The Study Of The Types Of Wheat Grass Weed In Shandong Province And Chemical Control Technique

A study was conducted on the species and community composing of graas weed in wheat field in Shandong province. Some main herbicides used currently in wheat field for graas weed control were screened both at greenhouse and field to determine the efficacy to control the graas weed grown in the wheat field. Based on the results of these two studies the integrated weed managemant technique on the grass weed control in the wheat field in Shandong province were studied out.1. The species, distribution and damage of the severe grass weeds in the wheat field of Shandong province.A survey was conducted to determine the species, distribution and damage of the severe grass weeds in the wheat field of Shandong province by visual 5 grades classification method. The results showes that there are 21 species of grass weed in wheat field in Shandong province. The main preponderant species are Bromus japonicus Thunb., Alopecurus aequalis Sobol., Paspalum sphondylodes Trin.ex Bge., Aegilops squarrosa L., Avena fatua L., Beckmannia syzigachne(Steud.)Fern. etc. A significant distribution difference was showed among these severe grass weed in wheat field in different regions. The main species are Bromus japonicus Thunb.at plain and hill area; Alopecurus aequalis Sobol., Paspalum sphondylodes Trin.ex Bge. along the area of the Weishan lake, Puccinella distans (L.) Parl. at salina soil, and Lolium multiflorum Lam. along the coast area wheat field.Among the severe grass weeds in the wheat field of Shandong province the most prevalent species is Bromus japonicus Thunb. with the frequency of 46.96% following by Alopecurus aequalis Sobol. 16.58%, Paspalum sphondylodes Trin.ex Bge.13.58%,Aegilops squarrosa L.12.91%, Avena fatua L.11.30%,and Beckmannia syzigachne(Steud.)Fern.10.63%. Bromus japonicus Thunb., Alopecurus aequalis Sobol., Paspalum sphondylodes Trin.ex Bge.cause severe yield loss to wheat in large area but Beckmannia syzigachne(Steud.)Fern., Aegilops squarrosa L., perenial ryegrass cause damage only in some areas.2. Herbicides screening test was conducted at greenhouse for controlling the severe grass weeds in Shandong province.The Lab efficacy test of the four herbicides Fenoxaprop-ethyl, Mesosulfuron-methyl, Clodinafop-propargyl, and Flucarbazone-sodium, to control Paspalum sphondylodes Trin.ex Bge., Alopecurus aequalis Sobol., Lolium multiflorum Lam., Bromus japonicus Thunb., Aegilops squarrosa L., Avena fatua L. and Beckmannia syzigachne(Steud.)Fern. showed that Bromus japonicus Thunb., Alopecurus aequalis Sobol., Paspalum sphondylodes Trin.ex Bge., Aegilops squarrosa L., Avena fatua L., and Lolium multiflorum Lam. are highly susceptive and plant fresh weight reduction treated with Mesosulfuron-methyl was 98.64%,.93.21%,100%,98.86%,98.70% and 87.29% after 30 days, respectively. Beckmannia syzigachne(Steud.)Fern. is less susceptive to Mesosulfuron-methyl. Bromus japonicus Thunb., Alopecurus aequalis Sobol. and Paspalum sphondylodes Trin.ex Bge. is highly susceptive to Flucarbazone-sodium and , plant fresh weight reduction treated with Flucarbazone-sodium was 100.0%,.93.90%,98.01%,after 30 days at the concentration of 26.25g a.i./hm2, respectively, Avena fatua L. and Lolium multiflorum Lam. is less susceptive to Flucarbazone-sodium, but Aegilops squarrosa L. and Bromus japonicus Thunb. are not susceptive to Flucarbazone-sodium. Paspalum sphondylodes Trin.ex Bge., Beckmannia syzigachne(Steud.)Fern. and Alopecurus aequalis Sobol. are highly susceptive to Clodinafop-propargyl,and plant fresh weight reduction treated with Clodinafop-propargyl, were 100.0% all after 30 days at the concentration of 45.00g a.i./hm2, respectively,Avena fatua L.and Lolium multiflorum Lam. are less susceptive to Clodinafop-propargyl, but Bromus japonicus Thunb. and Aegilops squarrosa L. are not susceptive to Clodinafop-propargyl.. Paspalum sphondylodes Trin.ex Bge., and Alopecurus aequalis Sobol. are highly susceptive to Fenoxaprop-ethyl and plant fresh weight reduction treated with Fenoxaprop-ethyl was 100.0% and.99.27% after 30 days at the concentration of 72.45g a.i./hm2, respectively, Avena fatua L. , Lolium multiflorum Lam. and Beckmannia syzigachne(Steud.)Fern. is less susceptive to Fenoxaprop-ethyl, but Aegilops squarrosa L. and Bromus japonicus Thunb. are not susceptive to Fenoxaprop-ethyl.3. On the basis of Lab screening trial field efficacy tests were conducted to screen suitable herbicides for different regions.Field trials were conducted at Licheng, Zhangqiu, Jiyang, Laizhou, Yutai, Linyi, Rizhao and Qingyun 8 locations. Mesosulfuron-methyl can control the grass effectively at all 8 locations and the prevention effect of weed number and fresh weight were above 85% in winter. Flucarbazone-sodium showed high control efficacy at Zhangqiu and Laizhou in the field with Bromus japonicus Thunb. as the main graas weed and at Rizhao with Lolium multiflorum Lam. as the main grass weed and the prevention effect of weed number and fresh weight were above 86% in winter. Fenoxaprop-ethyl and Clodinafop-propargyl showed high control efficacy in the wheat field following rice production at Licheng,Jiyang,Yutai and Linyi and the prevention effect of weed number and fresh weight were above 86% in winter..4. The safety evaluation of the tested herbicides to different wheat varieties.Mesosulfuron-methyl,Fenoxaprop-ethyl,Clodinafop-propargyl,and Flucarbazone-sodium are safe to the main wheat varieties, that are Jinan 17, Jimai 19, Jimai 20, Jimai21and Jimai22 if used in the recommended dosage at registration.5. The integrated weed managemant technique to control severe grass weed in wheat field of Shandong province was made out.It was the best to control the grass weed in wheat field in winter. Mesosulfuron-methyl and Flucarbazone-sodium were recommende to be used When Bromus japonicus Thunb. and Lolium multiflorum Lam. are the main preponderant species and in wheat field, while Mesosulfuron-methyl for Aegilops squarrosa L. and Clodinafop-propargyl and Fenoxaprop-ethyl for Paspalum sphondylodes Trin.ex Bge, Beckmannia syzigachne(Steud.)Fern. and Alopecurus aequalis Sobol..