Advanced Citrus Production Systems: Four Years of Evaluation in Florida.

During the past four years the “open hydroponics” (OH) method of growing crops has been intensively studied for proof of concept to develop new advanced citrus production methods in Florida. A major incentive for the more productive, efficient citrus production system is the need to remain economically viable in an era of endemic exotic diseases such as Huanglongbing (HLB). A successful OH system is based on early, high yields, made possible through 1) high density planting, and 2) accelerated growth from optimal balanced nutrition and water relations achieved with precise computerized fertigation. This poster presents the outcomes from four years of ‘Hamlin’ orange growth in a replicated Central Florida field experiment comparing two rootstocks, two fertigation delivery systems, three planting densities, and a control treatment that represents “conventional” citrus production. Cumulative fruit yields for years 2-4 were doubled relative to the conventional control in the best treatment combination of high planting density ( 897 trees /ha), drip OH fertigation, and C35 rootstock. The relative contribution of each production system component to yield improvement was 57% (planting density), 22% (OH fertigation), and 21% (rootstock). The drip and microsprinkler emitter devices were equally effective in delivering OH fertigation, with no significant differences in yield detected.