Obscure Scale on Pecan

Bill Ree wrote this for his newsletter and I thought it needed to be shared.

As the name implies infestations are obscure and difficult to spot. Infestations, especially heavy infestations will appear as if someone has sprinkled ash on the limbs as shown in the attached picture. When checking for this type of infestation it is best to check on 3 or 4 year old wood.

These insects feed by inserting their mouthparts or styles into the conductive tissue of the tree and feed on the plant sap. They do not produce any honeydew. Heavy infestations can cause limb dieback and will reduce overall tree vigor.

In the life cycle of this scale, females will excrete a waxy covering about 1/8 inch in diameter under which they feed and lay eggs. When immatures emerge from eggs they are referred to as crawlers  which is the only mobile stage of this insect. Once a crawler has moved and settled in a new location it begins to feed, excretes the waxy covering and it will never move again. Fortunately, there is only one generation per year.  

There are some beneficial lady beetles and mites that feed on scale and a few parasites which help, but if control is needed that control will have to come from the application of a dormant oil. Although we now have some highly refined light summer oils, pecan is considered an oil sensitive crop and any oil application needs to be restricted to the late dormant season.

It is the general thought that oils kill insects by suffocation where the oil covering prevents respiration. Although the exact mode of action can be debated the bottom line is that there has to be good coverage.

Scale control can be difficult and with heavy infestations it could take a couple seasons for management. Some of the difficulties for control include:  the scale's waxy cover provides protection against pesticide exposure; some crawlers tend to settle under the protection of older scale covers, thus producing a layering effect; and crawler activity extends over a long period of time.

During the growing season, when dormant oil cannot be used, insecticide treatments can be used to control crawlers but these treatments must be correctly timed for crawler activity.

There are several types of horticultural oils on the market today which can cause some confusion, plus, labels on horticultural oils will contain a different terminology. Not all horticultural oils are the same and an understanding of label information is necessary to know the difference. The following is a brief description of different types of oils and an explanation of some of the information that should be found on the label.

Dormant Oil: This class of oil is the heaviest of the horticultural oils and is formulated for use on dormant plants only. Apply these oils as late in the dormant season as possible but before budbreak. Dormant oil effectiveness increases as temperatures increase and insect metabolism is accelerated.

Summer Oils:  Summer oils are slightly lighter than dormant oils and are formulated for use during the spring and summer on some plants.

Superior Oils: This class of oil is the most highly refined of all the horticultural oils. These oils are used primarily during the growing season; however, they may be used as a dormant oil by changing the rates.

When purchasing a horticultural oil it is important that you understand the information on the label. The following information should be on the label and will assist you in determining the quality.

Unsulfonated Residue (UR): this number is a measure of purity or degree of refinement and is always listed as a percent with 92 being the minimum. The higher the percent, the higher the purity.

Viscosity: This is a property used to define oil heaviness and is expressed in seconds. Horticultural oils fall into the 60 to 200 second range, with the heavier oils rating 100 or higher. The higher the number the more persistent the oil on the plant. Dormant or semi-dormant plants will tolerate heavier deposits than trees in leaf.

Distillation: distillation temperature range is a measure of the volatility of an oil. Horticultural oils have a distillation range of 400 to 488 F. The lower the distillation temperature the quicker the evaporation. Dormant oils will have a distillation range of around 438 F while superior oils will be around 412 F.

Gravity: This is another method of weighing oil. When related to viscosity and the UR it can provide an index to oil paraffinicity. Oils should be largely paraffinic to be safe for plants. Gravity is measured in degrees and the higher the number the more paraffinic the oil. Thirty degrees is the minimum standard.

Horticultural oils are an effective and safe way to control scale on pecans. In Texas, dormant oils are permitted in the Texas Department of Agricultures certified organic production (Organic Food Standards and Certification, Texas Administrative Code, Title 4, Part 1 Chapter 18).

Pecan is considered an oil sensitive crop therefore only dormant oils are recommended. Before purchasing and applying any type of horticultural oil ALWAYS READ THE LABEL. When applying, make sure there is good agitation in the tank. Even though you are making an application to a dormant tree, injury or tree death can occur if there is poor agitation which allows the oil and water to separate and trees receive high concentrations of oil.

