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Introduction: Festuca species are forage grasses that are very important in terms of fodder supply and soil protection. The seeds of these plants have internal dormancy (physiological) and are unable to germinate easily. Therefore, they must be subjected to various treatments to germinate. In nature, this dormancy is broken during the cold period of winter (chilling). The purpose of this research is to investigate different methods of dormancy breaking in Festuca species for large-scale production and accelerate the germination process. Materials and methods: In this research, three species of Festuca (Festuca arundinacea, F. ovina, and F. rubra) were subjected to different treatments of chilling (4°C, 14 days), osmo-priming with potassium nitrate (KNO3) 1.5% and gibberellic acid 150 and 200 ppm. After 14 days of germination test, various germination indices including percentage and rate of germination, mean germination time, seed vigor index, length of radicle, shoot and seedling, and the ratio of radicle to shoot length were calculated. Results: The results of the analysis of variance showed a significant difference between species (except for germination percentage and root length traits) and treatments (for all traits). The interactions between the species and treatment were also significant for all traits (except for the length of radicle and seedling). Among the three species, the percentage of germination varied from 26.67 to 30.67% and the value of the germination rate varied from 1.92 to 3.31 n/d. The average time required for germination varied from 3.75 to 4.36 days and the seed vigor index varied from 26.74 to 43.02. The radicle length was between 37.22 and 45 mm and the shoot length was between 37.34 and 81.33 mm. Based on principal components analysis (PCA), percentage and rate of germination, seed vigor index, and length of radicle and seedling were introduced as the most important factors in creating diversity in Festuca species. In determining the correlation between traits, a high correlation of 70% was observed between germination percentage, germination rate, and seed vigor index. Conclusion: Among the three species, Festuca rubra was superior to the other two species by having the highest percentage and rate of germination, seed vigor, radical length, and the shortest time required for germination. Among the applied treatments, 1.5% potassium nitrate (KNO3) with chilling (4°C, for 14 days), had a positive effect on the percentage and rate of germination, radical length, and gibberellic acid (150 ppm) treatment had a positive effect on the length of shoot and seedling. The presence of high germination percentage and rate indicated higher seed vigor. [ABSTRACT FROM AUTHOR]

Long-term drought effect is one of the main factors of global climate change, with consequences for soil biogeochemical cycling of carbon and nitrogen and the function of soil ecosystem under drought conditions. We hypothesized that 1) the Bromus inermis, Dactylis glomerata and festuca arundinacea species would differ in their rhizosphere responses to drought and 2) combined plant species and drought would have offsetting effects on the soil biological traits. We tested these hypotheses at the long-term drought field expreiment at the Lavark Farm of Isfahan University of Technology by analyzing soil microbial biomass carbon and nitrogen and activity of β-glucosaminidase in the rhizosphere of Bromus inermis, Dactylis glomerata and festuca arundinacea species. Soil microbial biomass carbon and nitrogen responses to drought depended on plant species, such that the highest MBC was recorded in the Bromus inermis rhizosphere, while the lowest was in the Dactylis glomerata rhizosphere, thereby suggesting the greater microbial sensitivity to drought in the Dactylis glomerata rhizosphere. Genotype variations (drought tolerate and sensitive) mostly affected the change in the β-glucosaminidase activity, but they were not significantly affected by drought treatment and plant species. In general, the positive effects of the plant genotype could offset the negative consequences of drought for soil microbial biomass and traits. [ABSTRACT FROM AUTHOR]

