Abstract
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.