Performance of maize hybrids as a function of spatial arrangements during second growth season under irrigation

There is little information on how different spatial arrangements affect modern maize hybrids under irrigation in the maize second growing season in Brazil. The objectives of this study were to evaluate the performance of maize genotypes with different canopy architecture as a function of different spatial arrangements in the Southeast Brazil. Two maize hybrids with semi-erect (DKB 390) and erect (DKB 230) leaves were cultivated during the second season and evaluated for different plant densities (4, 7 and 10 x 10(4) plants.ha(-1)) and row spacings (0.25, 0.50 and 1.00 m), under irrigation in a tropical environment. The increase in plant density increased plant height and ear insertion height, but reduced stalk diameter. The absorbed photosynthetically active radiation and the leaf area index also increased in higher plant densities, with a reduction of the SPAD index. The increase in plant density enhanced grain yield, however, there was no difference of yield between different row spacings. The hybrid DKB 230 (upright leaves) showed greater yield potential compared to DKB 390 (semi-upright leaves). The critical leaf area index was 5.2 and 4.3 for the hybrids DKB 230 and DKB 390, respectively. The estimated plant density that provides the maximum yield are 9.7 x 10(4) and 8.8 x 10(4) plants.ha(-1) for the hybrids DKB 230 and DKB 390, respectively.

Automated summary

The study evaluated the performance of maize genotypes with different canopy architecture in Southeast Brazil under different spatial arrangements. Increasing plant density led to higher plant height and ear insertion height, as well as increased absorption of photosynthetically active radiation and leaf area index. The upright leaf hybrid DKB 230 showed greater yield potential compared to the semi-upright leaf hybrid DKB 390.