Do You Have Borers or Just a Woodpecker?

The yellow-bellied sapsucker (Sphyrapicus varius), a member of the woodpecker family, is a migratory bird whose summer breeding range includes Texas. The identifying field markings of adult birds are a black crescent on the breast, pale yellow belly, white wing stripe, and a crimson crown. The male also has a crimson chin and throat, distinguishing him from the female whose chin and throat are white.

Although insects make up part of its diet, the sapsucker is better known for its boring of numerous holes in the bark of live trees to obtain sap, the activity from which it derives its name.

The yellow-bellied sapsucker is the only member of the woodpecker family to cause this type of injury. More than 250 species of woody plants are known to be attacked. In Texas they love our oak species and seem to be particularly fond of red oak and burr oak but they love many species of trees and even shrubs.

The sapsucker bores neat rows of 1/4-inch holes spaced closely together through the bark of trees along and around portions of the limbs or trunk. As these holes fill with sap the sapsucker uses its brush-like tongue to draw it out. These holes are periodically enlarged and portions of the cambium and inner bark, together with the fresh sap, are eaten.  Puncture wounds and resulting sap flow on branches and trunks of trees are the most obvious symptoms of injury inflicted by the sapsucker.

After repeated attacks on the same area of a tree, large patches of bark may be removed but I seldom see this happen. If this area is girdled, the portion of tree above this point will die. Many small limbs are killed and sometimes the trunk is girdled and the whole tree is killed but not often. Sapsucker feeding on shade and ornamental trees leaves unsightly bleeding wounds that attract bees, hornets, and other insects to the sweet, oozing sap.

Early in the spring the sapsucker tests many trees around its selected nesting site by making sample drillings before selecting ones it prefers. These trees, because of quantity or sugar content of the sap, are visited several times a day for the rest of the season and sometimes are used as a food source for several years.

Feeding wounds serve as entry courts for a wide variety of wood decay or stain fungi and bacteria. On high quality hardwoods, sapsucker wounds cause a grade defect called "bird peck" that lowers the value of the trees. Many forest trees are attacked high in the crowns, making light feeding wounds or sample drillings less evident. A condition known as black bark may develop which results from certain fungi colonizing the sap flow and discoloring the bark, and is good evidence that injury exists.

To discourage sapsuckers from feeding on a favorite shade tree, wrap hardware cloth or burlap around the area being tapped or smear a sticky repellent material, such as bird tanglefoot, on the bark. On large acreage or orchards, leave favorite feeding trees of the sapsucker untreated. Birds will concentrate their feeding activities on these favorite trees, which often protects nearby trees from serious injury.

The Migratory Bird Treaty Act and Federal regulations promulgated under its authority prohibit shooting or trapping of sapsuckers. Shooting of this species would be an ineffective control anyway because transient birds tend to replace occasional losses to local sapsucker populations.

Bareroot, Balled and Burlapped and Container Grown Plants

Winter is a great time to plant trees and shrubs. It is highly recommended that you put any tree or shrub out well before hot weather to give plants a time to grow some roots before they have to face hot temperatures.

Container plants have the advantage of having all of their roots intact and ready to grow if the pot was properly cared for. Container grown plants are great but be careful! Nurseries grow plants in pots so that they can be sold easily but trees continue to grow even in a pot. This growing means that pots can become too small for the tree as it grows and so the plant becomes root-bound (stunted). To check and see if a plant is root-bound just hold the pot and lift the tree out of the pot. If the roots are just to the pot sides and no roots are circling then the tree should be okay. When planting a container grown plant dig a hole bigger than the plant by double the width but no deeper. Remove the container and plant into the hole as quickly as possible. Air kills the little white hair roots very fast if not put into the ground. Once the hole is back filled with soil then water thoroughly to remove the air spaces.

B&B or Balled and Burlapped plants are not container grown and you need to understand that before ordering them. These plants may have been grown in a nursery but they were dug out of the ground so that many of the roots have been cut off but the soil ball is still intact and very heavy. In fact there should be about 10-12 inches of ball for every inch of tree trunk diameter. When you get a B&B plant remove all plastic including any string or twine. You can leave the burlap only if it is not plastic. If there is a wire basket you can leave it as the roots will grow right through. The biggest problem with B&B trees is that the hole is usually dug with the same tree spade that dug the tree. Tree spades leave the hole sides very slick and hard for roots to penetrate. The best hole is wider but not deeper than the ball.

