Early Planting – When Is It Time?
Warm temperatures can cause spring fever. We all get the itch to scratch in the dirt. Some of us succumb to the temptation of planting when conditions aren’t fit, so I’m writing to remind you why it pays to wait.
Each corn kernel is a live plant that needs to develop. This is very important to keep in mind as you plan for early planting. Each kernel is waiting to absorb moisture to begin the process of developing into a seedling and ultimately into a viable plant.
To germinate and begin new life, a kernel of corn absorbs 30% of its weight in water. That’s why it’s so important that the water temperature does not impede the germination process. When cold water is absorbed by kernels, it can result in imbibitional chilling that damages cells and causes seeds to rupture. Seeds may shrivel; seedlings may emerge late, in a corkscrew shape, or not at all. If the cell development is slowed due to cold temps or a cold rain, it can take significant time to get the process started again.
Look ahead at the weather forecast, so you can make the best decisions when planting early. Soil temperatures should be monitored and averaged for the week preceding the projected planting date. To determine the soil temperature on the chosen planting day, take the temperature of the soil just after sunrise because that’s the coldest part of the subsequent 24-hour period.
Soil temperature changes more slowly than air temperature, however, air temperature is a strong indicator for what to expect with soil temperature. Remember to look at the temperature forecast for three or so days after planting – even if the soil has warmed enough for planting. If you see a significant downturn in the forecasted temperatures, you’re likely putting crop emergence at risk. Cold rains that fall three or so days after planting can slow cell development. If it is projected that soil temperature will remain above 50°F for 24 to 48 hours after planting, imbibitional chilling can be avoided.
Early planting is only advantageous when conditions are fit. Do what you can to delay planting when uncooperative weather is in the short-term forecast. I believe in planting corn early to maximize yield, but I also believe it is important to look at the forecast that does not inhibit development to establish your desired stand.