Effect of population density on the yield of export-type white yams (Dioscorea rotundata Poir.)

The limitations for yam crops destined for the export market include low yields per unit area and the production of deformed and overly large tubers that are rejected by the market, causing huge losses for small farmers. In order to increase the export competitiveness of yams, the effect of population density on the yield of white yams (D. rotundata cv. Brasilero) was evaluated. On the experimental farm of the Universidad de Córdoba, an experiment was conducted with a randomized complete block design and three replications using the following densities (treatments): 10,101; 22,727; 30,303 and 45,454 plants/ha, where the first treatment corresponded to the density used by producers (control). The following yield components were evaluated each time: number, shape, weight, size and production of export-type and non-export-type tubers. In addition, an economic analysis of the treatments was carried out to assess the impact of adoption. The export-type production increased as the population density increased, achieving the maximum yield with 30,303 plants/ha, surpassing the control by 197.75%; this population was also the most profitable, 116.67%. The shape, weight and size of the tubers were not affected by the population density; the cylindrical shape was the most frequent. It was concluded that the white yam cv. Brasilero population increase significantly influenced the number of export-type tubers per hectare, tripling the number, as well as increasing profitability