EFFECT OF RHIZOCTONIA SOLANI ON COTTON SEED GERMINATION AND ITS CONTROL BY USING SOME PLANT EXTRACT

This experiment was conducted to determine the effect of Rhizoctonia solani on cotton seed germination and its control by using some plant extracts. Results showed that six of ten isolates of the fungus Rhizoctonia solani completely prohibited seed germination of the cabbage, while the seed germination of the other four isolates ranged from 16 to 95%. The six isolates HS1,HS2,HS3,HS4,HS5 and HS6 significantly surpass decreasing seed germination of the cotton cultivar Cocker-310 which was zero in there treatments compared to 100% in the control treatment. The thermal treated and untreated filtrate of the fungus R. solani had significantly negative effect and completely prohibited seed germination. To control of the fungus R. solani by cauliflower powder at 2% inhibits 50% of its growth comparing to 100% inhibition when the fungicide Beltanol was applied at rate 0.25 CC/I, followed by pomegranate coats and colocynth fruits powder at rate 2% which inhibits the fungul growth 35.55 and 25.55% respectively. Also, it was found that the alcoholic extraction of the cauliflower powder at rate 2000mg/I caused 100%inhibition of the fungus R. solani on PDA culture medium, followed by pomegranate and colocynth which caused 75 and 50% inhibition, respectively and with significant differences compared to the control. To evaluate this efficiency on cotton seeds germination, the results revealed that the treatment of cauliflower alcoholic extraction and Beltanol with the presence of the fungus R. solani significantly surpassed the seed germination compared to the other treatments and was 50 and 60% ,respectively, while the R. solani treatment showed zero seed germination.