The wild weather of 2019 created challenging conditions, which caused many to implement unconventional practices on some farms. Heavy downpours on tight Midwestern clay soils delayed planting in much of our marketing area, and the shorter planting windows left farmers wondering, “Should I switch my corn hybrids to shorter-season maturities?” This question prompted our Practical Farm Research (PFR)® team at Beck’s to organize a delayed planting hybrid response study. 

Wet Weather

Saturated soils were typical field conditions in May and June. The data from the National Oceanic and Atmosphere Administration’s Regional Center (below) shows the monthly precipitation accumulation across the Midwest.

May 2019 Total Monthly Precipitation Accumulation – Midwest

June 2019 Total Monthly Precipitation Accumulation - Midwest

PFR Data

Our PFR sites in London, OH, and Atlanta, IN, were two sites that faced delayed planting conditions in 2019. A new study was implemented to test the impact of delayed planting on hybrid selection. We tested various hybrid maturities planted on the same day. These hybrids ranged from 96-day, 105-day, 108-day, and 112-day and were planted at the two locations. These Eastern Corn Belt locations typically plant 112-day hybrids. The Indiana and Ohio planting dates for this study were June 3 and June 7, respectively. Harvest dates were October 23 for IN and October 18 for OH. Our multi-location data emphasizes that when delayed planting conditions arise, switching to an unadapted early maturity hybrid that is not typical of the geography can be a costly strategy. The graph below shows the multi-location data for this year’s Delayed Planting – Hybrid Response study.

2019 IN & OH - Delayed Planting Hybrid Response Net Return

Implications of Switching to Shorter-Season Hybrids

1. Earlier hybrids brought South are placed into more heat stress and tighter soils – not the typical environments these corn plants were bred and are adapted for.
2. Sticking to the locally adapted maturity hybrid is encouraged because hybrids planted between May 1 through the second week of June require up to 6.8 GDU’s per day, delayed after May 1 (Nielsen et al., 2002).
   1. Growing Degree Days (GDD’s) are the compilation of daily heat units used to determine how long it will take a corn plant to get from planting (sometimes emergence) to physiological maturity. With delayed planting, comes a shorter growing season. Depending on the mid- and late-season weather conditions, this might not be the most profitable route. One thing to consider is that higher temperatures will produce more GDD’s per day, allowing late-planted crops to emerge in fewer calendar days per growth stage than earlier-planted crops.

GDD Accumulation for a 112-day hybrid in May & June of 2019

May 2019 GDD Accumulation

June 2019 GDD Accumulation
  

Additional Thoughts

• High-speed planting can reduce time spent planting per acre to counter shorter optimum planting windows. Stay tuned for the 2019 PFR Book to be released for this year’s high-speed planting findings; one high-speed study even features aftermarket closing wheels!
• More nitrogen is not necessary to compensate for late planting. 2019 PFR findings found that applying 150 units of anhydrous ammonia compared to 190 was more economical. Application of nitrogen between the rows pre-plant incorporated provided greater crop safety than below-the-row application.

Source

Nielsen, Robert L., Peter R. Thomison, Gregory A. Brown, Anthony L. Halter, Jason Wells, and Kirby L. Wuethrich. 2002. Delayed Planting Effects on Flowering and Grain Maturation of Dent Corn. Agron. J. 94:549-558.