Abstract

ABSTRACT In order to study the effect of Humic acid on morphophysiological parameters in varieties of tulips, an experiment was conducted in research farm of agricultural faculty, University of Zanjan in Iran during 2013 growing season. The experiment has two factors, including humic acid at 4 levels (0, 200, 400 and 800 ppm) and varieties of tulips (Tulipa Inzell, Tulipa 'Spryng', Tulipa Leen Van Der Mark, Tulipa 'Early Surprise). The experimental design was in a completely randomized design with 3 replications. The results showed that humic acid foliar application had positive effect on all attributes in this experiment. The results of the present study indicate HA treatment (800ppm) alone had the greatest impact on the amount of chlorophyll a, b, total soluble protein in a leaf and the peroxidase activity.Considering the time of flowering, application of HA treatment (800 ppm) took less than the control treatment. The highest value of Chlorophyll a, total protein and peroxidase activity were obtained from Tulipa Leen Van Der Mark. On the other hand, the lowest value of Total Chlorophyll and total protein and the peroxidase activity were seen in Tulipa Inzell. The shortest time of flowering was related to Tulipa Spring and the longest time was recognized in Tulipa Inzell. Interaction Tulipa Leen Van Der Mark with HA treatment (800ppm) had the highest value of Chlorophyll a and b, total Chlorophyll and protein and peroxidase activity. Tulipa Spring and application of HA treatment (800 ppm) had least length of time to start flowering.