پديد آورندگان :
چيت بند، علي اصغر دانشگاه لرستان - دانشكده كشاورزي , قرباني، رضا دانشگاه فردوسي مشهد - دانشكده كشاورزي , راشدمحصل، محمدحسن دانشگاه فردوسي مشهد - دانشكده كشاورزي , نبي زاده، محبوبه دانشگاه فردوسي مشهد - دانشكده كشاورزي
كليدواژه :
اختلاط علف كش ها , اثر افزايشي , مدل دز افزايشي , هم افزايي , هم كاهي
چكيده فارسي :
ارزيابي اثرات اختلاط مواد شيميايي مي تواند براساس مفاهيم مختلف سميت شناسي، داروشناسي و كنترل علف هاي هرز انجام گيرد. به منظور پيش بيني اثرات افزايشي، هم افزايي و يا هم كاهي اختلاط دو به دو مخلوط علف كشي دس مديفام+ فن مديفام+ اتوفوميست، كلريدازون و كلوپيراليد روي علف هاي هرز تاج ريزي سياه و تاج خروس ريشه قرمز، دو آزمايش بصورت دُز - پاسخ در گلخانه تحقيقاتي دانشكده كشاورزي دانشگاه فردوسي مشهد در قالب طرح كاملاً تصادفي با ۱۰۵ تيمار در سال ۱۳۹۲ به اجرا درآمدند. تيمارهاي آزمايش شامل هفت دُز خالص و مخلوط از علف كش هاي فوق با پنج نسبت اختلاط ۱۰۰:۰، ۷۵:۲۵، ۵۰:۵۰، ۲۵:۷۵ و ۰:۱۰۰ بودند و براي هر يك از اختلاط ها سه تيمار شاهد در نظر گرفته شد. نتايج آزمايش نشان داد كه اختلاط علف كش دس مديفام + فن مديفام + اتوفوميست با علف كش كلوپيراليد روي علف هرز تاج ريزي سياه از حالت هم افزايي و در مورد علف هرز تاج خروس ريشه قرمز بيشتر از حالت هم افزايي تبعيت كرد. اختلاط علف كش كلريدازون با علف كش كلوپيراليد بر روي هر دو علف هرز بيشتر از حالت هم كاهي تبعيت كرد، بطوري كه شدت اثرات هم كاهي در تاج خروس ريشه قرمز بيشتر از تاج ريزي سياه بود. همچنين، اثرات اختلاط علف كش دس مديفام + فن مديفام + اتوفوميست با كلريدازون روي علف هرز تاج ريزي سياه بيشتر از حالت افزايشي و در مورد تاج خروس ريشه قرمز بيشتر از حالت هم كاهي تبعيت كرد. كاهش كارايي اختلاط هاي علف كشي مي تواند به دليل محدوديت در جذب و انتقال علف كش ها باشد.
چكيده لاتين :
Introduction: Evaluating the effect of mixtures could be based on various concepts e.g. toxicology,
pharmacology and weed control. Combinations of certain herbicides can give better weed control than use of the
individual herbicide alone and/or loss of weed control when use of certain other herbicides in combination.
Herbicides in a mixture can, however, interact physically or chemically outside the plant or biologically inside
the weed or crop and assessing the joint action of herbicide mixtures is a pre-requisite for designing optimum
herbicide mixtures. With herbicide mixtures three scenarios can occur. Either the herbicides do not influence the
performance of each other (additivity) or the performance of one herbicide is either impaired (antagonism) or
promoted (synergism) by the presence of other herbicides in the spray solution. Predicting the joint action of
mixtures is extremely difficult, unless the compounds are known to interact at the same site of action. The most
common methods to analyze the joint action of herbicide mixtures are the Additive Dose Model (ADM) or the
Multiplicative Survival Model (MSM). The ADM assumes the two compounds have similar modes of action
(without interaction) in the receiver plant, i.e. effective doses of each component will not change by mixing.
ADM has been widely accepted as a valid method to estimate joint action of mixtures sharing the same or similar
action mechanisms in the receiver plant. Hence, a fundamental difference between MSM and ADM is that MSM
considers effects while ADM considers dose rates. MSM has been widely applied in weed science in the form of
Colby's equation, a simplified version that does not require the estimation of dose-response curves. MSM has
been reported to yield more accurate results for mixture toxicity with respect to ADM when the components
exhibited different or dissimilar modes of action in the receiver plant. Here, ADM was used to test for deviation
of additivity of doses using the ADM isoboles as reference model. Any deviation from the ADM was
characterized by antagonism when the efficacy of a mixture was lower than that predicted by the reference
model and synergistic when the efticacy was higher than the predicted value.
Materials and Methods: In order to determine joint action of some usable important broadleaf herbicides in
sugar beet, two dose-response experiments were conducted at the research glasshouse in Faculty of Agriculture,
Ferdowsi University of Mash had, Iran. The plants were sprayed with seven doses of commercial formulation of
desmedipham + phenmedipham + ethofumesate (Betanal Progress- OF®, 427 g a.i. L· 1, Tragusa, Spain),
chloridazon (Pyramin", 1361 g a.i. L· 1, BASF, Germany), clopyralid (Lontrel'~, 149 g a.i. L· 1, Golsam, Gorgan,
Iran) either alone or in binary fixed-ratio mixtures of the three herbicides. The ratio of the herbicides in binary
mixtures were 100:0, 75:25, 50:50, 25:75, and 0:100. Spraying was performed by overhead trolley sprayer
(Matabi 121030 Super Agro 20 litre sprayer), 8002 tlat-fan nozzle at 300 kPa and a spray volume of200 L ha· 1
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Plants were treated at 21 days (at the four- to six-true leaf stage) after planting. Dose-response curves were
estimated by fitting a three log-logistic dose-response model versus doses including EDso, EDso and ED,o
response levels. ADM was used as a reference model of joint action with their equations. As the results with the
herbicide mixtures was obtained from up to twelve separate experiments, it was necessary to standardize the xand
y-axes, so that the EDso, ED,u and ED'Ill doses of the herbicides applied separately were always fixed to I.
Results and Discussion: The results showed that mixture of chloridazon with clopyralid was less effective
than that predicted by ADM par1icularly on Amaranthus retroflexus at EDso and ED,o response levels. These two
herbicides binary mixtures either followed ADM or was less than that predicted by ADM on Solanum nigrum.
On the contrary, mixture of desmedipham + phenmedipham + ethofumesate with clopyralid was synergistic on
both species. Further, desmedipham + phenmedipham + ethofumesate and chloridazon binary mixtures was
antagonistic on Amaranthus retrojlexus and followed according to ADM on Solanum nigrwn
Conclusion: The results revealed that mixtures of photosystem n with lipid biosynthesis or auxin inhibitor
herbicides either followed ADM or performed better than that predicted by ADM. Therefore, applying mixtures
of these herbicides will not result in an excessive use of herbicide compared to applying the herbicides
separately. On the contrary, mixtures of chloridazon and clopyralid tended to be antagonistic, these two
herbicides should not be thus mixed.
