Influencia de la concentración de amonio de la solución nutritiva sobre el comportamiento agronómico del cultivo de la escarola

Abstract

[EN] Nitrate accumulation in leafy vegetables, as endives, Cichorium endivia L, could be influenced by nitrogen source supplied in the fertilizing. That is why it established as the objective of this experiment compares the influence of three fertilizing, with the same amount of nitrogen, three different with three ratios Ammonium /Nitrate different (N0:0/13; N5:0,65/12,32; N10: 1,30/11,72 mmol L-1 ), on the nitrates accumulation in leaves and the obtained final production. Also one tried to determine the evolution of different physiological parameters and of quality along the cultivation cycle. Also, it was about to elucidate, if the measurements realized with the SPAD and the colorimeter can to be included like effective hardware for the nitrates estimation in endive leaves. For all this, using cultivating of escarole ‘Cuartana‘ – of wide leave - it was analyzed periodically (0, 14, 28,42 days after the transplant) the evolution of different physiological parameters and of quality (content of chlorophylls (SPAD), (reflectometry) nitrates, nitrogen (Kjeldahl), phosphorus (colorimeter) and color of the leaves (scale CIELab)), and at the end of the cultivation, there were valued the percentage of commercial plants, its middleweight and the incidence of different fisiopatías ("tipburn" and increase to premature flower). The increase of the concentration of ammonium supposed an increase of the values of SPAD (content in chlorophylls) and a decrease of the parameters of color a* and b*. The values of SPAD increased with the development of the cycle, what was joined to a decrease of the yellow color (parameter b*). The increase of the concentration of ammonium did not decrease the accumulation of nitrates, which was increasing on having advanced the cycle.

[ES] El objetivo de este trabajo pretende establecer la influencia de la relación Nitrato/Amonio en las soluciones nutritivas, en la acumulación de de nitratos en hoja de escarola, así como en la producción obtenida. También se pretendió determinar la evolución de distintos parámetros fisiológicos y de calidad a lo largo del ciclo de cultivo. Material: se ha llevado a cabo un ciclo de cultivo primaveral con escarola de hoja ancha, cv. `Cuartana'.La plantación definitiva, bajo invernadero y en condiciones de hidroponía, se llevo a cabo en macetas de 8L, rellenas con una mezcla de perlita y fibra de coco (50-50). Metodología:En este experimento se analizó periódicamente (0,14,28,42 ddt) la evolución de los distintos parámetros fisiológicos y de calidad con la escarola ( contenido de clorofilas (SPAD), nitratos( reflectometría),nitrógeno (Kjeldahl), fósforo (colorimetría) y color de las hojas (escala CIELAB)), al final del cultivo se valoró el porcentaje de plantas comerciales, su peso medio y la incidencia de distintas fisiopatías (tipburn y subida a flor prematura)- Se emplearon tres soluciones nutritivas en las que se modificó la ratio amonio/nitratos; N0:0/13 N5:0,65/12,32 N10: 1,30/11,72 mmol L `^ -1.