Asparagus is a perennial vegetable, with an extensive productive stage and a progressive yield according to the age of the plantations; being the initial nursery stage determinant for the success of the crop and dependent on the starting system, management and quality of the seedlings. The objective of the study was to determine the effect of biofertilization (BF) on the growth of green asparagus seedlings (PEV) improving quality and implantation. An organic production trial was conducted (28/12/2021), in Tandil (Buenos Aires), using UC-157 genotype F2 and in pots. There were four treatments, a control without fertilization (T1), a fertilization treatment with arbuscular endomycorrhizae (T2-BRE), a fertilization treatment composed of micronutrients and plant hormones (T3-BFMH) and a combined fertilization treatment (T4-BRE+ BFMH). A heated greenhouse was used at the Faculty of Agronomy (UNCPBA) and a randomized block design with 3 replications, with weekly monitoring until the final size. Height (H) and number of stems (NT) were evaluated from 3/21/2022 to 5/31/2022. In the laboratory, fresh and dry weights of roots and stems (PFR-PFT-PSR-PST) were determined. Data were analyzed by ANOVA and LSD test (P≥0.05). The PFT and PFR in T4 were superior, finding no statistically significant differences in the biomass of stems and in PFR, surpassing T1, with T2 standing out with respect to T3 and T4. In summary, PEV BF increases biomass, mainly root biomass, constituting a valuable technique to achieve better plantations.

Argentina, one of the main South American strawberry (Fragaria x ananassa) producers, shows an increasing trend to reduce the use of agrochemicals (pesticides and fertilizers), and incorporate bio-inputs. In this context, the objective of this work was to evaluate the effect of MO.14 (a liquid organic amendment, rich in humic and fulvic acids), applied alone or combined with a biological activator (Biomix), on the yield and fruit quality of four strawberry cultivars. A trial was carried out in the 2016 productive season and part of 2017, in Famaillá (Tucumán). Treatments: MO.14 (drench), MO.14 (drench) + Biomix (foliar) and untreated control (T). Cultivars: Benicia, Camino Real, Merced and San Andreas. Yield (total fruit weight/plant, Yld), number of fruits/plant (NF), marketable fruit average weight (MFAW) and percentage of rotten fruits (%RF) were evaluated. Experimental design: CRD with three replications of 30 plants per cultivar and treatment. Data were subjected to ANOVA. Treatments improved Yld and NF, but not %RF and MFAW (genotypic effects prevailed). MO.14 showed Yld and NF values higher than MO.14 + Biomix. Treatment-cultivar interactions were significant for NF. Regarding the cultivars, Merced stood out (Yld, MFAW). In May 2017, when the first harvests of the 2nd year started, biostimulants exceeded T in Yld. Biostimulant treatments could reduce the use of chemical fertilizers in strawberry, contributing to agroecosystem sustainability, although new studies (dose, concentration, number of applications) should validate that.

Tomato crop is one of the most important vegetables because of its high demand. During the crop cycle it can be attacked by different pathogens, so the use of Plant Growth Promoting Rhizobacteria (PGPR) is an option for the protection of plants against pathogens. PGPR can be set endophytically inside the plant and trigger various defense mechanisms. One such mechanism is the synthesis of antimicrobial peptides. The aim of this research was to evaluate the protection of Solanum lycopersicum var. Río Grande previously inoculated with PGPR against infection with the necrotrophic pathogen, Sclerotium rolfsii. The percentage of mortality and peptides: defensin and snaking expression were evaluated. Combined experiments with Pseudomonas pseudoalcaligenes and Azospirillum brasilense inoculation and subsequent confrontation with S. rolfsii were performed. In plants treated with P. pseudoalcaligenes, mortality percentage was 40% lower than in control plants. Plants treated with A. brasilense were 20% lower. The expression of defensin and snakin messengers was higher in both cases for plants inoculated with PGPR. Based on these results, the use of PGPR is proposed as a biological alternative against S. rolfsii and could be evaluated for other soil pathogens.  

Vegetables inoculation with Azospirillum sp. enhances seedling growth and crop productivity. In lettuce (Lactuca sativa L.), inoculation with Az39, Pl64 and Pl3 strains of A. brasilense improved seedlings growth. The aim of this work is to evaluate morphological modifications of seedlings when these strains are combined in a formulation. Three trials were carried out using butterhead lettuce cv. Lores (Vilmorin®), performing the inoculation at sowing with a formulation which consisted of 1 x 107 UFC.ml-1 of a mixture of the strains Az39, Pl64 y Pl3 of A. brasilense, using not inoculated plants as control. It was dispensed 1ml of product per cell (1 x 107 UFC per seed). A completely randomized design with 20 replications was used. When plants showed 4 leaves, it was registered shoots, roots and plant fresh and dry weight, root absorption area and lineal length of root, submitting data to analysis of variance. Inoculated plants performed different depending on crop season. Root absorption area increased significantly in one of the three trials, exceeding the control by 27 %. Leaf, root and plant fresh weight were significantly higher in two trials, reaching values 11 %, 20 % and 12 % higher than control plants, respectively. No significant differences were observed on root length or dry weight.

The effects of soil solarization and the growth promoter rhizobacteria, Pseudomonas fluorescens P190 on tomato (Lycopersicon esculentum), grown under greenhouse conditions, were evaluated in 2006 and 2007. A trial was performed according to a factorial arrangement, using “solarization” and “pseudomonas” as factors and “presence” and “absence” as levels for each factor. Eight variables were recorded in order to evaluate treatments effect: weight and diameter of each fruit -disregarding those showing either damage or less than commercial size- as well as root, stem and leaf fresh and dry weight. Main component analysis was used to characterize experimental units as regards the presence or absence of the studied factors. ANOVA analysis and LSD means comparison test results showed that, both solarization and seed inoculation by themselves, increased crop yield by 15 % when considered separately. When combined, a synergistic effect was apparent, and crop yield was increased by 55 % as related to the control treatment.