Tuesday, September 27, 2011

Crunching Numbers Part 2

So it's good to be back. It has been cloudy and rainy the past several days, but still warm in the 60's. It hasn't frosted since a brief one last week that did only some minor frosting of some crop leaves. On September 5 I made a blog post called "Crunching Numbers" where I talked about how many Growing Degree Days (GDD) we still needed for our corn to reach maturity, or black layer. Growing Degree Days are calculated daily based on high and low temperature. (As a refresher, or for those who don't grow corn, the black layer forms when the kernal is mature and is no longer connected to the cob for nutrient and water uptake. So the "connectors" turn black as their use is complete.) We have received 2550 GDD since May 5 as of today. So any corn needing that much or fewer GDD would be mature. And such was the case of some 98 day corn that we planted on May 5 on Farm 3. It requires 2450 GDD for maturity, and as the picture below shows, it has reached black layer. But not all of the corn is so lucky. The corn below planted on Farm 7 is a 103 day hybrid that requires 2575 GDD to reach maturity, and it was planted on May 10. (Due to the wet spring, our planting sequence got a little out of sorts, and perhaps we should have switched hybrids and planted the fuller season ones first. But who knew.) The corn is still somewhat green, and is next to a soybean plot where most of the leaves have dropped. These were group 2.4 beans.
Since planting, it has received 2508 GDD and still lacks 67 GDD to be physiologically mature. I'm sure there is some "wiggle room" in these numbers, but they are a pretty good indicator. As you can see in the picture below, it is not at black layer, but is close. Now we estimate with current high temperatures in the low to mid-60's, and lows in the lower 40's, that we are getting around 7 or so GDD's per day. So I suspect we will reach maturity with this corn.

But this is probably not the case with all of our corn. Again, due to the exceptionally wet May, some of our corn did not get planted until June 1. We traded in our 103 day corn for a shorter maturity number, and planted some 96 day corn then. That was all that was available then. Now it requires 2410 GDD to reach black layer, and it has only received 2238 GDD since planting. So we are 172 GDD short as of today, and it is unlikely that we will be able to get that many GDD's before killing frost. So it will be harvested wet and with a poor test weight. But we only have one experiment with this corn, and the results will be meaningful. I feel it.

Also on Farm 7 are our Black Beans. Again due to rain and planting delays, they weren't planted till June 27 which is about 2 weeks later than normal. They are now pretty much mature and are dropping leaves. We hope to apply the defoliation treatment soon, but it has rained every day this week, with more in the forecast. Edible beans like our Navy Beans and these Black Beans are usually the first plots we harvest, and the defoliant helps to complete leaf drop and pod drying. Below Stephanie gives them an inspection.

Below is a dry pod that I opened to show the black beans inside. Aren't they pretty? In case you missed it, as I have said numerous times, Michigan is the nations' Number 1 producer of Black Beans. So be thankful next time you eat refried beans.

In fact, I'm headed for the Taco Bell drive-through right now. Adios.