Otimização da aplicação de um bio-estimulante para o aumento da produtividade e qualidade do morango

Biostimulants derived from natural products are being used by several strawberry growers to increase productivity and fruit quality. Given their high cost it is of utmost importance to carry out studies to validate their positive effect at plant level and to optimize their application. This study aimed at evaluating the effect of a commercial seaweed-derived biostimulant on yield and quality of strawberry produced in soilless cultivation system. Therefore, two application methods (fertigation and foliar application), two frequencies of application (every 15 and every 30 days throughout the cultivation period) and three doses of biostimulant (1.5, 3.0 and 4.5 l/ha) have been tested. In general, the application of biostimulant aiming at increased productivity proved to be more effective via fertigation compared to foliar application. The highest productivity was observed upon application of 4.5 l/ha every 15 days via fertigation (20% increase), with an increase in the total number of fruits produced (11%) and in the average fruit fresh weight (8%), compared to the commercial control (i.e. 1.5 l/ha every 30 days). As regards the quality parameters, there was a maximum increase of firmness (45%) when 4.5 l/ha of seaweed extract was applied via fertigation every 30 days. Foliar applications promoted the highest levels of soluble solids content and were efficient in maintaining the fruit brightness during storage. This study clearly showed that the method, dose and frequency of biostimulant application has a significant impact on the productivity and fruit texture.