Relações entre variáveis produtivas de cana-de-açúcar e de qualidade do açúcar mascavo

Abstract

Sugarcane is an important crop for the country's economy. Sugar is of great importance due to the high consumption, for giving sweet taste to food. Health concerns increase demand for brown sugar consumption due to healthier characteristics. Despite the growing demand for the consumption of this type of sugar, there is little study on sugarcane cultivars and harvest times more suitable for brown sugar production. In this sense, the purpose estimate the linear relationships between the characters of sugarcane production and brown sugar quality, to determine which traits can be used as a criterion for selecting genotypes with the highest yield and quality of the brown sugar obtained, and study the genetic dissimilarity of the genotypes and their respective productive response in brown sugar in the three harvest seasons during cultivation. A randomized block design in a 10x3 factorial was used, ten sugarcane genotypes (IACSP 93-3046, RB 96-6928, IACSP 95-5094, IACSP 97-4039, SP 81-3250, IACSP 95- 5000, RB 86-7515, IACSP 96-3060, IACSP 04-704, IACSP 04-656) and three harvest seasons (15, 17 and 19 cultivation months) with four repetitions. Technological variables related to quality parameters and agronomic variables related to the productive aspect were evaluated. Cluster analyzes were performed, principal components, path analysis and canonical correlation. The results show that all genotypes showed a better brown sugar production response in the second harvest season. The variables that most contributed to the variability were the apparent sugarcane, total recoverable sugars and soluble solids content of the cane. For each harvest season, different groups of genotypes were formed. Among the ten genotypes, eight showed higher brown sugar production after 17 months of cultivation. There was variation in the brown sugar color according to the harvesting season and the cultivar used to produce it. In the analysis of cause and effect, the broth variable per ton of cane had the greatest direct effect on brown sugar production, in the first and second harvest season. For the third harvest season, the variable content of soluble solids in the broth showed a greater direct effect on brown sugar production. With different responses in the three harvest seasons, canonical correlation analysis showed interdependence between groups of variables, showing that there are agronomic variables that can be used as an alternative in the selection of cultivars with higher brown sugar quality.