Benefits of using silicon as a nutrient in sustainable strawberry production
Wileman, H J
Silicon is not considered an essential plant element and strawberries are not considered to be silicon accumulators. However, work at the University of Hertfordshire shows that the use of a bioavailable silicon nutrient has multifaceted benefits on strawberry plants. Field experiments (2012-2018) on a commercial strawberry farm at Wisbech, UK, consistently showed that weekly application (spray or root via the fertigation system) of the silicon nutrient at a concentration of 0.017% (volume/volume) on strawberries reduced the severity of strawberry powdery mildew (Podosphaera aphanis), regardless of cultivar. Silicon also delayed the epidemic build-up in the silicon nutrient alone treatment for up to 14 days when compared with untreated control. Reductions in the severity of two-spotted spider mite (Tetranychus urticae) on strawberries (P<0.05) were also observed (2014 and 2015). Glasshouse hydroponic (in Hoagland's solution) experiments (2018 and 2019) investigating silicon deficiency and toxicity showed that weekly application of 0.017% (v/v) silicon nutrient on strawberries resulted in more leaves and fruits, higher chlorophyll content, and higher Brix levels in the fruit (P<0.05); no classic deficiency symptoms were observed in untreated plants, however, there was stunting compared with silicon treated plants. The weekly application of 1.7% (v/v) silicon nutrient was found to have toxic effects on plants but no albinism was observed. Silicon was found mainly deposit in the leaf cuticle, epidermis and palisade layers; it resulted in increased cuticle thickness and the density of leaf wax, enhancing the passive defence pathway. The silicon nutrient is not essential but has stimulatory effects on strawberry growth; it protects plants against disease and pests, thus reducing pesticide usage, and making a valuable contribution to sustainable strawberry production.