This study was undertaken to determine phenotypic and genetic correlation coefficients among several agronomic traits in sugarcane (Saccharum spp.) and to analyze their interrelationships through path‐coefficient analyses. Other objectives were to determine broad‐sense heritability and genetic advance under selection for the traits studied. Random selections from two biparental crosses (‘CP 59‐50’ ✕ ‘CP 57‐603’ and ‘CP 62‐374’ ✕ ‘CP 57‐614’) were evaluated in the field for several attributes in plant cane, and first‐ and second‐ratoon crops. Genetic path‐coefficient analyses indicated plant height to be less important than stalk diameter and stalk number as a component of cane yield; but at the phenotypic level, all three components were of equal importance. Sucrose (%) had a large direct positive effect on sugar per ton of cane (S/T) whereas Brix (percent soluble solids) had a small negative direct influence on S/T. The S/T component exerted a greater direct effect on tons per hectare of sugar (THS) than did tons per hectare of cane (THC). Broad‐sense heritability estimates based plot means for various traits ranged from a low of 77% for THS to a high of 94% for stalk diameter. Expected genetic advance for various traits was reasonably high under selection intensities of 2 to 30%. THC estimated from the weight of a 10‐stalk sample per plot was genetically and phenotypically correlated with THC determined by weighing the entire plot (rg = 0.92, rp = 0.64) which suggested that a 10‐stalk sample per plot would be adequate to determine THC.

Sugarcane (Saccharum spp.) is a successful crop in the Florida Everglades Agricultural Area (EAA) that is characterized by high‐N organic and low‐fertility sandy soils, periodic freeze, and flood events. After 50 yr of breeding, the possibility of a yield plateau was investigated in the cooperative Florida sugarcane breeding program via an assessment of yield gains in the industry and an evaluation of the contribution attributed to breeding efforts. Long‐term commercial and selection trial data, covering a 33‐yr period (1968–2000), were used in single‐degree‐of‐freedom regression analyses to determine rates of improvement in sucrose content (SC; kg Mg−1), cane yield (CY; Mg ha−1), and sugar yield (SY; Mg ha−1). Analyses of commercial data reflected yearly increases of 0.80 ± 0.08 kg Mg−1 of cane for SC, 0.31 ± 0.10 Mg ha−1 for CY, and 0.10 ± 0.01 Mg ha−1 for SY. Corresponding gains from selection trial data were 0.74 ± 0.15 kg Mg−1, 1.06 ± 0.40 Mg ha−1, and 0.16 ± 0.05 Mg ha−1, respectively. Improvements were significant for all three traits across plant‐cane, and first‐ and second‐ratoon crops grown on organic soils but not on sandy soils. About 69% of the total gain in SY was attributed to the cooperative Canal Point public breeding program, via a greater allocation of assimilates toward sucrose accumulation, resulting in a contribution of $99 to 203 million as additional profits to the Florida economy across the 33 yr. The genetic potential of the working germplasm has not been exhausted (no evidence of a yield plateau for SC) in this sugarcane breeding program. These gains and future advances are possible because of the use of a diverse gene pool and a breeding strategy that integrates growers’ participation into the program.

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