see aphid populations crash in July due to a naturally occurring fungus.  On late planted cotton aphids may infest cotton in the seedling stage.  Stress from aphid feeding on seedlings will slow development (delay maturity) which may limit yield potential of late planted cotton.
  3. Tarnished Plant Bug is a sporadic pest of cotton in Georgia. Plant bugs feed on small squares with needle-like mouthparts; damaged squares will be shed by the plant.  Plant bugs can be sampled with sweep nets or drop cloths.  Square retention should also be monitored.  Our goal is to retain at least 80 percent of first position squares when entering bloom.  Poor square retention will delay maturity and again have significant impact on yield potential of late planted cotton.
  4. Corn Earworm typically first infest cotton in mid-July. Corn earworm completes a generation in about four weeks.  In recent years there has been much discussion about corn earworm and erosion of efficacy with Bt cottons (this is especially true in the Mid-South and North Carolina.  Three gene Bt cottons are commercially available and will provide additional protection compared with two gene Bt cottons.  Bottom line is to scout and use thresholds and be timely with insecticides if needed regardless of technology used.
  5. Stink bug infestations are typically higher in June planted cotton compared with April and early May planted cotton. Scout and use thresholds.  Remember that the threshold is lower during the 3rd-5th week of bloom.

 

Planter Settings (Porter)

Proper planter settings are critical for acceptable stand establishment, this is especially critical during years with adverse conditions.  Very wet or very dry soil has a major impact on crop emergence.  Caution should be exercised when planting into very wet conditions.  From the planter mechanical perspective depth and downforce are most critical.  It is very important that you check that you are not placing the seeds any deeper than 1 inch.  Set this mechanically based on the planter manual and then check it in the field for all row units.  Sometimes you will find slight variability between rows.  Downforce should be reduced in very wet conditions compared to what you normally use.  The poundage should definitely be less than 100 lbs.  Check this in the manual on which slot to select if you have a spring downforce system, or set it utilizing your compressor or monitor if you have a more advanced system.  If you notice that your presswheels are leaving a trench or appear to be compacting the soil reduce the downforce.  This will cause problems with emergence and can cause crusting issues.  Studies performed at UGA have shown reductions of emergence of up to 50% for improper depth and downforce settings when compared to proper settings.  These problems are magnified when soil conditions are too wet.  Lack of stand early in the season or delayed emergence will lead to other issues later in the season, such as weed, pest, and disease problems.  These problems are translated to yield reductions at the end of the year.  Please contact your local UGA County Extension Agent if you have questions about your planter settings.

 

 

 

Fertility (Harris)

Replacing Nutrients Leached by May Rains

It seems like every time we get a lot of rain I hear people say “well, I guess I lost all my fertilizer”.  While nutrient leaching (nutrients dissolved in water moving downward out of the root zone of plants) is a legitimate concern, especially on our sandy Coastal Plain soils of South Georgia, this statement is not exactly true.  First, not all fertilizer nutrients are mobile in soil.  Phosphorous for example is usually considered immobile and most positively charged elements or cations, like calcium and magnesium adsorb to the cation exchange capacity of the soil and do not leach readily. Most micronutrients are held by organic matter and/or pH and do not move. Therefore, nitrogen, sulfur and boron are the most “mobile” in soil. Even then, they have to be in the right form, namely the negatively charged nitrate, sulfate or borate forms.  By the way, this is why most soil testing labs like UGA do not routinely test for nitrogen, sulfur and boron in soils.  They are considered “transient”, i.e. they can be there one day and (after a big rain) not be there the next. Oh, and what about potassium?  Potassium is more mobile than phosphorous but contrary to some current thinking, it is NOT as mobile as nitrogen, sulfur and boron.

So the next question is “how much fertilizer do I need to put back”?  There is no easy answer to this question because it depends on which nutrient, which form of nutrient, how much you put out, what soil type (i.e. how sandy) how much rain you got etc.  But let’s for example take the case of cotton fertilized in South Georgia before the heavy rains in May this year.  Hopefully most growers followed soil test recommendations and put about 30 pounds of nitrogen, 10 pounds of sulfur and the recommended P and K at planting.  The P didn’t move much at all, the K may have moved some but it is likely still where roots will get it eventually. So that leaves N and S.  Even if you lost half of your N and S you would only have to replace 15 pounds of N and 5 pounds of S.  This can easily be done at N sidedressing time between first square and first bloom. Boron can be foliar fed any time before first bloom. Our recommendation is for 0.5 lb B/a and can be tank mixed with herbicide or growth regulator sprays.  Bottom line is look to maybe sidedress on the earlier side, replace about 10-20 lbs N/a and include S with your sidedress N.

 

Fertilizing Late or June Planted Cotton – Reduce N Rates

Due to the heavy late-May rains, a higher percentage of Georgia cotton is going to be planted late, in June, this year.  The tendency is to think “hey its late, I need to rush this cotton so I am going to put higher rates of N out at planting”.  This is actually the opposite of what you should do!  While it is always important to get off to a good start, if you get off to TOO good of a start with extra N at planting, you could interfere with the “vegetative/reproductive” balance and reduce yields.  In other words, you want the plant to shift from vegetative (“growing stalk”)  to reproductive (flowering/fruiting) as quickly as possible (as early as 5 nodes) since there is not as much time to flower and put on fruit before frost.

So how much do I reduce my N rate by and when?  On page 76 of the UGA Cotton Production guide, it is recommended to reduce your total N rate by 25-30% .  It is not stated, but I would recommend taking some off of both preplant and sidedress applications if possible.  So instead of roughly 30 lb N/a at planting and 70 at sidedress for May planted cotton for a total of 100 lb N/a….consider 20 lb N/a at planting and 55 lb N/a sidedress for June planted cotton.  If you put out 30 lb N/a in early May before the rains and don’t plant until June, you still should have about 10-20 lb N/a available so could just plan on an early N sidedress.

 

Important Dates:

Scout Schools:

Tifton – June 11th – Tifton Campus Conference Center – RSVP Debbie Rutland (229) 386-3424

Midville – June 19th – Southeast Research and Education Center – RSVP Peyton Sapp (706) 554-2119

 

Field Days:

Midville – Southeast Research and Education Center – August 15th

 

 

 

For more information on any of the discussed topics please contact your local UGA Extension Agent.

Watermelon Research Field Day

2018 UGA Watermelon Research Field Day in Cordele

 

The demonstration trial evaluates the effects of fumigation and fungicide for management of Fusarium wilt in watermelon.

 

Details for the Field Day:

UGA Field Trial Site at Cordele, GA

Address. 1176 US Highway 280 W; Cordele, Georgia

Date: Thursday June 28th, 2018

Time: 9:30 a.m.