Improvement of the Yield and Essential Oils Quantitative in Calendula (Calendula officinalis L.) by Using Different Planting Arrangement and Potassium Fertilizer

This study was done to evaluate the effect of different planting arrangements(square, lozenge and rectangular) and various concentrations of potassiumsulfate (k2so4) fertilizer (0, 100, 200 and 300 kg/ha) on yield and essentialoils quantitative of calendula officinalis l., a medicinal and ornamental plant.the experiment was done as a factorial in randomized completely blocksdesign (r.c.b.d.) with 3 replications. the results showed that the plantheight, the number of flowers, flowers dry weight, potassium content of aerialpart, flower essential oil and carotenoids content in petals were significantlyincreased. the highest plant height (54.18 cm) was calculated from plantsgrown under 200 kg/ha k2so4 and rectangular arrangement. maximum numberof flowers per square meter (727.93), flower dry weight per square meter(140.58 g), potassium content of aerial part (0.9 mg/l), essential oils contentper square meter (0.27 g) and carotenoids content in petals (8.24 mg/l) wereobtained from plants grown under soil conditions containing 300 kg/ha k2so4and with square arrangement. the results of current study recommend using of300 kg/ha of k2so4 and square planting arrangement for increasing the yieldand essential oils content of calendula.