Early Corn (Zea mays L) Planting Date and the Effect on Yield.

Early corn (Zea mays L.) planting provides Mississippi growers an extended growing season and options to use full-season hybrids with superior yield potential.   Early planting is not a new concept in farming, but data for early corn production is lacking for Mississippi and this region.  We hypothesize that by planting corn earlier, yield will increase because heat and drought stress will decrease.  Shifting planting dates forward to the beginning of March or the end of February will increase the probability of timely rainfall during the reproductive phase and also reduce the impact of climate volatility like extreme heat that negatively impacts yield.  Cooler night time temperatures, reduced weed and insect pressure are also benefits of planting corn earlier.  Experiments were conducted at two locations in Mississippi to determine the effect of planting corn earlier than the suggested planting dates (March 15-April 20).  The experimental design was a randomized complete block with four corn hybrid varieties, four planting dates, and four replications. All plots received similar agronomic management and inputs; the only variable was planting date.  Preliminary data suggest a decrease of seven bushels per acre, per week, after the initial planting.  This trend was consistent across hybrids and locations.  Current planting date recommendations are based on optimum soil temperature at planting depth, ranging from 50 to 55 degrees Fahrenheit.  Advances in seed treatments and commercial hybrids have lowered the risk factors associated with producers planting corn in cool, wet soils.  By advancing corn production window forward to avoid the heat and drought of summer we hope to both increase and stabilize yield.