Surface Color Characteristic of Wheat Grains as Affected by Different Fertilization Rates
The objectives were to investigate the relationship between the surface color characteristics of wheat grains and phosphorous and iron fertilizer rates. The treatments were a combination of four rates of phosphorus (0, 75, 150, and 225 kg ha-1) and three rates of foliar iron (0, 1.2, and 2 L ha-1) with three replications. The results of the study showed that some of the surface color values of wheat grains were depended on the phosphorous and foliar iron application rates; resulting in color shift toward the lighter regions. Phosphorus rates created higher variations than iron rates. With increasing the iron rate from 0 to 2 L ha-1, the average value of L* and color units increased significantly from 40.01 to 41.16, and from 1.56 to 3.33 respectively. No effect of foliar iron on the b* value was observed. As the phosphorus rate changed from 0 to 75 kg ha-1, the mean values of L*, b* and of grains increased significantly from 38.98 to 42.02, from 27.90 to 29.78 and from 1.34 to 3.67, respectively, although, additional increase in the rate of phosphorus, caused a decreasing trend in the values of the above scales. No effect of phosphorus rate on a* value was observed.