How Long Will They Wait?
By: Jeanne Falk, K-State Agronomist for Wallace, Sherman, and Cheyenne Counties
There are certainly challenges with getting crops out of the field this harvest. And the question is how long will the crops wait? There is no easy answer to this, but certain items can help you decide which fields you’re going to target first for harvesting.
For corn, we would like to avoid the situation we were in last year with corn that had some issues with standing. Stalk rots were the main culprit. According to Doug Jardine, K-State plant pathologist, producers can check their corn for stalk rots by squeezing the lower stem with their thumb and fingers. If the stalks crush easily, they are probably infected with one of the stalk rot diseases and may lodge at any time. You can also cut open the stalks to determine the condition from the inside. If the fibers inside are discolored (dark gray or reddish) and look ‘stringy’, then stalk rot has infected the stalk. Check 100 plants to determine the percent of affected plants. If the percentage of stalk-rot-infected plants is high, corn should be harvested as soon as possible, even if it hasn’t dried down adequately in the field. If the stalks are firm, the corn will probably be able to stand just fine in the field for several more weeks if necessary.
Ear mold is another concern. If the corn has ear mold in it now, the problem may continue to worsen as long as the crop remains in the field. However, if there is no ear mold currently present, it will not develop on the standing corn now, even under wet conditions. Ear molds can infect corn through the silks during the pollination period, or following injury from insects or hail. Producers can go out now and check throughout the field to determine presence of ear mold. Be sure to check any low spots in the field, since those are the areas most likely to develop ear mold. If ear mold is present, the corn should be harvested as soon as possible and dried to a moisture content of 14 percent, if it is to be held in storage for more than just a short time.
The situation with grain sorghum is similar to corn. Grain mold can occur on grain sorghum, and turn the heads black, or greenish-black. If sorghum currently has some grain mold, the mold problem may continue to worsen as long as the grain sorghum remains standing in the field. If there is no grain mold at this point, it should not develop now, since grain mold infections occur at an earlier stage of development.
As with corn, stalk rots can be a problem in grain sorghum, so producers should check the condition of the lower stalks now, just as described above for corn. Also check the strength of the peduncle (the neck of the plant – between head and leaves). Large sorghum heads and strong winds can stress this part of the plant.