Very hot days and warm night temperatures the last couple of weeks concern agronomists and corn growers. Unfortunately, this period of hot weather occurred during tasseling and silking. However, the USDA-NASS July 25th Iowa Crops & Weather report indicates that 80 percent of the crop was still in good to excellent condition. Ninety percent of the crop had tasseled and 75 percent silked – both slightly behind last year but ahead of the five-year average.
I’ve heard several accounts -- both in Iowa and other states -- of longer than normal silks this year. I hope these accounts are rare! Silks elongate an inch or more per day until they intercept pollen and the ovules are fertilized. Six inches of silk extending from ears -- like I’ve seen in photos from central Iowa -- could indicate four to six days of growth without pollination occurring. Silks remain viable for up to 10 days and turn brown and separate from ovules when ovules are fertilized.
Iowa State University
Elmore, Roger W., "Long Silks?" (2011). Integrated Crop Management News. 282.
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