Efficiency of some Silicon Sources for Controlling Damping-off of pea

Three pea cultivars (Master B, Blmewar, and Sugar Gum) were evaluated for their resistance to pre- and post-emergence damping-off and the effects of seed soaking in silicate solutions on growth, chemical, and enzyme contents under field conditions. Soil fungi identified as Fusarium oxysporum, Rhizoctonia solani, Sclerotinia sclerotiorum, and Pythium ultimum caused varying degrees of damping-off in the cultivars during pot experiments. Treatments included magnesium silicate and potassium silicate (2 and 4 g/L) and Rizolex/Thiram (3 g/L), applied over two growing seasons (2021/2022 and 2022/2023) at Etay El-Baroud Agricultural Research Station, El-Beheira Governorate.Sugar Gum exhibited the lowest damping-off rates across both seasons, followed by Blmewar and Master B. Sugar Gum also showed superior growth characteristics, including greater root length, root fresh and dry weight, number of bacterial nodules, seed protein content, chlorophyll content (a, b, and total), root lignin content, and nitrogenase activity (first season). Additionally, Sugar Gum had the lowest levels of polygalacturonase and Cx-cellulase activities. Blmewar ranked highest in seed weight per plant.Although Rizolex/Thiram was the most effective treatment overall, magnesium silicate (4 g/L) significantly reduced pre-emergence damping-off and improved several growth parameters compared to other treatments. This treatment also resulted in lower polygalacturonase and Cx-cellulase activities, indicating its potential to enhance resistance to damping-off and support better overall plant health and growth. These findings suggest that silicate treatments, particularly magnesium silicate, can be a viable alternative to chemical fungicides for managing damping-off in pea cultivars.