Down The Back Stretch

I posted a while back about our planting date trial in soybeans.  I thought it was time to update our observations.  There is a lot we can learn about growth stages of soybeans and the effect of weather during the later development stages of the crop.

For a refresher these are the reproductive stages of a soybean plant.  The stages seem complicated, but you just have to look at the top of the plant to make the assessment.

R3 - Beginning pod, short pods visible in top 4 nodes of the plant.

R4 - Full Pod, pods 2 cm long at top 4 nodes of the plant.

R5 - Beginning Seed, seed .3 cm long at top 4 nodes of the plant. 

R6 - Full Seed, seed in upper pods fills the cavity.


The R5 stage is the most critical for yield development. The soybean plant can shake off earlier problems and still produce high yields if weather co-operates during this stage. It is why Horst Bohner will say it does not matter what happens to the crop until August.  He is right.  What is sometimes not mentioned however, is the effect of maturity in the yield equation.  That is why we are looking at full season soybeans planted early, May 11 and late (for this year), May 26. 

Pioneer variety 92Y12 is an early group 2 bean.  Early group 2 is approxmately 3050 CHU.  A lot of you would not consider plantring a bean this late.  Some of you do not want to plant corn hybrids in this maturity range either.  That is ok.  Very full season crops are not for everyone.  You have to feel comfortable with your maturity choice. 
The reason we looked at 92Y12 is purely yield.  This is one of the highest yielding group 2 varieties on the market.  Last year in our strip plot it yielded 72 bu/acre harvested on October 12.  We would not be doing our job as a Pioneer rep if we did not push the edge of maturity to see if it makes sense for some of us to try it on a larger scale. 



The May 11 planted 92Y12 were still producing a few flowers at the top pf the plant last week.  This is the late stages of R4.  The upper pods are forming.

Further down in the canopy the pods are flat.

The 92Y12 planted on May 26 is in the R3 stage of early pod formation.  A long way to go, but the growing season is not over. 

The other variety that is being evaluated in the planting date trial is 91Y61.  It is a mid group I variety which is  approximately 2900 CHU.  This is closer to the maturity that, at least in corn, many of you are comfortable with.

The May 11 planting date is just entering the R5 stage.   

The 91Y61 planted May 26 is close to the same maturity stage, late R4, as the May 11 planted 92Y12. 

For comparison we also have late group 0 soybeans planted on May 11.  A late group 0 variety is approximately 2750 CHU.

90Y90 is an example of this maturity. 

Soybeans in this maturity are well along in R5 and approaching R6.  These beans have had extreme heat and drought stress to contend with.  The R5 and R6 stages are both about 2-3 weeks in duration under normal circumstances.  Where the drought is worse it appears the early varieties have rushed through the R5 period quicker than normal.  What effect will this have on yield?  Probably negative. 

It is way too early to make many predictions.  August and September weather will decide who wins the gold in this race.

Does Anybody Know A Good Crop Consultant?

I blew it, big time.

Spider mites have been lingering in the area and I had seen some evidence starting to show up.  I had even taken some shots from a neighbour's field early last week.

I kept telling myself we have never seen major outbreaks before in this area and it was going to rain.  This problem would be isolated.  My soybeans did not have any spider mites.  Meanwhile Peter Johnson was yelling at everyone to spray for spider mites.  Populations will explode he warned.  Yeah Peter, you were right.  I was wrong.  Now there is injury in many fields and Brian has started spraying.  The problem is once you see this degree of injury it is almost too late.  It is like closing the gate after the cattle have got out.  We let a week go by and did not react.  Now it is a long weekend, retail outlets are closed and the supply of dimethoate is almost gone. 

Sometimes It Is Not As Bad As It Seems

I was out yesterday looking at more stressed corn.  The picture below is how the field looked.

Customers have been asking about corn plants burnt up to the ear and what to expect.  We all assume the worst.  A week ago this crop would make you cry.  It was shrivelling in the heat because the rains continued to go around.  3/4 of an inch arrived on Friday night.  I went about 10 rows from the edge and picked the ears shown below from 7 consecutive plants in the same row. 

Five of the seven are respectable.  And with a little more moisture it may surprise.  We all have been in a combine and seen a lot of little ears coming in the header and corn piling in the bin.  The season is not over and the plant can pack a lot of test weight into these kernels.  A week ago you would want to plow it under.  Yesterday, not so fast.

Fertility Tips

I was out this afternoon looking at some badly stressed corn.  It was easy to see how pollination was affected by the drought. 

My rough estimate would be 25% of the kernels on this ear were not fertilized.  That does not equate with 25% yield loss because if soil moisture levels improve the plant will put more weight into the fertilized kernels.  On the other hand if it gets drier, the yield loss will be worse.

