Share Facebook Twitter Google + LinkedIn Pinterest Ohio started corn harvest on Sept. 18, two to three weeks ahead of the normal corn grain harvest date. In the last three years most growers have had the benefit of letting the corn crop dry in the field and have experienced very dry grain at harvest that could easily be taken to the local elevator or quickly dried in the bin with some forced air. In these past years, growers have experienced grain moisture at harvest in the range of 17% to 18%.But what happens to the kernel after it reaches physiological maturity or “black layer” at 30% grain moisture? It has to dry by itself without much help from the plant. Once the black layer forms, the moisture and nutritional connection between the kernel and cob is broken. Therefore, the plant can no longer help the grain drying process. Field drying of mature corn grain is influenced primarily by weather factors like temperature and humidity. It’s not a mystery that warmer temperatures and lower humidity encourage rapid field drying of corn grain.Weather plays a big factor in drydown. However, modern corn hybrids have been engineered by plant breeders to have superior late season drydown by selecting for characteristics that promote drying. These are the hybrids that deliver maximum gross income and minimum grain shrinkage costs. The following characteristics are the ones that plant breeders have influenced to bring you very fast drying corn hybrids.Husk coverage of the ear — Some hybrids produce short husk leaves. Sometimes the cob and grain can be exposed from the tip of the ear. These hybrids dry faster but can be attacked by birds and insects. Genuity RIB Complete hybrids provide protection against Corn Earworm feeding on the tips of ears.Husk tightness — Loose husk leaves provide faster grain drydown. Hybrids with tight husk leaves tend to have more problems with ear rot diseases.Husk leaf number — The fewer the number of husk leaves, the more rapid the grain moisture loss. There is a big difference among hybrids.Husk leaf thickness — Thinner husk leaves provide more rapid grain moisture loss. If you hold these leaves up to the sun, thin husk leaves can appear to be “see through” or translucent.Husk leaf senescence — Some hybrids have brown husk leaves soon after black layer. The sooner the husk leaves senesce (die), the more rapid the grain moisture loss.Ear hang — The sooner the ears drop from an upright position after black layer to a downward position, the more rapid the grain moisture loss. It’s logical that upright ears can capture rainfall and dew, which can prolong the drydown process and accelerate ear rot diseases.Kernel hardness — The pericarp is the outer layer of the kernel. The thinner the pericarp the faster the kernel dries. Also, the endosperm (inside kernel) can have different levels of harness. Hard kernels dry slower but have higher test weight. Softer endosperm kernels dry fast.So what is the ideal corn grain moisture for harvest? We mentioned earlier that in past years growers in Ohio have had the luxury of harvesting corn at 15% to 18% grain moisture with minimal drying costs. But is this the most profitable grain moisture for harvest? The answer is not easy because one answer does not fit all grain operations. It depends on harvest equipment, labor, drying capacity, and storage space for grain.Here are a couple of points to consider about grain moisture harvest timing. The experts recommend corn harvest at 23% to 25% grain moisture to capture the most revenue per acre. This is due to the fact that after black layer, harvest losses are greater from ear droppage, broken stalks, wind damage, pest damage, disease, and mechanical harvest loss. Growers that delay harvest past that ideal moisture can typically experience 5% loss in October and if delayed into November that loss can grow to 8.4%. Also, it has been reported by researchers that some standing grain corn hybrids can lose 1% of it’s dry weight for every point of moisture drop after 28% grain moisture. In Ohio, grain corn usually dries at the rate of 1% moisture in three days after the black layer forms. Be safe, I wish you a speedy harvest.