Study On The Adaptability Of The Cool-season Turfgrasses In Hunan Province

With the development of lawn industry, cool-season turfgrasses are widelycultivated in China, this do much better in grass matching and the improvement of tuffquality, but some questions are also brought, such as in summer, the cool-seasonturfgrass can hardly survive because of heat stress.In order to solute this problem, a study is made. First 20 cool-season turfgrassvarieties is evaluated; then the mixed fertilization is designed to discover whether itcan do good in the improvement on the turf quality and the ability of resistance. Theresults are as follow items:1. Cool-season turfgrasses grow best in late spring and early summer; while insummer especially in the hot and drought period all introduced varieties' turf qualitybecome lower significantly: none of them can survive in summer. But there aredifferences between the species as well as varieties of the same species.2. Kentucky bluegrass' comprehensive performance is the best. according to theincidence order, the first three one: "Freedom 3","Merit","Nublue" are all belong tokentucky bluegrass, followed by tall fescue cultivars, "Huntdog5" are the fourth oneand "Arid3" is the sixth one in the incidence order, the worst is perennial ryegrassvarieties.3. Perennial ryegrass needs the least seeding days and lawn establishment days,the color in cold season is the best, yet, in early summer it is withered in large area.All these characteristics allow it become the first choice of the Dorment Lawn.4. Nitrogen can promote lawn growth speed, improve the turf quality andenhance turf resistant ability, there is significant difference between N level; the bestis N3(6g.m^-2), N2(3g.m^-2), N4(9g.m^-2) is the latter, and the difference between the 3levels is significant. Phosphorus and potassium could significantly reduce the cont oflawn leaves' malondialdehyde (MDA) and relative electrolyte leakage (EL); it canimprove plant antioxidant capacity and enhance resistance of kentucky bluegrass. Thebest level of phosphorus is P3(3.33g.m^-2), and potassium is the level of K4(5g.m^-2),but the difference between the levels of fertilization is not significant.5. Gray relativity analysis show: the treatment10(N6g.m^-2, P1.67g.m^-2, K5g.m^-2)do the best to the turfgrass, The speed of the lawn establishment is the fastest;the content of lawn leaves' malondialdehyde (MDA) is the least and the relativeelectrolyte leakage (EL) is the smallest; lawn uniformity, leaf chlorophyll content arebetter.