H. Botеva*

Vegetable Crops Research Institute Maritsa, 32 Bezovsko shoose, 4003 Plovdiv, Bulgaria
(Manuscript received 27 April 2016; accepted for publication 31 May 2016)

Abstract. Field experiments for the effect of bio-fertilizers: Labin, Bio One, Tecamin, Agriful, Humustim and Biohumus on productivity and fruit quality of determinant tomato, variety Trapezitsa were performed on strongly leached meadow cinnamonic soil at the experimental field of the Vegetable Crops Research Institute Maritsa during the period 2008 – 2010. The fruit number per tomato plant increased up to 38.2% towards the control (without fertilization) by using bio-fertilizers Tecamin and Agriful. Similar were the results for the mass of fruits per plant, where the increase was up to 33.3% towards the control. After mineral fertilization the total tomato yield is the highest on average for the period of study. An increase of the yield in tomato with reduced mineral fertilization is established after application of bio-fertilizers 12.1% on average from 7.8% /after fertilization with Labin/ to 18.3% /after fertilization with Tecamin/ towards the control. A positive effect by fertilization with Tecamin (38.8%) and Agriful (36.3%) is established on early production. In mineral fertilization this index is lower (23.7%). Bio-fertilizers Tecamin and Agriful have a positive effect on the content of vitamin C and dry matter.