Browsing by Author "Arias Flores, María Ignacia"

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    Newly established blueberry plants. The role of inorganic nitrogen forms in nitrogen and calcium absorption
    (MDPI, 2024) Arias Flores, María Ignacia; Nario, Adriana; Rojas Mego, Krystel Clarissa; Blanc, Poulette; Bonomelli, Claudia
    Efficient nitrogen (N) management is crucial for maximizing the growth of young blueberry plants (Vaccinium corymbosum). This study evaluates the effects of the N fertilization form (ammonium, NH4+; nitrate, or NO3-) and application timing on the blueberries' establishment, N and Ca absorption, and N distribution. The experiment was conducted in the southern hemisphere, in Chile, from October 2023 to January 2024. Six-month-old blueberry cv. Blue Ribbon plants were cultivated in pots. NH4+ and NO3- were used as full or split-dose applications using the 15N isotopic dilution technique. Plant leaves, stems, root growth, and biomass, as well as their N and Ca contents, were measured. Our results showed that 90 days after nitrogen application, blueberry plants obtained the lowest biomass in their leaves, stems, and roots when NO3- was applied in T1 or T1T2. The same pattern was observed for N and Ca contents, hence for N recovery. During the first period (T1) of application, heavy rain (100 mm) was registered over the course of a few days and caused leaching. Therefore, applying nitrate to young blueberry plants cultivated in areas with spring rainfall and low temperatures would not be recommended because the leaching losses and lower growth conditions, such as low temperatures and high precipitation, led to reduced transpiration, resulting in lower calcium and nitrogen contents. These confirm that N fertilization management (form and timing) can ensure a better establishment for young blueberry plants, optimizing their growth and sustainable production by minimizing nitrogen losses.
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    Response of tomato plants to water stress and calcium nutrition
    (2018) Arias Flores, María Ignacia; Bonomelli de Pinaga, Claudia María; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
    Calcium is widely accepted as the main factor responsible for blossom-end rotappearance in tomato fruit. However, there is no clear evidences of how this physiological disorder is trigger. In this study, tomato plants from hybrid cultivar H8504 were used to make a factorial arrangement with two factors, water and calcium, being a total of four treatments: water stress and without calcium supply, water stress and calcium supply, optimum watering and without calcium supply, andoptimum watering and calcium supply. The results of biomass, yield, fruit quality and nutrient content changed with water stress treatments, only the standard germination, was not affected. In conclusion according to these results, although the water factor is the main responsible for the development of fruits with Blossom-end rot, the combined water stress and without calcium supply treatment was the most unfavorable condition for the plant. This treatment also showed predominance of protoxylem traqueary elements, and a less developed xylem tissue compared to plants in treatment with optimum watering and calcium supply. This could indicate that the lack of calcium combined with less movement of sap in the xylem, derived from a water deficit, can affect the formation of xylem tissue during the development of the fruit. This difficult the movement of calcium towards the fruit by the xylem and according to this, blossom-end rot could be a primary consequence of ananatomical problem, and that can be affected the distribution of calcium within the damage fruit, healthy fruits have more soluble calcium than fruits that present this physiological disorder.