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.

Potato is naturally propagated by tubers, which go into a dormant state after harvesting. The objective of this work was to evaluate the effect of three doses of gibberellic acid (AG3) (10, 20 and 30 ppm) and three immersion times (5, 10 and 15 min) on sprouting of fresh potato tubers of the Spunta cultivar, under laboratory and field emergency conditions. The experimental design was randomized blocks, with a factorial arrangement plus absolute control (3 x 3 + 1) and three replications. In the laboratory, the following were evaluated: sprouting percentage, number, length and diameter of sprouts per tuber. In the field, the percentage of emergence and the number of stems per tuberswere evaluated. The collected data were subjected to analysis of variance and means compared by Tukey test at 5% probability. The results indicate that there was no interaction between the factors under study. In the laboratory, 43 days after the application of the treatments, with a dose of 30 ppm of AG3, 100% sprouting of the tubers was obtained and with 10 minutes of immersion, 93.89% sprouting. In the field experiment, with a dose of 30 ppm of AG3, the highest percentage of emergence and number of stems per tubers were obtained, while soaking the tubers for 15 minutes promoted the highest number of stems per plant.

The productive lifecycle of asparagus (Asparagus officinalis var. altilis L.) can exceed a decade, admitting the use of entirely male genotypes, with more uniform production than traditionally used dioecious. In order to study the productivity of seven Italian male genotypes of green asparagus (Italo, Zeno. Eros, Ercole, H-668, Marte and Giove) versus the American control (UC-157), a trial started in 2006 was evaluated at Chacra Experimental, Faculty of Agronomy - UNCPBA (36°48', lat.S-59°51', long.W). A total of 27 harvests were carried out in the period 09/18/2019–11/12/2019, quantifying total commercial fresh production (PFCT) and production by shoot length: : long (22 cm, PFC-L) and short (17 cm, PFC-C), in t.ha-1; Total number of shoots ( NTT) including total discard and commercial (NTCT), long and short (NTC-L and NTC-C) and unit weight (PPT-L), size distribution (J: Jumbo; XL: Extra-Large; L: Large; M: Medium; S: Small and A: Asparagine); discard (DE: spiked; MC: very short and OD: other defects) and response to foliar biological fertilizer (Arco-Plus, from Mycophos). Analysis of variance was performed with ANOVA-LSD test (P≥0.05). On average, the set of Italian genotypes exceeded 18% in t.ha-1,and 29% in NT, 13.5% in NTC-L, and 18.3% in NTC-C compared to the UC-157. In harvests, the following stood out: 18 and 19 (941,625a and 813,375a commercial shoots/ha, respectively), and the least productive were: 1-4 (average 729j). In shoots.ha-1, it was achieved, on average: NTT: 722562; NTCT: 403750; NTC-L: 225812 and NTC-C: 177938; while in t.ha-1: PFCT: 5.53; PFC-L: 3.4 and PFC-C: 2.12. The main defect was DE: 253125a shoots.ha-1. In PFCT, the following stood out: Ercole: 6.46ª; Giove: 6.03ab; Mars: 5.87ab; Eros: 5.55abc; H668: 5.47abc; Italian: 5.47abc); UC-157:4.76c and Zeno: 4.65c) t.ha-1. In PFC-L and PFT-C, Ercole stood out (4.02a and 2.43a t.ha-1 respectively). The favorable election of F was expressed in the variables: PFCT: 11%; NTC-L: 15%; NTC-C: 16%; and in the largest calibers (J: 11%; XL: 70% and L: 23%), therefore, the productivity of the Italian genotypes, especially Ercole, is encouraging.

Different agronomic practices can be implemented to increase productivity in squashes (Cucurbita spp.), although they do not always give the same results. They depend on environmental factors such as temperature, environmental humidity, water quality as well as nutrients availability in the soil, which among other variables influence the precocity of maturation, the culinary quality and the fruit preservation capacity. In this context, it is relevant to know the way in which flowering and fruit settling are being influenced, in order to understand which conditions are determining the best performance in yield, quality as well as fruit conservation. There is a lot of information about these factors, but it is scattered, which makes it difficult to answer questions that may arise about the influence of the genetic basis and the environment, as well as the hormonal processes in response to the signals of the latter. The objective of this literature review is to update the available information on the factors that influence the processes of flowering and establishment of the fruits of squashes, to extract central concepts that contribute to this better understanding. Each one is analyzed and the relationships that favor productivity are established, emphasizing on "Anco" squashes (Butternut type), which are the most cultivated in Argentina.

The production of micro vegetables or microgreens and of sprouts is an interesting alternative for the optimization of vegetable consumption admitting great diversity and feasibility at a family as well as a commercial level, and whose consumption provides multiple benefits. Both options have productive potential for entrepreneurs,especially in the Km 0 due to immediate consumption. These productive alternatives contain several times more nutrients than their adult counterparts and can be obtained by sustainable production means, as in the case of microgreens in the presence of light or sprouts in darkness. Both foster greater nutrient bioavailability which helps to increase immunity, decrease vulnerability to diseases and contribute to a better physical and mental development of the population. In this sense, in the current global and national socioeconomical and sanitary context due to Covid-19 pandemics where the optimization of consumption of food which promotes optimal nutrition becomes a challenge, this review article is carried out in order to show a panorama of the peculiarities and benefits of consumption as well as the potential market, especially as Km 0 products, of two innovative alternatives of production (microgreens and sprouts) which admit great biodiversity and to contribute to promote their production and consumption.

