6947

6490

كارشناسي ارشد

علوم خاك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

دوازده، 90ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

مهران شيرواني، اميرحسين خوش گفتار منش

حسين شريعتمداري، جمشيد رزمجو

24/5/91

حسين خادمي، نعمت الله اعتمادي

1396/09/18

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6490

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

AbstractHuge amounts of herbicides are being used every year to control weeds all around the world Thesechemicals not only have negative impacts on the environment but also harm human health Contaminatedsurface and ground waters can arise from run off and leaching downward of applied herbicides throughthe soil profile 2 4 Dichlorophenoxyacetic acid 2 4 D is a chlorinated phenoxy compound and the mostcommonly used herbicide in the world to control a wide range of broadleaf weeds This herbicide is oneof the most important herbicides that are used excessively in Iran as well 2 4 D is a water solubleherbicide and due to its low pKa value at 2 76 exists predominantly in anionic form Such anionicorganic compounds are weekly retained by most soil and subsurface materials therefore they are verymobile in the environment Ecologically acceptable organoclay based slow release herbicide formulationshave recently been developed and have demonstrated improved herbicidal activity inhibition of leachingand migration and reduced photochemical degradation and volatilization Little attempts have been madein Iran however to develop 2 4 D slow release formulations Therefore the aim of the present study wasto evaluat the sorption capacity of diverse organoclays for 2 4 D herbicide synthesis of slow release 2 4 D formulations and the efficiency of these formulations to release the herbicide and control herbscompared with commercial compound Bentonite and zeolite minerals modified withcetyltrimethylammonium CTMA were used to sorb 2 4 D herbicide Result showed that naturalbentonite and zeolite were poor sorbents for 2 4 D but CTMA modified clays were very good adsorbentsfor 2 4 D Sorption of 2 4 D increased as the surfactant loading on the clays increased The highestamount of 2 4 D sorption was related to modified bentonte with CTMA surfactant concentrationequivalent to 200 of its CEC Desorption of 2 4 D by Na bentonite was highly reversibile But 2 4 Ddesorption by the modified clays was much lower and decreased as the surfactant loading on the claysincreased The adsorption desorption isotherm of 2 4 D on organoclays showed that significant hysteresisoccurred between adsorption desorption reactions Commercial formulation released almost 100 of 2 4 D in the early hours but the slow release formulations gradually released 2 4 D during 168 hours Greenhouse bioassay with clover and lolium plants showed that all slow release formulations were nearlyeffective as the commercial formulation in the control of clover Leaching of 2 4 D from slow releaseformulation was less than that from the commercial formulation Finally application of slow releaseherbicide formulations is recommended to reduce leaching and increase the efficiency and performance ofthe herbicide

مهران شيرواني، اميرحسين خوش گفتار منش

حسين شريعتمداري، جمشيد رزمجو

حسين خادمي، نعمت الله اعتمادي