Corn in the backyard 2010, week 8

June 20

The growth rate data for the corn this year has been so interesting compared with last year, that I just had to share the data even though the corn is not done growing. Our initial impression that the stalks were growing slower this year was confirmed when the data from both years is plotted on the same chart as seen below.

Week one in each case is the first Sunday that the plants appear above ground, and you'll notice this year's corn is lagging the pace set by last year's crop. In weeks 6 and 7, the stalks were only half as tall as they were after the same number of weeks last year, although week 8 shows the 2010 corn increasing its growth rate at the same time the 2009 corn was slowing down as it approached full height. There could be several reasons why the stalks are growing slower this year, but I think one of the primary reasons is the weather. Because the 2010 corn emerged about 3 weeks earlier than last year's corn, it has had fewer hours of sunlight in which to grow. The weather was warmer and drier in April 2010 than 2009, which made it possible for many farmers to plant early, but cooler weather in May may have slowed the growth of the corn over the first few weeks of the 2010 growing season.

Consequently, it seems prudent to present the data with respect to calendar dates as this second chart shows. When viewed this way, the corn is much further advanced now than it was at the same time last year, and it looks like it could easily rival last year's crop. Farmer Wagenbach thinks the final height of the stalks could be shorter than last year based on the time of planting, since early crops generally don't grow as tall as later crops. He says that's primarily due to the difference in hot days experienced by the plant since corn grows taller in hot weather than cold (all else being equal). Ultimately the height of the stalk doesn't matter as much as the quality and quantity of the kernels produced by the ears, so we won't get too excited about the discrepancies in growth rates. Instead, we'll just enjoy another opportunity to play with some data and try to understand the world around us. Thanks for visiting!