Thursday, July 5, 2007

Knee High, By the Fifth of July

Since the days of my youth, too many years ago now, the old timers would talk about the corn crop looking good if it was "Knee high, by the 4th of July". Now this saying was directly related to the fact that the corn was typically not planted until after the 5th of May and sometimes the real procrastinators would not be done planting corn till near the 1st of June. Over the years we have learned something about growing corn. Every day after the 15th of May, some are saying the 10th, reduces yield by one bushel. In other words corn planted on the 20th of April should yield 20 to 25 bushel an acre more than corn planted on the 15th of May. Using a price of $3.00 dollars a bushel, we're talking about $60 to $75 dollars an acre for planting early. In the cutthroat farming game, those dollars are far to precious to let slip away. So, most corn planted in north Iowa this year was planted between the 20th of April and May 10th. This planting window allows for rainy days or even a week, multiple fields and other things which are required to produce a crop, such as manure hauling, fertilizer application and spraying.

All of which, helps to explain this picture. The corn was planted on (I think) April 28th, we have so far had adequate rainfall, and warm weather. Corn needs a certain number of "heat units", ie days with x amount of BTU's in sunshine, to reach maturity. I'm not giving a specific number because this number varies according to the number of days a particular varity takes to reach maturity. Some corn takes 98 days to reach maturity, some takes 114 days. A farmer will plant some corn from several different groups to spread his risk, each group will be affected differently by the weather conditions, rainfall during pollination, and other factors such as bugs, fungus, and wind. This corn in the picture has been growing for 68 days. It will tassel, and begin pollination in the next 5 days. Yields will be much better if we recieve rain during pollination. The the pollen falling down onto the silks on the ears of corn will stick and pollinate the plant better if they are wet.

As you can see, this corn is a little past knee high, on my seven year-old.

The crop is looking good. We'll need a rain in the next ten days, and not to much heat, it was over 90 today.