What you should know about corn yield estimates

It’s always important for producers of corn to estimate their corn yields so that they can know what they can expect at harvest. There can be a huge variation in corn yields within fields as well as from one field to another depending on date of planting, hybrid selection, and field uniformity. Ideally, there are five elements of corn yield that you can measure using a corn calculator. These include plants per acre, rows per ear, ears per plant, kernel weight, and kernels per row. 

These components are usually determined in a specific sequence during the growing season. Therefore, measuring these components to get corn yield is known as the yield component method. With this method, you can use it before harvest even as early as the milk stage of corn development. It’s crucial to quantify these components, especially when plant stressors happen so that you can know the affected components. This page discusses what you should know about corn yield estimates.

Plants per acre

You can determine the number of corn plants per acre by seed quality, seed rate, and the condition of the soil at corn planting and germination. It’s worth noting that there are also other factors that can affect the number of corn plants per acre. These include cultivator damage, crusting, hail, insect feeding, stalk lodging, green snap, and any other forms of damage. 

When it comes to ears per acre, then many hybrids usually grown by most producers have one dominant ear. Therefore, corn can develop more than an ear shoot per plant, though usually only the main earshot may produce kernels.

Ears per plant

Quite often, observing ears per corn plant and corn plants per acre are usually combined. You can do this by finding out ears per acre like plants per acre, but you should omit barren plants. These barren plants can be due to a high corn plant population, nutrient deficiency, moisture stress, or even a combination of all these factors. 

Besides, multiple ears per plant may be realized if corn populations are either low or other close plants are not there. This can occur at a field border where corn plants may have access to more nutrients, water, and sunlight.

You cannot determine ears per acre before pollination happens. To measure ears per acre, it’s necessary that you should determine this at several places within a corn field, especially if there is a low crop uniformity. At each estimation place, you can measure off a length of a row that is equal to 1/1000th acre, this is 30-inch rows which is 17 feet and 5 inches. After this, you can record the number of ears you can harvest.

Kernels rows per ear

Practically, you can determine kernel row number by the 6th stage also called V6. Hybrid genetics can be the most crucial factor that you can determine the number of kernel rows. But plant stresses may reduce the real number of kernel rows that are produced.

The number of kernel rows that are on an ear is usually an even number since the first kernel is split to form two rows from one. You can visually check kernel rows by splitting ear shoot during the late vegetative stages.

Kernels per row

You can determine kernels per rows, developmentally, at almost the 6th leaf stage called V6 up to tasseling known as VT. The maximum number of ovules come at least a week before silks start to emerge. There can be plant stresses at this point that may reduce the number of ovules that can develop.

Some studies suggest that there can be up to 1,000 ovules per ear. But the number of ovules that can be fertilized and retained may determine kernels per row. There can also be kernel abortion that happens during the milk stage called R3, especially if corn plant stress happens to the level where there is not enough resources. Kernel abortion happens beginning from the tip of the ear. You can determine and measure kernels per ear during the milk stage.

To determine average kernels per row and kernel rows per ear, you should record the number of full kernel rows per every 5th ear in the row. You should then multiply each ear’s row number by the number of kernels per row. The results give you the expected number of kernels per ear. 

Avoid sampling nubbins or even deformed ears unless you think that they represent the sample area quite good. If row number changes starting from butt to tip, then you need to estimate an average row number for that ear. However, avoid counting the extreme tip kernels, butt, or aborted kernels. If you find out that there are uneven kernel numbers per row among the ear rows, then you should estimate the average value for all kernels per row.

Kernel weight

You can determine kernel weight largely from the blister called R2 to dent stages also called R5. It’s quite common to utilize a generic and assumed value for kernel weight, especially when it comes to determining yield estimates. Many common kernel weights can usually be between 0.25 and 0.30 grams per kernel. With yield estimation, there is a correction factor of between 65,000 and 110,000 kernels for every 56-pound bushel utilized, but many corn producers mostly use 90,000. 

If you see that your corn crop is experiencing stress before R6, then it means there can be less starch accumulation in the kernels. Therefore, you need to reduce kernel weight at this point. You should adjust the kernels for each bushel upward. However, if your corn crop is almost in perfect conditions, then you can adjust the value downward. 

To conclude, yield estimation utilizing yield components can give you a good estimate for your corn. You can use a calculator to determine your corn yield for that season. As explained earlier, you can determine these yield components in a particular sequence during the corn crop growing season. You should also remember that there is an equation you can use to determine yield estimate.