[en] The effect of different irrigation strategies in water relations, vegetative growth and yield of early maturing peach trees, growing in Murcia, (Spain) was studied during two years. Treatments consisted on: a control T1, full irrigated (150% of ETc); T2, continuous deficit irrigation at 50% of ETc; T3, regulated deficit irrigation (RDI), irrigated at 100% of ETc only during stage III of fruit growth and 25% the rest of the growing season; and T4, with automatic control of irrigation based on capacitance FDR-type probe data, varying threshold values. The results indicated that irrigation deficits in T2 and T3 treatments induced the lowest soil water content and stem water potential(&Psi;stem) values during the postharvest period (e.g. &psi;stem up to &ndash;1.8 MPa in T3 during summer 2008); thus, a reduction in trunk growth and pruning weight, respect to control treatment values, was noted in both years. Also, peach yield was significantly reduced in both deficit irrigated treatments. The greatest irrigation water saving in T3 treatment (&asymp;60%) caused the higher water use efficiency values in this treatment. For these reasons, water deficit during the postharvest periods (extended in the early maturing varieties) must be limited if fruit yield is not to be reduced. Irrigation scheduling based on capacitance probes have become a useful tool in the control of soil water content. When threshold values were precisely defined, the slight water deficits limited only vegetative growth while maintaining similar peach yield to that of well irrigated trees.

[es] Se estudi&oacute; el efecto de distintas estrategias de riego deficitario en las relaciones h&iacute;dricas, crecimiento vegetativo y producci&oacute;n de melocotoneros extratempranos &lsquo;Flordastar&rsquo; en Murcia (Espa&ntilde;a) durante dos a&ntilde;os. Los tratamientos fueron: T1, control, riego diario al 150% ETc; T2, riego deficitario continuo (50% ETc); T3, riego deficitario controlado (100% ETc s&oacute;lo durante la fase III de crecimiento del fruto y 25% ETc el resto del ciclo) y T4, control autom&aacute;tico del riego basado diferentes umbrales de contenido h&iacute;drico del suelo con sondas de capacitancia. El d&eacute;ficit h&iacute;drico en los tratamientos T2 y T3 indujo los valores m&aacute;s bajos de contenido de agua del suelo y de potencial h&iacute;drico de tallo (&nbsp;&Psi;tallo) durante la poscosecha (&Psi;tallo = &ndash;1,8 MPa en T3, verano 2008); lo que provoc&oacute; una reducci&oacute;n del crecimiento del tronco y peso de poda, respecto a los valores del tratamiento control, en los dos a&ntilde;os. Adem&aacute;s, la producci&oacute;n se redujo significativamente en ambos tratamientos. El tratamiento T3 result&oacute; ser el m&aacute;s eficiente en el uso del agua debido al mayor ahorro de agua de riego (&asymp;60%). Por estas razones, los d&eacute;ficits h&iacute;dricos en poscosecha (muy larga en variedades tempranas) deben ser limitados si no se quiere afectar la producci&oacute;n. Las sondas de capacitancia son una herramienta &uacute;til para el control del contenido h&iacute;drico del suelo, permitiendo una programaci&oacute;n eficiente del riego. Cuando los valores umbrales se definen con precisi&oacute;n, se generan d&eacute;ficits h&iacute;dricos ligeros que limitan s&oacute;lo el crecimiento vegetativo manteniendo la producci&oacute;n similar a la de &aacute;rboles bien regados.