Vegeto-productive behaviour and fruit quality of two cultivars of apricot, 'Orange Rubis^®' and 'Farbaly^®', as influenced by different biostimulants

Agricultural biostimulants (ABs), products with specific action, natural or synthetic, mineral or organic, have been introduced recently as fertilizers that are applied in small quantities in order to increase nutrient uptake, growth and development of plants and improve quality, productivity, crop resistance and the environmental positive impacts. This trial aims to evaluate the effect of four different commercial ABs (Bion^® 50 WG, Hendophit^® PS, Ergostim^® and Radicon^®) on two cultivars of apricot ('Orange Rubis^®' and 'Farbaly^®'), grown in experimental field at Cerignola (Foggia district, Apulian region, southern Italy). The biostimulants used were related products of humic acids that induce effects on yield, fruit quality and grower income of some fruit trees. Several foliar treatments were applied at different times during the growth season of each crop. Total yield of fruits tree^‑1 was also determined. Other than that related with vegeto-productive behaviour, many fruit quality parameters were evaluated, including also total polyphenols content and antioxidant activity. Experimental data showed some specific differences among the biostimulant treatments. Growth was not affected while productivity was only moderately affected in one of the two cultivars and not always positively. Main influences were found regarding qualitative attributes of fruits. The soluble solids content in 'Farbaly' was clearly positively affected by Bion^® and Hendophyt^® treatments while no effect of ABs was observed in 'Orange Rubis'. Results suggest that effects of ABs are 'genotype dependent' and that probably doses and scheduling of ABs application should be precisely defined in each agricultural context.