Stability parameters for tillers,grain weight and yield of wheat cultivars in North-West of Pakistan

Thirteen spring wheat cultivars were evaluated for 2-years at 5 diverse locations of nwfp for stability analysis of tillers per m2,1000-grain weight and grain yield. combined analysis of variance revealed significant differences among locations,years and locationxyear interactions for these wheat traits. cultivar × year interaction was highly significant (p=0.01) for 1000-grain weight and grain yield,while cultivar × location interaction was highly significant only for productive tillers per m2. however,cultivar × location × year interaction existed for all traits (p=0.01). maximum number of productive tillers of 410 per m2 were produced by wheat cultivar dirk followed by fakhre sarhad (396 tillers per m2) and nowshera-96 (395 tillers per m2). cultivars dirk and nowshera-96 excelled in 1000-grain weight (43 g). maximum grain yield of 4259 kg ha-1 was produced by cultivar nowshera-96 followed by fakhre sarhad (4183 kg ha-1). wide range of stability statistics was observed among cultivars for all the three parameters. though none of the wheat cultivar had b- value equal to unity for tillers m-2,1000-grain weight or grain yield,but pirsabak-85,bakhtawar-92,nowshera-96 and fakhre sarhad were the stable cultivars on the basis of overall mean yields and stability parameters viz.,regression coefficients and minimum deviations from regression.