Benefits of using silicon as a nutrient in sustainable strawberry production
Wileman, H J
The UK now produces 80% of the strawberries on the UK market. Silicon is not considered an essential plant nutrient, 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 were done on a commercial strawberry farm in 2014/15, to assess the effects of the silicon nutrient on strawberries against Strawberry powdery mildew (Podosphaera aphanis) and two-spotted spider mite (Tetranychus urticae). Silicon nutrient (0.017% volume/volume) was applied via the fertigation system weekly. In both years, silicon treatments of plants decreased severities of both P. aphanis (P<0.05) and T. urticae (P<0.001). Silicon also delayed the epidemic build-up in the silicon nutrient alone treatment for 14 days compared with untreated control. Similar results on disease level showed on 2017-18 field experiment. Glasshouse hydroponic (in Hoagland’s solution) experiments were set up in 2018/19, to determine deficiency (2018) and toxicity (2019) effects of silicon in strawberry growth. Weekly application of 50ml of silicon nutrient at 0.017% (v/v) (2018 & 2019), 0.17% (v/v) (2019), 1.7% (v/v) (2019) and deionised water (control) were done. No classic deficiency symptoms observed in untreated plants. More leaves and fruits, higher chlorophyll content, and higher Brix levels (P<0.05) were found in 0.017% (v/v) silicon treated plants than untreated plants. The 1.7% silicon treatment reduced leaf number (P<0.05) and plant biomass compared to control, and caused plant death eventually. Silicon was found mainly deposit in the leaf cuticle, epidermis and palisade layers, enhancing the passive defence pathway. The silicon nutrient is not essential but has stimulatory effects in strawberry growth; it protects plants against pests and disease, thus reducing pesticide usage, make a valuable contribution to sustainable strawberry production.