Increasing plant production by protecting the environment is one of the main goals of today's agriculture. On the other hand, the use of both inorganic and organic fertilizers is becoming increasingly extensive. This study was
carried out in field conditions to determine the effects of organic and inorganic fertilization on yield and quality characteristics of industrial tomato (Solanum lycopersicum L., cv. Heinz 1015 F1). For this purpose, contents of
fruit total soluble solid contents, total dry matter, titratable acidity, lycopene, total carotenoids, and vitamin C contents and yield (marketable yield and paste yield) were determined. Experiments were conducted in randomized
blocks design with 3 replications. There were seven experimental treatments as of control (without fertilizer), chemical fertilizer, organic farmyard manure, sheep manure, poultry manure, vermicompost and leonardite.
According to the research results, the highest marketable and tomato paste yield were obtained from chemical fertilizer, followed by organic fertilizers and the lowest values were obtained from the control. As compared to
chemical fertilizers, organic fertilizers influenced fruit quality attributes more positively. The highest lycopene, total carotenoid and vitamin C contents were obtained from organic fertilizers, especially from poultry manure.
Fruit soluble solids and dry matter contents, important processing traits assumed by tomato industry, were obtained
from poultry manure treatments. Fruits from leonardite-treated plants had considerably higher titratable acidity
levels. Except for total dry matter and titratable acidity, lowest values of quality parameters considered important
in industrial tomatoes were obtained from unfertilized (control) plots. Present findings revealed that chemical
fertilizers were essential for high and economic yield levels in tomato farming, but organic fertilizers should also
be supplemented to improve tomato fruit quality attributes.