Browsing by Author "Sanchez, Javier"

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    High Nitrogen Fertilization Decreases Seed Weight but Increases Longevity in Tomato Seeds
    (2022) Sanchez, Javier; Albornoz, Francisco; Contreras, Samuel
    Nitrogen fertilization is a key practice in agriculture and its effects on yield and quality of most commodity products are widely known. However, the response of seed production to N fertilization, especially with regard to its effects on seed quality, is still poorly understood. The objective of this study was to determine the effect of N fertilization on tomato seed yield and quality. Six quality attributes were assessed (weight, standard germination, germination rate under normal and adverse conditions, dormancy and longevity) in tomato cv. Moneymaker plants fertigated with one of three nutrient solutions differing in their N concentration: 5, 15 or 25 mM. Seed weight decreased by 4% with increasing N fertilization while standard germination and mean germination time did not vary among treatments, with average values of 89.7% and 6.2 days, respectively. The percentage and rate of germination decreased when seeds were imbibed in solutions with reduced osmotic potential; however, this effect was less pronounced in seeds from the 25 mM treatment, indicating a lower dormancy. When germination was evaluated after accelerated aging, seeds from the high N fertilization treatment showed greater longevity. These results contribute to optimizing fertilization practices for the production of high quality tomato seeds.
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    Seeds Yield and Quality of Quinoa ( Chenopodium quinoa Willd.) Plants Grown Under Different Nitrogen Fertilization Doses
    (2024) Contreras, Samuel; Molina, Jorge; Garcia, Margarita; Sanchez, Javier; Chorbadjian, Rodrigo; Fuentes, Francisco; Albornoz, Francisco
    S. Contreras, J. Molina, M. Garc & iacute;a, J. S & aacute;nchez, R. Chorbadjian, F. Fuentes, and F. Albornoz. 2024. Seeds Yield and Quality of Quinoa (Chenopodium quinoa Willd.) Plants Grown Under Different Nitrogen Fertilization Doses. Int. J. Agric. Nat. Resour. 68-74. Quinoa ( Chenopodium quinoa Willd.) has been cultivated for more than 7,000 years in the mountain regions (Andes Mountains) of South America. Five ecotypes differing in their phenology, morphology and stress resistance can be found. One of these ecotypes corresponds to the coastal ecotype, which is cultivated mainly in Chile. Little information is available regarding the response of this ecotype to nitrogen (N) fertilization. In the present study, three N fertilization doses (low: 30, adequate: 140 and high: 280 kg ha -1 ) were evaluated in plants grown in containers. Seed yield and quality attributes, including seed weight, nitrate content, germination, and seed longevity, were evaluated. These results indicate that increasing N fertilization promotes increases in seed yield and weight. In terms of seed quality, although the fertilization treatments did not affect germination, seed longevity was reduced by increasing the N fertilization dose.