تاثير نسبت متفاوت نيتروژن آمونيومي و نيتراتي بر توليد گل بريدني ورد رقم وارلون

THE INFLUENCE OF DIFFERENT RATIOS OF NH4 AND N03 NITROGEN SOURCES ON ROSE (ROSA HYBRIDA L. ʹVARLONʹ) CUT FLOWER PRODUCTION

The influence of nutrient solutions with five different ratios of NH4+:N03" was studied on the quantitative and qualitative yields of rose cut flowers grown on perlite + sand (l:l,v/v). The ratios of NH4+:N03 in nutrient solutions of 1 to 5 was 0:12, 0.25:12, 0.5:12, 1:12, and 2:12, respectively. The pH of nutrient solutions was adjusted on 5.7 ± 0.2. The average day/night temperature was 25/18 °C and the average relative humidity was 75%. Experiment was carried out in a complete randomized design with three replications. Yield (number of cut flowers m"2 year"1) and shoot dry weight as quantity parameters and stem length and diameter, flower bud length and diameter, peduncle length and vase life as quality parameters as well as the effect of N forms on nutrient content of plant tissues were assessed. Increasing NH4+:N03" ratio in nutrient solutions increased the plant tissue N content and opossitly decreased the Ca content. Increasing NH4+:N03~ ratio increased the yield of cut flowers statistically significant only in the higher NH4+:N03" ratios but higher quality parameters such as high vase life and long and thick stems were observed in the mixtures of NH4+ and N03" in the nutrient solutions especially with the ratio of 0.25:12.