A field experiment was conducted during early kharif of 2008 on sandy clay loam soils to study the effect of nitrogen and zinc on yield and quality of guar [Cyamopsis tetragonoloba (L.) Taub.]. The experiment was laid out in a split-plot design and replicated thrice. The treatments consisted of three nitrogen levels viz., 20, 30 and 40 Kg N ha -1 in main plots and four zinc management viz., 0.5% ZnSO 4 spray at 25 days after sowing (DAS), 45 DAS, 0.5 % ZnSO 4 spray at 25 and 45 DAS including soil basal application of 20 Kg ZnSO 4 ha -1 . Significantly highest dry matter production was registered with 40 Kg N ha -1 , while it was the lowest with 20 Kg N ha -1 . Yield attributes and seed and stalk yield were the highest with 30 Kg N ha -1 . Among the zinc management practices 0.5 % ZnSO 4 spray at 25 and 45 DAS resulted in highest seed and stalk yield. With regard to quality parameters, protein content was found to be the highest with 40 Kg N ha -1 , which was however, comparable with 30 Kg N ha -1 . The highest protein content was recorded with 0.5 % ZnSO 4 spray at 25 and 45 DAS while it was the lowest with 20 Kg ZnSO 4 ha -1 .

The present investigation on correlation and path analysis studies helps to study the relationship among the yield and yield contributing traits along with the quality parameters. The observations were taken in the F1 population of 35 hybrids along with lines (7 lines) and testers (5 testers) for the traits viz. plant height (cm), number of sympodial branches per plant, the number of bolls per plant, boll weight (g), lint index (g), single cotton yield per plant (g), ginning outturn (%), upper half mean length (cm), elongation percent (%) and micronaire value (µg per inch). The results revealed that seed cotton yield per plant had strong and positive association with the traits namely number of sympodial branches per plant (0.646), number of bolls (0.633) and boll weight (0.652). Path analysis study revealed that number of sympodial branches per plant (1.5396), boll weight (0.6285), lint index (1.3526) and upper half mean length (0.3392) had high direct positive effects on single plant yield and indirect very high positive effects through the traits viz., number of sympodial branches per plant via., number of bolls per plant (1.5125) and boll weight (1.0121). Hence selection based on these traits that are positively associated and direct positive effect with the yield would produce the best outcome in the genotypes in further breeding programmes.