Bareroot trees are just trees that have been dug very carefully in the nursery so that the roots are pretty much intact but there is no soil. As you can imagine these trees are much more fragile but without the soil they are easier to handle both for the nurseryman and you. Most bareroot trees are dug and then “healed in” at the nursery till you purchase them. To plant them be very sure you keep the roots moist at all times while you’re planting. Dig the hole as deep as the roots go and just as wide. Put the tree in the hole and back fill slowly adding dirt while you pack it. Once the hole is full you need to water well to take out air pockets. Bareroot trees need to be planted now and most fruit and nut trees are sold this way.

God's Creation, Our Work and Happiness

This was my speech to a Men's Group recently and I thought it might generate a conversation or two!

I have three things I want to discuss with you this morning and they have been on my mind since I was asked to speak.  I want to get you think with me about God’s great creation, our work in that creation and what brings us happiness in that creation.

First, I am an agriculturist and a scientist/educator.  In these roles I find myself investigating many things but particularly those things related to plants and animals.  I am constantly amazed at how intricate and detailed the world is around us.  From the sub- cellular level to the infinite number of stars and galaxies there is a tremendous level of organization that points to a fantastic creator God.  Certainly the Bible speaks of his wonders but so does all the physical world that we live in.  All you have to do is look closely at your hand or listen to your own breathing or try to hear your heart beating in your ears and you realize God is at work.  On the cellular level we have now discovered that cells are composed of tiny machines with gears, tracks, engines and more.  There is even keys and locks so tiny we know they are there but can't see them.  On the galaxy level we now know that the sheer mass of space has a tremendous influence on our planet starting simply with gravity but also through normal matter and dark matter and holding us in our position relative to the sun.  If the moon was just a little closer the tides would cover large portions of where we live and make it impossible to even live near the coast.

That being said I was listening to a program the other day about a group, SETI, Search for Extraterrestrial Intelligence, that spends its life searching in outer space.  They are listening and looking into outer space hoping to find life and to hear ET reach out to us.  A PhD astronomer and SETI researcher Seth Shostak was speaking about how fascinating the multitudes of galaxies were and how intricately they fit together and worked together.  He was brilliant as he described in detail all the things “out there” and then he switched to the obvious reality that life is “out there” and his brilliance left him.  His comment was that with all this intricate detail that there had to be a chance that there is life out there and that they would most certainly be smarter than we are.  How can you go from discussing the detail you see in our universe to a conclusion that there is a “chance” that life exists somewhere else?  God creates with a purpose and all that he creates points to him.  If there were other forces at work then why do the laws that govern this world also govern the entire universe?

Let me give you a philosophy I have about our relationship with creation and God.  Number one, God is in control.  Number two, God gives us the knowledge we have.   All knowledge is from him.   We don't discover something new that he didn't know or give us himself. Number three, humans are Gods creation that he loves and has redeemed. They have more value than all else in creation.  His focus and ours is first on him, then people, then creation in that order.

For my second point let me start by saying that from the beginning of creation we see God working and after he creates man he puts him in the garden to work it.  God works and he created us to work and through that work to bring glory to him.  Sin came into this world and through it the ground was cursed but not our work.  In fact we know that we will work even when we are in heaven.  Even now physicists know that there is an underlying power or energy that is powering even our cells.  In science we point to matter/antimatter, light and more but still there is something underlying all these sources of power.  God is at work and if he stops working we cease to exist.

So, God is working and on a parallel track, God is also working through us.  Our work is from God and for God bringing him a great deal of pleasure and glory.  God loves what we do from the simple street sweeper/dishwasher to the President of the United States to the Pastor of our churches.  At the foot of God we all have equal worth and our work, all our work, has equal value.  Too much of the time we look on work as bad, something to be endured when we should be looking at our work as worship.  Follow the logic, if God wants us to work as he is working, our work gives glory to God, so our work is not just about us it is about us and God in partnership.  God is doing his part and we have our part, God creates the cow, we milk it!

