This is a 3 year study to test 5 soil applied treatments to prevent HLB infection in newly planted citrus trees and also the test the ability of treatments to maintain tree health should they become infected. The materials are to be Product A � Numbered Compound. Product B � Aliette Product C � Serenade Soil as well as 1 combination of A+B. The impact of treatments on new tree health, foliar nutrition, disease rating, HLB status, root density, subsequent yield and fruit quality will be evaluated. The trial will be located at a single Florida site and will incorporate well-managed trees from a commercial nursery in a new planting. This trial will be large enough to be statistically significant with treatments within label guidelines for products B and C which are registered for citrus. Our main responsibility is to examine annual root density and Las population in the root in year 2 and year 3. Product C contained Bacillus subtilis as active ingredient, so the root colonization and survival rate in soil were tested under greenhouse conditions. 15 ml of product C was applied to Valencia seedlings. The roots and rhizosphere soil were harvested at 1dpi (days post inoculation), 7 dpi and 15 dpi for root colonization and survival analysis. Product A was not available, product B did not contain bacteria. Roots were extracted from 500 cc aliquant of each soil sample over a 2 mm mesh sieve. For each treatment 30 replicate trees were measured. Notably, these trees had much less roots than project 928 samples. The root mass of treatment A was significantly higher than treatment D (t test, P<0.01). There was no significant difference between other treatments.