It may be a traditional holiday for most laborers today, but Indiana farmers are going to be happier if they're in the field working. A prolonged spell of wet, cool weather has pushed back planting, especially for soybeans, and left finishing corn to a race with the calendar. Already, folks who can find a good supply of soybean seed are talking about switching fields where they didn't already have anhydrous ammonia applied to soybeans because of the lateness of the season.
If you just look at Corn Illustrated demonstration plots a year ago, you wouldn't be encouraged if you've still got corn to plant. Yields from May 21 on went down the tubes, to 50 bushels per acre and below. That was on land underlain with gravel and without irrigation. The plots held well until August unleashed a heat wave that led to a total of 40 days of 90 degrees F or above, including record-setting late heat in October.
Every year is different. Old timers talk about planting in late May and harvesting good crops. However, their idea of a good crop and you're idea of a good crop today to meet the budget you've set for yourself, based on incredible input prices, may not be the same.
Long-term data compiled by Purdue University agronomists, printed in a chart in the Purdue Corn and Soybean pocket guide, the bible for corn and soybean growers in Indiana for the past 10 years, published by the Purdue Diagnostic Training Center, says that if you planted May 25 and obtain a final stand of 28,000 plants per acre, you can expect about 86% of potential yield had you been able to plant on time. That means on average, that if the potential realistically was 200 bushels per acre, you're now looking at likely topping out just above 170 bushels per acre, if the weather is average from here on out.
If you are still planting at the end of this week, on May 30, the historic Memorial Day of decades gone by, potential based on history drops to 81%. And if final stand is only 24,000 planted May 30, it's only 78%. By June 4, it's 75% at 28,000 final stand. Based on the table, if you're still planting corn June 9, expect about two-thirds of what you could have harvested with timely planting, had mother nature cooperated, assuming you achieve 28,000 final stand. Now your 200-bushel field is down to about 135 bushels per acre at best, if it's a normal year. Odds are it won't be normal from here on out. Whether it's more favorable or less favorable than normal is anybody's guess. Remember farming is all about risk, and roll the dice.