The simultaneous effect of water stress and biofertilizer on physiology and quality of processing tomato

This study investigated effects of plant growth promoting rhizobacteria (PGPR) on processing tomato 'Uno Rosso' F-1, grown under three different water supplies. Field effectiveness of both pre-transplant inoculation and post-transplant reinoculation of rhizobacteria on total biomass, yield, water use efficiency (WUE), SPAD, canopy temperature, proline, and main antioxidants were examined. The open field experiment was conducted on the experimental farm of the Institute of Horticulture at Szent Istvan University, Godollo, Hungary, in 2015. The propagation was carried out in a greenhouse by using Klasmann TS3 substrate and inoculated with liquid PGPR solution Phylazonit (Phyl+) or not (control). After planting out half of the inoculated seedlings were inoculated again by adding 1% of the solution by the drip irrigation system (Phyl++). There were two different irrigation treatments: deficit water supply (W50), and optimum water supply (W100), compared with rainfed control (W0). Drip irrigated water was given out according to the calculated daily evapotranspiration based on data from the National Meteorological Institute. A single harvest was conducted on August 25, total biomass and marketable yield were assessed. The analytics of ingredients was made using HPLC by evaluation of total carotenoids, lycopene, beta-carotene and ascorbic acid. The marketable yield ranged between 14.7 and 93.8 t ha(-1), depending on the treatment. The average degrees Brix of the treatments ranged from 3.5 to 8.2. The total average carotenoids concentration of the treatments ranged from 62.0 and 167.2 mu g g(-1). The average lycopene concentration of the treatments ranged from 45.4 to 130.9 mu g g(-1). The effect of PGPR treatment was clearly positive for harvested yield, but this effect only prevailed under irrigated conditions. The double PGPR treatment continued to increase production with optimal water supply.