Seminole Crop E News

Agricultural News for Farmers and Agribusiness in SW Georgia

Posts Tagged ‘grain sorghum’

Sugarcane Aphids in Grain Sorghum

Posted by romeethredge on November 5, 2015

Sugarcane aphids have been a real problem in grain sorghum since they came in last year. Thomas county Agent, Andrew Sawyer had a good poster at a meeting this week and I will post it here. He found a beneficial wasp that is working to help us control the aphid and that’s good news.

Click here to go to directly to Andrew’s excellent Blog.

Fullscreen capture 1152015 92853 AM

Posted in Entomology | Tagged: , | 1 Comment »

Grain Sorghum Harvest and Dessication

Posted by romeethredge on October 22, 2015

Dr. Eric Prostko, UGA Extension agronomist says, ” We are getting questions about the dessication of grain sorghum aka milo.    The use of harvest-aids in grain sorghum has shown little effect in reducing grain moisture content.  A summary of 2 older papers is as follows:

1) Hurst, Harold.  1991.  The Use of Dessicants For Field Drying Grain Sorghum With and Without Weeds.  Mississippi Agricultural and Forestry Experiment Station Bulletin #974.

“Overall, these studies did not result in any distinct advantage for application of dessicants to reduce grain sorghum moisture.”

2) Olson, B.L.S, T. Baughman, and J.W. Sij.  2001. Grain Sorghum Dessication with Sodium Chlorate and Paraquat in the Texas Rolling Plains.   Texas Journal of Agriculture and Natural Resources 14:80-83.

“Results from our 2-year study indicate that dessicant applications were generally ineffective (and most likely uneconomical) in reducing grain moisture in late-planted grain sorghum.”

In my opinion, the major (only?) benefit of using a harvest-aid in grain sorghum would be to reduce the amount of green plant material that goes through the combine and might end up in the grain.  I know of only 3 things that will dry down grain sorghum seed: time, a hard freeze, and/or a grain dryer.”

IMG_9160

We are harvesting some grain sorghum now. We checked the moisture on some grain sorghum this week by threshing it by hand and it was 12.2% moisture (photo of it above). It’s dryland and it looks good. Generally it should be dried or let dry to 12 % if it will be stored below 80 degrees F or to 10% if not, especially for south Ga storage.

We have a good UGA publication you can access here about Grain Sorghum harvest. Here’s an excerpt from that publication.

“Grain sorghum plants mature when the moisture in the grain drops to about 30 percent; however, the seed are usually too soft for harvesting when moisture content exceeds 25 percent. Attempts to harvest above 25 percent moisture will usually produce either unthreshed heads or cracked grain. The optimum harvest moisture, about 20 percent, minimizes harvest losses and drying expense.

Because field drying is difficult and leads to excessive field losses from birds, wildlife and lodging, harvest early and dry your sorghum mechanically to maintain quality and minimize harvest losses.

You can harvest sorghum using row crop or sickle bar headers. Raise the header high enough to harvest only the grain heads with a minimum of leaves and stalks.

Narrow row spacing helps to discourage lodging due to adjacent plants supporting broken stalks. Consequently, a 30-inch row is usually easier to harvest than a 40-inch row.

Combine header losses are usually less at a speed of 2.5 to 3 miles per hour; however, this speed may exceed the capacity of the combine rack and shoe if the stand is dense. In this case, you might want to take a partial swath to prevent overloading and still maintain field speed.

Set combine reel bat speed 15 to 25 percent faster than ground speed to minimize losses. Set the reel height high enough to avoid catching under and throwing the grain heads on the ground. You may need wide reel bats if plant height varies greatly.

Set your combine cylinder and concave to separate the seed from the head without over-threshing. The cylinder speed for sorghum should be less than that for wheat. Some combine manufacturers recommend removing concave bars. Concave clearance should be about 1/2 inch in front and about 3/16 inch at the rear. Clearance for rotors in rotary combines is usually greater. See your combine instruction manual for details about adjustments.

