More acres = more problems, it seems. Picking the right conditions to plant is always the best option, regardless of what the calendar says. For growers needing to cover more ground in such a tight window, the unfortunate reality is that we must push into unfavorable conditions to get done in time.
With that being said, we’ve had a fair amount of corn planted in very good field conditions prior to the most recent cold snap. The following is a reminder…an annual reminder of what we are working through this particular spring.
Planting into soils less than 50°F increases the incidence of:
1. Deformed or corkscrewed mesocotyl
2. Delayed or failed emergence
3. Leafing out underground
Temperature before, during, and after planting effect quality of stand and emergence
1. Air Temperature Wednesday at 10 am [4/26] was 60°F but fell to the high-30’s by Thursday morning. A day after the front arrived [4/27] average soil temperature stayed up - 47°F at 6 am. The following morning we saw average soil temperature drop to 41°F at 6 am.
2. What does this mean? This is a significant drop in soil temperature over the span of a day. It also rained, and wetter soils push oxygen out of the soil. This starves seeds and limits respiration. Pythium, among other seedling diseases are a consideration in cold, wet soils.
Average 4 week POST-planting soil temperature effect on stand
1. 56°F = 90%, 48°F = 81%, 41°F = 61%
2. What does this mean? Because of the stress already incurred in planted fields, and because we have yet to break the cold weather pattern, we may have a hard time reaching 80%-90% stand uniformity.
Herbicide-Environment Interaction [watch-outs]
1. Group 15 [Zidua, Focus, Sinch, Harness]: leafing out underground, buggy-whipping
2. Flumetsulam [Python in Hornet, SureSTart, TripleFlex]: bottle-brush roots
3. Prowl: clubbed roots
Considerations moving forward
1. Delayed planting is generally okay. Statistics on killing frost and other weather events are an AVERAGE – every year is different.
2. Delayed planting adjustment: corn will compensate. According to research at Purdue University [Nielson], corn GDU requirement decreases by 7 GDU/day May 1 – May 15.
3. Statistically speaking, there is no significant drop in yield potential if corn is planted prior to May 8.
4. Yield loss [statistically] week of May 8 – May 15 is LESS THAN 1 bushel/acre/day. So, a minimal drop in total potential can be anticipated if corn is planted prior to May 15. If conditions are NOT optimal prior, a consideration must be made for stand loss to environment factors prior to May 15. The question is, and will always be: will I lose more in emergence than I will to planting date?