Soil water repellency can affect several soil properties such as aggregate stability. Soil texture and organic matter are two main internal factors responsible for the variability of soil water repellency. Major sources of organic matter in soil include plant residues, and exudates of plant roots and soil microorganisms. Tall fescue (Festuca arundinacea Schreb.) as an important cool-season perennial forage grass is usually infected by a fungal endophyte (Epichloë coenophiala) which often enhances resistance to biotic and abiotic stresses as well as altering the litter decomposition rate and soil properties. In this study, the effects of endophyte-infected (E+) and endophyte-free (E−) tall fescue residues (in three different levels of 0, 1 and 2%) on soil organic carbon, basal microbial respiration, water-dispersible clay and water repellency index (determined by intrinsic sorptivity method) were investigated in four texturally-different soils in the laboratory. E+ and E− tall fescue residues were completely mixed with moist soil samples and then were incubated at 25 °C. During two months of incubation period, the amended soil samples were subjected to 10 wetting and drying cycles and then, the above-mentioned soil properties were measured. The results indicated that soil organic carbon and water-dispersible clay were greater, while basal soil respiration and repellency index were lower in fine-textured soils. Water repellency index was increased by production of hydrophobic substances (for the rate of 1%) and was reduced by induced greater soil porosity (for the rate of 2%). Presence of endophyte in plant residues had no significant effect on water sorptivity, ethanol sorptivity and water repellency index; nevertheless, E+ residues increased soil organic carbon and decreased water-dispersible clay significantly. Overall, it is concluded that tall fescue residues, especially those with E+, can improve soil physical quality due to improving soil organic carbon storage and water repellency index and decreasing water-dispersible clay (as an index for aggregate instability). These E+ species and the residues have great potential to be used in sustainable soil conservational managements.

One of the main problems of Shiraz city’s green space is the change of color and visual quality of turf during cold months. Therefore, we aimed to evaluate tall fescue in order to find if it is suitable for replacement. This experiment was in the form of complete random blocks and it was done during two consecutive years. Each treatment had 4 repetitions. Data were analyzed using SPSS software, version 16.0, and the means were compared using t or LSD tests at a significance level of 5%. The results showed that tall fescue was superior to normal sport grass in cold months with respect to its chlorophyll, catalase, protein, prolin, and soluble sugar content, as well as its visual quality and root depth. Prolin fluctuations in tall fescue were very high which showed that these types of grass can increase the plant’s prolin content under stress. Therefore, there is a fivefold increase in the prolin content of the grass in cold months (cold tension) compared to the beginning of spring (best condition for growth). However, this change does not exist in sport grass. Based on the obtained results we can conclude that tall fescue can resist environmental tension, especially coldness, using different mechanisms, and is a good substitute for normal sport grass.

Soil water repellency can affect several soil properties such as aggregate stability. Soil texture and organic matter are two main internal factors responsible for the variability of soil water repellency. Major sources of organic matter in soil include plant residues, and exudates of plant roots and soil microorganisms. Tall fescue (Festuca arundinacea Schreb.) as an important cool-season perennial forage grass is usually infected by a fungal endophyte (Epichloë coenophiala) which often enhances resistance to biotic and abiotic stresses as well as altering the litter decomposition rate and soil properties. In this study, the effects of endophyte-infected (E+) and endophyte-free (E−) tall fescue residues (in three different levels of 0, 1 and 2%) on soil organic carbon, basal microbial respiration, water-dispersible clay and water repellency index (determined by intrinsic sorptivity method) were investigated in four texturally-different soils in the laboratory. E+ and E− tall fescue residues were completely mixed with moist soil samples and then were incubated at 25 °C. During two months of incubation period, the amended soil samples were subjected to 10 wetting and drying cycles and then, the above-mentioned soil properties were measured. The results indicated that soil organic carbon and water-dispersible clay were greater, while basal soil respiration and repellency index were lower in fine-textured soils. Water repellency index was increased by production of hydrophobic substances (for the rate of 1%) and was reduced by induced greater soil porosity (for the rate of 2%). Presence of endophyte in plant residues had no significant effect on water sorptivity, ethanol sorptivity and water repellency index; nevertheless, E+ residues increased soil organic carbon and decreased water-dispersible clay significantly. Overall, it is concluded that tall fescue residues, especially those with E+, can improve soil physical quality due to improving soil organic carbon storage and water repellency index and decreasing water-dispersible clay (as an index for aggregate instability). These E+ species and the residues have great potential to be used in sustainable soil conservational managements. [ABSTRACT FROM AUTHOR]