The Effect of Potassium Biofertilizer and Chemical Fertilizer on Quantitative and Qualitative Traits of Periwinkle (Catharanthus roseus Cv. ‘Acillata’)

The effect of potash biofertilizer and chemical fertilizer was studied on quantitative and qualitative traits of periwinkle in a factorial experiment based on a Randomized Complete Design with three replications, 48 experimental units, and two factors: (1) different methods of potash bio-fertilizer application at four levels of control (B0), seed inoculation (B1), root inoculation (B2) and seed inoculation × root inoculation (B3), and (2) different rates of potassium on fertigation at four levels of 0 (K0), 100 (K1), 200 (K2) and 300 mg L-1 (K3). It was found that the longest shelf life of 35.58 days was related to the treatment of root inoculation × 100 mg L-1 K. The highest number of auxiliary branches (3.66), number of leaves (42.88), plant fresh weight (17.69 g), number of flowers (4.46), and chlorophyll a (10.61 mg g-1 F.W.) were obtained from the treatment of seed inoculation × 300 mg L-1 K. The treatment of root inoculation × 200 mg L-1 K was the best treatment for plant potassium content (28.9 mg kg-1). The highest petal anthocyanin content amounted 178.04 mg 100 g-1 D.W. was observed in the treatment of ‘seed inoculation × root inoculation’ × 0 mg l-1 K. The best treatment of enhancing of qualitative and quantiative traits of periwinkle was seed inoculation × 300 mg L-1 K.