Relationship between fruit quality and nutrients in soil and leaves of 'Hongmeiren' citrus hybrid cultivated in eastern Zhejiang province

Abstract:【Objective】In order to reveal the relation of ‘Hongmeiren' citrus fruit quality with the soil property and leaf nutrition in eastern Zhejiang, we analyzed the key factors influencing fruit quality and yield.【Methods】Thirty-three samples of fruits, leaves and rhizosphere soil were collected from eastern Zhejiang. Afterwards, the citrus yield was counted immediately. Fruit quality characteristics, mineral element contents in fruits and leaves as well as physical and chemical properties in the soil were measured in lab separately, and then the relationship among fruit quality, soil characteristics and leaf nutrients was studied.【Results】In‘Hongmeiren'citrus orchards located in eastern Zhejiang,the primary nutrients such as nitrogen(N), phosphorus(P) and potassium(K) elements in the soil were basically in proper or higher levels, while K content was lower in leaves. Meanwhile, it was shown that the fruit soluble solid content was negatively correlated with soil pH value and exchangeable calcium(Ca) content,suggesting that a moderate decrease of soil pH contributed to the improvement of fruit soluble solid content(SSC). However, excessive amount of soil exchangeable Ca could lead to the decline of fruit soluble solid content. There was a significant positive correlation between total acid and manganese(Mn)content in leaves. There was a significantly positive correlation between leaf Mn content and available Iron(Fe) and Mn contents in the soil, but a significantly negative correlation existed with soil exchangeable Ca content,suggesting that the excessive Mn content in soil and leaves may increase the total acid,while the excessive soil exchangeable Ca content may decrease the total acid.【Conclusion】To prevent antagonism among different nutrient elements, the balanced fertilizer application should be considered in‘Hongmeiren'citrus orchards of eastern Zhejiang. The deficiency of medium and trace elements,such as Ca, magnesium(Mg) and boron(B) due to the unreasonable pH value was the main reason for limiting the fruit quality of ‘Hongmeiren' citrus, so that foliar fertilization was needed timely. The single fruit weight and fruit soluble solid content were closely related to the soil pH value and exchangeable Ca content, and hence, the soil pH value should be adjusted according to the soil property of local orchards, and the medium and trace element fertilizers should also be applied to mitigate the nutrient deficiency symptom.