Today, take a moment to consider what you do and who you are working for.  Don't consider your job, your work, as something you have to hurry through but actually something that God created for you that is good for you and also brings God glory.  Now with sin and our fallen world there is much that frustrates us but this frustration is not the work we do but sin that has frustrated our work.  

Lastly let me talk about two things that will make your “work” more enjoyable.  First, psychologists have published study after study that prove it is good mental therapy when we do something for someone else more needy than we are.  People who struggle with self esteem issues, depression, etc all benefit when they get outside themselves and serve other people.  So, in the process of doing your work for God also do your work for someone else.  If I remember right we are to love God and love our neighbor which just is what our work can do as we if we do our work for God and for others.

The second thing about our work that will make us happy is through the money we earn in our work.  You have heard many times that money can't buy you happiness but we now know that it can.  Michael Norton with Cambridge University did a study in Canada with money and college students that is quite interesting.  He randomly gave college students different amounts of money and told them to either spend it on themselves or on someone else.  After they spent the day doing this then Michael asked them that night to rate their happiness.  Overwhelmingly the group who spent on others was happier than the group that spent on themselves.  Michael was so impressed with the results in Canada that he went to a country that is much poorer, Uganda, and repeated the test.  Again, the people who spent on others was consistently happier than the group that spent on themselves.  Wasn’t this the problem with the rich, young ruler who questioned Jesus.  I believe he knew something was wrong with himself but couldn’t put his finger on just what.  Jesus went to the heart of the matter, give your money away!

As I finish let me leave you with this.  Recognize God in his creation and spend time understanding your role in that creation.  Your work does matter, it fits into what God is doing and even though he is sovereign he has chosen to work in this world through you. Pure joy is knowing these two points while recognizing that God loves us all and when we serve others like us with our work and our money we are in God’s will doing what he is doing.

Soil Temperature to Plant

I get asked all the time when its time to plant.  Well the best answer is it depends. The reason it depends is that each species of plant will germinate at different soil temperatures. Right now we are buying seed for planting both corn and sorghum.  Corn needs 50 degree or higher consistent soil temperatures and sorghum needs 60.  Pioneer has a great article on corn emergence you should read:   https://www.pioneer.com/home/site/us/agronomy/soil-temp-corn-emergence/

Grasshoppers in Winter

You don't imagine that a grasshopper can survive a winter but here is one!  It is Sunday, February 8, 2015 on a warm, bright afternoon and out jumps this grasshopper. I was surprised that she even moved but she did more than that as I tried to catch her.  I sure hope we aren't plagued again this year like we have been the last few years!  

Bermudagrass Stem Maggot

Late this past year a new forage insect that has been slowly making its way here from Georgia invaded bermudagrass fields in Texas.  In 2010, entomologists in Georgia found the Bermudagrass Stem Maggot in hay fields and since that time this Central and Southeastern Asia insect has been steadily moving west.

Dr. Vanessa Corriher-Olson, Extension Forage Specialist at Overton in East Texas found damage in July last year in a number of East Texas coastal bermudagrass hay fields and she identified the insect causing the damage as the Bermudagrass Stem Maggot (BSM).  In late August I was called to come by some fields north of De Leon to see a problem and the damage was something I had never seen.  My first call was to Dr. Allen Knutson, Extension Entomologist and after a few email pictures he confirmed the damage as BSM.

The adult fly of the BSM lays its eggs on bermudagrass leaves.  Once the eggs hatch, the larva or maggot goes into the stem and begins feeding on the leaf tissue right at the uppermost node.  As a result of the feeding the top 2-3 leaves will die as you can see in the picture.

After the leaves die the maggot leaves the stem and goes into the soil to pupate.  After pupating for 7-10 days the adult fly emerges to lay a new round of eggs. It is estimated that if the infestation is severe that over 80% of the tillers in a field can be affected.

The field that I scouted north of De Leon, Texas had between 70-80% of the tillers dead and the hay  yield was going to be severely affected by the maggot.  The producer immediately cut the field and then a following last cutting was not damaged.

