Contrary to some studies, dry matter losses after blacklayer are not overwhelming. Still, growers should carefully manage their corn harvest timing to minimize loss altogether.
Factors to Consider
- Harvest schedule
- Storage type
- Moisture level
- Respiration rate
- DETERMINE CROP DEVELOPMENT STAGE. Blacklayer, or physiological maturity, occurs at 55 to 65 days after silking or about 20 days after denting. Kernel dry weight usually reaches its maximum at blacklayer and is said to be physiologically mature and safe from frost. Kernel grain moisture at this stage averages 30 percent, but can range from 25 percent to 40 percent.
- MONITOR SOIL MOISTURE LEVELS AND RESPIRATION RATES. In previous trials, corn at temperatures of 75 F to 85 F showed a 1 percent dry matter loss after 10 days. With harvest temperatures more likely to be around 60 F, it could take up to 50 days to realize a 1 percent dry matter loss. Respiration rates are highest when corn is around 50 percent moisture and lowest at 15 percent moisture. Fifty percent moisture is well above moisture at physiological maturity or blacklayer. At these moisture levels, the plant has not yet reached its full yield potential.
- HARVEST AT OPTIMUM MOISTURE LEVEL. Harvesting at optimum moisture levels, rather than calendar dates, will reduce field losses and kernel damage. Generally, 20 percent moisture is considered optimum for corn harvest. Other considerations that drive harvest schedules vary among hybrids and fields. Factors that can potentially increase harvest losses include stalk quality and ear retention. Studies indicate storage environment is of little significance to dry matter loss.
Harvesting at optimum moisture levels will minimize dry matter losses and kernel damage. If you have questions about kernel loss or grain corn drydown, contact your local Mycogen Seeds customer agronomist or trusted agronomic adviser. For more information, contact your local Mycogen Seeds customer agronomist or trusted agronomic adviser.