Combined applications of endophytic fungi and vegetal extracts improve crop productivity and economic profitability in processing tomato

Plant biostimulants, including microbial and non-microbial based products, have been successfully used to improve agriculture productivity due to their ability to stimulate nutrient uptake, plant growth and to improve tolerance to abiotic stresses. An open field experiment was carried out on processing tomato (Solanum lycopersicum L.) with the aim to evaluate the effect of microbial and non-microbial plant biostimulant applications on yield, yield components, nutritional and functional quality attributes as well as on economic profitability. Two treatments were tested: untreated control and biostimulant treatments (mycorrhizal fungi and Trichoderma koningii in combination with vegetal extracts). All plant biostimulants were applied through fertigation during the growing season. Biostimulant applications increased the marketable yield by 15% compared to untreated tomato plants. The higher marketable yield in biostimulant-treated plants was attributed to an increase of mean fruit weight and not to the number of fruits per plant. Physiological parameters, such as SPAD index and fluorescence, were not affected by biostimulant applications. Vitamin C and lycopene were boosted by biostimulant applications while no significant differences were observed for total soluble solids and pH of fruit juice. The better crop productivity observed in the current trial could be attributed to the better nutritional status in biostimulant-treated tomato in terms of higher N concentration. Our findings can assist processing tomato growers in adopting innovative and sustainable tools such as plant biostimulants to boost crop productivity to a level resulting in higher economic returns.