Mathematical models were tested to correlate the leaf area index (LAI) of maize to the percentage of light intercepted by the canopy (% LIC) and this with the total dry matter of aerial parts (TDM), as well with the grain yield (GY). The experiment was conducted in a randomized block design, with four replications. The treatments consisted of hybrid maize at five plant densities: 4.0, 2.66, 2.0, 1.6, and 1.3 plants per m² (pl m-2). At densities of 4.0 and 2.66 pl m-2, the average LAI and TDM did not differ among themselves but were significantly higher than those presented at the densities of 2.0, 1.66 and 1.3 pl m-2, which also did not differ among themselves. The number of corncobs per plant (cob pl-1) and GY behaved similarly. The LAI grew exponentially with the plant density. For all ages of plants, the exponential model fit well with the % LIC values according to the LAI and also fit well to the data of dry mass as a function of % LIC. GY depending on the density fit well to quadratic, exponential straight line and logarithm-modified equations, and the number of cobs per plant depending on the density fit well to hyperbolic and exponential-modified equations.
age; corn; radiation; yield
