Some plant genetic traits are offensive traits, including rate of regrowth for alfalfa and grass and corn hybrid ear fl ex; they increase crop yield. Other traits including disease resistance are defensive traits, they protect yield. Alfalfa varieties with multiple disease resistance don’t cost much if any more than those with resistance to only a couple of diseases. (All modern varieties have at least some disease resistance.)
This is not the case with the genetically modified traits available on today’s corn hybrids. In most cases, adding genetic traits adds to the price of the seed corn. And remember that most of these traits are defensive, including Bt for corn borer and rootworm, and the more recently introduced trait for nematode protection. Even the drought resistance trait is mostly defensive since it’s intended to protect the plant from drought stress. The reason I say “mostly” is that there’s some indication that even without drought stress some of these hybrids yield a bit better, though time will tell if this is a consistent advantage.
Why mention this? If you’re convinced that you don’t need a trait, don’t spend the extra money on it, because if the threat isn’t present you shouldn’t expect any yield increase. Not only will you grow corn for a bit less per bushel or ton, but you’ll help delay the advent of insect pests that are resistant to that trait.
Source: Miner Institute
