Agronomic response of short-stature corn hybrids to varied row spacing and planting densities

Abstract

Context The recent commercialization of modern short-stature corn ( Zea mays L.) hybrids (<2.2 m) poses a promising opportunity to enhance grain production efficiency and agronomic resilience in U.S. corn systems, particularly under increasingly variable and extreme weather conditions. Narrow-row spacing has been used to mitigate yield limitations in densely planted full-stature corn, however, the architectural advantages of short-stature hybrids may further improve productivity under high planting density scenarios. Objective This study evaluated the agronomic performance, grain yield, yield components (kernel number and kernel weight), and physiological traits (plant height, ear height, stem diameter, and leaf area index) of short-stature corn hybrids in response to varying row spacings and seeding rates. Method: Four site-year field trials were conducted across Indiana using a split-plot, randomized complete block design with 18 treatments and four replications. Three short-stature hybrids (PR111–20SSC, PR112–20SSC, and PR106–21SSC [with PR106–21SSC replaced by PR116–20SSC in 2024]) were evaluated across two row spacings (51 cm and 76 cm) and three plant populations (84,000, 104,000, and 123,500 plants ha −1 ). Results Optimal ear height for yield and harvest efficiency ranged from 55 to 70 cm, though this relationship differs across hybrids and location. Ear position below this threshold (55 cm) increased the risk of harvest losses. Beyond ear height, these short-stature hybrids showed positive performance to higher seeding rates, particularly when paired with narrower row spacing. Narrow rows retained the targeted plant density, which likely contributed to the observed yield advantages. Conclusion Yield response to increasing seeding rates was most pronounced under narrow rows at two of the four site-years. These findings support the integration of both narrow rows and higher plant populations in short-stature corn systems to optimize productivity.

The authors' abstract, as published at the source. Field Crops Research, 2026 · DOI ↗