Comprehensive Management Technology And Demonstration Of Rape Field Weeds

There are more than182kinds of weeds in Qinghai spring rape fields, the communitycomposition is complex in different ecological zones,and the dominant populations vary widely,hazard rate of weeds is70-80%generally, and serious hazard rate is50%, it have no harvest inthe rape fields full of Bromus tectorum L., Chenopodium album, Herba Sonchi Brachyoti,Elsholtzia denas, Lepyrodiclis holostecides, control is difficult and those weeds are bottleneckwhich constraint rape industry development. The long-term single use of herbicides such astrifluralin resulted in the control effect decreased even be ineffective to Elsholtzia denas, Bromustectorum L, Lepyrodiclis holostecides, it is difficult to achieve the desired control effect ifincrease the amount, the rise of resistant weeds, The weeds comprehensive management is theonly way of weeds sustainable governance.New herbcides were introduced for the trial of herbicidal effect and safety in spring rapefields, and excellent herbicides were selected for large-scale demonstration in differentecological zones. Combined proper rotation, adjustment of sowing date, shallow ploughing,Manual weeding measures with new herbicide,did trials and demonstrations in differentecological zones, according to the dominant weed species in different ecological zones, developcomprehensive management measures. the results reported below:1. Screening12kinds of new herbicides, the four of twelve were used to control gramineousweeds, the main weed is wild oats, and three of the four were for cauline leaf treatment and1forsoil treatment. With the recommended dose, the control effect on wild oats reached80%;Another four of thirteen were used to control broadleaf weeds, which are all for cauline leaftreatment, were mainly used to control Cephalanoplos seyetum, Herba Sonchi Brachyoti,Chenopodium album and so on. with the recommended dose, the control effect reached morethan75%. Four herbcides were used to control both wild oats and broadleaf weed, they weredragon fist mixed agent, napropamide, trifluralin and napropamide mixtures,33%PendimethalinEC. The dragon boxing mixture was uesd for cauline leaf treatment, and the rest were for soiltreatment, the control effect all reached85%. The dragon boxing mixed agent was used tocontrol perennial weeds such as Cephalanoplos seyetum, Sonchus brachyotus and Elsholtziadensa. The three kinds of soil treatment agents were mainly used to control annual broadleaf weeds, With the recommended dose, the effect all reached75%. All of above herbcides were safeto rape in selected dose range, the yield increased significantly after application. So all of themcould be recommended to apply large areas in production.2. There was a new demonstration of5herbcides in different ecological zones in Qinghai.They were mixed herbicides of Youtianqing, Youcaoku,75%Clopyralid SGX,30%clopyralidAS and28.6%Picloram·Glopyralid AS. Youtianqing was soil treatment and the rest of4kindswere cauline leaf treatment. The control effect of these herbcides in different areas were goodand consistent. It was safe to rape and yield increasing was prominent. The use of30%Youtianqing decrement was appropriate in the fileds with Avena fatua L..Youtianqing must beused with the generic dose in the broad-leaved weed fields. If decrement was needed in specialcases, which should not be more than10%.28.6%Picloram·Glopyralid AS was demonstrated inthe experimental fields of academy of agricultural sciences. The fresh weight effect againstbroad-leaved weeds had no difference between single600ml/hm2using or mixed with the1050ml/hm2of Quizalofop-Pethyl10%EC. The control effect of fresh weight againstChenopodium album was over80%after40days, which showed influence on the growth ofdouble cropping wheat and broad bean after180days, and there were slight influence onfollowing crops of potato, highland barley, wheat, broad bean and pea.3. The wheat rape rotation combined with manual weeding and combined herbicideseffectively controlled farmland weeds, for example, Maikuojing was applied during wheatseedling period and You caoku or You tianqing were applied in next stubble rape fields, controleffect to weeds was significant and the number of weed decreased by65.5%. The rotation ofrape-wheat combined with manual weeding, controlled Galepsis bifida Boenn and Lepyrodiclisholosteoides (C. A. Mey.) Fisch. et Mey., while Chenopodium album L., Galium maborasenseMasamune and perennials like Cephalanoplos setosum populations increased slightly, butwithout the spraying, weed control field, the succession of Avena fatua L, Thlaspi arvense L.,Chenopodium album L, and Raphanus raphanistrum trend to speed up after three years. TheWheat-oilseed Rape-Wheat reasonable crop rotation combination with manual weedingcontrolled Avena fatua Linn and Thlaspi arvense Linn., but Elsholtzia densa Benth, Galiummaborasense Masamune and Raphanus raphanistrum had obvious increasing trend, combinedapplication of herbicides control, Elsholtzia densa Benth, Chenopodium album L., Galiummaborasense Masamune had the increasing trend and other weeds got better control. Reasonablerotation, not the spraying not weed control area, the plant numbers of Avena fatua Linn, Galepsisbifida Boenn, Lepyrodiclis holosteoides (C. A. Mey.) Fisch. et Mey. Chenopodium album L.,Galium maborasense Masamune, Thlaspi arvense Linn., Raphanus raphanistrum, and Lamiumamplexicaule Linn. had increasing trends. 4. Brassica napus L. and Brassica campestris L. do not fit early sowed, to avoid early frost,Irrigation region should begin to sow around on April1st, Hill Regions should sow on April10th,Brassica campestris L. in cold Haomen farm should sow about on May10th. Youtianqing andPendimethalin were Shallow tillage treatment in different area soil surface, the control effectshowed shallow tillage late sowing>Normal sowing>Shallow tillage and early sowing, controleffect of You Tianqing was higher than control Pendimethalin; The control effect of late sownYoucaoku was better than normal sowing field and early sowing field. The control effect ofYoutianqing was better than Pendimethalin after soil tillage treatment.5. In different ecological area of Qinghai province, two kinds of herbicides Youtianqing andYoucaoku were combined with rape wheat rotation, appropriate late sowing, shallow tillageplanting and other agricultural measures, which could effectively control weeds in rape field.The whole control effect of wheat rape rotation, Youtianqing combined with artificial weeding inrape field of plain water district was96.04%, compared with the control one, the yield increasedby37.66%. The comprehensive management technology of Brassica napus in hill regions waswheat rape rotation, Youtianqing combined with artificial weeding, the overall control effect ofrape fields was95.78%, the yield increased by34.97%; The comprehensive managementtechnology of Brassica campestris L. was wheat rape rotation combined with Youcaoku, theoverall control effect of the rape fields was88.6%, compared with the control one, the yieldincreasing effect was26.81%. The overall control effect of shallow plowing, appropriate latesowing together with Youcaoku in rape fields of Haomen was90.63%, the average yieldincreased by33.18%; shallow plowing, appropriate late sowing combined with Youcaoku couldalso be used to weed the field dominated by annual weed, the overall control effect ofdemonstration zones of rape field in Haomen farm, Haiyan and Gonghe was87.27%, the averageyield increased by21.76%. In different ecological demonstration zones where there were moreCephalanoplos segetum and Herba Sonchi Brachyoti, another two kinds of herbicides (75%longquan SGX and30%clopyralid No2AS) could be combined to use, the ultimate controleffect of Cephalanoplos segetum was84.63%~91.38%, the ultimate effect to Herba SonchiBrachyoti was82.37%~89.31%, compared with blank control, the yield increased by21.66%~29.64%.