ncreasingly aggravating rainfall throughout southern Indiana continues to interfere with the completion of corn and soybean planting. As of June 1, the Indiana Ag. Statistics Service reported that only 51% of the intended corn acres and 22% of the intended soybean acres had been planted in the southern crop reporting districts of Indiana.
Corn growers are particularly frustrated with the delayed planting situation. Last week I indicated that one small bit of good news is that southern Indiana corn growers can avoid drastic changes to hybrid maturities for quite some time due to that areas longer growing season and corns ability to adjust its heat unit requirements with delayed planting (Nielsen, 2003).
Listed here again are the safe hybrid maturities for two planting periods:
* Safe hybrid maturities for planting in southern Indiana through June 10
Southwest: Fuller season maturity than most plant anyway
Southcentral: Hybrid maturities from 115 to 118 CRM (Pioneer® brand rating)
Southeast: Hybrid maturities from 116 to 119 CRM
* Safe hybrid maturities for planting in southern Indiana through June 20
Southwest: Hybrid maturities from 117 to 120 CRM
Southcentral: Hybrid maturities from 109 to 112 CRM
Southeast: Hybrid maturities from 110 to 113 CRM
While a switch to significantly earlier hybrid maturities is not physiologically warranted for a couple more weeks, growers may nonetheless want to consider switching to earlier maturities to reduce their potential grain drying costs in the fall. Long-term plot data from Pioneer Hi-Bred International (Iragavarapu, 2003) indicates that the yield potential for late, medium, and early maturity hybrids becomes very similar as planting is delayed beyond June 10 in the central U.S. Corn Belt. Grain moisture differences at harvest, on the other hand, remain similar among the hybrid maturities, if not more dramatic, as planting is delayed.
Final Note of Caution: Growers who elect to switch to earlier maturity hybrids for mid- to late June plantings in southern Indiana must also remember to select hybrids with acceptable disease tolerance because of the greater risk of leaf diseases with late-planted corn (Vincelli, 2003). This is especially true if you are considering maturities unusually early, and therefore agronomically unadapted, for your location.