Pak. J. Bot., 36(1): 83-92, 2004. PERFORMANCE OF PROMISING SUGARCANE CLONE FOR YIELD AND QUALITY TRAITS IN DIFFERENT ECOLOGICAL ZONES OF SINDH IMTIAZ AHMED KHAN, ABDULLAH KHATRI, MUHAMMAD AQUIL SIDDIQUI, GHULAM SHAH NIZAMANI AND SABOOHI RAZA Plant Genetics Division, Nuclear Institute of Agriculture, Tando Jam, Sindh, Pakistan. E-mail: niatjam@hyd.paknet.com.pk Abstract A new sugarcane clone AEC86-347, was obtained from seed (fuzz), of a cross combination of NCo 310 x CP57-614, imported from ARS, USDA, Canal Point, Florida, USA. The genotype was evaluated for the stability of its performance for economic characters at six different locations in the Province of Sindh for the two consecutive years. Significant (P≤0.01) differences were observed in genotypes and locations x genotypes interactions for the three traits i.e., cane yield, commercial cane sugar and sugar yield. This phenomenon indicates the presence of genetic variability amongst the genotypes and their differential response to varying environments. High mean performance of AEC86-347 with ‘b’ values more than 1.00 for cane yield, sugar yield and CCS (%) indicated its potential to take advantage of favourable environmental conditions for yield under different locations. Introduction Estimation of stability of a new genotype for yield and quality traits is pre-requisite in plant breeding programme prior to its release for commercial planting. Productivity of a genotype in favourable environments does not indicate its adaptability and stability, whereas performance of a genotype in diverse environments is somehow a true evaluation practice of its inherent potential for adaptativeness (Pandey et al., 1981). Therefore, varietal trials are normally conducted over various locations for different years, after achieving meaningful results before deciding the release of a new cultivar in a particular region (Narendra et al., 1988; Bakhsh et al., 1991; Basford & Cooper 1998). Stability analyses of sugarcane cultivar performance tests conducted under different environments have been reported by many researcher, (Pollock 1975; Ruschel 1977; Tai et al., 1982; Kang & Miller 1984; Milligan et al., 1990; Khan et al., 1997). Productivity stability is shown by some cane varieties in both predictable and unpredictable environments. In a predictable environment (i.e. climatic, soil type, day length and controllable variables such as fertilization, sowing dates and harvesting methods), a high level of genotype and environmental interaction was desirable, so as to ensure a maximum yield or financial return; whereas, in an unpredictable environment (inter and intra-season fluctuation, fluctuation in quantity and distribution of rainfall and prevailing temperature), a low level of interaction is desirable so as to ensure maximum uniformity of performance over a number of locations or seasons (Khan, 1981). After examining the stability of standard variety in varietal trials of sugarcane Pollock (1975) and Ruschel (1977) have suggested that clone selection against the average of several standard varieties was better than against a single one as the ‘b’ values were more precisely estimated when several rather than one standard variety was used to