Journal of Experimental Agriculture International

The genus Amaranthus comprises several species of the Amaranthaceae family whose leaves and seeds are regularly consumed as food by populations in several countries, among which Brazil is not yet included. The objective of this work was to evaluate the productive potential of amaranth (Amaranthus cruentus cv. BRS Alegria) as a function of different seasons and sowing densities in succession to the soybean crop in the region of Lucas do Rio Verde, MT. The experimental design was a randomized complete block design, with four replications, in a 5x4 factorial scheme. The first factor refers to the five sowing seasons (16/02/2013; 26/02/2013; 05/03/2013; 20/03/2013 and 05/04/2013) and the second factor the four sowing densities (11.4, 20.0, 28.5 and 37.1 ppt m^-2). The evaluated characteristics were: plant height (AP, in meters); stem diameter (DC, in millimeters); panicle length (CP, in millimeters); dry panicle mass (MSP, in g); dry mass of stalk (MSC, in g); sheet dry mass (MSF, in g); total dry mass (MST, in g); final population of plants (POP, in plants ha^-1); productivity (PROD, in kg ha^-1). The experimental data were submitted to analysis of variance and when means were significant the Tukey test to was utilized to compare the means. There was significant difference (p>0.05) in sowing density between the seasons, thus validating the variation of the desired sowing density between the seasons. The obtained real population and the different seasons of sowing were adopted as sources of variation of the other evaluated attributes. The later sows determined a longer time interval between sowing and panicle emission, as well as harvesting. The cumulative precipitation until the panicle and harvesting emission showed a great reduction as a function of the planting times. It is concluded that the productivity of the Amaranth crop is influenced directly by the number of plants per square meter and by the sowing season in succession the soybean crop.