Where’s the water? What will be the yield?

With the recent lack of rain in our area and around the state many are wondering where is the water. At the Franklin County Extension office we haven't had a rain give us more than a tenth of an inch since June 9^th. During this same period our estimated evapo-transpiration has averaged about two tenths of an inch per day. This has left us with dry soils and corn that is showing signs of stress. The real question that comes up though is what does any of this mean for yield? For this we need to go back to the physiology of corn and look at what is happening currently and how stress will affect that. In general, when talking strictly about grain yield, our younger corn will weather a dry period without yield losses much better than our older crop. These younger crops are typically developing roots which may be limited due to drought but can recover if good moisture follows. The only real critical time for this young corn is the V-4 to V-5 stage where the number of kernel rows is determined by the plant.

Typically the corn that has not reached V-12 will have little yield loss. At the V12 to V14 stage the corn plant is initiating multiple processes which will set in stone what the maximum yield will be. These include; ear number determination (only on prolific hybrids), ear size, and number of kernels per row. Once these variables are in place we head into the critical time around silking. From R1 to maturity we have to have good conditions for the ear to silk in time for pollen shed as well as pollinated kernels to fill. Drought conditions around the silking time may lead to unfertilized kernels, thus decreasing yields. Once fertilization has occurred moisture and nutrients are still required to push fill.

This may seem like an effort in futility since we have little to no control on the amount of water our crop receives. However, if you are looking to make management decisions based on yield projections now is a good time to make sure you adjust yields if you feel your corn has been stressed to that point.

Frost Damage

With an unusually warm April is seems strange to be talking about frost damage in the second week of May, however here we are. Some of you may have experienced some localized frost damage in corn fields on Sunday to Monday night. If you have recently scouted your emerged corn you may have found water soaked leaves that are unusually dark in color or brown leaves depending on how soon after the frost you may have discovered the corn. These are typical symptoms of frosted corn. If you're wondering what will happen now the best answer is just wait. Prior to making any replant decisions allow a few days to a week for the corn to recover from the frost damage. At the stages that most of our corn is at (emergence-V4) we should be ok. Due to the lack of prolonged cold in our area you will likely find any frost damage sporadic at best with little to no pattern in the field. Low lying fields and areas of fields are more likely to have been damaged as well as fields no-tilled with substantial cover. Again, corn is very resilient at this point in time so give it a little while before decisions are made to replant. I would be very surprised if we have any stands that warrant a replant for frost damage.

Soybeans, on the other hand, are less resilient to frost. I am not aware of any beans that were up and damaged by frost, however if temperatures hold below 30 degrees for any extended period of time beans will die. Again, I would be surprised if we have this type of damage, however localized damage may have occurred in low lying area and could warrant a quick check if you know you had some emerged beans.

The ‘Corn Guys’ have left the county!

Penn State has established two plots in Franklin County to help you make better decisions when buying next year's corn for grain and/or silage. In cooperation with Professional Dairy Managers of Pennsylvania (PDMP) Penn State established a corn silage hybrid test plot. This plot will include both full season and short season varieties and will be taken to harvest where quality samples will also be analyzed from each hybrid. In addition to the research going on we will also have a field day held at Burk-Lea Farms in association with this plot on August 12^th.

The other plot established in the county is a corn grain hybrid trial. This trial will be similar to the PDMP trial; however it will be taken to yield for grain. Measurements from this plot will include yield and grain quality.

All of this data is then compiled into the 2010 Pennsylvania Commercial Grain and Silage Hybrid Corn Test Report. These reports come out over the winter and are typically available during our winter meetings. The reports give you a way to see local data as well as the other sites around the state. Hopefully this will help you in your future decisions for what varieties may suit you the best.

Budget Savvy Corn

As markets continue to be volatile and margins are scrutinized we all are looking for a place to save some green, is your corn doing the same? Recently there has been a lot of attention focused on corn hybrids and their use of nitrogen. What if genetic advancements allow us to change our nitrogen recommendations on corn, how about if you use the same nitrogen but increase the yield? Research has already shown that yield response to nitrogen is not only based on amount but also tied to soil type and yield potential so it seems only natural that the specific genetics of the plant may also be a player. Recent research and demonstration has also shown that some of the most striking differences with hybrids is how fast they can recover after a time of stress. Another interesting article was also recently posted on AgWeb looking at some of the possibilities to advancing corn yields in the future by minimizing stress to individual plants. Individual plants must compete with each other for nutrients in order to have consistent growth across the field, so if these plants can get better at competing hopefully they will utilize more of the nutrients available to them in the field.

