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Eucryphia cordifolia (Ulmo), a woody species, endemic of southern Chilean Andes temperate forests, is present in Argentina between latitudes 38°S and 43°S, below 700 m above sea level. Its flowers contain an aromatic nectar, being a melliferous species. The objective of this work was to evaluate the response to agamic and sexual propagation using different pregerminative treatments. To evaluate the breaking of seed dormancy, a control (T) and 2 pregerminative treatments were carried out: cold-wet stratification for 60 days (EFH60) and soaking in gibberellic acid at a concentration of 250 ppm for 12 hours (AG₃), in a randomized block design trial. For each treatment, the germination power (PG) at tray peal date, survival percentages and growth variables: plant height and number of stems were evaluated. The germination percentages at 60 days (PG60) were 22.60% for (T), 38.90% for (EFH60), and 29.03% for (AG₃). For agamic propagation, suckers were collected and 20 cm long cuttings with 4 knots were prepared. The rooting percentage was 32% after 5 months, flowering in the second year of cultivation. It was concluded that for agamic propagation, the results are encouraging to advance in the definition of better rooting and cultivation conditions. It is also possible to propagate the species sexually, although it is necessary to evaluate other seed treatments to improve germination percentages.

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The phenology of fruit trees allows us to understand their adaptive responses to the environment. The almond tree is widely cultivated, spreading through the incorporation of new plant materials, as is the case with late flowering cultivars in the arid regions of the province of San Juan (Argentina). The objective was to analyze the phenological and agronomic responses of Marinada, Tarraco and Vairo cultivars under arid environmental conditions in San Juan. Phenological stages were recorded using the BBCH scale and agronomic characteristics were evaluated by measuring trunk cross-sectional area (TCSA), linear floral density (FD) and fruit yield. The study was carried out in the experimental field of INTA EEA San Juan. The cultivars differed significantly in phenological stages during the period 2016 to 2021. Flowering (from start to finish) occurs between August and September, first in the cv. Vairo, then in the cv. Marinada and finally in the cv. Tarraco. FD differed significantly between cultivars since 2017, with higher mean values in Marinada and Vairo cultivars compared to Tarraco. TCSA differed significantly between cultivars only in the first crop cycles. The cv. Tarraco has problems in fruit set and/or fruit growth. Fruit ripening of the cultivars Vairo and Marinada ends in February. Cultivars Vairo and Marinada have higher fruit yields than cv. Tarraco. Leaf fall and winter dormancy in cultivars Vairo, Marinada and Tarraco were recorded from May onwards. Marinada, Tarraco and Vairo almond trees cultivars (during 5th and 6th year of field) needed between 685 HF and 857 HF (direct method) until the break of winter dormancy (from May to July).

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Rhaphithamnus spinosus is an evergreen, thorny shrub with violet flowers and violet colored nucleus fruit; endemic from the north of the Andean Patagonian forest. Previous works indicate that the seeds have a physiological and mechanical dormancy in their fruit. The objective was to evaluate the methods for sexual and asexual propagation of the species. The viability of the seeds was analyzed with a germination and 2,3,5-triphenyltetrazolium tests. Four pre-germination treatments were tested: T1: Cold-wet stratification for 60 days, (T2): Scarification with sandpaper + cold-wet stratification-60 days, T3: Scarification with sandpaper + soak 1000 ppm gibberellic acid (GA3) for 24 hs and T4: Scarification with sandpaper + soak water / 24 hs as a control in two seed samples. Seeds were sown at 18 °C, with a photoperiod of 12 hours and subsequently sown in a multicell tray. The agamic method consisted in hardwood cuttings that were cut during autumn, and placed in multicell trays, treated with a 1500 ppm indole-3-butyric acid (IBA) solution, with basal heating (20 ºC±2) and mist. In sexual propagation, the germination percentages per treatment were: T1: 4.81 %, T2: 6.29 %, T3: 47.78 % and T4: 2.59 %. Growth in height and ramifications were analyzed. Asexual propagation reached 96 % rooting at 90 days, and plants were then transferred to 3 L pots. It is concluded that the application of combined pre-germination treatments improves the germination percentage. These resultssuggest the possibilityfor professional propagation and container cultivation.

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Due to droughts and water shortage in Mendoza Province (Argentina), urban green areas have been reduced with the consequent decrease in landscape quality. Replacing exotic plants with native, less water consumers, could make landscaping more sustainable. Lack of information and low availability in nurseries is a limiting factor. Sphaeralcea genus, native from arid and semiarid regions of America, is characterized by a brilliant, profuse and prolonged flowering. In this work we evaluate the potential of Sphaeralcea miniata and Sphaeralcea mendocina to obtain commercial cultivars. Variation of ornamental traits and commercial propagation were studied. Six populations were evaluated, flower and leaf samples were collected, seeds of both, autopolinated and open pollinated plants were cultivated in the nursery. Seed stratification and scarification techniques and rooting in stem cuttings were evaluated. Phenotypic variation in flower and leaf traits was found, this variation was found between and within populations and in the offsprings. Germination did not exceed 60%, probably due to physical rather than physiological dormancy. 60 to 68 % rooting of cuttings was obtained. The natural variation in ornamental traits is an indicator of the possibility to obtain different cultivars. Superior genotypes could be propagated by rooted cuttings. New research is necessary to improve seed germination.

