PHOTOSYNTHETIC CAPACITY, YIELD COMPONENTS, AND POPULATION DENSITY OF A LOCAL CORN GENOTYPE FROM ECUADORIAN AMAZONIA

Abstract

Population density is one of the most important agronomic factors in corn (Zea mays L.) for achieving high agricultural yields. In the Ecuadorian Amazon, there are no studies that allow us to determine a population density that is suitable for the edaphoclimatic and cultural conditions of the region. This work was carried out at the Experimental Center for Amazonian Research and Production (CEIPA) of the Amazon State University. The effect of population densities of 31 250, 41 666, and 62 500 plants per hectare of the local variety Tusilla on physiological indicators, yield components, and crop agricultural yield was studied. A randomized block experimental design with three treatments and three replicates was used. The data was tested for normality using Shapiro-Wilks, followed by an analysis of variance and a mean comparison test using Tukey (p ≤ 0.05). Increased population density reduces leaf area and dry matter production per plant while increasing leaf area index and net assimilation rate. Each individual plant showed higher leaf area values at the lowest population density, with averages of 1.18 and 1.56 m2 at 55 and 75 d, respectively, and higher dry matter production in stems and leaves, with 61.15 g plant-1 at 75 d. The highest net assimilation rate was 9.05 g m2 d-1 at the highest population density. At lower population densities, yield components are favored; however, a higher agricultural yield of more than 6405 kg ha-1 is obtained at higher densities due to the greater number of plants per unit area.