There is a good video from the Pioneer website describing the impact of severe drought on both corn and soybeans.

https://www.pioneer.com/home/site/us/agronomy/crop-management/videos/pioneer-moment/

The Following Message Has Been Approved By The Kirkton Horticultural Society

Justin Toews sent this picture to me wondering what had left this tangled mess on his soybean leaf.  I suspect others have asked the same question this year walking their soybeans and finding this symptom.  You will see it on random, widely scattered plants.  The chewing is confined to one or two leaves and doesn't spread to other leaves or plants. 

It is caused by the thistle caterpillar which during the process of building his home leaves a tangled web and chewed up leaf.   It takes him about a week to do his business and then he pupates.  This is when the Horticultural Society gets excited.

The adult of the thistle caterpillar is the painted lady butterfly.  Flower lovers adore butterflies.  A few mangled soybean leaves are a small price to pay in order to keep the Horticultural Society happy.

Keep Trying Sabine

Sabine Maas was telling me last week how she has tried everything she can think of to make it rain.  Leaving the van windows open, washing the house windows and leaving home with laundry hanging outside on the line has not worked.  Yesterday around St Marys and east toward Embro, it actually rained about 1-3"depending on the cloud you were under.  No such luck on this end of Line 6.  Which leaves us like Sabine, not so patiently waiting.

The corn plant is moving on through the pollination stage of development.  Brown silks are evidence that pollination is complete.  You can tell how successful pollination has been by carefully removing the husks.  Fertilized silks fall off the cob and unfertilized silks stay attached to the cob.

 This ear is fully fertilized with 18 rows of kernels.

This ear has mostly green silks and they still are attached to the cob.  In this field this is not a problem because pollen shed is in full swing and in a couple of days all silks will be fertilized.  We have a lot of growing season left and yield potential is still high in a lot of fields.  I believe we are 1" of rain away from a crop that will be much better than it appears now. 

Even plants that look like the ones above,

Will change to looking like this one after a good shot of rain. It will surprise us what they can produce, but they need rain now.

Many have been questioning the value of fungicides, given the lack of rain.  I remain an optimist and believe the rain will come in time to make fungicide use worthwhile.  This morning I was out with Brian applying a test strip of Acapela on his corn.  Acapela is a new fungicide product from DuPont that belongs to the strobiluron class of fungicides. 

If your corn looks like this, fungide will pay.  Typical yield response is 7-10 bu/acre.

If your corn looks like this, the answer is obviously no.  But there is a lot more good corn than poor corn in our neighbourhood which I believe is still worth protecting. 

Just don't ask Brian to do it.  He cursed the whole time we were in the field and this is what his radiator looked like after one round. 

After my post last week looking for blinders Bill Arthur's daughter offered to design human blinders for interested clients.  Ask and you will find.

Where Can I Buy Some Blinders?

That didn't take long.  Wheat harvest started and finished in 7 days.  Yields were respectable, 80-100 bu/acre, some more, some less.  Pioneer wheat varieties performed well, especially 25R40 and 25R39. 
Dan Mitchell, service manager for Stratford Farm Equipment, phoned last Tuesday wondering why so many farmers were complaining about the poor samples coming from their Case combines especially with varieties like 25R56.  My experience has been tough thrashing wheat is usually a genetic problem.  We were spoiled for years with 25R47 which always produced a clean sample regardless of conditions.  Some of the newer varieties that delivered more yield were not as pleasant to work with.  Hulls glued to the kernel, more cleanout at the elevator and more diesel fuel were the end result of planting this type of wheat. 
Pioneer's new 25R40 takes us back to the easy thrashing days of 25R47 with improved yield potential.  It's family tree includes a connection to 25R47.
The other thing making the situation worse this year was the dry spring.  Dry cold weather in April delayed tiller heads from maturing as quick as the main heads.  Rain in June encouraged the delayed tillers to grow and produce wheat.  These later maturing tiller heads were impossible to work with.  This made Dan's life miserable, but it sure wasn't the combine's fault.

Horse trainers use blinders to block distractions and keep the horse focused straight ahead on the road or track.  The drought has been causing a lot of distractions as I drive down the road.  It is painful to see crops suffer and know that we are powerless to do anything about it.  We are actually lucky in this area.  It is not as bad as it sometimes appears.

The two pictures above are from the same spot in the field.  The top one was taken at 3:00 in the afternoon.  The bottom was taken at 9:00 the next morning.  The best time to evaluate drought stress is early in the morning.  If the corn recovers and the leaves unroll over night the yield loss from drought is almost zero.  Growth and development occurs at night.  If the moisture stress is relieved over night, the plant functions close to normal.  It will sacrifice some plant height, but grain yield potential is still excellent.

This picture was also taken locally and these plants will obviously not recover fully.  The crazy part of farming in our part of Ontario is 10 feet away from this picture I took the next picture.

The two pictures are from the same field and the same hybrid.  Because I prefer to be an optimist, I know which picture I am going to focus on.  I am going to ask my neighbour Don Thomson the ferrier, if he can make me a set of blinders.