Early September is Critical for Pecans

This information was taken from Dr. Lenny Wells' Pecan Blog

The nut sizing period normally occurs from May 1 through August 15. Although not a critical water use stage for pecan, serious drought conditions during this period can affect yield. The most common visible effects of an extended drought during this period are excessive nut drop and “shell hardening” on small nuts. Lack of sufficient water during the nut sizing period causes small nuts and may lead to water stage fruit split, resulting from a sudden influx of water during the nut filling stage in some varieties.

The nut filling stage occurs from about August 15 to the first week of October, depending on variety. The most critical period for water use is during the first two weeks of September. Lack of sufficient water during the nut filling stage will lead to poorly filled nuts, which will result in poor nut quality.

Reports from other areas of the country indicate that as much as 350 gallons of water per day can be required by each tree during the nut filling stage. Based on this recommendation, if a mature orchard has a plant density of 12 trees per acre (60' x 60' spacing), then 4,200 gallons per acre per day may be needed. For a density of 20 trees per acre (46.5' x 46.5'), 7,000 gallons per acre per day may be needed.

Pecans can have high water requirements, using as much as 60 inches of total water (including rainfall) during the growing season. Drip and micro-irrigation system design capacity for a mature pecan orchard should be 3,600-6,000 gallons of water per acre per day.

New Sorghum Pest

The sugarcane aphid has been around for a while.  It was first observed in Florida on sugarcane in 1977.  Then in 1999 it was discovered in Louisiana on sugarcane.  It was not until 2013 that it was found in Texas and this time it was found on sorghum. 

Since this discovery it has been found as far east as Alabama and it now looks like it has made it into western Georgia.  Roger Sinyard and Bill Starr responded to a call from a local grower who was seeing something weird in his field.  It is somewhat ironic that we visited a field day in Plains GA, earlier in the week and learned about this new and emerging pest of sorghum. 

When David Buntin (UGA Entomologist) spoke about it I remember thinking that we should have a couple of years before we see it here.  Well, I was wrong.  This aphid can be seriously damaging in more ways than one.  Early infestations can kill or stunt small sorghum.  Late infestations can result in large amounts of honeydew.  This excessive stickiness can interfere with harvesting.

It is unofficial until our entomologist examine the samples sent last week, but we are pretty sure that we are seeing the sugarcane aphid in our area.  to learn more you can visit this site
http://www.amsac.org.mx/docs/PUB0272_SugarcaneAphidPublication.pdf

Disease Resistance

In a year like this you expect to see plenty of Pecan Scab on trees that have not been sprayed.  Pecan scab is always worse in years when we have ample rainfall in early spring.  That is exaclty what we saw this year and last as well.  However if trees are taken care of and the proper fungicides are applied we should be able to control this devastating disease.

Pictures came from Patrick Connors (UGA Pecan Breeder) website

So why are we seeing so much scab in treated orchards?  It could be due to diseases becoming resistant to certain fungicides.  We are not seeing complete resistance like we see with resistant pigweed, but we are seeing a shift in sensitivity to certain fungicides. 

Several local growers have participated in a program offered by UGA.  They have been submitting samples of scab from orchards across their farms and the results are pretty interesting.  Across many of the test sites there was at least some level of insensitivity to several of the fungicides.  

There was low to moderate insesitivity to the triazole fungicides like propiconazole and tebuconazole.  There was low to high insensitivity to strobilurin fungicides like azoxystrobin, and TPTH (Tin).  In the samples submitted there was little to no insensitivity to Dodine and Thiophanate Methyl.

This does not mean that we have widespread disease resistance.  It does make me want to recommend growers submit disease samples for analysis.  If we can find insensitive scab then we can change our spray program to better control the disease.  The only thing that it will cost you is postage and the time it takes to get the sample.

You can get instructions for collecting and submitting samples at the following link
http://www.caes.uga.edu/commodities/fruits/pecan/documents/PecanScabSamplingInstructions-REVISED.pdf

Spray System Cleaning

The basic cleaning methods for agricultural sprayers is to empty the tank on the approved crop.  Fill the tank 10% with water and flush the lines.  If you plan to add a tank cleaner you should do that on the second rinsing.  Fill the tank mostly full on this rinse, and flush the system.  For the third step repeat the initial rinse.

