Abstract
Eighteen sunflower hybrids of diverse origin were evaluated for nine agronomic characters under field conditions at NARC, Islamabad. Data were recorded on days to flower initiation & completion and days to maturity were recorded on plot basis while Plant height (cm), Stem girth (mm) and Head diameter (cm) were recorded on 10 randomly selected plants in central two rows. Seed yield per plot in grams (Fresh weight). Seed yield per plot in grams (dry weight), Seed yield per plot on dry weight basis and then converted into kg ha(-1). The objectives were to estimate the genetic parameters, genetic diversity, correlation coefficient and path analysis. The highest seed yield 3409 kg ha(-1) was produced by the hybrid "FSS 50" followed by FH-385 and Barracuda. All the characters had positive correlations with seed yield and 100 seed weight except head diameter where it was negatively correlated. Oil contents (-0.058) also had negative genotypic correlation. Therefore, it is suggested to break this negative correlation through conventional or novel breeding techniques to breed high yielding hybrids with higher oil contents. Positive direct effect was also observed with days to flower initiation, plant height, head diameter and oil contents on seed yield. Maximum positive direct effect (38.944) was observed with days to flower initiation followed by plant height (11.771). Cluster diagram based on Euclidean dissimilarity revealed 3 clusters at 50% linkage distance. Cluster-I had 9 genotypes, cluster-II had 6 and three in cluster-III had three genotypes. Hybrids in cluster-I had tall plants and were high yielding. Hybrids in cluster-II are desirable for large scale cultivation because plants of these were medium with larger heads, high yielder and late in maturity. These hybrids were also high in oil contents can be more desirable for large scale cultivation on the basis of high oil yield. The hybrids in cluster-Ill were earlier in maturity, shorter in stature, had more 100 seed weight but lower in seed yield.