Open Hydroponics An Approach for Greening Pete Spyke

Open Hydroponics – An Approach for Greening Pete Spyke Arapaho Citrus Management, Inc.

What is OHS? Elements: Drip irrigation Close spacing Fertigation Canopy Mgmt Intensive mgt. High yields Early $$

One approach to Greening • New grove goals: – Reach breakeven ASAP; – Improve overall income – Improve greening mgt. – Outrun tree losses! • Mature grove goals: – None – infection spreading too fast

WATER • Calculated for daily applications based on root growth, ET, and canopy development. • Apply in pulses. • Minimize effort for uptake. • Good root aeration. • Salinity Management.

CROPPING • Occurs naturally in 2 years, or • Enhanced with girdling. • Heavy Cropping aids in Tree Vigor Control

NUTRIENT MANAGEMENT • Fertigate to provide non-limiting conditions • Amount of nutrients directly related to tree growth. • Proportions according to annual growth cycles (phenology). • Salinity Management • No Florida Recommendations!

Close spacing/Tree precocity • Conventional grove: 15 x 25 ft. (116 trees/acre) • Modern grove: 10 x 20 ft (218 trees/acre) • High density grove: 8 x 15 ft (363 trees/acre)

Lemon/RL planted 1999 @ 5 x 16 ft. Trees were planted on shallow ridges and produced ~140 boxes/acre @ 14 months, 500 @ 36 months and 800 in 2005.

Will the system work……. in Florida? – Sandy soil – Florida rainfall vs. root concentration – How is this system different from what we are already doing? – General economics. – Fruit quality. – Excessive flushing?

Rock Bottom OHS/APS Comparisons • 10 acre grove in Ft. Pierce Cooperators – Dr. Bill Castle & Japie Kruger

Rock Bottom OHS/APS Comparisons • • Ray Ruby, Rio Red, Flame Grapefruit, and Minneola – Gpft 11/06, Minneolas 2/07 Minneola Rootstocks: – – – • Sun Chu Sha Swingle Gou Tou Grapefruit rootstocks: – – – Smooth Flat Seville Flying Dragon Trifoliate Cleopatra Mandarin X 639 US 897

Rock Bottom OHS/APS Comparisons • Tree spacing 6 and 8 feet in 20’ rows (363 and 272 trees/acre) • Drip vs. Microjet • Winder/Chobee soils • Saline canal water • Greening all around

January 2007 – 2 months after Planting

Drip - Ray Ruby/SFS @ 9 Months

Microjet – Ray Ruby/SFS @ 9 Months Granular Slow Release Fertilizer, plus run system every day with liquid fertilizer

Question: • Will Roots Cluster Under Emitters? • Keep roots bathed in nutrient solution • Rapid uptake of injected materials • Moisture stress management

Questions: • Can we control tree size? – – Rootstocks Pruning Fruit Tree Manipulation – Flowering Control

Questions: • What is the best spacing? • Canopies touching in row @ 24 months = 1 st crop as high as possible Ray Ruby/FD @ 8’ Minneola/Gou Tou @ 6’ Spacing will be scion/rootstock/soil dependent.

Questions: • Profitable? – Higher cost/acre for establishment – Much lower cost/tree than “conventional” = earlier operating profit – Lower irrigation, fertilization, weed control, routine labor costs – Higher pruning costs – High production in early years – 80% Less Water and Fertilizer Year 1 & 2 – CHEAP!

Experiments Under Way • Rock Bottom – Dr. Bill Castle and Pete • SWFREC – Dr. Kelly Morgan • CREC, Gapway Groves – Dr. Arnold Schumann • USDA Picos Road – Dr. Ed Stover • Conserv – Drs. Castle, Parsons, Morgan • More planned – Geo. Spider? -- Looking good so far --

Why? • Whatever the solution to Greening, it will involve new groves • Valid approach even with current knowledge base • Early profit will be primary motivator to reestablish the industry

It’s Possible! Needs More Work! Arapaho. Citrus. com