I bring this up because of something I learned at a meeting yesterday.  Dow AgroSciences had a field day to introduce some new technology.  One of the stations talked about sprayer clean out and its improtance.

John Deere conducted a study on a sprayer with a 100 foot boom and 1000 gallon tank.  After spraying the tank out they took the sprayer back to the shop and drained all of the liquid.  So what they collected was water that was in the pumps, low hanging lines, filters, etc.  They collected this water multiple times and ended up with between 50 and 100 gallons of water still in the system. 

So if you were spraying 15 gallons of water per acre you would have enough spray left in the lines to treat almost 7 acres.  This is very important if moving sprayers between highly sensitive crops. and will be very important as we move to new weed resistant crops in the near future.

More Problems for Pests

It is amazing what you will see if you just slow your pace down a notch.  The following are good examples of natural insect control.  These are all from large row crop operations in both Taylor and Peach Counties

 Above is a Damsel Bug that has caught a three cornered alflafa hopper in soybeans

 A Robber Fly that has captured a moth

 This appears to be a caterpillar pest that was killed by a pathogneic fungus.  There are also viruses that kill insects. 

A Syrphid Fly larvae feeding on aphids.

I believe this is some sort of Flea Beetle, and it has an appetite for Pigweed all over Middle Georgia. 

Corn, Cotton, Peanuts and Soybean Field Day

On August 20th there will be a row crop field day in Plains Georgia at the Southwest Georgia Research and Education Center.  Topics will include Peanut Varieties and Cropping Systems, Cotton Insect and Weed Management, Thrips Management and Corn Insect Management.  We will also hear from the UGA Soybean, Cotton and peanut Breeding Programs.

The meeting starts at 8:30 and there will be a sponsored lunch. After lunch there will be a drone demonstration.  Please contact Linda Hagerson if you plan to attend.  229-824-4375, hagerson@uga.edu

Pesticide credits will be available.

If you plan on attending let me know.  Maybe we can carpool.

Bollworm Meets Wasp

Predators and parasites are one of the reasons that we do not have to spray many insecticides in Cotton.

I was in a cotton field with a fairly high number of bollworm larvae.  The size of the worms and where they were on the plant would make it almost impossible to kill them with insectidcides.  This wasp was doing a good job of reducing the pest populations for this cotton grower.

Nothing to Do with Agriculture

But I guarantee this would have scared my daughter out of her shoes.  I found this walkingstick hanging out on her cereal bowl this morning. 

I am glad I got there before she did.  Walkingsticks are herbivores (they eat leaves) and obviously their body helps them blend in with their surroundings.  Unless they are on a princess bowl.

Worms are Everywhere

We are seeing armyworms in grasses and soybeans, budworm/bollworm in cotton, and cutworms in sesame.  Yes I said sesame.  we are even being overrun in the landscape and garden.  Most of these larvae (caterpillars) are immature moths.  The moths fly to a suitable host and lay eggs.  These eggs hatch in about 3 days and the small caterpillars begin to feed. Feeding lasts about 2 weeks.  After the caterpillar has done the damage they usually pupate for about 10 days.  After this time the adult emerges and starts the cycle over again.

Here are some images to help you identify your pest.  You can also visit http://www.bugwood.org/ to view all sorts of insect images from across our area.

Peanut Maturity

We still have plenty of time before peanut harvest, but i had a request for the following chart so i thought i would go ahead and post it.  We know roughly the number of days to maturity for all of our recommended varieties so you shold be able to use this chart to at least determine when you need to start working on the inverter.

For example:  Georgia 06G has a mautirty range of 145 - 150 days.  So if you planted on may 31st you would be at 145 days on October 23rd.  This means that you would probabaly want to start scrapping peanuts the first of October. If you planted into June you can contact me and i will send you the remainder of this chart.

Unusual Yellowing in Soybeans

If you are seeing symptoms like the images below give me a call or post a comment.  We are seeing this yellowing in different areas of middle georgia and are trying to figure out if it is related to variety. 

In affected fields or areas of fields leaves tend to yellow around the edges and some cup upward as seen above.  The only thing that these fields have had in common so far is high numbers of potato leafhopper.  This is the same little insect (1/8" ) that causes hopper burn in peanuts and there are reportedly large migratory populations.

Let me know if you have anything resembling this injury or if you have a heathy population of the above insects.