Influence of Pinching and Potassium Sources on Growth and Flowers Yield of Calendula officinalis

Document Type : Original Article


 THIS study was planned to increase natural colors of Calendula officinalis using natural treatments. Two field experiments were carried out during the two successive seasons of 2010/2011 and 2011/2012, to study the effect of different Potassium sources (Potassium sulphate, 50% K2SO4+K-Mag, 50% K2SO4 + Salicylic Acid (SA) , 50% K2SO4 +K-Mag +SA, Flespar +K-mag or Potassein) and pinching (at 0.0,7.5,10.0 and 12.5 cm) on Calendula officinalis. Data indicated that, all Potassium sources had positive effects in increasing growth characters and flower yield. The treatments of 50% Potassium sulphate with K-Mag and Salicylic Acid were the most effective treatments for growth and carotenoids content of flowers petals. On the other hand, pinching at 10 cm from the soil surface of the main stem was the best for different growth parameters and flowers yield. The best interaction treatments were treatments of 50% Potassium sulphate with K-Mag + SA, and pinching at 10 cm achieved improving growth, flowers yield with 60% over than the control (average of two seasons), obtaining the highest content of natural pigment and saving 50% of Potassium sulphate fertilizer and its negative impacts on both human health and environment.