DOSAGES AND FREQUENCY OF POTASSIUM-NITRATE APPLICATION ON THE RANGPURLIME AND CLEOPATRA MANDARINE SEEDLINGS GROWTH

The objective of this work was to evaluate the effects of dosages and frequency of potassium nitrate application on the growth of citrus roo tstocks cultivated in containers. Three frequencies of application (on e, two and three times per week) of four rates of KNO3 (0.15; 0.30; 0. 45 nd 0.60%) plus a non-fertilization control for each rootstock, were tested. The KNO3 addition improved shoot and root growth of both root stocks, but caused a negative growth effect, including a leaf burn, wh en applied three times per week. The maximum plant growth value was ob tained using 0.45% KNO3 dosage applied weekly, for the Rangpur Lime, a nd using 0.45% KNO3 rate applied two times a week, for the Cleopatra m andarin.