“Benefits of Silicon Use in Containerized Crop Production and Challenges to its Commercial Adoption"
Greenhouse Production Research Group, USDA-ARS
Silicon has been shown to ameliorate many biotic and abiotic stresses in field-grown, agronomic crops. However, the majority of those studies and adopted practices were done in monocots. In contrast, a number of scientists in ornamental crop production have focused on evaluating Si-mediated responses of greenhouse-grown ornamental crops, with the majority of these studies performed on dicots. We have demonstrated reductions in symptoms from the pathogens powdery mildew and Tobacco ringspot virus, decreased aphid population growth, reduced susceptibility to copper toxicity, improved salt tolerance during growth, and increased post-harvest longevity. Significantly, we have measured changes in nutrient regulation and alterations in stress enzyme activity in both Si-accumulating and non-accumulating species. Despite clear, beneficial responses to supplemental Si in containerized production, there is currently considerable debate regarding the value of widely supplying supplemental Si in fertility programs and as such, the element is not typically included in fertility programs in floriculture crop production. Supporting this reluctance, it isn’t clear if the cost:benefit ratio is in favor of incorporating Si use, methods of application into containers is still unrefined, it is difficult to predict bioavailability of Si from different sources in commonly used substrates, and there is a pervasive attitude that other management practices can eliminate the need to incorporate Si. So while clear benefits can be derived from incorporating Si into fertility programs in ornamental crop production, significant hurdles to its adoption remain.
Silicon has not been given the same level of attention as a limiting factor in soil fertility and crop production as other nutrients. This view is changing as agronomists become more aware of the valuable function of silicon nutrition in crops and soils and even animal life. Research conducted on many soils worldwide has shown that supplying crops with plant available silicon can suppress disease, reduce insect attack, improve environmental stress tolerance and increase crop productivity. Silicon is now officially designated as a plant beneficial substance by the Association of American Plant Food Control Officials (AAPFCO). Plant available silicon may now be listed on fertilizer labels.