A Ray of Sunshine

On a cloudy cool day in June, when it should be summer but it is not, this is nicest ray of sunshine you will ever see.  Say hello to Salome Kodde, courtesy of mom Sharon.

When Is Yellow A Problem?

A lot of questions this past two weeks about yellow corn.  We have several things going on. 

Here is the latest one, random yellow plants throughout the field without any pattern.  This one is easy.  It is surfactant burn from post emergent glyphosate applications.  The surfactant is what the chemical manufacturers use to carry the active ingredient, in this case glyphosate.  Different manufacturers use different surfactants, not an issue, generally the newer surfactants are safer.  But this year we had the perfect storm for surfactant burn.

A lot of corn was sprayed last week because the week before most sprayers were busy the week before applying fungicides to winter wheat.  And good spraying days have been few and far between the whole season.  This corn was growing rapidly and pushing the upper limit of safety for glyphosate application.  We don't talk about the upper limit very much because glyphosate tolerant corn is hardly ever injured.  We will get some injury though if the cuticle, or skin, of the corn plant is in a delicate condition.  The corn has delicate cuticles this year because it has not been hot and dry.  Corn skin is like human skin.  Expose it to sunshine and dry conditions and it will get tough.  Humid and cloudy weather keeps the skin more delicate.  Sensitive cuticles will react with the surfactant and bleach yellow.  It is a temporary condition which will disappear in a week as new leaves emerge from the whorl and for this reason the yield impact will be negligible.
Some hybrids do not show this flash because their genetic disposition leads them to create thicker cuticles.  It is the same as some humans have fair skin which burns easily and some humans have dark skin which does not burn as quick.  Does this mean much?  Not to a corn plant.  Not much to a human either unless you are very fair skinned and want to stay outside your entire life.

One last comment. The condition that also leads to thin cuticles is very rapid cell growth.  You can see a corn plant growing rapidly by looking at it's leaves.  If you see some twisting and curling, you can be sure is growing out of its shorts, like the plant below.

In the old days we would blame this on the dicamba or Banvel that was used on 100% of the corn crop in the 80's and 90's.  My old buddy Martin Harry would spend weeks holding hands and saying a prayer over corn fields that were a lot worse than this.   

A much more serious yellow can be seen in fields like this one.

This spring gave no room for error.  The trails through this corn were created by manure tankers.  You can even see cultivator trails on other fields.  Man made compaction and natures' compaction produced by pounding rains are showing up all over the place.  Compaction makes corn roots' lives miserable and starves the plant for oxygen.  Nutrient uptake and growth grind to a snails pace.  This is trouble that relects in the bin.

This is not so much compaction, but side hill seepage from a clay knoll.  Often clay knolls leach water out of their sides and the water will cause the corn to turn yellow too.  Same reason, lack of oxygen in the soil. 
The bad news is there is little we can do to make the corn feel better.  The good news is that 11 moths from now we get to try it all over again.

A Weird One

Diseases can be strange.  They don't always follow the pretty pictures in textbooks.  This picture was taken a week ago at heading time.  Brian noticed these heads from the cab of his sprayer when he was applying Prosaro for headblight control.  He saw it in more than one or two fields.  The number of heads affected in the field will not have a yield impact, there isn't enough of them, but the partially bleached heads stick out like a sore thumb against the green backdrop.

A head like this one matches the classic textbook picture of fusarium head blight in wheat.  Fusarium causes partially blank sections of heads that turn white.  Except, it is way too early for head blight to express itself.  So, what is it?

A survey of qualified experts left some heads scratching.  Obviously a physiological response to the environment within the field.  That is a bit like a doctor telling you the symptoms you have are an idiopathic response.  In plain language that means the doctor does not know what is causing the symptoms. 

Some believe it is form of take-all disease.  This is the most plausible explanation because of timing.  Take-all prevents the head from flowering so you are left with a blank white head.  Except as the name take-all implies, this disease "takes all" and does not leave part of the head healthy. 

I suspect the real culprit will remain unknown.

After The Ducks Left

On Friday May 13, we experienced a quick downpour, over 2" in 30 minutes, probably more because most of it came in sideways with a nasty north wind.  The shot above is from my neighbour George's corn field.  It had been planted the day before.  The front edge of the field was overwhelmed with water.   Everyone can relate because over the last month these cloudbursts have been a common occurance.

This picture was taken on Tuesday this week of the corn in the same field outside the wet hole.

Looking respectable.  You can tell this ground does not have a high clay content.  As one smart *** neighbour would say, "you can broadcast corn seed on this farm and it would still grow". 

Here is what the corn looks like in the wet hole. 

I often remenber the words of an old farmer spoken to me years ago. A dry year will scare you to death, but a wet year will starve you to death. 

Send These Guys To The Olympics

Soybeans planted a week to 10 days ago are having a tough ride.  Seedbed conditions were lousy all spring.  Now the rains have stopped.  Crusts have formed as the surface dries and there is not much you can do but wait and hope  Rotary hoes are useless.  They only work, sort of, when the ground is still soft.  A RTS or coulter cart may work if set real shallow, but you are going to break some necks.  A timely shower is the only perfect solution.  Beans planted in May got those showers and are looking pretty good.  In the mean time, the June planted weight lifters have to show their stuff.

Will these beans make an acceptable stand?  To early to say, but I think they will.  Crusting and stand establishment problems are the reasons why we over populate our soybean fields.  The second reason is the use of drills which do not have accurate depth control.  We can loose 30% of a 200,000 seed drop and still have excellent yield potential.  We can't loose 30% of 150,000 and still have the same potential.

It Is Not A Question Of If

I admit to being biased, considering my son does this stuff for a living, but there is no doubt in my mind we all need to be using fungicide on our wheat crop and the time is fast approaching.
New crop wheat is over $6.00 and Dr(?) Peter Johnson's data documents a 7 bu yield advantage for fungicide application at heading.  Don't worry about those nasty tramp lines, just go and do it with either Caramba or Prosaro.

The only question remaining is when.  Judging the right stage of the wheat crop is as much art as science.  The wheat shown below is not ready. 

We want to see 75% of the heads fully emerged from the flag leaf. This is known as day zero and this wheat is still 2-3 days away from that point. Time to get prepared.

This next head is fully emerged and when most of his neighbours are at this stage we are at day zero.  The trick is, wheat plants don't head at the same time and that is where the art takes over.

Fortunately, we have 5 days to get the fungicide on after day zero.  This gives us some slack.  If the custom app guy is a day or two late, don't sweat it.  It will still work well. 
Few fields are 100% even from one corner to the next, so go to the best areas and stage your wheat there.  The best wheat in the field is the highest yielding wheat and this will give us the best return for the money spent.

Post Emergence Thoughts

There are a bunch of corn acres out there that were planted 3 weeks ago without herbicide.  Now a window has opened to get this job done.  What are the options?

This is an example of how to count leaf stages for herbicide application.

Primextra is extremely popular in this area either as a set up program in RR corn or in combination with Calisto as a one shot early post treatment in conventional corn.

Primextra can be applied post emergent. It is labelled up to 5 leaf corn, but the more important criteria is the stage of the weed. Grasses must be no more than 2-3 leaf at most. If you have 5 leaf corn, I guarantee the grasses are too big for Primextra. 
In RR corn, add Touchdown Total to catch the bigger weeds.  DO NOT add any other form of glyphosate to the tank because to use Steve Johns' of Novartis words, "you may get a tank of snot".
In conventional corn you may have to switch to an Ultim based program, eg. Ultim plus Marksman, to get the bigger weeds.