University of California, Riverside researcher, Prof. Hailing Jin, has shown that several citrus small RNAs are induced upon infection by Candidatius Liberibacter asiaticus (Las). These miRNAs and siRNAs would enable the early diagnosis of HLB in citrus trees and nursery stocks. In addition to the identification of the miRNA biomarker, Prof. Jin also discovered that treating Las infected trees with phosphorus oxyanion improved fruit production. These studies of the improvement in yield in HLB infected citrus was demonstrated in a 3-year field trial in Florida. Fig. 1 shows the relative expression levels of miRNA399 in HLB infected citrus. Infected trees express high levels of miRNA 399. Fig. 2 shows leaves from trees that did or did not receive phosphorus oxyanion treatment over a one year period. Leaves treated with phosphorus oxyanion are healthier than leaves from untreated trees.