A study on the effect of biostimulant application on yield and quality of tomato under long-lasting water stress conditions.

Recently, the use of plant-derived biostimulants has been suggested as a sustainable way to improve the nutritional quality of tomato and mitigate the effects of environmental stresses In this regard, a two-year experiment was conducted in open field on four cultivars of tomato (two commercial tomatoes and two local landraces of long shelf-life tomato), to assess the crop response, in terms of fruit yield and quality traits, to the foliar application of two plant-derived biostimulants based on protein hydrolysates (PH), under opposite water regimes (no irrigation and full irrigation), in a semi-arid environment of South Italy. Tomato plants in field were sprayed with a solution containing one of the two biostimulants approximately every 15 days. Full irrigation significantly promoted plant productivity, leading to yields the 22 % and 57 % higher than those produced under no irrigation.