Substrate and nutrient solution frequency in strawberry soilless culture: fruit production, growth, and water consumption

ABSTRACT The adoption of soilless systems has introduced challenges related to substrate and nutrient solution (NS) management. This study aimed to evaluate strawberry growth, production, and water consumption under substrate formulations and NS frequencies. The research was conducted in Caxias do Sul, RS, using the San Andreas strawberry cultivar. Three substrates were tested: 100% composted pine bark (0% parboiled rice husk - PRH); 80% pine bark + 20% PRH; and 60% pine bark + 40% PRH. NS application was studied at three frequencies across two phases: FI-1 (once a day in phase I - vegetative growth, twice a day in phase II - fruits production), FI-2 (twice a day in phase I, four times a day in phase II), and FI-3 (four times a day in phase I, eight times a day in phase II). The experimental design consisted of a randomized block design with split-plot and four replicates. Growth and production were quantified by biomass. A multivariate regression model was developed to estimate strawberry water consumption. NS frequency influenced vegetative growth; FI-3 promoted growth in 40% PRH, while FI-1 was more effective with 0% PRH. Substrate formulations did not affect total fruit production, which averaged 1,304.4 g per plant. Higher application frequencies and lower volumes led to greater fruit production. Water consumption ranged from 50.2 to 390.0 mL per plant per day. According to the model, leaf area, average temperature, and fruit production are the variables with the most significant influence on strawberry water consumption.