Modern greenhouse production methods have often eliminated conventional earth as a growth medium and, with that, eliminated silicon, a mineral naturally found in soil.
Greenhouse growers should consider adding silicon back to their nutrient applications, irrigation or potting mixes, according to Agricultural Research Service (ARS) scientists. A growing body of research suggests that silicon boosts yields and protects plants from toxicity and fungal diseases. Silicon may reduce the need for plant growth regulators and disease-control pesticides.
Horticulturists and plant pathologists with the ARS Greenhouse Production Research Group have studied silicon uptake in a variety of ornamentals, including begonia, carnation, geranium, impatiens, marigold, orchid, pansy, petunia, snapdragon, verbena and zinnia. X-ray analysis has shown that some of these plants — such as New Guinea impatiens, marigold and zinnia — accumulate silicon in significant concentrations in unique cells in their leaves.
Scientists have also found that silicon helps reduce symptoms of powdery mildew in zinnia but has no effect on species such as begonia and geranium, which do not accumulate silicon.