Effect of NPK fertilizer and compost on the growth and development of two buxus sempervirens cultivars 'Elengantissima' variegated and 'vader valley'

الملخص EN

This study was carried out in the lath house of Agriculture College, Duhok University, Kurdistan region, Iraq, during the period between 17th August 2015 and 3rd May 2016.

The experiment aimed to evaluate the effect of three levels of NPK fertilizers low (180, 90, 60), medium (270, 180, 120) and high level (540, 270, 180) mg.l-1 and three level of local compost (0, 50 , 100) on two cultivars of Buxus sempervirens ‘Elegantissima’ variegated and ‘vader valley’ .The results summarized as follow: High level of NPK had significant effect on plant height, plant growth index, nitrogen and potassium percentage, whereas the branches number, plant leaf area were decreased with the high level of NPK.

The media which consist of 100% compost gave significantly the highest values of plant height, branches number, Plant growth index, plant leaf area, Potassium and phosphor percentage when compared to media with 0% compost.

Generally the best interaction between the three factors which gave the highest significant values of plant height (61.25) cm was for Elegantissima cultivar which grew in 100 % compost and fertilized with high NPK level, whereas the highest plant growth index (18660) cm3 , potassium percentage (5.14) and plant leaf area (32321) cm2 were for the same cultivar at 100% compost and medium level of NPK, While the highest branches number was for vader valley cultivar at all compost percentage and received medium and high level of NPK.