The Comparision Experiment Of Four Bothriochloa Ischaemum Populations Under The Condition Of The First Year Growing Period In Shanxi

The comparision experiment of four Bothriochloa ischaemum populations in Jinzhong areas of Shanxi was carried out, for the purpose of breeding high yield of Bothriochloa ischaemum varieties, providing forage resources with strong adaptability for shrub grassland vegetation restoration and ecological construction in warm temperate zone .The experiment designed by random complete block design. The growth stages, production performance and nutritional quality were studied under the condition of the first year growing period. Results as follows:Four B. ischaemum populations were able to complete the entire growth period in Jinzhong areas of Shanxi in the first year growing period, with a strong adaptability. The growth period was 130-145 d. The growth period of Pinglu population was shortest and earlier than other populations in every period. The dynamic of plant height of four B. ischaemum populations was "S". The rapid growth of plant was in the later Jointing stage and Booting stage, and the growth speed was 2.39～2.85 cm·d-1. The regrowth speed of the short term after mowing was lower, and increased rapidly about 15～20 d. The tiller number of four B. ischaemum populations increased firstly and decreased subsequently. The agronomic traits of four B. ischaemum populations was different, the coefficient of variation of leaf number, internode number and racemes number were 19.93%、14.54%、12.90% respectively.In terms of production performance, the fresh yield, hay yield, hay fresh ratio and CP yield of four B. ischaemum populations had significant difference. The fresh yield, hay yield, hay fresh ratio and CP yield of Taigu population were the highest, which reached to 32.17 t·hm-2,10.53 t·hm-2,0.34,1041.00 kg·hm-2 respectively, and the hay yield and CP yield of Taigu population were significantly higher than others (P<0.05). The fresh yield, hay yield and CP yield of the first cutting were higher than the second cutting, which accounted for more than 80% of amount, showing that the first cutting was very important. The grass yield of Taigu population was exceeded other populations in the first cutting. Regrowth speed and regrowth strength of four B. ischaemum populations had no significant difference (P> 0.05), the regrowth speed was 0.31～0.34 cm·d-1,the regrowth strength was 25.34～33.50 kg·hm-2·d-1.The seed yield of four B. ischaemum populations was 263.83～322.73 kg·hm-2. The seed yield of Taigu population was the highest, which reached to 322.73 kg·hm-2, and the seed yield of Pinglu population was the lowest, which was 263.83 kg·hm-2.In terms of nutritional quality, the CP, Ca and P contents of Taigu population were the highest, the DM, EE and Ash contents was lower than others, the NDF and ADF contents were the lowest. In addition, the CP, EE,Ca and P contents of Taigu population in the first cutting were the highest, which reached to 9.75%, 3.30%,0.45%,0.18% respectively, the DM and Ash contents was lower than others, the NDF and ADF contents were the lowest. Taigu population exceeded other populations.Adaptation performance characters in agronomic traits, production performance and nutritional quality three aspects of four B. ischaemum populations grown in the Jinzhong areas of Shanxi province were measured and analyzed by the grey correlative system. The comprehensive performance of Taigu population was best in the study area, following was Pingding and Dai county populations, whereas the Pinglu population had relatively low adaptive productivities. The order of weight index in the grey correlation analysis was: NDF> ADF> EE> stem diameter> internode length> leaf length> hay fresh ratio> CP> biomass per plant> leaf width> plant height> Ash> fresh yield> leaf stem ratio> internode number> hay yield> leaf number. The weight index of NDF、ADF、EE which represented nutritional quality were biggest, and the weight index of stem diameter, internode length, leaf length, biomass per plant, leaf width and plant height which represented agronomic traits were bigger,whereas the weight index of hay fresh ratio, fresh yield, leaf stem ratio and hay yield which represented production performance were smaller.Comprehensive analysis showed that Taigu population had the best performance, with great potential for establishing pasture.