As we look down the road we may see more ways that corn becomes budget savvy. This shouldn't be a surprise to us since in some sense it has already happened. With new traits we can now plant corn resistant to pests allowing us to spend less on chemicals and applications (while more for the bag of seed) and also saving us some time. As we move forward in the market there is no doubt our corn will continue to get 'smarter' and hopefully widen our margins on the farm.

Here we go!

Corn is 'rolling' out of the fields in Franklin County. Though a lot of corn is still standing we are starting to take high moisture off and it looks like quite the crop so far. Today I was in a field that was running about 24% and with a corrected yield of 230 bu. It looks like most of this years corn will be a great crop. This field was an early planted field with 114 day corn. Overall I believe we will see high yields across the county. Most silage has been running around 25 tons on the better soils with highs in the 30's. Some of the less productive ground has been running around 15-18 tons which isn't bad at all! Tomorrow I'm going out to harvest the Franklin Co. bean plots so hopefully I have some information on what the bean crop looks like as well.

Corn drying well

I have been taking a few samples in the fields to see where some of the grain corn is at as far as moisture's. To be honest I have been surprised at the numbers I've been seeing. Most early planted corn I have been testing has been around 20-26% moisture. I have noticed a few combines running, and for good reason. If you are looking to shell high moisture corn and have some mid length corn (around 114 day) that was planted in good time this year it may be time to take a sample through the field to see where you are at. We had trouble getting whole plant moisture to the place we needed it for silage, however our ears have been drying well, even on green stalks. Make sure to take a representative sample from your fields, now just the outer rows.

Selling Considerations; Shell versus Silage

As corn dries down many look to prices and markets to see what options they have. In Franklin County we typically have the option of either selling silage or grain depending on what seems to have the most favorable economics. I am not an expert in the markets so I'm not going to tell you that this is black and white, however I do have a few considerations you should make prior to selling your crop.

The main difference on the agronomic side of silage versus grain is the nutrients removed from the field when we take the whole plant versus just the grain. For this example I'm going to look at only phosphorus (P) and potassium (K). Nitrogen can also play a role but the system is very complex so it is not clear exactly how much we will keep around until next years growing season either with or without cover crops (this is why we test prior to side dressing N).

So if we look at removal of P and K from silage we can estimate (using Penn State's Agronomy Guide) that we will remove approx. 5.0lbs/Ton of P and 11.0lbs/Ton of K. As a rough estimate we typically consider the conversion from bushels of corn to tons of silage as 6.5-7bu/ton of silage. If we use this conversion for our removal rates for grain end up at 2.8lbs of P and 2.1 lbs of K removed (7*book values for grain removal). This means that roughly twice the amount of P is removed and over 5 times the amount of K is removed when comparing silage to grain.

So let's do a quick example to clarify. Initial estimates show a 150 bu/ac grain yield or 21.5 Ton/ac silage yield in a specific field. We are trying to decide if we should sell it to the neighbor or keep it for grain. December futures are showing a price of $3.09/bu or$464/ac on this yield. The difference between grain and silage in nutrients removed at this yield will be 47.5 lbs of P and 191.5 lbs of K. With today's price of $0.25/lb. P and $0.50/lb. K this is a difference of $107.63/ac. just to buy back the nutrients you lost by selling silage. If we add that into our grain price ($464) we need $572/ac. or about $27/ton (on 21.5 Ton/ac) to break even with our grain price of $3.09. Obviously neither of these take into account the cost of harvest etc. so keep in mind who is paying for that when pricing your corn.

Corn Silage Update

As of today our plot is just over 33% D.M. I have noticed a descent amount of silage coming off especially in the southern portion of the county. We are almost where we need to be if we are filling trenches, but we need to be careful we don't push it too quick going into uprights. Again review the comments I have below about setting your kernel processors, I believe this will be crucial.

Check you ears!

No pun intended actually, we really do need to get into the cornfields and check your ears prior to harvest. I received a call today from a local crop scout who has been seeing and hearing of 'beer can' ears around the county. This is a phenomenon where the bottom few rows of the ear are properly filled while the top of the cob is barren. This obviously can cost a lot of yield.

It is believed that this phenomenon is usually due to a cold snap when the corn plant is forming the ear (V5-V8). This always occurs in this manner since corn will always develop kernels from the bottom of the ear to the top. So what fields are at risk? Well typically it appears that it takes lower 40s to stress the corn so I dove into the this years temperature records to try to pin this down.

