Wet weather this week is giving us time to formulate a plan to work with what is turning out to be a delayed planting year for corn. Other states, including the Midwest, are also struggling to plant under cold, wetter conditions. Tennessee producers are reporting having 40 to 90% of their corn acres planted, with most planning to plant at least through next week when it looks like weather will give us a break.
Should we continue to plant corn? Absolutely! Our long-term dryland corn planting data indicates there is no yield difference between corn planted the last week in April through the first week in May. We are heading into May with tremendous soil moisture potential which will benefit the crop this spring. Bottom ground, fields under irrigation can be planted well into May without heavy yield penalties. However, once we move beyond May 10, growers might consider switching to beans on more droughty ground or hill ground with no irrigation. Growers can obtain full coverage crop insurance for corn planted up to May 20th in west Tennessee or up to May 25th for Tennessee river counties, middle and east Tennessee.
What adjustments should we make for later planted corn? With warmer, drier conditions ahead, producers should keep planting depth at 2″ and adjust seeding rates down slightly if the practice is to overplant by 10% or more to meet a stand goal. A well-adapted fuller hybrid can yield better than an early hybrid under later planting conditions, based on multi-year data from Pioneer. Plant Bt hybrids with more tolerance to southern rust and gray leaf spot. Consider drought tolerant hybrids in nonirrigated fields. Later planted fields should be scouted for diseases and insects and treated where needed. Because pollination dates will be shifted slightly later, later planted corn needs to be irrigated timely during pollination.
What about replants? Ideally we would like to have a minimum of 25,000 plants per acre without too many runt plants (plants that are 2 or more growth stages behind the leaders) or skips in the field. I would urge growers to be patient. We have had below normal temperatures topped off with too much rain which is really slowing emergence. Dry and warmer weather next week will help us gauge more accurately how our stands turned out for corn planted 2 to 3 weeks ago.