EFFECT OF CHALCONES ON Fusarium oxysporum and Rhizoctonia solani ISOLATED FROM SEED AND ROOTS OF Kochia scoparia.

Fungi had been isolated from the roots and seeds of Kochia scoparia, it was found that Fusarium oxysporum was the most predominant as it was about 33 % from the whole number of other fungi (isolated from the roots) and Rhizoctonia solani (which had been isolated from seeds) by 11 %. Substituted and an substituted chalcones were prepared (1, 2, 3) and four concentrations of them were used (0,25, 0,5, 1,0, 2,0 g/l), their inhibition effects on the growth of F. oxysporum and R.solani were studied. The conc. 0,25 g/l of chalcone (1) gave an inhibition percentage of 57,3 % for the mean perpendicular diameters (MPD) for the F. oxysporum at the 7th day of incubation.The inhibition surface area (ISA) for the F. oxysporum 64 % , while the same conc. 0,25 g/l gave 100 % for the MPD on R. solani at the same period. The inhibition surface area for F. oxysporum was 97.7 % using conc. of (2 g/l), the same conc. gave 100 % inhibition for R.solani at the 7th day of incubation. The conc. 0,25 g/l of chalcone (2) causes the inhibition 7 % of F. oxysporum at the 7th day of incubation for MPD and the percentage of ISA was 14,3 %, while the same conc. 0,25 g/l manifests an inhibition of 86 % for R. solani at the 7th day of incubation for MPD, while ISA was 92,7 % . The conc. 2 g/l of chalcone (2) causes the inhibition of 92 % for MPD at 7th day for F. oxysporum , while ISA was 95,2 % , the same conc. 2 g/l displayed 100 % inhibition on R. solani for MPD and ISA. The conc. 0,25 g/l of chalcone (3) causes an inhibition of 32 % for F. oxysporum to MPD at the 7th day of incubation, the ISA was 43,3 % and the inhibition was 100 % for R. solani , while conc. of 2 g/l of chalcone (3) causes the inhibition of 100 % for F. oxysporum and R.solani at the 7th day of incubation.