Print version ISSN 0006-8705
AGUIAR, Eduardo Barreto et al. Effect of plant densities and harvest dates on the production of sweet cassava roots. Bragantia [online]. 2011, vol.70, n.3, pp. 561-569. Epub Sep 30, 2011. ISSN 0006-8705. http://dx.doi.org/10.1590/S0006-87052011000300011.
In sweet cassava production, economic yields of high quality roots are obtained only after a growing season of eight to ten months. In addition, cassava plants under little competition present higher yields per plant. The objective of this work was to study the handling of population densities in the sweet cassava crop, as a tool to obtain high yield of high quality roots in earlier harvests. Seven plant densities, from 5,000 to 20,000 plants ha-1, were tested with growing cycles of six, eight, ten, twelve, fourteen and sixteen months, in a field trial using the cv. IAC 576-70. Total root yields increased with time, being the highest values obtained with the highest plant densities. It was estimated, with a regression model, a maximum yield of 26.8 t ha-1, when using 20,000 plants ha-1 and a growing cycle of sixteen months. On the other hand, the highest yields of marketable roots were obtained with smaller plant densities in all harvests, which was caused by lower root discard rate at low populations. The maximum yield was 19.1 t ha-1 in the latest harvest by using 5,000 plants. In earlier harvests, after six and eight months, the marketable yields estimated were 5.9 t ha-1 and 11.1 t ha-1, when using 5,000 plants; and 5.0 t ha-1 and 7.2 t ha-1 with 20,000 plants. In this way, low population densities for the sweet cassava crop enable earlier harvests, at six, eight and ten months after planting with good yields of commercial roots.
Keywords : Spacing; earliness; cultural practices.