Jason Karl used this specially constructed greenhouse to grow a 48-foot-tall cornstalk.J. KARL
At a whopping 48 feet (14.6 meters), a corn plant in Costa Rica is now tallest in recorded history. Last year, agricultural scientist Jason Karl grew a strain of maize, Chiapas 234, to be 45 feet (13.7 meters) tall. He got it to attain that height by tweaking a gene called Leafy1 and adjusting the plant’s exposure to light. Now, Karl has managed to coax another three feet out of the corn.