Should You Be
Around this time of year, planting corn and soybeans is in full swing. With lots of rain in the forecast, we fully expect to see a rise in the amount of corn being planted. In order for corn to emerge, it takes around 90 to 120 GDD. With the temperature staying relatively mild, any corn planted in early spring should soon be peeking through. Now is the time to be scouting.
Tips for Scouting
First of all, you need to determine what your seedling population is. Save some time by determining what the row width is in correlation with the row length to equal 1/1000 of an acre. For instance, if the row width is 15 inches the row length would be 34 feet 10 inches. On the other hand, a row width of 38 inches would have a row length of 13 feet and 9 inches. Next, count the amount of emerged plants in a row and multiply that number by 1000. This will calculate the number of plants per acre and can be done many times throughout your field.
Next, you’ll need to calculate the amount of attrition losses. As a general rule, if you experience attrition losses of more than 10 percent, dig up the seeds to determine the cause. It could be possible that from the get go the seeds had bad germination ratings. Another possibility is insects such as cutworms, wireworms, and white grubs. Seedling diseases are another huge factor and are caused by pathogens in the soil. Unfortunately, they are hard to diagnose because many seedling diseases have the same symptoms.
Additionally, side wall compaction or soil crusting can both hinder your seedling emergence. If you’ve planted corn early in the Spring, it’s possible that water from the cold soil was absorbed. Cold soil could negatively impact your seedling population.
In order to prevent competition between crops and weeds such as giant ragweed and marestail, burndown and the use of pre-emergence herbicides is a must. As a matter of fact, fields with only post-emergence herbicides experience a great deal more early season competition. While taking action early on is extremely important, don’t neglect the use of post-emergence herbicides either. Some weeds that emerge later in the season are waterhemp and velvetleaf.
Making the Decision to Replant
It’s not totally necessary to replant just because of uneven emergence heights. But, if the plant populations are diminished you may want to consider replanting. Since you’ve already estimated the seedling population, it should be easy to determine expected yield. When deciding, compare what you expect with current stands with what you could have if replanting was done. Also, take into consideration the cost of replanting. For example, tillage, seed, fuel pesticides and of course labor are all an added expense. Since you’ll want to avoid fall frosts, look into a shorter season hybrid seed.