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ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Publications at this Location » Publication #68915
Title: RAPID CANOPY CLOSURE FOR CORN PRODUCTION IN THE NORTHERN U.S. CORN BELT. I.RADIATION USE EFFICIENCY AND GRAIN YIELD

Author
item Westgate, Mark
item Forcella, Frank
item Reicosky, Donald
item SOMSEN, JERALD - SOUTH DAKOTA STATE UNIV

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Decreasing profit margins in the past decade are forcing corn producers to seek greater efficiency and higher yields from the corn crop. We tested whether planting corn in rows narrower than conventional and at plant populations greater than conventional might help achieve this goal in the Northern regions of the Corn Belt. We also examined the possible benefits of dwarf plant stature under narrow-row, high-population conditions. Planting a tall hybrid in narrow (15-in) rows did not increase total light interception by the canopy or grain yield compared to planting in wide (30- in) rows. High plant populations were not suitable for the dwarf hybrid which was prone to produce barren plants, but yield of the tall hybrid increased with population up to 40,000 plants per acre each year. These results indicate corn producers in the Northern Corn Belt can decrease row spacing to 15 in without yield penalty. But greater productivity may be realized by increasing plant populations above those currently recommended even in relatively dry years.

Technical Abstract: Slow development of corn canopies in Northern growing areas may limit total light interception and potential productivity. We tested whether planting corn in narrower rows and at higher population than usual would cause earlier canopy closure and lead to increased radiation use efficiency (RUE) and grain yield. A tall hybrid (Pioneer Brand 3790), typically grown in 30-in rows at 30000 plants per acre was sown in narrow 15-in and 30-in row at plant population densities up to 50000 plants per acre. A dwarf hybrid (Cargill S.X. 123), was sown in 15-in rows at populations up to 100,000 plants per acre. Maximum light interception increased, total intercepted radiation increased, and thermal time to 50% light interception decreased with increasing plant population in both hybrids. Planting the tall hybrid in narrow rows did not improve light interception compared to wide rows. Nor did it affect grain yield, which increased with population up to 40,000 0plants per acre. Grain yield for the dwarf hybrid decreased at population greater than 50,000 plants per acre due to an increased number of barren plants. Both hybrids exhibited an optimum rate of canopy development for maximum grain production. The optimum rate varied across years, but was similar for both hybrids and row spacings. Farmers can decrease row spacings for corn without yield penalty. But greater productivity per acre may occur by increasing population densities to levels greater than currently recommended for the Northern Corn Belt.