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Onion (Allium cepaL.) is one of the main horticultural species in Argentina. The supply of seeds of this species is mainly from national production. Gibberellic acid (AG3) in onion is effective to induce flower buds when applied before or during the period of low temperatures.Throughout three seasons in La Consulta, Mendoza, Argentina, AG3 was tested to determine its effects on the seed production of onion cv Valcatorce INTA using the seed-to-seed method. The treatments were 0-200-400-600 mg.L-1 of AG3 in the first season and 0-300-600-900 mg.L-1 of AG3 in the other two; the plants were sprayed when they had between 5 and 7 leaves.The design was complete blocks with random plots and five replications. The number of umbels per plant, the seed yield per plant and unit area, and the seed quality, were determined. Gibberellic acid increased the number of umbels per plant.In the first two seasons, the highest seed yield per unit area was achieved with the use of the highest dose of AG3. However, in the third season, the best performance was obtained with 300 mg.L-1. The application of AG3 with the highest doses tested decreased the weight of a thousand seeds in two seasons without impairing germination.

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About 50% of species of the botanical family Asteraceae have been studied in relation to their morphogenesis capacity in vitro; in the case of the genus Tagetes, only 5% of the species have been explored. Research on the in vitro culture of cells, tissues and organs of this genus was reviewed as a basic reference to explore other species, highlighting the critical role of factors involved in in vitro morphogenesis of Tagetes. Callogenesis is promoted by a ratio of auxin and cytokinin concentrations, and 2,4-dichlorophenoxyacetic acid is a frequent inducer of callus. Another auxin used successfully has been naphthaleneacetic acid. Organogenesis is influenced by the type of growth regulators and the auxin / cytokinin ratio. The best responses have been recorded using indoleacetic acid, naphthaleneacetic acid, benzyladenine and kinetin. The genotype is also important, since a relationship of growth regulators can induce shoots in one species or variety, but in another it can generate different responses. To induce direct organogenesis, gibberellins play an important role, since they inhibit callus formation. Embryogenesis is regulated by the auxin / cytokinin ratio; being 2,4-D, supplemented with benzyladenine the most used. These factors to induce morphogenesis basically correspond to domesticated species, and it is expected that such factors will be useful for ruderal, weed or wild species of this genus.

Agrohomeopathy: New tool to improve soils, crops and plant protection against various stress conditions. Review

ADVANCES IN HORTICULTURE - REVIEW | Prieto Méndez, J. - Prieto García, F. - Hernández Pérez, A.D. - Quijada Morales, L.M. - Aquino Torres, A. - Acevedo Sandoval, O.A.

Tags: agroecology, homeopathy, secondary metabolites, salt stress, agriculture

PDF 962.9 KB (4728 downloads)

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.

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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.

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Onion seed represents a high percentage of the total economic value of vegetable seeds marketed worldwide. In Argentina, onion seed production is carried out in San Juan and Mendoza, where open-pollination (OP) cultivars and first generation hybrids are used. An OP variety has good seed yield, but the yield of hybrid seeds is erratic and considerably lower. Seed yield and quality depends, among other factors, on fertilization. Nutrients such as boron, zinc and calcium are essential for the growth and development of plants. Foliar fertilization allows the supply of nutrients to specific organs when the growth stage, internal demand and environmental conditions limit their delivery. The objective of this study was to evaluate the effect of the foliar application of boron, zinc and calcium, on the yield and quality of onion seed. The study was conducted on cv. Angaco INTA in a commercial farm located in the department of Pocito, San Juan. A completely randomized design with four replications was used. Three doses of boron, calcium and zinc, plus a combination of the three nutrients and the control were evaluated. The foliar application of boron, both simple and combined with zinc and calcium, produces a greater fruit set, while calcium improves germination. No significant effects on seed yield were observed.

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The objective of the research was to compare the effect of priming with calcium chloride (CaCl2), potassium nitrate (KNO3) and polyethylene glycol (PEG) on germination of lettuce at high temperatures. Priming was carried out in Petri dishes with 50 seeds, placed in a culture chamber at 25 °C and darkness. The osmotic potential of the solutions was -1.5 MPa. Two treatment intervals were studied: 2 and 4 days. After the treatment seeds were placed to germinate in a culture chamber at 30 °C and darkness. Germination was evaluated for 7 days. Germination percentage (GP) and mean germination time (MGT) were calculated. Calcium content was determined in seeds treated with CaCl2. The best germination was obtained with CaCl2, followed by PEG and KNO3 (93, 72 and 63% GP respectively) with 2 days for all treatments. The prolongation of priming from 2 to 4 days in all cases reduced GP. There were no differences in MGT. The chemical analysis of seeds treated with CaCl2 indicated an increase in Ca2+ content.