According to Dr. Dennis Hancock, University of Georgia Extension Forage Specialist the damage appears to begin toward the end of the first cutting through the middle of the second cutting.  In general the damage begins to taper off as fall weather changes begin.  I was not able to find any damaged fields by late September.

What can we do?  There is not a lot we know about this insect and certainly not a lot of control measures.  Here is a list of things that can help you manage for BSM:

•        The larva causes the damage by feeding inside the stem.  Since the maggot is inside the stem, conventional insecticides will not touch them.
•      The adult fly does not move far, in fact they only move about 10 feet in any single flight.  The flies stay deep in the canopy unless disturbed so chemical control has to penetrate the canopy to be effective.
•         If you see damage and are even within 10 days of harvest then harvest!  When you harvest you will remove the maggot and help lower fly numbers.
•          If you do make a harvest and will have maggots again then treatment is an option.  Dr. Hancock has found that you can apply an inexpensive pyrethroid insecticide like Silencer.  Silencer does not have a label for BSM but it is labeled for most insects in bermudagrass including armyworm and grasshoppers.  Apply a pyrethroid when the grass is growing 7-10 days after harvest and then again 7-10 days later.  The cost of the two treatments is easily justified by the forage yield saved!
•   ·     Alicia, Coastal and Tifton 44 are the most susceptible since they are finer textured bermudagrasses.  Tifton 85, which is a coarser grass, has shown to have fewer tillers damaged and so less yield loss.

Texas Wintergrass

Most people don't know Texas  Wintergrass is commonly known as "speargrass".   Texas Wintergrass is a perennial that comes out each fall from roots and grows all winter before seeding out in May.  The seed are the spears that kids throw at each other!

This grass has good nutritional qualities now but as it matures it loses quality. Fortunately we have other newly emerged plants in early spring that take up the slack. 

One problem with this grass has been the invasion of this grass into bermudagrass hayfields. The drought has caused much of this and producers are scrambling to get rid of it.  Our only options are chemical controls in the winter. 

Rust in Wheat

I was looking at a wheat field today and was surprised how yellow it was.  Looking closer I found lots of rust on the older leaves.

As you can see in the picture the rust is quite prevelant and damaging.  There is really nothing to do now but keep watch. I saw that the new growth is good and not infected. The warm weather is helping tremendously now. We won't think about spraying until flag leaf. For now we monitor. 

Agriculture in Copan

January 19-26, my daughter Kate and I traveled to Copan Ruinas, Honduras to visit agriculture projects and teach.  We are working as a part of Baptist Rural Life Ministries and have been for 10 years.  We visited Chorti communities and toured fields to first see what some of the problems were and then we finished the week with training.

There are three major crops we are concentrating on; corn, coffee and cacao.  The Chorti mainly grow corn but as world coffee prices have increased they have steadily grown more and more coffee. 

Cacao, or as we know it, chocolate, is from the Americas but over the years has been replaced by other crops and the original knowledge about growing cocoa is gone. Africa is the world's largest producer now but Honduras has potential to grow and export cacao too. 

We are showing the Chorti how to grow cacao, varieties to plant, when to harvest and ferment cacoa and how to process seeds to sell. We have no plans to develop actual chocolate products but some individuals might!  

Right now Honduras is seeing a lot of land planted to Arabica coffees.  Arabica is the highest quality coffee type and so brings the highest prices.  Honduras grows only Arabica types and is know for producing superior coffees. We visit and work in the Copan area which is know for growing some of the best shade grown coffees in the world. 

Unfortunately the typical coffee varieties grown in Honduras are very susceptible to the disease, "La Roya." This is a rust type of fungus which kills the leaves, defoliates the plant and eventually kills it. In the picture you can see a coffee plant devastated by La Roya next to Kate.  This plant will die and be replaced by another.

Part of our work in Honduras with the Chorti is to teach them how to grow and process superior coffees and sell them for higher prices. In that we are evaluating disease resistant coffee trees with the hope that in the future our farmers won't be wiped out by diseases. We are reaching out to World Coffee Research at Texas A&M and to IHCAFE, the Honduran Coffee Growers Association. 

It is our hope to be able to introduce new varieties while we improve their production practices.  Still a long way to go!