Study On The Joint-Effect And Mechanism Of The Rice Security Against The Mixtures Of Pre-emergence Paddy Herbicides

The mixture of chemical herbicides, an effective and vit4 technical means of killing the field weeds, has the advantages of killing more kinds of weeds, improving the effect of the herbicides, decreasing the cost of the production, prolonging the herbicide spreading time limit as well as weakening the resistance of the weeds against herbicides. Weeds in the paddy-field include i4 e following three types:gramineae weeds, broad-leaf weeds and cyperaceae weeds. Amide compound is a very efi ctive herbicide for killing gramineac weeds. Sulfo ylurea herbicides is the excellent herbicide for broad-leaf weeds and cyperaceae we ls The mixture of these two chemical compounds can contrpl the w eds in the paddy-fields and achieve the effect of removing the weeds from the paddy-field all the rice growth period round once this mixture Is applied. The following are the applicable chief pre-sproute paddy-field herbj ides:amide compound includes acetochlor. Pretilacbror. metolachlor.. R(-)naprppamide.. niefenacet and butachlor; sulfonylurea compound includes benu1 on-methyl metsulfuroit ethyl.. cinosulfuron and pyrazosulfuron. These ten herbi ides are all applied to rice planting, and some two-substance and three-substance mixtures from them are widely applied. The joint-effects of the rice security against the mixtures of p鏴-sprou paddy- je1d herbicides lay the foundation for the study and developing of the techi ology of the herbicide mixtures. The research work on the security against ierbicides has pen done mainly by visual measurement instead of by numberical analysis ur a long time. Without scientific way of classification or standard evaluation, the ra 4om mpng and misuse of the herbicides have brought great damage to farming. Ih yi。of he aove－mentioned cases,山e aUhr i幻w的es ndnd evatviIJatethe resp咖ye Jo——e历白d一 on恤 paddyvice seop pd皿幻 hew阳咽山幻a比e ndnd threethree s讪St8llGe nuxtures omof山e忆np卜－SptOlltwi－6ddh山ddes mcludin山e populanzpd nd plicabl allllue COopunds nd 4 sulfoplllreo COopund,nd tries to probeu矿othemectl81llsmofthe effeCsCs ofSOmeMical曰山du卜s．Here re he二M OftheS stud: (l))classifi一 d删咖 ofev咖咖n on hejoM effem on nce secmp q凶切血血咖地。…－SptO1paddy．nce咖帆s are pl0nNarQ． 1sejoM e＊W can be ivided咖 3 wes,namlX nrnrfiedPOison effeCt, addition and nidohon．lbkillu CHC nd H as he cieion, when CHC"100 or 北0＜h＝uM＝lx:x,帅一伽1S删d叭咖D0班100 m肌"删,:Is MllSM…测；伽删(100洲帖删,Ms讪哪d恤d皿 (二)he secuiy en of the psddwice at hel．l！eaf p dthe four kinds of sulfonyluxea paddy－ield heicidesis d as he following accordin to theif IDI。:benSulfilrolkInethyl＞PmpsulWC1I1Osulforoll＞工llmethl． hn PyTWsulfuron nd cinosulfuron re Illlxed ih po fCSp咖VCly3 heif md6XtS Of CHC50 816 bisgrr thanl 00,nd he IlliXT［ltCS show 聊arellt intensfied poison efeC．hen posulfilroll is nllxed ih bensul愉n－m砌 and he doop Of he lal:Uer is 4．sl且．m毛,ih its CHC。。 ObSWOds SllUQOQOll (3)he security degrbo of he pce at hel．lleaf qe painst he paddy－ieldmide he巾ici血s is anan吵 as he follo删g whm heir ID10恤 IDso are co。e4:me抽肌驴5呐讪Of＞卧…啊。屹…las」。pm咖冰m皿＞ atchochiOL he indexes Of IDSO l ID10 Of he two－subhape 11llMllteS Out Of he six amlde cpe are more or less srn」er仇m tha of伽 s吻 niidual herblc血．巾m呛 血sc 血加皿s,肋 血加皿of 明伽讪or 饲 butacliloY3R－)napropannde nd acetochior ave no intens...