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 (×10 3 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.

Location Effects and Their Implications in Breeding for Sugarcane Yield and Quality in the Midlands Region in South Africa

“…However, ratooning effects are confounded with year effects (Kang et al, 1987) and are therefore more complex to manipulate. Moreover, the crop‐year effects are also confounded with the variability in weather patterns within years, making it difficult to select accurately for ratooning effects (Ramburan, 2013; Zhou and Shoko, 2012b). Although the crop‐year effect confounding is present, genotypes that produce higher yield across crop‐years are preferred because they are expected to be more stable across crop‐years and would provide stable yields across ratoons.…”

“…Enhancing selection for ratooning ability via yield components could improve gains in the ratooning ability of the crop. Selecting for high stalk population (Zhou, 2004a; Zhou and Shoko, 2012a) also enhances breeding for ratooning ability and should be adopted as a future strategy.…”

Association of Physiological Responses and Root Distribution Patterns of Ratooning Ability and Yield of the Second Ratoon Cane in Sugarcane Elite Clones

“…Environmental factors greatly affect the ratooning ability and yield of the ratoon crop [13,14]. The germinating bud is initially dependent on the nutrients and water in the set, developing its own root system after about three weeks under proper conditions [15].…”

Location and Seasonal Effects on Irrigated Sugarcane Breeding for Yield and Sucrose Content in South Africa

“…In sugarcane ( Saccharum spp.) breeding, genotype testing trials are established across representative locations and seasons and harvested for several crop‐years to increase precision in determining genetic values (Kimbeng et al, 2009; Zhou and Shoko, 2012b). Increasing the accuracy of determining genetic values improves the estimation of genotype differences and improves selection precision (Zhou, 2015).…”

“…Ratooning refers to the practice in sugarcane whereby after harvesting, the crop regrows and several crops are harvested from the same planting. Ratooning increases the profitability of sugarcane cultivation (Ellis and Merry, 2004) because the cost of planting is higher than that of ratoon maintenance (Zhou and Shoko, 2012a). Locations represent the inherent characteristics of the site such as soil types and prevalent agroclimatic conditions (Zhou et al, 2011).…”