Twin Rows Minimally Impact Irrigated Maize Yield, Morphology, and Lodging

Twin rows are being promoted as a means to increase maize yield through increased interception of photosynthetically active radiation (PAR) and plant morphology modifi cation. Th e objective of this research was to explore the interactive eff ects of maize hybrid, plant population, and row confi guration on grain yield and grain yield components, interception of PAR during vegetative growth, plant morphology, and percent lodging. Twin-row irrigated maize produced the same grain yield as single-row production. Small changes in plant morphology and grain yield components and 2.3 to 4.2% increased interception of PAR at the V9 (nine leaves with visible collars) stage were documented for twin rows, but the sum of these did not result in changes in grain yield. Twin-row production increased lodging by 3.5%. Few interactions between row confi guration and hybrid and target population were found, leading to the conclusion that twin-row production of maize aff ords little opportunity to increase maize grain yields. Hybrid and plant population had a much larger eff ect on grain yield and lodging. Increasing the maize target population to 93,000 plants ha -1 maximized grain yield at 14.3 Mg ha -1 , and led to small changes in plant morphology that increased lodging from 6.8 to 14.9%. Ear height had the highest direct eff ect on lodging in both the low (2009) and high (2010) percent lodging years. Based on these results, current promotion of twin rows is not justifi ed for irrigated maize production in the western Maize Belt.