Grain sorghum stalks contain more moisture and are smaller than most corn stalks. As a result, grain sorghum stalks are more likely to be chopped up and carried to the grain tank. Pieces of stalk returned to the cylinder in the tailings will be further ground into fines. The chaffer extension can be closed to prevent this material from entering the tailings conveyor. Sorghum stems often catch and choke the straw walkers, which may cause inconvenience and lost time. Some manufacturers make straw walker covers with smaller holes that stop stems while allowing the grain to drop through.

Inspect sieves often during operation to check for matting or clogging. Set the upper sieve 1/2 to 2/3 open with the lower sieve 1/3 to 1/2 open.”

Posted in Agriculture | Tagged: , | Leave a Comment »

Sugarcane Aphid Management 2015

Posted by romeethredge on May 7, 2015

Dr. David Buntin, Grain Entomologist, University of Georgia, has prepared this concerning this aphid pest.

In late August 2014 a new aphid was found attacking grain sorghum in Georgia.  This aphid is the sugarcane aphid (Melanaphis sacchari).    I was contacted by Roger Sinyard county agent in Marion County, GA and by the end of the season the aphid infested most sorghum in central and southern parts of the state.  Infestations reached very large levels in many fields and most sorghum fields were treated one or more times to control the aphid.   I anticipate that sugarcane aphid will be a serious pest of sorghum in 2015 and most likely will require active management in near all sorghum fields in the state.

Background:  The sugarcane aphid (SCA) has occurred in Florida since 1977 and Louisiana since 1989 feeding on sugarcane.  About 2 years ago the aphid shifted hosts and a strain with a preference for grain and forage sorghums appeared.  First found in eastern Texas near Beaumont, this new strain has rapidly spread eastward across the southern United States in 2014.  It is now widespread across the southern U.S. and occurs from Texas, Oklahoma and southern Kansas to central Florida, most of Georgia and as far east as Florence, SC.  It most likely will continue to spread to new areas in 2015.  The aphid infests all types of sorghum including Johnsongrass, Sorghum halepense.  Indeed Johnsongrass supports populations in areas were grain sorghum is absent.  The aphid must overwinter on green sorghum plants in areas where volunteer sorghum and Johnsongrass do not go completely dormant.

Xinzhi Ni, USDA-ARS

Identification: It is important to scout sorghum fields in your area for its presence.   It is fairly easy to identify.  Wingless forms are a uniform pale cream to yellow with black feet and black cornicles (the small tubes present on the end of the abdomen).

Damage: Where it has been found in Georgia, it is present at very high numbers of several thousand aphids per plant across entire fields.  Large populations of fluid sucking aphids cause serious injury to the plants including death of leaves and sometimes plants. Feeding injury causes reddish lesions on the stems and leaves.   Studies in MS in 2014 showed that the greatest yield losses occurred during pre-boot, boot and early panicle emergence stages with yield losses of 52 – 100%.  Pre-boot infestations at this time can prevent heading and infestations during boot and early panicle emergence can cause sterile heads.   Infestations during soft dough also reduced yield by about 20%. The aphid can remain present in large numbers in the field until harvest.  It produces large quantities of honeydew, a sticky sugary substance that adheres to the plants, which may interfere with harvest and could damage combine harvest equipment.

Photo by Pat Porter, Texas A&M, AgriLife Extension

Management Practices for SCA Aphid

1) Plant early – Although the aphid was not in Georgia at planting time last year, experience in the Delta region found that aphids did not usually infest sorghum until later in the season and early planting may avoid very large infestations.   In other words, late double-crop plantings are at greater risk of severe infestations.

2) Use an insecticide seed treatment.   Trials in the Delta region last year found that insecticide seed treatment would limit seedling infestations for 30 – 40 days after planting.   All registered neonicotinoid insecticides are effective including thiamethoxam (Cruiser), clothianidin (NIpsIt Inside, Poncho) and imidacloprid (Gaucho others).

3) Scout early and often.   Fields can quickly be inspected for the presence of aphids by looking are on the underside of leaves.  Once aphids are detected, scout at least once, preferably 2 times per week, because aphid numbers build very quickly.  Shinny lower leaves with honeydew are a clear sign of infestation.

4) Beneficial insects usually do not control infestations.   SCA and their honeydew attract large number of beneficial insect predators such as lady beetles, syrphid fly larvae and lacewings.   No aphid parasites were observed in Georgia last year but a parasitic wasp is present in TX and LA and could move eastward.  No aphid fungal disease has been observed either.  Generally the rapid rate of increase in aphid populations overwhelms the beneficial insects and severe plant damage usually occurs.

