Preliminary Study On Allelopathic Effects Of Garland Chrysanthemum (Chrysanthemum Coronarium L.) On Watermelon (Citrullus Vulgaris Schrader)

The allelopathic domino offects of garland chrysanthemum(Chrysanthemum coronarium L.)on watermelon(Citrullus vulgaris Schrader)was sudied.The allelopathic physiology and biochemistry mechanism of Chrysanthemum coronarium L.on watermelon was analysed.The effects of Chrysanthemum coronarium L.on watermelon autointoxication was studied by means of the experiment of seed germination and seedling growth.The effects of cropping with Chrysanthemum coronarium L.on watermelon growth and yield was tested by means of pot and field experiment.The results showed as follows:1 Chrysanthemum coronarium L.root,stem and leaf extracts could stimulate watermelon seed germination and seedling growth.The stimulative effect gradually increased when the concentration rised.2 Different concentration Chrysanthemum coronarium L.root,stem and leaf extracts had some stimulative effects on watermelon amylase and lipase activity,could improve watermelon photosynthetic pigments conten and photosynthesis,advanced watermelon seedling POD,SOD,CAT activity,reduced watermelon MDA content and electrolytic leakage.3 At the same concentration,the allelopathic effect of Chrysanthemum coronarium L. root,stem and leaf extracts on watermelon was leaf extracts > stem extracts > root.4 Chrysanthemum coronarium L.root,stem and leaf extracts,which content was 80g.L^-1, could also weaken the autointoxication of benzoic and cinnamic,which content was 0.8 g.L^-1,on watermelon seed germination and seedling growth.The higher content and the better effect.And its lightening degree was still leaf extracts > stem extracts >root.5 From pot experiment,we could know that cropping with Chrysanthemum coronarium L.could reduce root activity sorbing area of watermelon,but increased fibre number at the same time,which leaded to increase root ratio surface,then enhancd the ability of root sorbing water.From field experiment,we could know that ropping with Chrysanthemum coronarium L.could stimulate watermelon growth,decrease fusarium wilt,increase watermelon yield.