INTERACTION EFFECT OF DATE OF PLANTING, BULB SIZE AND FERTILIZATION ON YIELD AND QUALITY OF TUBEROSE PLANTS.

Abstract

A field experiment was carried out on tuberose plant during 2004-2005 and 2005-2006 seasons at a private farm at Demyana near Belqas Dakahlia Governorate. The main objectives of the study were to find out the effect of using NPK compound fertilizer (19:19:19) the common name (High Fertal) fertilizer at three levels (5, 10 and 15g/plant) either alone or combined with compost (150, 200 and 250g/plant). Tuberose bulbs were graded into large, medium and small sizes and planting was during April, May and June of both seasons .Thus, the experiment was a split split plot design with 3 replicates. The obtained results indicated that large size bulbs planted during April and fertilized with the higher levels of NPK +compost gave the maximum number of cut spikes/ pot with more length compared to using medium or small bulbs receiving the same treatment. Large bulbs also produced spikes of more number of florets spike, more spike diameter, and the number of days from planting to opening of the 1st florets was reduced. Also, higher levels of NPK or NPK+ compost increased N, P and K contents in the leaves of large bulbs planted during April, while the lowest contents were for June planting. Thus, it is recommended to use large size bulbs for planting during April and application of NPK at balanced levels along with compost for improvement of soil properties a matter reflexes on flower production.