The objective of this work was to evaluate the effects of dosages and frequency of potassium nitrate (KNO3) application on macronutrients contents of two citrus rootstocks. Seeds of Rangpur Lime (Citrus limonia Osbeck) and Cleopatra mandarin (Citrus reshni Hort. ex Tanaka) were germinated in speedlings flats, containing 128 pyramidal cells holding about 75 cm³ of vermiculite and pinus rind substrate. Three frequencies of application (1, 2 and 3 times per week) of four dosages of KNO3 (1,5; 3; 4,5 and 6 g.L-1) plus a non-fertilization control for each rootstock, were tested. Increasing the dosages and the frequencies of KNO3 application resulted in higher N and lower P, K, Ca, Mg and S concentration in plants dry matter at 120 days after sowing.
Citrus; propagation; nitrogen and potassium fertilization; nutrients; mineral nutrition
