Chemical Control On Growth And Stress Resistance In Tall Fescue

Tall fescue(Festuca arundinacea Schreb.) was widely used in landscape garden and build playground in recently years. But tall fescue growth fast, cause the problem as more workload to trim and high cost to management more easily. So study on the plant growth retardants how to regulate lawns growth is very significant to save cost and do manage efficiently. We have some interesting ideas: can we find some new plant growth regulars to dwarf the lawns efficiently, and can we mix the plant growth regular with some other materials which are good for lawns growth to research one compound. Hope the compound can delay the growth of tall fescue, increase the tillers, make the leaves color greener, also can improve the ability to resistance, having no pollution to environment and low residue.There are many researches on the effect of uniconazole to lawns. The effects of uniconazole compound and Primo MAXX on the growth, photosynthesis and the ability to restress of tall fescue were studied. The results showed that uniconazole compound and Primo MAXX inhibited the growth of height, leave and root of tall fescue, shorten the distance between the leaves, improve the root-shoot ratio, tiller number and the content of chlorophyll. Among then, the effect of 100 mg/L uniconazole is the most obvious. The stomatal conductance, intercellular CO₂ concentration was decreased and transpiration rate became slow after treated with uniconazole compound. 100 mg/L uniconazole decreased the net photosynthetic rate of tall fescue. But Primo MAXX had no effect to them.Uniconazole compound and Primo MAXX decreased the electrolyte permeability and MDA in tall fescue leaves. 100 mg/L uniconazole and Primo MAXX both improved the activities of SOD. 50 mg/L uniconazole and Primo MAXX both improved the activities of POD, and Primo MAXX was more effective. The activities of CAT were improved by 100 mg/L Uniconazole compound, but the activities of CAT were both decreased by 50 mg/L Uniconazole compound and Primo MAXX.It was the first time to study methyl dihydrojasmonate (MDJ) on the growth and drought resistance on tall fescue. The results showed that MDJ inhibited the plant height of tall fescue seedlings in a dose-dependent manner. Deal with 400 mg/L MDJ after 16 days, the plant length was only 80.78% of the control. Above-ground fresh biomass was decreased in the prophase of MDJ treatment and had no obvious difference between MDJ-treated seedlings and the control in the anaphase but the effect of MDJ on chlorophyll content was just opposite. Moreover, MDJ inhibited the root weight, but had no significant effect on root elongation. Under drought stress, MDJ increased both the relative water content and the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Under drought stress 2 days, processed with 200 mg/L MDJ the activities of SOD, CAT and POD were 156.06%,123.81%,148.80% of the control. And MDJ decreased the electrolyte permeability, MDA in tall fescue leaves. Therefore, MDJ treatment can enhance drought resistance of fall fescue seedlings.