Eficiência nutricional de cultivares de cana-de-açúcar

• Autor(a) principal: Mendes, Lester Carvalho
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4492
• topic: Cana-de-açúcar; Absorção de nutrientes; Sugar cane; Absortion of nutrients; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

This work aimed to determine the nutritional efficiency of sugar cane cultivars in the first two crop-growth cycles (plant and first-ratoon crops). Thus, biological utilization coefficient and apparent sucrose yield ha-1 (TPH) were evaluated. The experiment was set up on mid February 2003 in a clayey textured Red Yellow Argisol, and arranged in a randomized block design, with four repetitions. On December 2003, when the crop reached its maximum growth phase, +3 leaves (third leaf with visible auricle) were collected from the central rows of eac h plot and submitted to N, P, K, Ca and Mg analyses for foliar content determination. On July 2004, 18 months after planting, the aerial part was collected to evaluate fresh matter, dr y matter and industrializable culm production, sucrose accumulation, and nutrient accumulation. On February 2005, +3 leaves from first ratoon crop were collected to evaluate the nutritional state of the plants. Samplings of the aerial part of the first ratoon crop were carried out in July 2005. Nutrient accumulation and TPH values in the plant and first ratoon crops were used to estimate the biological utilization coefficients. The foliar contents found in the plant and first ratoon crops corresponded to those found by other researchers, both in the past and recently, indicating that the present cultivars maintain the same level of nutrient concentration in the leaves, although with greater yield, what, in some way, highlights the benefits of the breeding program. In the plant crop, cultivar RB867515 presented greater nutritional efficiency for phosphorus , potassium, and calcium, while cultivar RB855536 presented greater efficiency only for phosphorus . In the first ratoon crop, the cultivars with high nutritional efficiency were SP80-1816 for nitrogen and phosphorus; RB835486 for phosphorus and magnesium; RB867515 only for phosphorus and SP80-1842 for phosphorus, potassium and magnesium .