Annette from Cypress, Ca writes
When using Monterey Garden Phos Systemic Fungicide for root rot on avocado trees, the methods to treat are either a tree injection or a foliar spray. For a tree injection, you will inject trees at spring flush maturity. Repeat treatment in February or March. Drill holes 3/16 inch (5 mm) in diameter and 1 inch (25 mm) to 2 inches (50 mm) deep with slight downward angle in trunk. Place syringes in the main trunk of the tree and space evenly around the circumference of the trunk. Suitable for use with Chemjet tree injectors, Ag-murf gun, or hydraulic tree injection. Do not prune back trees before injection process as burning of new growth may occur. Do not inject trees in winter months. Do not cut back the canopy of injected trees. Do not add any other material, other than water , to AGRI-FOS Systemic Fungicide by trunk injection. Do not inject more liquid in a lesser number of syringes than directed. The rates for application are as follows:
Skeletal trees 1st year: ¼ fl. oz. undiluted product per yard of canopy diameter.
Other situations: 1/8 fl. oz. diluted with ½ fl. oz. of water per yard of canopy diameter. For a foliar spray, the mixing rate is 1/3 fl oz per gallon of water. You will spray to run off at 2 – 2½ gallons of spray solution per adult tree. Start applications in spring, up to 4 applications a year at two-month intervals. Ensure thorough coverage.
Answer last updated on: 08/24/2017