Accumulation of Dry Matter, Nitrogen, Phosphorus and Potassium in Sweet Sorghum Crop.

The sugar cane and sweet sorghum [Sorghum bicolor (L.) Moench] are presented as promising for ethanol production, according to their agronomic and industrial yield. Studies about uptake and accumulation of nutrients by sweet sorghum, are essential factors for the development of a rational fertilization program. Thus, this work aimed to establish curves of dry matter accumulation, nitrogen (N), phosphorus (P) and potassium (K) in the sweet sorghum crop. The hybrids Advanta 81981 and Monsanto 80147 XBSW  were used in a experimental design in randomized blocks, with the treatments arranged in split-splot scheme as function of time, the main treatments were two sweet sorghum hybrids and the secondary the samples. Plant samples were collected at intervals of 15 days after emergence and separated into leaves, stems and panicles. Determined the dry matter of each part of the plant and the concentrations of N, P and K for calculation of nutrient accumulation. The Advanta 81981 and Monsanto 80147 XBSW hybrids accumulated dry matter during all cycle and were produced 17,400 and 16,150 kg ha^-1 of dry matter, respectively; maximum accumulation of N, P and K was observed in the period of flowering plants, in both sweet sorghum hybrids; the nutrients accumulation in the shoots follow the order: K > N > P.