The Effect of Olive Tree Stock Plant Nutritional Status on Propagation Rates

Abstract

<jats:p>The global production of olives (<jats:italic>Olea europaea</jats:italic> L.) has increased rapidly over the last decade as a result of the expansion of orchards with high tree densities. Most olives are propagated from rooted cuttings. The present study evaluated the propagation rate of rooted cuttings as a function of the nutritional status of the stock trees. Rooting ability was evaluated for cuttings taken from container-grown stock plants exposed to eight concentrations of nitrogen (N) (ranging from 0.4 to 14.1 m<jats:sc>m</jats:sc>), seven concentrations of phosphorus (P) (ranging from 0.01 to 0.62 m<jats:sc>m</jats:sc>), and five concentrations of potassium (K) (ranging from 0.25 to 5.33 m<jats:sc>m</jats:sc>). Increases in N level negatively affected rooting rate and cutting survival. Propagation success was increased threefold as N in irrigation water was reduced from the highest to the lowest treatments. Enhanced root development under low N concentrations resulted in higher root weight compared with the high N concentrations. The high concentration of N fertilization negatively affected the propagation rate but was not reflected in N concentration of diagnostic leaves. There was, however, a significant negative correlation between N in twigs and propagation rate. Regarding response to K concentration, no effect was found on rooting rate or cutting survival. Except for reduced rooting at the lowest concentration, P had a negligible effect on rooting rate. The experimental results indicate the need to avoid overfertilization of olive stock trees with N to promote successful propagation.</jats:p>

Higher stock plant nitrogen and phosphorus levels favor rooting on mini cuttings of tea tree

“…This study showed that fertilizer treatments to tea tree stock plants influences the rooting of coppice‐shoot mini cuttings. While a number of studies suggest that moderate N deficiency in stock plants enhances rooting of cuttings (Dag et al., 2012), our experiment showed that a high N application rate improved mini cutting rooting and growth. Higashi et al.…”

“…Adequate N% level for Eucalyptus stock plants is considered to be between 2.5% and 3% (de Assis et al., 2004). In olive trees ( Olea europaea L.), between 1.5% and 2% N in leaves was sufficient for successful propagation (Dag et al., 2012). In our study, tissue N levels of 1.4% from stock plants given the high rate of N in the N experiment were associated with improved rooting and propagule growth, and was higher than the low N rate with tissue levels of 1.0% (Table 1).…”

“…While a positive effect on cutting rooting percent was found in Eucalyptus dunni Maiden (Rosa et al., 2009) and in E. nitens Labill. and E. globulus Deane & Maiden (Close et al., 2004) with an increase in the application rate of N, other studies reported that higher N treatments resulted in lower propagation success, and that optimal rooting of cuttings occurred when N levels applied to stock plants were moderately low (Dag et al., 2012). One possible reason for reduced propagation rates when high rates of N are applied is a reduction in carbohydrate storage due to increased energy use for vegetative growth of the stock plants (Druege et al., 2000).…”