Phenotypic Evaluation of Energycane Varieties for Bioenergy

The need for renewable and carbon-neutral energy is growing as fossil fuel supplies decrease and concerns of climate change increase. C4 grasses are among the most efficient carbon accumulators. Sugarcane (Saccharum officinarum) is a renewable bioenergy crop with low inputs and high yields, but it is limited to tropical and sub-tropical climates. A close relative, Saccharum spontaneum, readily hybridizes with S. officinarum. S. spontaneum lends cold tolerance and higher yields to the hybrid progeny, called energycane. The Sugarcane Breeding Unit (USDA, Houma, Louisiana, USA) selected twenty-six genotypes for testing at Mississippi State University to determine production and cold tolerance at latitude 33.4552° N. Twenty of these genotypes were chosen after the first year for further testing against an energycane check (Ho02-113) and a sugarcane check (L01-299). Seed cane were harvested and planted in the fall of 2019 and 2020 in randomized complete block design with four replications. Plots were 6.1 x 1.8 m, fertilized once at a rate of 168 kg N ha-1. Cane heights and stand counts were collected to monitor genotype growth. At the end of the season, canes were taken for fresh weight, dry weight, °Brix, and sap volume. End of season characteristics of first year growth were: Mean height ranged from 73 to 204 cm; cane number ranged from 9,530 to 68,171 canes ha-1. Plot fresh weights ranged from: 19.9 to 61 Mg ha-1. Mean value of °Brix ranged from 8.9 to 13.7. Mean extractable sap volume ranged from: 2311 to 16,821 L ha-1. Theoretical ethanol yield was calculated for sap and from dry matter. Total theoretical ethanol yield ranged from 939.8 to 3261.2 L ha-1