Production of Stalks and Technological Evaluation of Sweet Sorghum Genotypes in Different Periods after Flowering.

Since the sweet sorghum have a short cycle, easy mechanization and appropriate technological characteristics, it can be considered as a culture that have the potential to complement the production of ethanol in Brazil on the period between sugar cane harvests. Thus, this study aimed to evaluate genotypes of sweet sorghum sown at two different times, as the production of fresh stalks and values ​​of Brix and Sucrose in different samples after flowering. Sorghum was sown on 12/03/2011 and 01/03/2012 in Fazenda de Ensino, Pesquisa e Extensão of UNESP – Ilha Solteira Campus, located in Selvíria county, Mato Grosso do Sul State, Brazil (20º22'S, 51°22'W and 335 m altitude, approximately). The genotypes were Chopper, V 37003 and Sugar Graze, sowed at a spacing of 0.7 m between rows and population of 130,000 plants/ha. The sowing fertilization was performed with 20, 70 and 40 kg/ha of N, P₂O₅ and K₂O, respectively. Topdressing was performed with 80 kg/ha of N. From flowering in each genotype 4 samples were taken, spaced 15 days at approximately. In each evaluation, it was determined the amount of fresh weight stalks and values ​​of Brix (° Brix) and Sucrose (%), similar to that used in sugar cane. It was concluded that Brix and sucrose have similar performance as a function of sowing dates, genotypes and sampling; Brix values ​​and Sucrose increased with the sampling and the highest values ​​obtained were 17.85 and 13:40, respectively; Sugar Graze and V 37003 genotypes, showed higher Brix and Sucrose; preferentially, the genotypes should be sowed in early January; the fresh weight of stalks was higher in V 37003 genotype (74.340 kg/ha) and decreased as a function of sampling.