studies on the host-parasite relationship of phanerogamic parasite

27Trade/common name of.the weedicideWeedar 96Weedar 32Weedone 48WeedexKarmexBasa I i nBasag ra nSencorCopper SulphateDuallgranStompAfalonGramoxoneFernoxoneTolkanDalapanAtratafTafazineManufacturer/dealerAGROMOREAGROMOREAGRQMOREAGROMOREAGROMOREBASFBASFBAYERBOHCIBA-GEIGYCIBA-GEIGYCYANAMI DHOECHSTICIICIMAY & BAKERMYSORE AGRO CHEMICALSRALLISRALLl SOne litre each of three concentrations, 500, 1000 and 5000 ppm. of aqueoussolutipns of weedicides were injected into infested trees. Six herbicides, selectedafter preliminary screening were further used in the concentrations of 0.05 to 0.30percent a. i. All the concentrations used were replicated four times.Effect of the chemical both on the host and the parasite were noted systematically.Following score card was developed to record relative effectiveness of the,chemicals on the host as well as on the parasite.Symptom onRelative reactionHostParasite___ --Blotching or scorching of Yellowing of leaves. + (mildly effective)young leaves.Wilting of leaves and theyoung budsWilting of leaves, youngshoots and flowers followed++ (moderatelyeffective)Defoliation, splitting ofby heavy defoliation.Drying of leaves, flowers +++ (highlybark and discolouration of and fruits. Ultimate drying e t f ec t ive)wood along the path of the and death of the wholechemical Such parasite clump.trees usually die.