Reciprocal effects of huanglongbing infection and nutritional status of citrus trees: a review

In the past 15 years, the global citrus industry has experienced significant losses in the fruit production, largely due to the huanglongbing (HLB). This bacterial disease impairs water and nutrient uptake by roots causing nutritional disorders and, reciprocally, metabolic imbalances associated to oxidative stress and carbohydrate distribution in trees. The sustainability of optimum yield and fruit quality of citrus are achieved by growing canopy and rootstock varieties with superior horticultural characteristics in well-established orchards, which relies on efficient irrigation and/or fertilization, as well crop protection. Then, attention to enhanced nutrient supply increased significantly in commercial groves. In order to better understand the pathological processes, this review discusses recent scientific advances and major findings in most citrus-producing regions of the world, critically analyzing nutrient management practices as a component of an intricate strategy to maintain tree health, fruit yield, and quality. Moreover, we consider the role of balanced and constant nutrition of citrus trees to sustain citrus production under endemic HLB or non-HLB conditions.