The citrus grove of the future and its implications for huanglongbing management

Authors: Stover, Eddie; CASTLE, WILLIAM - UNIV. OF FLORIDA,IFAS; SPYKE, PETER - ARAPAHO CITRUS MANAGEMENT

Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2008
Publication Date: 6/1/2009
Citation: Stover, E., Castle, W.S., Spyke, P. 2009. The citrus grove of the future and its implications for hunaglongbing management. Proceedings of the Florida State Horticultural Society. 121:155-159.

Interpretive Summary: The disease Huanglongbing (HLB), also known as citrus greening, is likely to force dramatic changes in the way citrus is grown in Florida. Other tree fruit industries have been pressured by economic needs to change the way they grow fruit, by using more trees/acre and using more intensive production practices. More trees / acre results in earlier cropping but higher cost to establish each acre in an orchard, because of the need to buy more trees. HLB infected trees will need to be identified and removed, and loss of scattered trees in an orchard with many more trees/acre is expected to show less yield decline ss the same percentage of trees are lost. Citrus production practices, which may allow citrus to be grown profitably in Florida using HLB susceptible varieties, have been dubbed Advanced Production System combined with Open Hydroponic System. These practices have been adopted in a number of citrus producing countries, but need to be evaluated and adapted to Florida conditions. Practices which provide early yield and high fruit quality are critical to profitable production when planting expensive orchards with many trees per acre. Many practices, such as careful control of water and nutrients to manage tree development, girdling, spraying of plant hormones, planting larger trees initially, and tree supports may increase early crops and help keep trees small. In the more distant future, genetic engineering may also significantly contribute to changing citrus production. The purpose of this paper is to stimulate discussion and help develop useful ideas in facing this challenge, and coordinate efforts within Florida to get useful production and economic data on these practices as quickly as possible.

Technical Abstract: Revolutionary changes face Florida’s citrus industry as huanglongbing becomes widespread. Changing economic realities have encouraged many tree fruit industries to modify planting density, tree architecture, and training / production systems. More trees / acre translate into earlier bearing and less yield disruption as trees are lost, but with greater establishment and management costs per acre. A similar model for citrus production, which may permit profitable production in Florida using huanglongbing susceptible material, has been dubbed Advanced Production System combined with Open Hydroponic System. These practices have been adopted in a number of citrus producing countries, but need to be evaluated and adapted to Florida conditions. Practices which facilitate early cropping and fruit quality are critical to high density orchard profitability. Control of water and nutrients to manage tree development, girdling, use of GA-biosynthesis inhibitors, larger planting stock, and tree supports may maximize early yields and help contain canopy volume. In the more distant future, GMO solutions may contribute additional tools. The purpose of this paper is to stimulate discussion and facilitate assembly of diverse useful ideas in facing this challenge, and coordinate efforts within Florida to get a critical mass of production and economic data as quickly as possible.