Changes of soluble carbohydrates in three species of Dactylis glomerata, Bromus tomentellus and Agropyron intermedium in three phenological stages

In order to study the changes of water soluble carbohydrates in different phenological stages, sampling of Bromus tomentellus, Agropyron intermedium and Dactylis glomerata was performed in Taleghan. Samples were taken randomly. Three samples in five repetitions (5 samples from each stem) were taken during three phenological steps (growth, flowering and complete growth). Percentage of soluble carbohydrates was measured using NIR. Analysis of variance of data was done based on factorial. Results showed that there was a significant difference between main and reciprocal effects in different steps of phenological growth. In all mentioned species percentage of carbohydrates increased with the growth rate. Quality of different species of grasses in terms of soluble carbohydrates showed significant difference. Mean values of water soluble carbohydrates in A. intermedium، D. glomerata and B. tomentellus were 13. 8%, 9. 4% and 8. 2%, respectively. Percentage of water soluble carbohydrates in A. intermedium and D. glomerata increased with growth rate and in B. tomentellus was highest in vegetative period. The highest level of water soluble carbohydrates was measured in A. intermedium (17. 4%) in complete growth stage. This shows that this species is valuable for delayed grazing.