Optimization Of Plant Density And Nitrogen Regimes To Mitigate Lodging Risk In Wheat

Influences of planting density and nitrogen rate have been investigated frequently in targeted wheat (Triticum aestivum L.) research. Few studies have investigated interactions between these inputs. The objective was to determine the combine effect of N and seeding rates on culm morph-physiological traits for lodging tolerance and grain yield. The experiment used a split-split randomized block design using two wheat varieties 'AnNong0711' and 'YanNong19', split by four seeding (180, 240, 300, and 375 x 10(4) ha(-1)) and four N rates (0, 180, 240, and 300 kg ha(-1)). Lodging traits of plant height, culm height center of gravity, and internode length, increased (p < .05) however, stem diameter, wall thickness, and stem breaking strength decreased with increasing N and seeding rate. Stem breaking strength was negatively correlated with culm height center of gravity (r = -.869, p = .01), internode length (r = -.872, p < .01), and lignin (r = -.746, p < .01) but positively correlated with internode diameter (r = .715, p < .05) and wall thickness (r = .696, p < .05). Culm lodging index and cellulose showed positive correlation (r = .807 and .913 respectively) with lignin. Compared to YanNong19, AnNong0711 showed higher grain yield and culm lodging index of 9 and 20.49%, respectively. For improved grain yield, 180 plants m(-2) was optimal in surface combinations with 210 kg N ha(-1) for AnNong0711 and 200 kg N ha(-1) for YanNong19. These combinations of seeding and N rates could successfully mitigate lodging and improve grain yield.