UF research into oak lives and HLB to find what is in oak trees that apparently helps citrus cope with HLB. . Researchers have found that applying Oak leaves around citrus trees increased phosphorous, magnesium and potassium levels in the soil. Further as the leaves were broken down, oil organic matter increased plus more water was trapped in the soil. Over the next two years, Hallman and his research partners at the USDA hope to identify which compounds are beneficial, where those compounds are found in the tree, which oak species hold these compounds and how much of the right compounds will control the disease.