It appears the May 14th and 19th are likely the main dates when damage likely occurred. Hagerstown Airport reported a low of 41 degrees for both days. If we look at the fact that it typically takes 4 weeks to reach V8 (where ear development is thought to be complete) and V5 is normally about 3 weeks after planting we can assume the highest risk corn for this abnormality was planted between April 14th and April 28th (due to two dates with low temps). Obviously any fields around this period should be checked. Overall, you may want to check all your early plantings.

The main issue with this abnormality would be decreased yield when shelling the corn. If you have the ability to chop this corn for silage and shell another field it may be advantageous. Of course you will take a hit on energy in your silage as well, however it may be a better option.

Adjust those kernel processors!

As the corn slowly dries down I'm seeing some drier ears on some very green stalks. If we continue this trend it may lead to some issues in getting available energy in our silage. If you have a kernel processor you are steps ahead in this area already. However, just because you put out the cash doesn't mean it will work without some attention. When you are out harvesting make sure to take some samples early on to see how the processor is working. To check the kernels take a handful or two of silage and place it in a 5 gallon bucket. Fill the bucket with water then slowly pour off the water. Once the water is pretty well gone you should be left with only kernels. Carefully inspect the kernels to make sure they are well processed and cracked. If the kernels are not cracked adjust the processor to a narrower spacing and test again.

Corn Starts to Dry Again!

I just got done looking at moisture on our plot. In review this was planted on the 29th of April and the variety I'm looking at is a 114 day variety. The moisture this morning finally has moved from the 30-31% D.M. we have been holding at for about a week. Today we are standing at 31.7% D.M. Although this isn't a huge jump it is finally in the right direction. The downside to this is that we are to have rain today and tomorrow which means we probably won't be drying down much going forward. So with all this said it looks like we may be into September before we really get silage harvest rolling. I know many have been pulling into the fields this week but I think for the most part in the county we are still waiting. The silver lining to all of this is that we have quite the crop sitting in the field when we do start in.

Silage continues to wait

Checked the plots again today since the research team is ready to get started on harvest. It still is hanging around the 30-31% D.M. We are sitting right around 2400-2500 growing degree days (GDD) according to Pa Pipe. This puts us about 100 days behind average. This would explain why we are seeing things so slow to mature around the area.

Other observations in the corn plot

Just a quick note of some other observations in the corn plot this morning. The corn overall is very impressive with nice sized ears and good height. I noted that milkline has begun to move on some varieties, however, as noted the total plant moisture has not changed. I also noticed a fair amount of grey leaf spot in the plot, however this will have little to no affect on the plant at this stage. It seems around the county in general we are set to have a great crop this year. Even much of the late corn planted is looking great especially after Friday's rain. Hopefully we will get some real nice corn silage put up so we can make the milk roll once prices return and help fill in the gaps created by this price slump.

Corn Silage Dry Down Slows

I tested the PDMP plot again this morning and it appears our 1in. + rain on Friday has slowed us down a bit. The plot tested at 31% D.M. which is the same figure as Friday a.m. prior to the rain. This combined with an overcast day with some drizzle on Saturday seems to be holding the dry down off for a bit. The U.S. Weather Service is calling for cooler temperatures the begining of the weak with no precip. Hopefully low humidity and clear skies will help the corn to dry down again. I'll keep an eye on the silage plot and will have another posting on moisture on Friday if not before. Just in review this plot was planted on April 29th so you may want to adjust accordingly for your planting dates.

Corn Silage Dry Down

I sampled the PDMP plot this morning and I got a result of 31% dry down. That means in the last 4 days it has changed 6%, or 1.5% per day. In all honesty I thought it may be a little faster then that, however if this trend continues we are looking at harvest to start in another 5-6 days. This seems late for typical harvest, however we have had a cooler than normal growing season, so our degree days haven't mounted as fast as typical.

Other observations this morning was that most of the corn was at dent, however very little to any milk line was present.

Corn Silage Harvest Drawing Near

Corn Silage harvest is just around the corner and I've started taking moistures on the PDMP test plot we have here in the county. On Monday the plots were at 27% D.M. so a little ways to go until we reach 40. We certainly have varied planting dates and stages of maturity around the county, however I do believe we start to see our earliest plantings getting close in the next week or so. The plot I'm sampling was planted on the 29th of April. I'll take another sample tomorrow and post the details.