The present study was conducted on 11-year-old Washington navel orange trees budded on
sour orange rootstock grown in loamy sand soil under surface irrigation system at a private orchard,
Toukh region, Qalubia Governorate, Egypt during 2015 &2016 seasons, to investigate the influence
of foliar application with citric acid (CA) 1g/L, ascorbic acid (AA) 1g/L, mixture of micronutrients
1.5g/L and mixture of macronutrients 3g/L on vegetative growth (No. of shoots/ one-meter limb,
shoot length & thickness, No. of leaves per shoot, leaf area and assimilation area per one shoot) and
nutritional status (leaf N, P, K, Ca, Mg % and Fe, Mn and Zn ppm). Anyhow, the treatment T12
(ascorbic acid 1g/L+ mixture of micronutrients 1.5g/L + Mixture of macronutrients 3g/L) was
statistically the superior for Washington navel orange trees during two experimental seasons. Also,
T11(citric acid 1g/L+ mixture of micronutrients 1.5g/L+ mixture of macronutrients 3g/L) came
second. The reverse was true with the water sprayed treatment (control) which ranked statistically the
last rank during the two experimental seasons. On the other hand, the remained investigated
treatments were in-between the aforesaid two extremes, in spite of the statistically varied as compared
to the abovementioned superior (T12) and inferior (T1) treatments during two experimental seasons. |
