Diagnosis and management of nutrient constraints in citrus

Abstract Citrus is one of the most widely cultivated fruit crops in the world (grown in six continents). Due to its diverse adaptation to different climates, soil types, and production practices, there are number of challenges to nutrition management of citrus for optimal fruit production. Citrus is an evergreen perennial tree with long fruit-growing period, mostly grown in regions where soil has limited organic matter and nutrient-holding capacity. Therefore, citrus production needs good fertilization program year round. Furthermore, Huanglongbing (HLB) has become a serious threat to citrus industry especially in the United States and Brazil. HLB affects the root system of the tree and therefore limits the nutrient uptake potential, therefore posing challenge for nutrition management of trees. In this chapter, we will discuss the citrus production and producing regions (soil type, spoil pH, etc.), effect of nutrition of citrus yield and fruit quality, type of fertilization, and, finally, HLB and nutrition interaction.