Phenology and Growth of Forage Sugarcane Cultivars According to the Planting Cycle

Context: Plant phenology and growth exhibit quantitative relationships that help in understanding its biomass production capacity. Therefore, a detailed understanding of its general and specific characteristics is crucial for efficient exploitation.

Aim: To characterize the phenology and growth of forage sugarcane cultivars C97-366 and C99-374 according to the planting cycle.

Methods: Two experiments were planted during the spring (April) and cold (October) cycles in the areas of the Sugarcane Research Institute (INICA) in Camagüey, Cuba, under rainfed conditions. A randomized complete block design with two treatments (cultivars) and three replicates was used. Evaluations were conducted monthly, between 181 and 368 days. The variables evaluated were fresh and dry plant weight, dry matter, and green and dry biomass production.

Results: The forage cultivars did not show similar growth dynamics across planting cycles. These variations were significantly influenced by the seasonal behavior of climatic variables, particularly precipitation and temperature. Both cultivars achieved average green biomass values (80-135 t ha^-1) and dry biomass (30-38 t ha^-1) that exceed the average reported in Cuba under rainfed conditions. The cultivar C99-374 achieved the highest productivity and stability in each cycle.

Conclusions: The forage cultivars can be used year-round to feed ruminants due to their high genetic potential for biomass production.