Abstract
Sodium and potassium silicates were in vitro evaluated against seven Fusarium species; causing cotton seedling damping-off. Scanning electron microscopy-SEM was used to investigate the morphological changes in the fungal hyphae. All collected data were statistically analyzed, and the least significant difference was used to compare means. Mycelial growth of the tested isolates was strongly inhibited by both silicates. Varied morphological changes in Fusarium mycelia following silicate treatments were observed including; asymmetric mycelium compared with the control. Silicate-treated cultures of Fusarium species were generally characterized by wizened mycelia, curling, twisting, and distorted hyphae. Diameter of silicate treated hyphae of Fusarium species was generally smaller than the control. Promising antifungal activity of potassium and sodium silicates in vitro; suggest that phytopathogenic species of Fusarium could be controlled by both materials. Further researches are needed in order to confirm the in vivo effects of such materials and identify the optimal effective doses.