Fruit production and quality of tomato plants (Solanum lycopersicum L.) are affected by green compost and arbuscular mycorrhizal fungi

Green compost, produced from green wastes, is characterized by high quality standards. The influence of soil amendment with green compost and with an arbuscular mycorrhizal (AM) fungal-rhizobacterial mixed inoculum on plant growth and on yield and quality of fruits in tomato was studied. Inoculated and non-inoculated plants were transplanted in pots with soil added with different compost proportions (0, 25, 50, 75 and 100%). Tomato fruits were analyzed for glucose, fructose, nitrate, nitrite, malate, citrate, carotenoids, and ascorbic acid content. There are significant differences in shoot and root dry weights between mycorrhizal and control plants, whereas the addition of compost to substrate until 75% increased shoot dry weight. AM tomato plants showed significantly higher concentrations of glucose and malate in fruits. Citrate was higher with 50% and 75% compost, while its lowest concentration was detected in plants without compost. Nitrate content was increased by AM inoculum and compost; nitrite content was decreased. Higher amounts of compost increased carotenoid content; ascorbate levels were significantly higher in control plants. These results show that the use of AM inoculum and green compost can improve fruit quality, affecting biochemical composition and relative proportion of various compounds.