Crop inoculation with plant growth-promoting rhizobacteria (PGPR) is a sustainable alternative to diminish the excessive use of chemical fertilizers in agriculture. However, there is little information about PGPR inoculation effects under field conditions and even less on industrial tomato production. We aimed to study the effects of a sole inoculation at seedling stage with Pseudomonas fluorescens Rt6M10, Azospirillum brasilense Az39, and their combination on growth and yield of two industrial tomato varieties UCO 14 (UCO) and Harris Moran 3861 (HM). We compared these PGPR inoculation treatments with chemically fertilized and nonfertilized (control) seedlings under field conditions. We found that inoculation with Rt6M10, Az39, and their combination increased seedling root dry weight by 62%, 41%, and 23%, respectively and shoot dry weight by 29%, 23%, and 2%, respectively compared with non-inoculated control, improving tolerance to transplant stress. Inoculation with Rt6M10, Az39, and their combination increased stem diameter by 15%, 16%, and 13%, respectively, while Rt6M10 and the combination treatments increased leaf chlorophyll and carotenoid levels compared with non-inoculated plants. Az39 increased fruit number (35%) and fruit weight (38%) per plant in HM, whereas in UCO variety, the increase was the highest (48% and 49%, respectively). Seedling inoculation increase fruit firmness and equatorial and polar fruit diameter by 24%, 10%, and 12%, respectively in HM and by 21%, 14%, and 14%, respectively in UCO. Overall, bio-inoculation with Rt6M10 and/or Az39 was beneficial for tomato seedlings at transplanting and supported fruit yield and quality (total soluble solid content, pH, and titratable acidity) equally or better than chemically fertilized seedlings.

Selenium (Se) is an essential element for humans and has anti-cancer function. Garlic can accumulate Se, so it is an option to Se supplementation in the human diet. The aim of this research was to study Se uptake and accumulation during garlic growth. Four doses of Na2SeO4 and Na2SeO3 solution were applied in the substrate (0, 5, 10 and 15 kg ha-1 Se) for one time in August 2014, with a random plot design and 3 replicates on garlic clone Rubi INTA. Three harvests were made, in September, October and December 2014. After each harvest, leaves, bulbs and roots were separated and conditioned (peeled and chopped), lyophilized, and finally acid-digested prior to Se, Mg, Zn, Mn, Cu, Fe, P and S determination by inductively coupled plasma mass spectrometry (ICP-MS). The Se accumulation was proportional to Se doses and did not affect garlic growth. Also, Se distribution among different organs was related to the garlic growth cycle. The Se presence decreased accumulation of Mg, Mn, Cu, Fe, P and S but increased Zn accumulation in plants. Garlic can be an important Se source to humans but it is important to consider Se-doses for biofortification.

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