Estimating corn yield can help you with harvest planning and you can use different methods to estimate yield potential at different times during the growing season. Remember that crop uniformity can have a huge influence when it comes to accuracy of any estimation method. You need to take samples randomly throughout the field to get the right estimate. 

You also need to take more samples in a nonuniform field so that you can get almost an accurate estimate. Some of the most popular ways to estimate corn yield are perhaps the corn ear weight method and the corn yield component method. This article discusses the best methods you can use to estimate corn yield.  

Corn yield component method

While there are various pre-harvest corn yield estimation methods, the corn yield component method is the most popular one. This is because you can use this method quite early during the milk stage or roasting ear of kernel development. 

Under any normal condition, this kernel milk stage can happen about 18 to 22 days after completion of pollination. Estimates that you can make during the earlier development of corn period risk having overly optimistic if there are severe stresses that leads to unforeseen corn abortion.

The yield component method came up several years ago and is usually based on the assumption that you can estimate corn yield from estimates of the corn yield components that make up corn yield. Therefore, these corn yield components can include the number of kernels per ear, number of ears per acre, weight per kernel, and number of kernels per row. You can easily measure the ear number, kernels per row, and kernel row in the field.

You cannot measure weight per kernel until the corn is mature. Technically, you can do it when a grain moisture is at least 15 percent because that is the normal moisture value. As a result, an average value applicable to kernel weight can be used to express fudge factor in the corn yield estimation.

It’s worth noting that kernel numbers that are 5-lb bushel among fields within years may vary a lot and can be influenced by hybrid genetics and growing conditions. Kernel weight of hybrids can also easily vary significantly from less than 65,000 kernels per 5-lb bushel to at least over 100,000 kernels per 56-lb bushel. When it comes to kernel weight from one year to another for the same hybrid, it can also vary by 20,000 kernels per bushel or even more just because there is variability in growing conditions in the corn filling period.

Remember that crop uniformity can also influence the accuracy of any corn yield estimation technique. So the less uniform the corn field, the greater is the number of samples that you need to take so that you can estimate corn yield for the field. Also, there is a fine line between sampling randomly in your field and fairly sampling in disparate areas of your field.

Remember that the corn yield component method and estimated corn yield calculator you can utilize to estimate pre-harvest corn yield can only provide an estimate. Because kernel size as well as weight can vary depending on environment and hybrid, this yield estimator can only be utilized to determine ballpark grain yields. 

You can easily overestimate corn yield in a year that has poor grain fill conditions like low kernel size and weight with a drought year and underestimate in a year with great grain fill conditions, such as larger kernel size and weight with non-stress grain fill periods. The sample that has a closer kernel black layer stage means that there is more accuracy to your estimate regardless of whether kernel weight is above or even below average for that year.    

Remember that this corn yield component method you can use to estimate corn grain yield may only be accurate within 20 bushels of the actual yield. Therefore, the more ears you can sample in your field, the more accurate you can get the variability of yield within the field. You can utilize the yield estimates you get using this method for planning purposes only.

There are several apps out there you can download to either your smartphone or even any mobile table that you can use to get the calculations of the yield component method. There are some crop scouting apps that come with grain yield estimators as part of their features. But you need to make sure that you test the calculations of any app you decide to purchase on your phone to make sure that it gives the correct math.  

Some of these apps provide several kernel fudge factors, though they don’t literally specify the number of kernels per 56-lb bushel they utilize. There are also others that allow you to test 3 ears at a time. However, most of these apps don’t allow you to sample and even save the results of several sites in a field or several fields in an operation.

Corn ear weight method

The corn ear weight method is another method that you can use only after your corn has reached maturity or black layer. Keep in mind that this method can be more accurate than the yield component method. This is because this method is based on the actual kernel weight, but it does rely on average shell out percentage.  

To use this method, you need to sample multiple representative sites in your field. Then you should count the number of ears that can be harvested in 1/1000th of an acre for each site.

Therefore, you need to weigh every fifth ear and then calculate the average ear weight for each site. You can hand remove kernels from these ears and find out the average grain moisture using a moisture tester. 

After taking the above steps, you must calculate the average yield potential for each site. That said, it’s important to note that both of these corn yield estimating methods can assist you to plan your corn harvesting. Therefore, it makes sense to use them so that you can get the rough estimates.