1a.Objectives (from AD-416)
To determine the role of calcium nutrition in citrus in relations to plant growth and tolerance to citrus canker and Huanglongbing (HLB).
1b.Approach (from AD-416)
Conduct factorial experiments to isolate the effects of calcium on root and shoot growth and tolerance to citrus pathogens. Fertilizer treatments will be conducted under "clean" (i.e. no plant pathogens) in a protected-environment structure (i.e. greenhouse). Citrus trees will then be moved to the field where citrus canker and HLB are prevalent. Citrus trees will continue to receive their respective treatments in the field and will be routinely monitored for development of aforementioned citrus pathogens.
The relationship of the project to the objectives of the in-house project includes the development of integrated horticultural production systems, in this case fertilization, to improve nursery and field citrus tree production. Progress includes the completion of the citrus nursery production under protected greenhouse environment and establishment of a field trial where supplemental applications of calcium nitrate, rates increasing from 50 to 800 parts-per-million calcium, are being evaluated for effects on growth and development of citrus foliar pathogens.