Simultaneous selection for yield and ratooning ability in sugarcane genotypes using analysis of covariance

Abstract

Ratooning ability increases sugarcane production economics by reducing frequency of planting. During sugarcane breeding, indirect selection for pest resistance and direct selection for high ratoon yields increases ratooning ability. The objective of this study was to describe the simultaneous screening of genotypes for yield and ratooning ability in sugarcane breeding trials using analysis of covariance. Data for cane yield (tons ha^–1) and stalk population (×10³ ha^–1) collected from five trials harvested from plant to fourth ratoon crops were analysed using the Statistical Analysis System (SAS). There were significant differences in parameters for yield (intercept) and ratooning ability (slope) among test genotypes indicating potential for simultaneous screening. Comparison of genotypes to a control with known ratooning ability identified higher yield and good ratooning genotypes. Graphical trends identified genotype differences in yield and ratooning ability. The economics of yield and ratooning ability of two varieties was compared providing a mechanism for variety choice at planting. The method described provided statistical tests that would increase genotype selection efficiency for ratooning ability. The decline in yield among genotypes is slowed by the increase in stalk population.

Keywords: ratooning cycles, sugarcane breeding method, Saccharum officinarum L

South African Journal of Plant and Soil 2012, 29(2): 93–100