Reduced application of a plant growth regulator may increase yield and added net return of processing tomato in mediterranean climate conditions

Among the most valuable horticultural produce, tomato is cultivated for both fresh consumption and processing purposes. Therefore, good agricultural practices secure better production and income for farmers such as the adoption of biostimulant application throughout the growing cycle. The presence of different biostimulants in the market urge its testing to depict wider aftermath on a variety of crops. A field experiment was conducted on processing tomato where a plant growth regulator (PGR; Atonik) composed of phenolic compounds, was applied following a different schedule of field applications to improve growth and fruit setting and quality. Two interventions of this PGR increased tomato marketable yield by 32.1% including fruit number per square meters (+30.8%), while four applications increased few qualitative parameters such as total soluble solids (+15.4%), firmness (+15.3%), total flavonoids (+142.6%) and total polyphenols (+33.5%). However, the added net return was higher when only two applications were done. This finding underlines the utility of testing biostimulants on different crops and depicts the best agricultural practices in term of application number in order to maintain the best net return. However, qualitative aspects should not be underestimated when pricing horticultural commodities, since quality is equally an important target to be reached in food industry.