اثر علفكش هاي پيش و پس رويشي و تلفيق آنها بر كنترل علفهاي هرز و عملكرد گلرنگ

چكيده انگليسي :

84 Effect of Pre and Post Emergence Herbicides and Their Combination on Weed Control and Yield of Safflower Fereshteh Ramezanzadeh Hozhabr fereshteh hojabr @yahoo com 14 03 2009 Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiK Razmjoo Assoc Prof Supervisor krazmjoo@cc iut ac irAbstractWeeds could decrease agricultural productions in different ways like competition for water nutrients andlight allelopatic effects interfering in harvesting Although chemical control creates several problems suchas damage to crop herbicide residues in soil damage to subsequent crop and environmental pollution but allof these problems may be reduced by choosing the right kind of herbicides timing amount of herbicide andherbicide s usage There is low safflower growth rate in Rosset stage while weeds grow rapidly and competewhith safflower To recognize of the two preplanting s effect trifluralin and ethalfluralin and their combinations with threepostemergence setoxydim cycloxydim and haloxyfop herbicides and also two postemergence desmedipham and phenmedipham herbicideds it was study on control of weeds and growth and yield ofsafflower at the Lavark Reasrch Farm Isfahan University of Technology Isfahan Iran in 2007 In this studyten herbicide treatments along with the weedy control and hand weeded wich were evaluated using arandomized complete block design with three replications Also post emergence herbicides were applied inthe 6 8 leaves stage Furthermore hand weeding was done in hand weeded plots continuously untill thephysiological matural stage The weeds species in the field were identified and number of plants plant s height and dry matter weremeasured for the each weed species To determine the effect of herbicides and the weeds competition onsafflower the height and dry matter of safflower were measured Samplings were done three times includingbefore the use of postemergence herbicides at pollination and physiological matural stages The yield andyield components included head plant seed head 1000 seed weight were measured and the harvest index were determined The major weeds in the field were Amaranthus retroflexus Chenopodium album Malva neglecta andCovolvulus arvensis The preplanting herbicides had controlled the weeds totally 100 and as a effectmostly reduced the whole number height and dry matter of weeds The postemergence desmedipham and phenmedipham herbicides significantly reduced the height drymatter yield and yield components of the safflower compared to the hand weeded and other herbicidetreatments It was reduced due to the weed competition and the herbicide injury to safflower There was nosign effect on weeds that were studied in this project because they are narrowleaf weed killers There were nosignificant differences in the yield of safflower in according to the result of acting of the combination pre andpost emergence herbicides with the hand weeded control treat and the treat in which just pre emergenceherbicides were applied therefore these herbicides did not cause any safflower s injury Strong compotition of weeds with safflower especially at emergence reduced yield components and yield incontrol 2056 27 kg ha 1 compared to hand weeded control 3259 27 kg ha 1 All preplanting treatmentsincreased the yield and yield components of safflower Highest safflower yield was obtained withethalfluralin 3142 40 kg ha 1 and trifluralin 3095 69 kg ha 1 application Thus ethalfluralin and trifluralinmight be recommended for weed control with no apparent safflower s injury under conditions similar to thisexperiment Keyword safflower weed herbicide chemical control

رمضان زاده هژبر، فرشته

اثر علفكش هاي پيش و پس رويشي و تلفيق آنها بر كنترل علفهاي هرز و عملكرد گلرنگ

كنترل شيميايي , روش هاي مبارزه , تاج خروس