Mohammad saeed Hasanvandi; Masoud Rafiee; Azimeh bagheri
Abstract
Growth analysis is a valuable method in the quantitative analysis of crop growth, development and cropproduction. In order to evaluate effects of nitrogen rates and plant density on physiological growth indicesof safflower, an experiment was conducted at Khorramabad, Lorestan province in 2008. The experimentwas ...
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Growth analysis is a valuable method in the quantitative analysis of crop growth, development and cropproduction. In order to evaluate effects of nitrogen rates and plant density on physiological growth indicesof safflower, an experiment was conducted at Khorramabad, Lorestan province in 2008. The experimentwas carried out as split plot in basis of randomized complete block design with four replications. Threenitrogen application rates were as main plots (N1=control, N2=75 and N3=150 kg/ha net nitrogen) andplant density was as sub plots in 3 levels (D1=40, D2=50 and D3=60 plant/m2). The growth degree dayindex was used to examine more closely fitting growth curves using non-linear regression models.Appropriate model was selected for each growth index. The results showed that application of nitrogenled to increasing of growth indexes including leaf area, total dry matter and crop growth rate. But, netassimilation rate was reduced. Growth indexes such as, leaf area, total dry matter, did not change withincreasing plant density, due to branching of safflower. However, crop growth and net assimilation ratewere reduced in plants. Overall, the results show that applied nitrogen has a more positive effect onsafflower growth index compared to density changes.