Agronomic and chemical characteristics of RB83-5486 and RB86-7515 sugarcane varieties under irrigated and rainfed conditions

摘要

The study aimed to evaluate the agronomic characteristics and chemical composition of sugarcane varieties, harvested at the end of the dry season, under irrigated and rainfed conditions. The experimental design was in a completely randomized blocks with six replications. Two varieties (RB83-5486 and RB86-7515) under irrigated and rainfed conditions were studied. The stalk and dry matter yield were improved by irrigation, especially in case of RB86-7515. Higher contents of crude protein, acid detergent fiber, cellulose and lower contents of dry matter, Brix, non-fiber carbohydrates (NFC) and in vitro dry matter digestibility (IVDMD) were obtained in the varieties under irrigation. The neutral detergent fiber (NDF) and NDF/brix were higher in irrigated conditions, variety RB86-7515 showing higher values. The lignin content was higher in the RB86-7515 under irrigated conditions. The RB83-5486 presented a better content of Brix, NFC and IVDMD than the RB86-7515. High productive potential was expressed under irrigated conditions, with emphasis on the RB86-7515. Irrigation influenced the chemical composition, negatively affecting the nutritional value of varieties. The RB83-5486 showed a better nutritional profile to be used as forage.