Assess Correlation between Traits Affected Different level of Nitrogen Fertilizer (Urea Source) and Interval between Irrigation Round of Sorghum

BACKGROUND: Knowing about grain yield issue and its components plays an important role for being successful in evaluative programs. Success in breeding and having fruitful varieties of agricultural products with a higher quality depends on knowledge about genetic grain yield controlling and its relation with seed yield components, also to phonologic traits and forage quality. OBJECTIVES: This study was conducted to predict the most effective traits on sorghum seed yield according correlation between characteristics in response to apply different interval irrigation round and urea fertilizer. METHODS: To investigation the effect of different level of Nitrogen fertilizer and irrigation method on crop production of Sorghum (Speed feed cultivar) a farm research was arranged via split plot experiment based on the randomized complete block design with three replications in 2012. Main plots were included apply three levels of interval between irrigation (I1: 8 day; I2: 12 day; I3: 16 day) and the sub plots consisted three level of urea fertilizer (N1: 200, N2: 300, N3: 400 kg.ha-1). RESULT: According result of analysis of variance effect of different level of irrigation regime, urea fertilizer and interaction effect of treatments on all measured traits (instead harvest index) was significant. Simple correlation coefficients between traits were estimated according to Pearson coefficient. The most positive and significant correlation was observed in total dry weight (r=0.91**), fresh forage yield (r=0.85**) and number of seed per panicle (r=0.79**). The traits of Panicle length (0.69*), 1000-seed weight (r=0.67*), number of racemes in panicle (0.64*) number of fertile tiller (r=0.61*) and seed protein content (0.51*) had correlation with the seed yield was significant at 5% probability level. CONCLUSION: According to the results of this research, traits of total dry weight, fresh forage yield and number of seed per panicle, had the most positive-direct effects on Sorghum seed yield can be proposal to plant breeder to more studied process such as stepwise regression and path analysis.