Controlling dodder (Cuscuta planiflora) in Egyptian clover with silica nanoparticles and a novel bioherbicide

Dodder (Cuscuta planiflora) is a major parasitic plant species affecting the productivity of Egyptian clover (Trifolium alexandrinum L.), an important forage crop in Egypt. A field trial was executed on Egyptian clover heavily infested with dodder during the winter seasons of 2021/2022 and 2022/2023. The aim of this study was to investigate the effect of cultivar choice and seven dodder control treatments on dodder growth performance as well as growth and yield components of Egyptian clover under infestation conditions. Results indicated that Helali was the most tolerant cultivar to dodder infestation. Moreover, treatments using Fusarium incarnatum-based bioherbicide, silica nano-particles (Si-NPs), and chemical herbicide (glyphosate) effectively controlled dodder after parasitism. The application of Si-NPs at 22 and 30 g fed^-1 and bioherbicide at 20 and 30 kg fed^-1 effectively reduced dodder biomass while increased biomass and seed yield of infested clover. The interaction between the Helali cultivar and Si-NPs at 30 g fed^-1 was the most effective in reducing dodder biomass. Anatomical investigation of the stem revealed that Helali exhibited the greatest tolerance against dodder penetration. The electrophoretic protein profile indicated an unchanged protein pattern for Helali under infestation conditions. These findings suggest that Helali possesses a robust defense system and genetic diversity, making it the most tolerant cultivar to dodder infestation in conjunction with the high efficacy of the dodder control treatments used in this study.