Techniques For Seed Production In Tall Fescue And Kentucky Bluegrass In Shanghai

With the development of environmental proctection in China,lawn industry develops rapidly,but the turfgrass seed is not self-sufficient which is highly dependent on import.In numerous perennial forage grass,turf grass and ecological grass,only cool-season turgrass tall fescue（Festuca arundinacea Schreb）and Kentucky bluegrass（Poa pretensis L.）can reach the level of anniversary evergreen if using good cultivars and correct management measures in China’s Yangze River downstream area.So it’s important to studu the seed production of tall fescue and Kentucky bluegrass in Shanghai area.The objectives of this study were to explore feasible measures to improve the tall fescue and Kentucky bluegrass seed yield by fertilizer application rates,foliar spraying different chemical regulators,the suitable harvest time and harvest heights.Results from the experiments were summarized as in the following:1.Application of N-P₂O₅-K₂O（15-15-15）compounded fertilizer at 875kg/hm² for tall fescue and at 500 kg/hm² for Kentucky bluegrass in autumn in Shanghai were a sufficient rate and a suitable fertilizer type.They had more fertile tiller number and seed yield under the fertilizer application rate.2.Foliar spraying effective dose of 3.0kg/hm² chlormequat chloride or0.1875kg/hm² pacloburazol at the blooming stage,and effective dose of0.75kg/hm²（NH₄）₆Mo₇O₇.4H₂O or pH=7.0 PB of 50mmol/L at spring regreening stage,booting stage and the blooming stage could improve tall fescue seed yield.Foliar spraying effective dose of 1.125kg/hm²（NH₄）₆Mo₇O₇.4H₂O and pH=7.0 PB of 150mmol/L after heading but before flowering and at the blooming stage or at spring regreening stage,booting stage and the blooming stage could improve Kentucky bluegrass seed yield.3.The best harvest time of tall fescue was 22 days after florescence in Shanghai.At this time,there were relatively plump seeds and the highest seed yield.4.When the seed was ripe,the effect of different harvesting stubble heights on seed yield for tall fescue and Kentucky was not significant.5.Different genotypes had different seed yield.The highest seed yield of 6 clones and 2 control materials of tall fescue was‘TF36’,whose yield obtained 1780.8kg/hm² under fertilization.The highest seed yield of 2clones and 2 control materials of Kentucky bluegrass was‘KBG04’,which obtained high seed yields of 957.4kg/hm².Under good control of weeds,techniques for seed production in Tall Fescue and Kentucky bluegrass in Shanghai is that applying compound fertilizer of 875kg/hm² and 500kg/hm² in autumn and foliar spraying pH=7.0 PB of 50mmol/L and 150mmol/L respectively,then harvesting seed22 days after florescence for tall fescue and just harvesting seed head,finally being dried and threshed.