EFFECT OF PHOSPHORUS ON N, P, K, Mg ACCUMULATION AND PLANT GROWTH OF DIFFERENT CITRUS ROOTSTOCKS

Abstract

Abstract. Phosphorus is an essential nutrient for the growth of citrus plants. A pot experiment was conducted in greenhouse to investigate the citrus cultivars grafted on 10 rootstocks (Cuningmeng, Suanju, Suancheng, Honglimeng, Zhike, Goutoucheng, Xiangyuan, Hongju, Xiangcheng, and Zhicheng) in response to the different phosphorus treatments viz, low P (LP) = 0.01 mmol L −1 , moderate P (MP) = 0.5 mmol L −1 , high P (HP) = 1 mmol L −1 ) concentrations. All P concentrations were employed in pots containing Hoagland solution. The leaves, branch, root, and total dry weight, and nitrogen, phosphorus, potassium and magnesium concentrations in the different plant parts were determined. Results showed that P application increased N, P, K and Mg content in different plant parts. With increasing P application, the root dry weight, branch dry weight, leaves dry weight, and total dry weight increased whilst low P treatment affected the P, K, and Mg accumulation in root and ultimately plant growth. Moreover, low P concentrations also affected Mg content in leaves, that can lead to low plant photosynthesis and finally decreased the plant dry biomass

Effect of nitrogen, phosphorus and potassium deficiencies on some morphological and physiological properties and nutrient uptake by two almond rootstocks

“…On the other hand, the lack of P in the nutrient solution reduces the concentration of Ca and Mg in the shoots of the BA seedlings. Moreover, P deficiency in the soil is one of the critical aspects that limits the production and yield of many plants; high or low concentrations of P may stop the absorption of elements such as N, K, Fe, Zn and B (Tu et al, 2018). In agreement with these results, Tu et al (2018) showed that low P application in citrus rootstocks can reduce the concentration of Mg in the leaves and thus reduce the photosynthetic activity of the leaves, ultimately reducing the dry weight of the plant.…”

“…In addition, leaf chlorosis due to K deficiency can be due to oxidative degradation of chloroplasts and chlorophyll molecules due to increased production of oxygen free radicals (ROS) (Cakmak, 2005). Leaf chlorosis in the absence of N and P can be directly related to the lack of these elements in the structure of the chlorophyll molecule or indirectly due to the reduced absorption of other elements such as Fe, Mn and Mg (Taiz and Zeiger, 2010;Chen et al, 2018;Tu et al, 2018). In confirmation of this, Figure 1E shows that the concentration of shoot Mg in the BA seedlings was 44% and 52% lower in N and P deficiencies, respectively, than in the control plants.…”