Effects of nitrogen and potassium fertilizers on rice (Oryza Sativa L.) genotypes processing characteristics.

In order to consider effects of various levels of nitrogen and potassium application on kernel processing characteristics of rice cultivars, an experiment was developed in 2004 and 2005 using Tarrom (a local Iranian landrace) and Neda (an Iranian improved cultivar). In this experiment four levels of nitrogen fertilizer (0, 50, 100 and 150 kg N ha(-1) from urea source) and four levels of potassium fertilizer (0, 75, 150 and 225 kg K2O ha(-1) from potassium sulfate source) have been applied using a split factorial design with 3 replications. Nitrogen fertilizer have been applied in three stages (1/3 in transplanting stage, 1/3 in tillering stage and finally 1/3 in flowering initiation stage) and potassium fertilizer have been applied in two stages (1/2 in transplanting stage and 1/2 in shooting stage). Results showed that application of nitrogen cause an increase in amount of bran production and have shown significant effects on percentages of bran, head and brewers rice, husking efficiency and transformation degree. However, potassium application has increased percent of bran and husking efficiency and has decrease percentages of brewers rice and has not demonstrated significant effects on percentages of husk, head rice and transformation degree. Furthermore, simultaneous application of nitrogen and potassium in Tarrom genotype has not shown significantly effects on percentages of husk, head and brewers rice and transformation degree. In Neda, cultivar has not also shown significant effects on percentages of bran production, head and brewers rice and husking efficiency, respectively. In Tarrom genotype amount of husk, bran, brewers rice and transformation degree were higher than in Neda cultivar, however, amount of head rice and husking efficiency in Neda cultivar were higher than in Tarrom genotype.