Spinach is characterized by having a high water content and different vitamins and minerals. However, this vegetable could have high oxalate and nitrate concentrations and can affect human health if consumed.The aim of this study was to evaluate the nitrogen fertilization effect on the yield, nitrate and oxalic acid content of spinach produced in an autumn-winter cycle under different growing systems. Spinach was grown in soil in a greenhouse and in an open field at the experimental field of the Faculty of Agronomy of the University of Buenos Aires. Soil treatments were 0.50 and 100 kg N.ha-1. Another culture was in substrate (perlite) where nitrogen supply restriction was applied 15 days before harvest. Color, leaf area, harvest index, yield, nitrate and oxalic acid levels were determined for each crop at harvest. Leaves were selected and 60 g were packaged in 31 micron polyolefin bags. Bags were stored in a refrigerated chamber at 5 ºC for 9 days. The nitrate and oxalic acid content of spinachwas also determined at the end of the storage period. Yield and leaf area were higher with 100 kg N.ha-1 without differences between greenhouse and open field. Oxalate content was higher in spinach from the open field, showing the highest value in the case of 100 kg N added, without changes at the end of postharvest period. The maximum nitrate content was 2.7 in greenhouse with 100 kg N.ha-1. The nitrogen restriction reduced the commercial yield, oxalic acid and nitrate content at harvest in perlite. The difference was maintained postharvest, except for the nitrate content.

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.

The formulation of substrates for ornamental plants in containers implicates a compromise between physicochemical and biological characteristics, costs, andenvironmental impact for the use of peat. A way to optimize this relationship is by using local components. This work proposes the elaboration of a substrate based on Sphagnum peat and perlite, complemented with compost from regional agricultural residues as a possible replacement for a commercial substrate. The growth and development of Impatiens walleriana and Antirrhinum majus L. plants were compared in containers with different substrates: commercial (SC), peat/perlite 9/1 (TP), pure compost (C), and four TP/C mixtures (v:v): 8/2, 6/4, 4/6 and 2/8. The parameters evaluated in Impatiens walleriana were foliar area, number of flowers and accumulated biomass and in Antirrhinum majus L., plant height, nodes per plant, chlorophyll content (SPAD), estimated flowering percentage and accumulated biomass. A physicochemical characterization was carried out for the substrates, and it showed that the main limitation of incorporating compost is the increase of electric conductivity and pH, but with good management it is possible to increase its proportion in the mixtures. The TP/C 8/2 treatment obtained the best results among the mixtures, significantly exceeding the rest. No significant differences were found with the commercial substrate for most of the parameters measured in both ornamental species. The TP/C 8/2 treatment is the more economical and sustainable option due to the reduction in the use of peat and the recovery of wastes.

Homeopathic treatments influence growth, production of secondary metabolites, essential oil yield, phytochemical profile, and tolerance to salt stress, among others, when applied to various crops. Homeopathic ultra high dilution is used safely for various purposes (seed germination, soil health improvement, seedling growth, flowering, fruiting, disease protection and to overcome environmental stress). Proper selection of Homeopathy medicament for each case is very important, to have hight efficiency and profitability. The agrohomeopathy can increase farmers' income by reducing the cost of use chemical fertilizers and insecticides. Literature articles on research related to the use of homeopathic preparations in plant cultivation were collected. Their impact on growth, yield, essential oil composition and tolerance to salt stress was emphasized. Various publications in which homeopathy was applied to various crops and its use increased crop yield, production of secondary metabolites (coumarins, alkaloids, phenylpropanoids), absorption and growth of nutrients in medicinal plant species, as well as tolerance to saline stress. Therapeutic treatments for human and animal health are shown to be important for various plant crops. The application of homeopathic preparations is an alternative for plant growth, friendly to the environment. It is also affordable for farmers and researchers, however more studies are required to improve its influence and effects.