Onion plants (Allium cepa L.) have a low competitive capacity against weeds, so these must be controlled from the beginning of the crop cycle. Plant communities respond differently to the management practices used in the fore crops (eg. tillage and fertilization). The objective was to evaluate the effect of different fore crops on the weed communities in direct seeding onion crops. During the 2015/16 season, an onion crop was implanted in the Lower Valley of the Rio Negro by direct seeding in plots with different fore crops: tomato, soybean, corn and carrot. The emergence of weeds was evaluated 15 and 45 days after sowing (DAS). The weeds on the ridge were collected in a 30 x 30 cm frame to determine the number and biomass for each species, and to calculate the richness and diversity. Ten weed species were observed in a cotyledonal state at 15 DAS, without differences between treatments. At 45 DAS, Lamium amplexicaule L., Xanthium spinosum L., Polygonum aviculare L., Picris echinoides L., Sonchusasper L. and Echinochloa crus-galli L. were the most frequent species. The greatest richness, density and diversity was observed after rotation with tomato. The differential response of the weeds to the fore crops would help design the rotations for more efficient weed control in an onion crop.

Cercosporiosis is considered the most destructive beet disease in the world. Control is carried out with resistant cultivars and application of fungicides; however, new alternatives are fundamental for sustainability. The objective of this research paper was to verify if potassium phosphite, manganese phosphite and silicon (Si) can induce resistance to cercosporiosis in beets. The experiment was carried out at the Federal University of the Southern Frontier, Chapecó campus, Brazil, in a randomized block experimental design, in a 2 x 4 factorial scheme (cultivars x resistance inducers). The cultivars used were: Early Wonder Tall Top and Vermelha Comprida. The resistance inducers were: Silicon monoxide, potassium phosphite, manganese phosphite and water (control). Symptom assessments were performed every seven days, from 30 to 70 days after transplantation (DAT) of seedlings, according to a diagrammatic scale. At 75 DAT the harvest was performed and the productivity determined. The results were submitted to analysis of variance and comparison of means (Scott Knott p <0.05).Under the conditions under which the test was carried out, potassium phosphite may induce resistance of beet plants to cercosporiosis at the initial stage of the crop cycle; manganese phosphite increased productivity, and silicon not only induced resistance at the beginning and end of the cycle but also increased beet productivity. New repetitions of these studies in successive years may allow the confirmation, with greater statistical accuracy, of the observed results.

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.  

The postharvest disinfection by applying sanitizers by nebulization could be a promising technology to extend the storage period of fresh strawberries (Fragaria x ananassa Duch.) The objective of this work was to model and optimize the operation of disinfection of fresh strawberries by nebulization with an ecological commercial disinfectant based on peracetic acid (PAA), aiming to reach microbiological reductions and not to alter the general quality, the content of bioactive compounds and the antioxidant capacity of the fruit. The disinfection of fruits of the ‘Camarosa’ variety was studied in a specially designed chamber, varying the concentration (3.4, 20.0, 60.0, 100.0 and 116.6 μL APA 5% per liter of air) and treatment time (5.7, 15.0, 37.5, 60 and 69.3 min). The count reduction of total mesophilic aerobic microorganisms and yeast and molds of nebulized strawberries was greater as PAA concentration and treatment time increased. However, PAA oxidizing properties negatively impacted on anthocyanins and total phenols, vitamin C, antioxidant capacity and color of the fruits, to varying degrees, depending on the spraying conditions. The optimization of fogging operation based on a microbiological reduction target of 2.0 log cycles, maximum retention of bioactive compounds and antioxidant capacity and no change in color, allowed to determine conditions of optimal treatment: 10.1 uL PAA / L air and 29.6 min. Additional experiments at these conditions validated the methodology. This postharvest disinfection treatment would allow obtaining strawberries with microbiological quality up to 7 days at 2ºC without affecting their sensory quality and bioactive properties.

The cultivation of edible and medicinal mushrooms generates large volumes of substrate degraded by fungi (SDF). Mushroom cultivation implies a solid-state fermentation (SSF) with production of fungal metabolites and the consequent biodegradation of lignocellulosic materials. SSF accelerates organic matter mineralization; therefore, at the end of the cultivation cycle, SDH has greater stability than the original substrate. SDF properties depend largely on whether prior to inoculation of the mushroom species, the starting substrate is composted or just decontaminated. In the first case, the cultivated mushroom species are more substrate-sensitive. In the latter, the mushroom species used are more substrate-adaptable, and are the most widely adopted by small and medium-sized producers as well. After mushroom cultivation, SDF is removed from the production site. Henceforth, depending on its further use, certain storage conditions should be observed, and physical and/or chemical conditioning is usually needed. In horticulture, particle size reduction and dilution of excess salts, by mixing with other materials or leaching, are especially required. The aim of this review is to highlight SDF’s potential as a valuable resource. Particularly, the physical and chemical properties of SDF reported in the literature are summarized, and its different uses evaluated in horticultural systems are described. Among these are: substrate for seedlings, soil amendment and biofertilizer.