Seedling stage is the most critical phase in the life of a corn plant. The young stage of every organism is critical for development and productivity as adults. If you understand how crops grow, you can do a better job of meeting their needs and improving yields.

Let’s look at what happens as a young corn plant develops. Here are specific things to watch for and think about as plants grow. As this point in the season, some of your plants may be past one or more of these stages, but it’s good to understand plant development from the beginning.

• Watch for these things at V1 and V2. It takes 110 to 120 growing degree days after planting for corn seedling emergence. The seedlings emerge when the coleoptile, the spearlike leaf, pierces through the ground. First and second leaves develop six to seven days after the seedlings emerge. The first roots start to supply water and nutrients to the young seedlings at this time. Roots are very small, and banded fertilizer close to the roots at this stage should be very helpful in stimulating early growth.

• Pay attention to root growth. About two weeks after emergence, the third leaf starts to develop. Plants are at V3 and preparing for V4.Seedling roots stop at this stage, and the secondary roots known as nodal roots start growing. These become the permanent root system of the plant. At V3 to V4, make sure weeds are under control. Apply postemergence herbicides, if necessary. Even small weeds can affect yield.

• Know where the growing point is. The growing point stays belowground for three to four weeks and is protected from frost or insects on the surface. Don’t cultivate too close to the plant after this stage because the roots may be damaged. A freeze at this stage may hurt leaves, but the growing point isn’t destroyed since it’s belowground. Don’t start thinking about replanting if damage occurs until you see if plants will grow back. Nodal roots are growing fast and start taking over the responsibility of gathering water and nutrients for the whole plant. Root hairs also start growing.

• Be ready for the V5 stage. This stage of development is critical. Four nodes develop below the ground. Generally, the first node above the ground is the fifth node. Even at this early stage, leaf and ear shoots are starting to develop.

• Understand seedling threats. At emergence, young plants face many hurdles. These include nutrient deficiencies, seedling diseases like pythium and Stewart’s bacterial blight, slugs, and insects like black cutworms.

• Watch for corn rootworm beetle larvae. If you didn’t opt for GMO belowground pest protection this year, these larvae can attack roots. Larvae typically hatch in early June. By early July, adult beetles can clip silks and may interfere with pollination. Watch out for these insects if you’re growing GMO corn without the rootworm trait, or non-GMO corn and you haven’t used insecticide.

• Watch for slugs. In a wet spring, you need to watch out for slimy little creatures like slugs. They appear harmless but can cause considerable damage, especially in low-lying areas.

• Time sidedress applications correctly. At V6 to V8, be sure to sidedress with nitrogen before plants are too tall. Check for deficiency of nutrients like sulfur, as well as zinc, magnesium and other micronutrients.  

Nanda is president of Agronomic Crops Consultants LLC. Email him at [email protected], or call 317-910-9876.