P 43 Combining growth inducing bacteria and fungi increased growth and yields in a commercial tomato soil culture Prof. François Lefort hepia Route de Presinge 150, 1254 Jussy, Geneva, Switzerland francois.lefort@hesge.ch Ph.: +41 22 546 68 27 François Lefort, Stefano Pedrazzi, Pegah Pelleteret, Romain Chablais and Julien Crovadore Plants and pathogens group, Research Institute Land Nature and Environment, Geneva Institute for Technology Architecture and Landscape (hepia) University of Applied Sciences and Arts Western Switzerland Increased use of chemicals has led in a few decades to human health problems, development of resistance in plant pathogens and environmental pollution. Beneficial microorganisms promoting growth yield and plant protection could allow for lower production costs by reducing the use of pesticides, growth regulators and fertilizers and contribute to healthier food production. The objective of the work presented here was to test commercial products based on Pseudomonas, Trichoderma and Glomus spp. in production conditions of a tomato soil culture under plastic tunnel. Materials and methods The total production of tomatoes per plant indicated that the [P + T + G] treatment was statistically superior to the control (pval = 0.074 <0.10) and yielded 40% more tomatoes (Fig.3) than the control. The [P+G] treatment was not statistically different from the control but however gave very good results too. Experiments were conducted in a commercial tomato production. Seedlings of variety Coralina F1© were grown in a plastic greenhouse on the substrate soft Brill Typical Type 4 soft© and transplanted after 9 weeks in soil under a plastic tunnel until October. The tomato cultivation pattern consisted of a randomized complete block with a total of 288 plants. C P T G P+T P+G T+G P+T+G Each block received 8 treatments using the commercial products described in Table 1. Inoculation of microorganisms was performed 3 times through watering the substrate (Fig.1). Each treatment contained a total of 8.4 g powder (mixed or single commercial products) in 100 mL water. Figure 2: Tomato plants with different treatments after 5 weeks in plastic greenhouse Figure 1: Inoculation of microorganisms by watering the substrate. 2 4 6 8 10 12 Control P T G P+T P+G T+G P+T+G Treatments Total average yield of tomatoes per plant [kg]] A Firm Commercial name Microorganism Abbr. Concentration Ithec© Myc800© G. intraradices G 800 spores/g Biovitis© Pseudomonas© P. putida P 107 UFC/g P. fluorescens Trichoderma© T.harzianum T 5.105 UFC/g Pseud + Tricho© P + T T. harzianum Table 1: Commercial products used in this study Figure 3: Yield in tomatoes per plant in kilogramme Results Discussion Coralina F1© variety well responded to the inoculation with the combination [Pseudomonas-Trichoderma-Glomus] with a 40% yield increase Several mechanisms could occur and explain this good response: Incrementation of the mineral nutrition (Glomus, Trichoderma and Pseudomonas), Production or degradation of phytostimulating compounds (Pseudomonas, Trichoderma) Increase in water absorption (Glomus). Five weeks after sowing (Fig. 2), tomato plants with treatments [P], [G], [P+T], [P+G], [T+G] and [P+T+G] were significantly taller than the control (pval <0.01). Effects after 5 weeks compared to the control (C) : [P+T+G]: 80% increase of seedling growth (pval<0.05) : increase of opened number flowers [P+G]: 106% increase of seedling growth (pval<0.05) : increase of stem diameter [T+G]: the highest increase in seedling growth: 124% The [P+T+G] combination, [Pseudomonas putida + Pseudomonas fluorescens +Trichoderma harzianum + Glomus intraradices], resulted in a gain of one week on the plant growth and yielded 40% more tomatoes along the culture period. 2nd World Congress on the use of Biostimulants in Agriculture  Florence Convention Centre, Florence, Italy 16th -20th November 2015