Wednesday, November 4, 2009
Seasonal Plant Affective Disorder...
I don't know about you, but it seems like the weather throughout the summer has had a severe negetive impact on many things planted related. The disease pressure for plants like tomatoes and ornamental crabapples was high and multiple calls were received in regards this those problems. Of course, even though I look at things from a ornamental horticulture prespective, I also look at other aspects, like how this wet weather, and for the most part, a cool summer impacted commodity crop production like corn and soybeans. I know that in many areas of Illinois that planting for corn and soybeans was extremely delayed and I was told that the delay in planting corn past a certain date begins to negatively effect the overall yield for that year. Let's hope that next year will be better and that at all levels of things growing, the summer will be more normal.
Subscribe to:
Post Comments (Atom)
The overall cool summer certainly was more welcome by people than the corn and soybean crop, particulary corn. Corn plants need to "accumulate" or be exposed to so many growing degree days (GDD)or heat units to reach physiological maturity. Due to the cool summer many corn hybrids in northern Illinois did not accumulate enough GDDs before the killing frost experienced on October 9 and 10.
ReplyDeleteGDD for corn is calculated on a base 50 degree basis by determing average temperature during the growing season with 50 degrees Farenheit being the minimum daily low and 86 degrees Farenheit being the maximum daily high. For example if a day has a low of 50 degrees and high of 70 degrees then the average temperature is 60 degrees. 60 minus the base of 50 equals 10 GDD accumulated that day. Also, if a day would have a low of 40 degrees and high of 70 degrees the GDD accumulation would still be 10 GDD as the minimum temperature used in this example would still be 50 degrees.
When corn reaches what is known as kernel "black layer" then maximum dry matter has occurred. Numerous fields in northern Illinois did not reach black layer prior to the aforementioned killing frost. So there will be some potential yield that was never realized due to the slow GDD accumulation. However, the big problem presently is the high moisture content in the field as most reports indicate corn is being harvested at 30% or more moisture. With the temperatures that we have in November and beyoond there will be little further field drydown. To put things into perspective, in years when corn would of reached maturity in early September and we had a normal temperature fall, corn would probalbly be around 18% or lower in the field on November 1.
Dr. Emerson Nafziger, University of Illinois extension agronomy specialist wrote an article recapping the corn maturity dilemna in the October 9, 2009 issue of the University of Illinois, Pest Management & Crop Development Bulletin. This article was written a few days prior to the northern Illinois killing frost and can be accessed at http://ipm.illinois.edu/bulletin/article.php?id=1236 This article presents some examples of normal GDD accumulation compared to 2009 GDD accumulation during the growing season---Dale Baird
So with this cooler weather and a killing frost occurring when it did, what is the potential effect on overall yield for the season? A colleague of mine who farms a small acreage said that his yield for soybeans was the best he ever had, but I was curious to see if this was a statewide occurrence.
ReplyDeleteThe killing frost's effect on corn prior to maturity was primarily in northern Illinois and eastern Illinois. I suspect the average yield effect will be in the 5% to 10% range in reducing yield, which is just an educated guess. Of course some fields will have no effect. Presently, corn is still at high moisture and not drying much in the field. Sixty acres of corn was harvested last week at my Lee County residence and semi loads of grain ranged from 28% to 32% moisture. Also, due to field conditions, some producers are dealing with moldy kernels (still on the ear in the field)and mycotoxin issues.
ReplyDeleteThe vast majority of soybeans were at physiological maturity when the frost occurred so there will be no significant effect on yield. I have heard of some real good soybean yields as well but when everthing gets done 2009 will be just an average soybean yield year. Overall average yields throughout northern Illinois were reduced due to a soybean disease, white mold, which was prevalent in late July and August. White mold as you may quess is typically more prevalent during cool, moist growing conditions.
Today's harvest progress report from the National Agricultural Statisityics Service indicates 31% of the state's corn crop has been harvested which is the slowest pace since 1946.
Now a horticulture question. I assume the later turning and dropping of leaves from trees was also due to the cool season. Is this correct? Did the cool, wetter season effect the color of the leaves as I didn't notice as many red leaves this fall?-Dale
Actually the extremely cool night temperatures are what can reduce the bright fall colors we are used to seeing. As cholorphyll breaks down in the fall it exposed other pigments that provide the coloring. If extremely cool night temperatures come in before the cholorphyll has finished breaking down, it can reduce the colorful displays as all parts of the leaves are then damaged. Stress factors such as drough and disease can also reduce the display of color.
ReplyDeleteWell I mentioned the wet weather last summer contributed to a very widespread incidense of a soybean disease, white mold, throughout northern Illinois. The record preciptation received in October I suspect will effect the 2010 corn and soybean crop as well. Large, heavy harvesting equipment operating on near saturated soils have caused compacted soils which will be evident next spring. I predict one will be able to see stunted corn plants next spring that follow equipment wheel tracks. Also, there was some soil comapction caused by planting equipment operating this spring in less than ideal soils. The wet weather not only affected 2009 crop yields but will affect some 2010 yields-Dale
ReplyDelete