Yellow corn and soybeans have been widespread the first part of July in most of Ohio. Since May 1,
many parts of Ohio have received at least three to four inches above the five-year average. Growing Degree Days (GDD’s) for the same period have accumulated 1,300 to 1,400 units, which is 200 to 300 GDD’s ahead of normal. We use the GDD’s to track the overall progress of corn development. I like to consult the numbers weekly to track the progress of rainfall and temperature in the state. You can also track these at the Ohio page for the National Agricultural Statistics Service: http://www.nass.usda.gov/Statistics_by_State/Ohio/Publications/Crop_Progress_&_Condition/index.asp
Another great service for tracking rainfall comes from The Climate Corporation. Climate Basic is a free service that will send you e-mail alerts when rainfall is detected at your farm. The nice feature of Climate Basic is that it will send you alerts daily on a field-specific report. That means that every field that you sign up will get a rainfall report. You can access this at:
Productivity issues for your 2015 corn crop to consider:
• Corn pollination — Most of Ohio’s corn crop pollinated from July 15 to 27 in nearly ideal conditions. The first two weeks of August are an especially critical time for ear development, so be sure to follow the traditional, good management practice of checking your plant’s pollination and kernel development status. Carefully remove the ear husk leaves making sure to not disturb the silks. Gently shake the ear and let the silk fall to the ground. The silks that fall off the ear have pollinated the kernel. Those still attached have not pollinated the kernel.
• Kernel counts — By Aug. 1, you should be conducting kernel counts to determine or predict potential yield of each field. To calculate Corn Yield, pull several ears from different parts of the field to obtain an average. Bushels per Acre = (number of kernels around the cob) X (number of kernels long) X (plant population per acre with an Ear) divided by 90,000 kernels in a bushel. Counting kernels always overestimates Yield, therefore, reduce your yield count by 10%.
• Visit insectforecast.com — By checking out www.insectforecast.com, you will find risk assessment maps showing the prevalence of insects such as the Western Bean Cutworm, Western Corn Rootworm, and Corn Earworm. This is a great interactive tool for growers to keep up to date on these insect threats.
There are 2 late season insect pests that Ohio Growers need to be aware of in their soybean crop.
• Japanese beetles — The primary soybean insect affecting Ohio is the Japanese beetle. It is especially important to ensure their populations do not get too high, as Japanese beetles feed on almost all parts of the soybean plant including leaves, and soybean pods. If you have 30% defoliation you will start to lose yield. If you see the number of Japanese beetles growing and feel your yield is being affected, consider applying chemical control to your soybeans.
• 2-spotted spider mites — One of the benefits of a rainy summer is that spider mites are usually kept in check. They love it hot and dry. The numbers of mites can explode very fast, however, under these weather conditions and growers need to be scouting their fields for mites if conditions get dry this month. Check the underside of the leaf blades and lower canopy. Look for mites, eggs, and their webs. You may also see leaf discoloration from mites feeding on leaf tissue that usually starts at the edge of the field and works its way to the middle of the field.