With grain prices reaching all time highs, it is extremely important to get every bushel we can. Even with elevated input prices, we have an opportunity to have high ROI’s with your 2022 crop. Since we already have a lot invested in this crop it makes more sense than ever to protect it.

So why is late season plant health so important? As you can see on the graph below, when corn begins to dent at the R5 stage we only have 45% of the dry matter in the kernel. As you probably know already, the corn plant can get dry matter from sugars in one of three places:

• The roots - which are all but done pulling in nutrients at that stage
•  The stalks - which have a finite amount in them and if that cannibalizes at a high level that will cause standability and other issues
• The leaves

           

Source: Bob Nielson, Purdue University
 
The Bottom Leaves Still Matter
As you can see below when the bottom leaves are removed from the plant at tassel time (VT) yield dropped by 63 bushel. Adding fungicide to the leaves below the ear added back over 20 bushel of that loss.

The key to getting good coverage top to bottom is to use Masterlock adjuvant that combines Interlock and Drop Tight additive technology to enhance spray coverage. This is critical for protecting against diseases like tar spot that can start in the residue and work their way up the plant.
 

 
How does this increase yield?
 
It’s all about the math. Since you can no longer add population, kernel rows, or length in the late season, the only thing you can influence is to reduce the number of kernels it takes to make a bushel of corn. If adding fungicide, that will reduce the number of kernels it takes to make a bushel by 5000.  
 
For example: Lets say you have 34000 plants per acre with average ears that are 16 rows around and 34 kernels long.
 
            34000 x 16 x 34 = 18,496,000 kernels per acre
 
            At 85000 kernels per bushel you would have a yield of 217.6 bu/acre
 
            At 80000 kernels per bushel you would have a yield of 231.2 bu/acre
 
Thats an increase of 13.6 bushel!! At $6 corn that is an extra $81.60 per acre for a $30ish per acre investment or a $50 return on investment.
 
In areas where you can’t get a plane or helicopter to spray fungicide, consider Xyway fungicide that can be used with liquid fertilizer at planting time. Ask your United Cooperative agronomist for more information on all the fungicide and Masterlock options.