Abstract
Seventeen promising new sugarcane hybrids and three check varieties were planted in the Lajas valley, a semi-arid and irrigated area of southwestern Puerto Rico. Plant cane and ratoon crops were evaluated for yield and resistance to smut (Ustilago scitaminea Syd.) and rust (Puccinia melanocephala H. Syd. & P. Syd.). All new hybrids tested were resistant and tolerant to smut and rust. The smut incidence on susceptible check increased after ratooning. However, rust resistance and susceptibility of sugarcane hybrids and check varieties remained unchanged throughout a three-crop cycle. Combined analysis of variance of 2 years (plant and first ratoon crops) indicated that yields (sugar ton/ha) of five hybrids were consistently higher than those of the other genotypes tested, including the standard check variety PR 980.