5) Treat when aphids reach threshold levels.  Several threshold levels are being used in the Delta region for 2015.  One conservative threshold is 25% infested leaves with 50+ aphids per leaf at whorl from preboot stage through dough stage.  In MS, the threshold at pre-boot and boot stages is 20% infested plants with large aphid colonies (100+) and localized areas of heavy honeydew present.  From bloom through dough stage the threshold is 30% infested plants.  I think either of these sets of thresholds will prevent serious yield losses and would suggest using whichever threshold is easiest for you to use.   Once threshold is reach do not delay application because infestations can very quickly go from the threshold level to 100% infested plants and hundreds of aphids per leaf.

6) Use an effective insecticide.  PYRETHROID INSECTICIDES ARE NOT EFFECTIVE and may flare infestations by killing all the aphid predators.  Regardless of the insecticide, rapidly expanding populations are difficult to control.  Foliar insecticide options for SCA are:

  • Transform WG (Dow AgroSciences). Transform WG is not fully registered yet, but Georgia, Alabama and several other states haves a section 18 emergency exception approved for 2015 until Nov. 20, 2015. In my insecticide trails last season, rates of 1.0 and 1.5 oz per acre were effective.  Use the 1.5 oz rate if aphid populations are increasing rapidly.  The label allows for 2 applications per season and not more than 3 oz per acre per crop and has a 14 day PHI.
  • Sivanto (Bayer Crop Protection). Sivanto has a full section 3 label and a supplemental 2ee label for lower rates on sorghum and other grain crops. The 2ee rates are 4 – 7 fl. oz per acre.  Sivanto was very effective in my trials at rates of 3, 5, and 7 fl. oz. per acre, so the 4 fl. oz. rate should be effective.  At the 4 oz rate it can be applied up to 7 times during the season but has a 21 day PHI.
  • Chlopyrifos (Lorsban Advanced, Nufos, other). Lorsban is labeled at 1 to 2 pints per acre.  The 2 pint rate has a 60 day harvest interval and 1 pint a 30 day harvest interval.   The 2 pint rate was 80-90% effective in my trial last year but could not be used after the boot stage due the 60 day PHI.  The 1 pint rate was variable and only partly effective.  DO NOT USE CHLORPYRIFOS ON SWEET SORGHUM.
  • Dimethoate ( Dimethoate, Cygon). Is labeled up to 1 pint per acre with a 28 day PHI.  Most dimethoate products cannot be used after head emergence. Dimethoate was variable in my trials and not recommended without further testing.

7) Good coverage is key to effective control.  Use tips and GPA for maximum coverage especially lower in the canopy. A minimum of 10 gpa by ground and 5 gpa by air is highly recommended.

8)  Avoid pyrethroid insecticides for other sorghum pests.   For sorghum midge try to avoid routine pyrethroid sprays for sorghum midge.  Instead scout and treat at 1 adult per panicle.   Chlorpyrifos (1 pint per are) for low to moderate infestations.   Early plantings often avoid serious midge infestations.  For fall armyworm in the whorl, the threshold is 50% infested whorls.  Use Belt, Prevathon or Lannate which are specific to caterpillars.  For headworms, corn earworms fall armyworm, sorghum webworm, the threshold is 1 worm per head and use Belt, Prevathon, Beseige or Lannate.

9) Check fields 2-3 weeks before harvest for infestations.   A treatment may be needed if large numbers are in the head to prevent damage to combines.  Hybrids with taller stalks and more space between the grain and upper leaves may make harvest easier by reducing the amount of leaf material going through the combine.  Large infestation producing large amounts of honeydew and sooty mold may interfere with harvest desiccants.  Transform WG can be applied up to 14 days before harvest.

Summary.   Most likely SCA will infest sorghum statewide in Georgia and occur much earlier than in 2014. SCA will be difficult to manage cost effectively.   Planning and scouting will be keys to successfully managing this new invasive pest and prevent serious losses to sorghum in Georgia in 2015.

