Prof. Abdou Mahdy Mohamed Mahdy :: Publications:

This study aimed to evaluate the effects of four chemical salts (cobalt sulphate CoSO4. 7H2O, KMnO4, calcium sulphate CaSO4 and potassium mono-hydrogen phosphate (K2HPO4)) each with 3 concentrations. cobalt sulphate at 1, 5 and 10 ppm, KMnO4 and calcium sulphate caso4 at 1000, 2500 and 5000 pmm and K2HPO4 which used at 50, 100 and 200mM on the linear growth and spore germination of F. oxysporum. The obtained results revealed that, all the four salts under study decreased the linear growth and spores germination of F. oxysporum with different degrees. KMnO4 at 5000 ppm was the best effective salt that was reducing the linear growth of F. oxysporum by 15.67% followed by KMnO4 at 2500 ppm and CoSO4 at 10 ppm were reducing the linear growth of F. oxysporum by 11.65%. On the other hand calcium sulphate at 1000, 2500 and 5000 ppm did not effected on the linear growth of F. oxysporum. While KMnO4, K2HPO4 at all concentrations and CoSO4 at 10 ppm & CaSO4 at 5000 ppm completely inhibited spore germination of F. oxysporum. The same chemical salts at the same concentrations were used to test their efficacy in reducing disease incidence and disease severity of cucumber fusarium wilt disease. Cobalt sulphate and K2HPO4 are used as seed soaking while KMnO4 and CaSO4 added to the sterilized soil. The obtained results showed that, in general, both disease incidence and disease severity of fusarium wilt disease were reduced as a result of treatment by all chemical salts compared to the control. Percentage of disease incidence and disease severity was decreased by increasing the concentration of tested chemical salts. In all cases, CaSO4 was the most effective on disease development as it reduced the percentages of disease incidence and disease severity and increased the percentage of survival plants in addition CaSO4 at 2500 and 5000 ppm completely prevented the disease followed by KMnO4 at 2500 ppm and CoSO4 at 10 ppm reducing the disease severity by 96.67%. On the other hand, CoSO4 at 1 ppm was the least effective concentration and reduced the disease severity by 90.00%.