Growth and yield of autumn-sown sugar beet: Effects of sowing time, plant density and cultivar

Abstract

Over a period of three years two trials were carried out on autumn-sown sugar beet ( Beta vulgaris L.), grown under normal Mediterranean climatic conditions, to study the influence on growth, yield and sugar quality of three sowing dates (October, November and December), two plants densities (100 000 and 80 000 ha −1 ) and three cultivars (Monauta, Monatonno and Kaweinterpoly). The weather influences dry matter accumulation and leaf growth. Sugar beet began active growth 160 days after sowing, at the end of winter, and achieved a maximum dry matter accumulation of 20–25 g m −2 day −1 and a leaf area index of 3.9–5. The earlier sowing produced a larger quantity of dry matter and more leaf growth and this resulted in higher root and sugar yields. Plant density of 100 000 plants ha −1 tended to produce better growth and higher yield than 80 000 plants ha −1 although the differences were not significant. No significant differences were noted between cultivars in any of the parameters measured. Net assimilation rate and crop growth rate values were similar to those obtained by others authors with spring-sown sugar beet, but relative growth rate and leaf area rate were lower. Optimum sugar yield and greater economic benefits for the farmer are obtained under Mediterranean conditions when the autumn-sown sugar beet is sown early in autumn at high plant density.