For additional information and photos see:

http://www.amsac.org.mx/docs/PUB0272_Sugarcane%20Aphid%20as%20a%20Pest%20of%20Sorghum%20-%20David%20Kerns.pdf

http://www.mississippi-crops.com/2015/02/24/management-guidelines-for-sugarcane-aphids-in-ms-grain-sorghum-2015/

http://news.utcrops.com/2015/03/sorghum-thinking-sugarcane-aphid-control-2015/

http://bug.tamu.edu/cdn/Villanueva%20New%20Aphid%20Pest%20of%20Sorghum%20AgriLife%20Extension.pdf

https://sites.aces.edu/group/crops/blog/Lists/Posts/Post.aspx?ID=73

Posted in Entomology | Tagged: , | Leave a Comment »

White Sugarcane Aphid now in Georgia

Posted by romeethredge on August 28, 2014

NEW APHID PEST OF SORGHUM

We are finding a new pest in Georgia grain sorghum. I first heard about it in our area on Saturday from consultant Jim Griffin, and County agents reported finding some on last Friday in Marion County, Georgia. Then I found it in 3 grain sorghum fields at moderate levels this week here in Seminole County.  The new aphid is the white sugarcane aphid (Melanaphis sacchari).  It has now been reported in several counties in Georgia and reports are some have been found in Florida and was  found in at least 12 counties in Alabama https://sites.aces.edu/group/crops/blog/Lists/Posts/Post.aspx?ID=48 and seems to be widespread in Mississippi, Louisiana, and eastern Texas.

Here’s a  couple of photos I took of  winged adults and the immature aphids feeding on grain sorghum that is not yet heading.

_DSC8372

whitesugar

sugarcane

The aphid is light in color with no obvious markings other than black legs and “tailpipes” (cornicles).  Other aphids usually have spots, a green stripe or a black head.

 David Buntin, UGA Grain Crop Entomologist says,”

A new aphid, the white sugarcane aphid (Melanaphis sacchari), has been found attacking sorghum in Georgia.   I was contacted by Roger Sinyard county agent in Marion County last week about a very large infestation of aphids in grain sorghum.   The aphid was the white sugarcane aphid.  Subsequent reports find the aphid in 9 total counties in the southwest quadrant of the state (Marion, Decatur, Early, Seminole, Colquitt, Taylor, Terrell, Randolph, and Tift counties).   More counties most likely will be added to this list in the next few weeks.

The white sugarcane aphid (WSCA) has occurred in Florida since 1977 and Louisiana since 1989 feeding on sugarcane.  About 2 years ago the aphid shifted its host preference to grain and forage sorghums.  First found in Texas, this new strain has rapidly spread eastward across the southern United States in 2014 and is now widespread in Mississippi, Louisiana, and eastern Texas, and Arkansas.  It is expected that WSCA will continue to spread rapidly throughout Georgia over the next few months.   It is important to scout sorghum fields in your area for its presence.   It is fairly easy to identify.  Wingless forms are a uniform pale cream to yellow with black feet and black cornicles (the small tubes present on the end of the back).

Where it has been found in Georgia, it is present in many fields at very high numbers of several thousand aphids per plant across entire fields.  The aphid sucks plant fluid and these large populations are causing serious injury to the plants including death of leaves and sometimes plants. The aphid remains present in field until harvest.  It produces large quantities of honeydew, a sticky sugary substance that adheres to the plants, which may interfere with harvest and may damage combine harvest equipment. Entomologist in Texas, Louisiana and Mississippi report 20 to 50 % yield loss and sometime the total loss of the crop from harvest damage.   A tentative threshold is:  treat if more than 30% of plants are infested AND there is an average of 100 – 250 aphids per sorghum leaf.   This publication from Texas AgriLife Extension shows the different aphids on sorghum and information about white sugarcane aphid biology and damage. http://nueces.agrilife.org/files/2014/05/Sugarcane-Aphid-Publication.pdf   Interestingly a study by Kathy Flanders at Auburn University suggests this new strain prefers sweet, grain and forage sorghum over sugarcane and it does not attack millets.  Johnsongrass is also listed as a host for WSCA.

