Effect of early evaluation of genotypes on genetic variability repeatability and predictability in plant and ratoon crops of sugarcane

Abstract

Genotypic and phenotypic coefficients of variation (GCV, PCV), heritability, genetic advance in per cent of mean, genetic relationship, repeatability and predictability were studied on plant cane and the first ratoon of sixteen early maturing sugarcane genotypes for yield characters and sugar content at Sugarcane Research Institute, Shahjahanpur, India. Result showed that the GCV, PVC, heritability, genetic advance in per cent of mean were higher for stalk weight, NMC and yield in both plant and ratoon crops, whereas stalk height was higher only in ratoon. Repeatability of characters between crops was 0.97**, 0.96**, 0.97**, 0.79**, 0.75** and 0.71** for juice brix, sucrose per cent (7 months), yield (10 months), stalk height, number of stalk and stalk diameter (7 months), respectively. The genetic association among characters were relatively low in both crops (r = -0.15 to 0.78), stalk diameter was the most predicatable characters followed by stalk number, stalk height, juice brix and sucrose per cent at grand growth stage for yield potential of genotypes in plant cane as well as ratoon. These characters may serve as a reliable selection critaria for yield and sucrose accumulation of early maturing high sugared genotypes from plant cane to the first ratoon. There were best estimated at 7 months when the genetic expression for yield contributing and quality characters were maximum.