SHADING EFFECTS ON SOYBEAN AND CORN

W. Shading effects on soybean and corn. BIOTRONICS 22, 15-24,1993. Shadesfor reducing available irradiance were placed over field-grown plants tomeasure light effects on root and shoot morphology and phenology. Asreported in the past the ratios of leaf and shoot biomass to leaf area decreasedwith shade intensity. The 20%-of-ambienttreatment greatly reduced corn rootgrowth, but the trend from 70 to 27% ambient was weak. Kernel row numberson the corn cob were sensitive to shade level. In general soybean was moreshade tolerant than corn. The treatments supplying 49 to 20%-of-ambientresulted in longer internodes in soybean, which induced severe lodging. Themany measurements reported are useful for generating logic for biomassdynamics in crop stands.Key Words: Zea mays L., Glycine max CL.) Merr., maize, shading, roots