WSCA is difficult to control and populations may bounce back quickly following an application. Currently labeled insecticides in grain sorghum are not adequate.  High rates of Lorsban (24-32 oz) appear to provide decent control but cannot be used for late-season infestations because of the 60 day preharvest application restriction.  Dimethoate, malathion and the 1-pint rate of chlorpyrifos provide only about 50% control.  Pyrethroid insecticides are not effective and may flare aphids.  If headworms occur, consider using Belt or Prevathon for control.  The states of Texas, Louisiana, Mississippi, Arkansas and Oklahoma have a Section 18 (emergency use exception) exception approval to use Transform WG (sulfoxaflor, Dow AgroSciences).    Studies in these states show an application of 1.0 – 1.5 oz per acre is about 90% effective, although aphids can build back in a few weeks.   We are working on a section 18 emergency use exception request for Georgia, but Transform WG is currently not allowed in Georgia.”

Some related articles from other states include:

http://news.utcrops.com/2014/08/white-sugarcane-aphids-found-in-tennessee-sorghum/

http://www.arkansas-crops.com/2014/07/14/sugarcane-grain-sorghummilo/

http://www.mississippi-crops.com/2014/06/26/white-sugarcane-aphid-a-potentially-devastating-pest-of-grain-sorghum/

http://www.mississippi-crops.com/2014/07/11/white-sugarcane-aphid-update-and-impact-on-midge-applications/

http://www.mississippi-crops.com/2014/07/15/treating-white-sugarcane-aphid-decision-aid/

http://www.mississippi-crops.com/2014/07/25/white-sugarcane-aphid-update-7252014/

http://www.mississippi-crops.com/2014/08/01/white-suagarcane-aphid-update-812014/

http://louisianacrops.com/2014/07/17/sorghum-midge-and-white-sugarcane-aphid-concerns/

http://louisianacrops.com/2014/06/20/white-sugarcane-aphid-considerations-and-status-in-louisiana-grain-sorghum/

http://louisianacrops.com/2014/06/16/sugarcane-aphid-numbers-increasing-in-grain-sorghum/

This publication from Texas AgriLife Extension shows the different aphids on sorghum and information about white sugarcane aphid biology and damage. http://nueces.agrilife.org/files/2014/05/Sugarcane-Aphid-Publication.pdf

Fullscreen capture 8262014 21550 PM-001

 

 

Posted in Agriculture, Entomology | Tagged: , | Leave a Comment »

Blackbirds a Problem again

Posted by romeethredge on November 26, 2013

Blackbirds are causing problems again. Some growers have said that blackbirds are worse in certain areas. We have large roosting areas along the Chattahoochee river here and it may cause it to be a worse problem locally. Here’s a link back to another post I’ve done with some remedies.

https://seminolecropnews.wordpress.com/2012/11/30/blackbirds-everywhere/

Here are some photos I took last week of the problem in grain sorghum. The propane exploders help. I like these because they move around and so the main blast of noise goes into different directions.

_DSC1604

_DSC1598

_DSC1608 _DSC1606

Posted in Wildlife | Tagged: , | Leave a Comment »

Grain Sorghum After Corn

Posted by romeethredge on July 16, 2012

Corn Harvest is proceeding well and folks are looking at alternatives for planting after corn on Irrigated acreage.

Late planted grain sorghum aka milo is an option after corn harvest.  It can be harvested for silage or grain.

Here are some keys to late planting:

Deep till if there hasn’t been any deep tillage within the last few months.

Watch for chinch bugs and lesser cornstalk borers, use insecticide treated seed if possible. Use Cruiser or Poncho treated seed if possible to help with insect problems. During flowering stage watch for midge.

Plant  80,000 to 100,000 seeds per acre on irrigated land.  Narrow row plantings are best, 14 to 22 inches.

Plan on using 60 to 100 units of Nitrogen.

If you use Concept treated seed you can use metolachlor (Dual)  herbicide at planting.  Atrazine can be used on any sorghum when it has 3 leaves.

Early cold in the fall can hurt yields and test weight and make drying in field difficult.

Dr Dewey Lee , UGA Extension scientist, has some good info concerning late planting of Grain Sorghum on his blog at this link.

http://georgiagraincrops.com/herbicides/216

Posted in Agriculture, Corn | Tagged: | Leave a Comment »

 
%d bloggers like this: