Studies On The Control Technology Of Glyphosate For Perennial Sowthistle In Soybean Field

As a kind of perennial troublesome weed, Perennial sowthistle (Sonchus brachyotus DC.) mainly occurred in the North of China, infesting upland crop such as Wheat, Soybean and corn .During recent years , continuous cropping Soybean , lack of soil tillage and lack of effective herbicide for Perennial sowthistle caused Perennial sowthistle rampant .The paper tried to use glyphosate in Soybean field and discussed the safe applying date of glyphosate under different condition in Soybean field, at the same time the paper studied the control technology of glyphosate for Perennial sowthistle, preliminary.By pot trial and field trial the safe applying date of glyphosate using before Soybean seeding ,the influence of soil water content and applying dosage on the safe applying date of glyphosate was studied.The result showed that: (1) the safe applying date of glyphosate 1845g a.i./hm2in Soybean field was befoe the moment that the folded cotyledon was elevated above ground but the applying dosage of glyphosate was increased ,the safe applying date of glyphosate would be earlier ;(2)Soil water content under 40% did not affect the safe applying date of glyphosate.By pot trial the relationship between the leaf stage of perennial sowthistle, the bud root length, the applying dosage of glyphosate and the length of dead bud root .was studied using method of three factors, five levels rational regression design The result showed that: leaf stage of Perennial sowthistle, the length of bud root and the applying dosage of glyphosate can affect the length of dead bud root significantly, when Perennial sowthistle was 8-1eaf stage ,the maximal length of dead bud root killed by glyphosate 2827g a.i./hm2 was about 36.40cm.By pot trial the influence of APSA-80 on the length of dead bud root killed by glyphosate was studied with method of two factors; five levels rational regression design.The result showed that: the length of dead bud root killed by glyphosate was increased at the aid of adjuvant APSA-80. when Pernnial sowthistle was 3-stage ,the length of dead bud root was 15.61cm.The maximal length of dead bud root was 31.05cm killed by glyphosate 1845g a.i./hm2 added in APSA-80 with the volume of 0.28%By pot trial the effect of different adjuvants on the control efficacy of perennial sowthistle with glyphosate was studied .The result showed that : different types of adjuvants can alsoimprove the aboveground parts control efficiency of glyphosate for Perennial sowthistle.But the effect of non-ionic surfactant APSA-80 on glyphosate was the best /ollowed by oil adjuvant HASTEN ,and the effect of silicon adjuvant SILWETL-77 on glyphosate was the least apparent.Candidate: Gu Chengbo Speciality: PesticidesTutor : Associate-Prof. Zhao Changshan...