By Dave Nanda, Ph. D. Director of Genetics & Technology Seed Consultants, Inc.
When the developers of technology for Roundup resistance and Liberty (Ignite) resistance released these products for marketing to the farmers, they were recommending that farmers let the weeds grow until the corn and soybeans are fairly tall to form a canopy and then spray their weeds and kill them all in one pass. Well, it was a good salesmanship and many farmers bought into it as a way to save money on weed control. Little did they realize that the smaller weeds also hurt the yield potential of the crops.
Studies conducted by several universities and my own observations have indicated that smaller weeds do reduce the yield potential of the crops. When the infra-red light is reflected from the chlorophyll of the neighboring plants, whether crop plants or weeds, each individual plant, because of its micro- environment, “decides” early on how many ears and the seeds on the ears or how many beans it will try to produce. Based on the macro-climate of the location (soil type, fertility, rainfall, temperature etc.) it “wants” to produce the maximum number of seeds it can. So, controlling the weeds early creates a better environment for the plants to grow in. The weeds don’t just rob the crop plants of water and nutrients but also sun light. Besides, smaller weeds are easier to kill than bigger weeds. If you have not used a pre-plant or pre-emergence herbicide, make sure to spray a suitable and safe weed killer even when they are small. Not doing so will reduce your yield.
Let’s hope for a better growing season thru the rest of 2011. We deserve a break!