CITRUS ROOTSTOCK AND SCION CULTIVAR DEVELOPMENT FOR AN HLB-ENDEMIC FLORIDA

Produce, evaluate and subsequently release new citrus rootstocks that induce HLB-tolerance into grafted scions, and that induce superior field performance and fruit quality from all commercial scion cultivars, have improved tolerance to other important biotic factors including Phytophthora, various nematodes, Diaprepes, citrus tristeza virus [CTV], and citrus blight, and environmental stresses (cold, salinity, high pH and calcareous soils, and drought). Tree size control potential is also an objective for a subset of developed rootstocks. Produce, evaluate and subsequently release processing sweet orange cultivars with higher total soluble solids and juice color scores, expanded maturity dates to facilitate NFC )not from concentrate) production, and better flavor than current cultivars, and with increased HLB-tolerance when possible. This includes sweet orange-like hybrids that can meet the evolving standard of identify for sweet orange; and also the development of superior HLB-tolerant mandarin hybrids that can be blended with orange juice to improve color and flavor. Produce, evaluate and subsequently release promising HLB-tolerant fresh fruit cultivars, including grapefruit/pummelo cultivars with improved color, flavor, and appearance; seedless, easy-to-peel mandarin cultivars that would be available throughout the season; and acid fruit (lemon/lime) cultivars with improved disease resistance, cold-hardiness, and industrial applications. When possible, genes for resistance to diseases (including CTV, canker and greening), cold, and pests will be incorporated into cultivars in each group. Efforts will be made to extend, or to fill gaps in, the normal fruit maturity seasons.