“I’d like to thank the PA Corn Growers for sponsoring my talk here today,” said Eric Rosenbaum, one of the presenters at the 2015 Farming for Success at Penn State’s Research Station in Lancaster County, PA. The corn growers association, he added, “is active within the state. We are doing a lot with education, not only to educate farmers on what we can do to increase yields and profitability, but also to educate the non-ag community on what is considered a normal farming practice, why we do the things we do, why we have big sprayers, why we have big combines, why we’re using pesticides and why we’re using GMOs.”
Rosenbaum broke his topic of corn plant reading into three sections: Reading a plant from planting to V5, V5 to tassel and tassel to black layer. Planting to V5 is probably the most important stage of growth because the things you do at this point certainly affect the end result. That includes getting your planters set up, and making sure that you can uniformly and consistently place a seed two inches deep across a variety of conditions. This matters a lot more than just about anything else that you do. Referencing the field he was standing in, Rosenbaum said that “when you look at this field, you can tell there is something basically wrong with it, and it doesn’t take a lot of diagnostics to figure out that this corn was planted about a half inch deep. That is a huge problem. When corn seed germinates, seminal roots are the ones that come out first. They go from the seed down into the soil and they basically sustain the plant for 10-to-14 days, until nodal roots form. When you plant corn a half inch deep one of the issues you have is that nodal roots form above the seeds. If you don’t have enough soil between the seed and the soil surface to support those nodal roots, you will have really pathetic looking roots.” He went on to say that this half-inch seed planting will make a crop that never recovers, and which will never produce an optimal ear. And make a note that before you get to V5, all herbicides should be applied.
Between V5 and V7 the corn is determining how many rows around the ear it is going to set. Typically, that number is 18, but if there is any stressor on the plant it might set less. The stressor could be the half inch planting or an herbicide injury applied 10 days previously. What about insects? “This year, I didn’t see a lot of insect pressure. Probably the biggest insect I saw this year was on double crop corn planted after small grain silage; we had thrip infestations on just about every field I looked at. I’ve never seen thrips bad enough to spray corn. But this year, if people were going through with their post-emerge glyphosate applications, we were having them put an insecticide in to address thrips. We are starting to see some yellowing and discoloration on leaves because of the thrip feeding.” When corn is waist high, V10 or V11, it is getting into its critical state of nitrogen accumulation. Good root systems are needed to get that nitrogen in. “These plants right here,” he said, showing some waist high corn and some a bit taller, “are taking in about seven pounds of nitrogen per acre per day and also potassium by the same measurement.”
The second most critical period for corn growth, maybe two weeks prior to tasseling, is when the corn is going to set the number of kernels per row. Any stress during that time will affect this process. Going into tasseling during what’s known as the blister stage, environmental stresses will likely impact the corn’s ability to retain those kernels that it was able to set in that pre-tassel stage. After tasseling, it’s a good idea to walk your field and determine how well pollination worked. Pull the ear leaves back, shake it until all the silk falls off. If the silk falls off, the pollination was successful; if it doesn’t, you might not have waited long enough or were simply not getting pollination of those plants.
About 10 to 14 days after the silk has emerged, you should be able to tell if the operation was a success. Environmental stress is usually the villain in these particular cases rather than something herbicidal or anything related to nutrient deficiency. “If we get into a drought period,” Rosenbaum says, “where pollen sheds before silks emerge, or if we just don’t have enough moisture to keep those silks hydrated, there will be issues with pollination.”
Rosenbaum also called on H. Grant Troop, Executive Director of PCGA, to give an update on repealing the Renewable Fuel Standard Repeal Act (RFS).
“The RFS requires ethanol to be in our gasoline at a certain rate,” Troop began. “In this country we now produce 5.5 billion bushels of corn that we didn’t produce in 2008; that is extra production for the ethanol industry. We still grow the same amount of baseline production of corn for everything else we use it for.”
“Could you imagine if all of a sudden, the requirement to have ethanol gasoline was pulled out from under us across the country? What on earth would we do with five billion bushels of corn! Corn now is down to close to the cost of production. It would put that much unsold corn on the market and totally crash the price of corn. We’d be under two dollars again. The basic argument [in a recent debate] if you pull that RFS requirement out from under the country, it would send the ag economy into a depression. You would have 5.5 billion bushels with no place to go. When the corn economy goes into a depression, six to 18 months later, the whole country would be in a depression. This is without exception if you follow the history of our country.”
Eric Rosenbaum has his own consulting business, Rosetree Consulting. He serves as a member of the Pennsylvania Corn Growers board of directors. He and his wife have an association with Penn-Ag Industries to spread the word about the PA 4Rs Alliance.