Canopy characteristics of high-yield maize with yield potential of 22.5 Mg ha−1.

Over three continuous years (2013–2015) of high-yield experiments, maize hybrid DH618 was grown at densities of 12.0 and 13.5 × 10 4 plants ha −1 at Qitai Farm (89°34′E, 44°12′N), Xinjiang, China, and broke the record for the highest yield in China. Therefore, it is considered to have plant characteristics that approach those of the ideotype. In 2014 and 2015, various canopy characteristics were measured. On average, the dry matter gain of hybrid DH618 was 20.0, and 36.5 Mg ha −1 during post-silking and at maturity, a transfer rate from vegetation organs of 8.7%, and harvest index of 0.54. On average, it had a leaf area index of 7.53 at silking, a leaf area of 3.99 × 10 3 and 1.90 × 10 3 cm 2 above and below the ear, and a spatial density of leaf area of 0.17 and 0.08 cm 2 cm −3 above and below ear, respectively. The average light transmissions were 3.7% and 1.1% at the ear and bottom respectively, and the attenuation coefficient was 0.63. The plant height and ear height were about 287 and 113 cm. The average leaf orientation values were 51.9 and 49.2 above and below ear, respectively. These results will be of great significance for ideotype breeding programs and maize yield improving. [ABSTRACT FROM AUTHOR]