Phenological phases of two early-maturing sweetpotato (Ipomoea batatas [L.] Lam.) cultivars

Abstract

Introduction. In Cuba, only general descriptions of sweetpotato phenology have been documented, without detailed information for producers and researchers. Objective. To characterize the main phenological phases of two early-maturing sweetpotato cultivars (Ipomoea batatas [L.] Lam.) under Cuban conditions. Materials and methods. A randomized complete block design with 10 replicates per cultivar was conducted at the Research Institute of Tropical Roots and Tuber Crops (INIVIT), Cuba. Two early cultivars from the INIVIT breeding program were evaluated: CEMSA 78-354 and INIVIT B-50. Evaluations were performed every seven days from 2 to 128 days after planting (DAP). Results. Plant tubering initiation began at 28 DAP for both cultivars. In the final phase (100 - 128 DAP), CEMSA 78-354 increased yield by 14.18 t·ha⁻¹ and INIVIT B-50 by 11.84 t·ha⁻¹. From 86 DAP onward, Degrees Brix (°Bx) remained stable until harvest. The greatest increase in dry matter content occurred between 51 and 107 DAP: from 15.9% to 26.4% in CEMSA 78-354, and from 16.6% to 26.9% in INIVIT B-50. At 128 DAP, dry matter reached 28.15% (± 0.72) and 27.07% (± 1.11), respectively. Conclusion. In the second half of the cycle, CEMSA 78-354 allocated 63.1% (0.96 kg ± 0.13) of accumulated weight to tuberous roots, while INIVIT B-50 allocated 46.9% (1.08 kg ± 0.24). Three well-defined phenological phases are proposed for Ipomoea batatas: rooting (0-28 DAP), growth (29-65 DAP), and accumulation (66-128 DAP).