Given the importance that, for the health of the population, an adequate consumption of products of plant origin has, and in order to have a diagnosis on the intensive vegetable production of healthy foods (PVIAS) of proximity, at the level of urban family gardens and of commercial ventures, their production, processing, marketing and consumption preferences, in the current socio-economic and productive context, an inter-institutional survey called “ProALIM Km 0” was carried out. It was organized within the framework of the inter-institutional project CIAC-940186 (INTA – AUDEAS – CONADEV) “Intensive Vegetable Productions of Healthy Foods - PVIAS”, using Google form (Google Forms). The main objective of this work to know the habits, preferences and changes produced in the population, regarding the production, agroindustry and / or consumption of vegetables, fruits and medicinal aromatics (intensive vegetable productions - PVIAS), in the current socio-economic and productive context. The surveyed population demonstrated to know and have interest in the production, agribusiness and consumption of PVIAS, and it was detected that, in many cases, this interest is not specified in practice, especially in relation to the consumption of vegetables and water, in the that reality is, to a great extent, far from national and international recommendations. These differences would indicate that, from the institutions, actions must be carried out that make it possible to translate into practice, aspects that the population knows of their convenience.

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.

Quality and food safety are of concern in the population, leading to a growing demand for organic food. The study was conducted in Viedma, during the production cycles autumn-winter and spring, between 2007 and 2009. Various organic fertilizers were used with different doses, including composted cow manure, onion-manure compost and a commercial organic fertilizer. Crop yield and the mineral content in edible parts were evaluated in each cycle, and at the time of harvesting, hygienic and sanitary quality of the spinach by microbiological analysis and the content of iron and vitamins A and C were determined. The results indicate in both crop cycles that the organic greenhouse spinach production is feasible in this region, with yields exceeding 5000 g m-2 and suitable for human consumption according to the hygienic quality – healthcare obtained in compliance with current regulations. The obtained values of ascorbic acid and beta carotene were higher compared to the reference values of conventionally produced spinach. In all cases the contents of Ca, K, P, Zn and Fe were optimal for crop development.

The aim of this study was to analyze the impact of different doses of compost obtained from fats waste of dairy industry mixed with a commercial peat-based substrate (CS) in the development of pepper seedlings. The effect of these mixtures on germination was also determined. Fat compost (FC) was obtained by the aerobic composting of sewage mixed with industry prunings (wood chips and grass). In order to check the maturity of compost, and thus, that it can be applied as a substrate, an aqueous extract thereof was prepared and phytotoxicity in seed germination and root development was analyzed. The result indicated 99.7% relative seed germination and 74.10% of germination rate. Different culture media were prepared by mixing 0, 10, 20 and 40% of FC with CS. The results showed that the application of FC on CS respectively produced increased dry matter (DM) of plants. Seedlings germinated and developed in FC 40 reached 250 mg plant-1 DM. The application of FC at germination and seedling growth showed a marked improvement in terms of development in general, DM plant, height / diameter stem, leaf area and the concentration of total chlorophylls.

The Sphagnum peat and the mineral soil are materials widely used as components of substrates, but for environmental, economic and legal issues, substitutes are searched. Therefore, an alternative is the use of compost from different wastes. The aim of this study was to evaluate the use of compost of horse straw bed (CCC) to make suitable substrates for the development of Petunia hybrid plants. With this purpose substrates were made with 100%, 50%, 20% and 0% of CCC and mixed with a standard substrate (SE), which was made with Sphagnum peat, composted pine bark and perlite.  All the substrates were physically and chemically analyzed. Dried biomass of stems and roots of plants developed on each substrate, were measured. All the substrates showed adequate physical and chemical properties, except the one with 100% CCC, which showed a pH of 7, 4. Plants developed in each substrate did not show differences in root biomass. But, they showed differences in the aerial biomass.  The substrates with 50% of CCC and 100% of SE fertilized, achieved the highest values without differences between them. The CCC could be used 50% with other materials with acidic pH. In this case, the compost provided the necessary nutrients for development of the plants without fertilization.  

Environmental factors and fertilization practices can affect the accumulation of nitrate in leafy vegetables. This research was carried out under an organic greenhouse, in the autumn - winter and spring production cycles, between 2007 and 2008 in Bajo Valle del Rio Negro, Patagonian Argentina. Various fertilizers with different doses were used, including composted bovine manure, onion-manure compost and commercial organic fertilizer. The accumulation of nitrate in leaves and petioles was evaluated. The concentration of NO-3 was related to temperature and incident solar radiation. The results indicate that organic production of spinach in the greenhouse is feasible in this region, in both crop cycles, keeping the nitrate content below the internationally established limits. The concentration of nitrate in spinach responded to the incident radiation with a correlation of -0.34 in spring and of -0.58 in autumn-winter. The highest contents were observed in periods of lower radiation during the autumn winter and lowest during spring.