By Richard Godke
I am a Midwest boy that was trained by some of the leading corn professors in the world. After building a 20 foot tower with a grow light inside an upside down garbage can in my back yard with; full sun, 5 feet topsoil, and the best corn fertilizer program available. My corn plant reached 17.5 feet. I asked my professor why after following all of the best management practices, why did the corn plant not break the world record which was 21.5 feet then.it not grow higher? His answer surprisingly was day length. When summer starts, June 21 the days get shorter and this tells most corn plants that it is time to prepare to tassel. It may take different number of days to tassel depending on the corn variety. My stock started tasseling in mid July.stopping its upward growth. That year I moved away from my tower, excellent soil and a full sun yard so I have never tried again.
Key to growing the tallest corn plant is a shade program that does not let the corn plant know the days are getting shorter starting June 21. It is easier to set a system that limits light rather than trying to substitute artificial light. My garbage can with a 100 watt grow light had little effect on the day length effect, according to the expert. So build a tower that you can keep 100 % of light out, and can open it up every day so the plant thing the days are getting longer the plant will never try to set a tassel so it will keep growing upward. This takes a lot of planning and limiting the day length at the beginning of the growth.