Share Facebook Twitter Google + LinkedIn Pinterest Can small weeds hurt yield?Yes. Here is why:• Plants appear to know quickly whether they have enough elbow room to grow. They are healthy and strong with plenty of space, but weak and spindly when crowded. It doesn’t matter if neighbors are corn plants or weeds.• It’s especially important to control weeds early so herbicide-resistant weeds don’t get started. As young corn seedlings, their leaves and roots are not long enough to touch other plants and ‘feel’ that they don’t have elbow room. So how do they know they have too much company?• Research studies have shown that light reflected from chlorophyll of neighboring plants signals how close those plants are to them. All green plants have chloroplast cells that capture energy from sunlight to produce sugars. Stomata or leaf openings allow them to obtain carbon dioxide from the air. They give off oxygen during the day. Roots collect water, nitrogen and other nutrients. With these ingredients plants make sugars, then starches and proteins. Eventually, these products are deposited in kernels.• It doesn’t matter that many of the plants are weeds. Corn plants see them as too much competition and make decisions early which can reduce yield potential. If weeds or other corn plants are too close, plants grow taller and are spindly. They are trying to beat other plants to sunlight.• Knowing about light reflection signals and how plants react to crowded conditions, so what can you do to create an environment for maximizing yields? First, plant high enough population so there isn’t wasted space, but don’t plant so many seeds to cause excessive competition.• Early weed control is very important to reduce light reflection from weeds. If you wait to spray until plants get taller, you decrease yield potential. Corn plants already sensed competition from weeds and programmed themselves to produce smaller ears with fewer kernels. Control weeds early or pay yield penalty later!