The tropical fruit and vegetable industry in South Florida is thriving, with imports of mangos, papayas, and tropical vegetables becoming a major area of expansion. An increasingly aware U.S. public has created a stronger demand for both Florida-grown and imported tropical commodities whose retail quality has increased due to improved handling and transportation practices. Systems for product temperature management, washing, grading, coating, and packaging are being modified to accommodate the conditions present in South Florida, Central and South America, and the Caribbean. The recent widespread approval of hot-water quarantine treatment of mangos has facilitated international trading and allowed U.S. fruit companies to maintain nearly uninterrupted supplies.
Craig A. Campbell
Craig A. Campbell
This paper describes the field research and development (FRD) process followed by agrochemical companies when developing a new plant growth regulator (PGR). Specific approaches used by Valent BioSciences Corporation in developing EcoLyst, a newly registered PGR for use on orange (Citrus sinensis) in the United States, are cited as examples of this process. Agrochemical companies acquire some new PGR compounds from outside sources, while others are discovered internally. Internal development of new compounds is simpler to control and manage. When a new PGR is identified from an outside source, a company must first determine if the compound is available for licensing or outright purchase. If so, they assemble a team of internal experts to review all available data (due diligence) to determine if it has sufficient value to warrant pursuit. Once a PGR passes the initial screening processes and is approved for acquisition and potential development, negotiations begin with the owner of the compound. Many projects stop abruptly when the negotiating companies fail to reach an agreement. Immediately after an agrochemical company successfully acquires a new PGR, a well-coordinated chain of events is initiated throughout the company's organization to accelerate work on the project. One component of this involves the FRD team, which creates a comprehensive field research plan for the PGR containing clearly defined development goals that are global in scope. The FRD team works throughout the world, near important crop production areas, conducting research with the company's products. Members of the FRD team generally report to a research leader located at the company's main headquarters. The FRD team is one part of a larger development team, that works collectively to find and develop promising new compounds and new uses for existing company products. If initial research results from a new compound are favorable, the objectives of the workplan increase significantly after the first year. University and government researchers are generally brought into the research programs after a year or two of in-house testing. Early stage work is often done under a secrecy agreement in order to protect proprietary information and interests. Specific control points are identified in the development process, where decisions are made to continue or not, based on reviews of research data, business plans, and regulatory progress.
Craig A. Campbell
The purpose of this presentation is to describe the general Field R&D process undertaken by Abbott Laboratories and other agrochemical companies when developing a new plant growth regulator (PGR). A recently registered PGR for citrus named `EcoLyst' is used throughout the presentation as an example of common development strategies. Agrochemical companies acquire many new PGR compounds from outside sources, while others are discovered internally. Internal technology is obviously much simpler to control. In Abbott's case, most of the new PGR compounds are brought in from other places as a result of focused efforts to find new technology for development. Researchers, sales and marketing personnel, and full-time acquisition specialists all share the responsibility for finding new prospect PGRs. After a new PGR is identified, a company like Abbott must first determine if the lead is potentially available, and then, if it has sufficient value to warrant acquisition or in-licensing efforts. Once a PGR passes an initial screening process and is approved for potential development, a coordinated chain of events is initiated throughout the company's organization to accelerate work on the project. Field R&D creates a comprehensive research plan for the PGR that contains development goals. The scope of the research program increases significantly after the first research year, provided results are favorable. University and government scientists are generally brought into the research programs after a year or two of in-house testing. At predetermined control points in the development process, go/no go decisions are made based on reviews of research data, business plans, and regulatory progress.
Craig A. Campbell
Frederick S. Davies, Craig A. Campbell, and Matthew W. Fidelibus
It is desirable to mix gibberellic acid (GA3) with other commonly applied materials to reduce application cost. However, applying GA3 with some compounds can reduce its efficacy or cause phytotoxicity. We conducted experiments in 1997-98 and 1998-99 to determine if GA3 (ProGibb) can be tank-mixed with fosetyl-Al (Aliette), or avermectin (Agri-Mek) and oil, without reducing GA3 efficacy. In addition, we compared Silwet and Kinetic adjuvants for enhancement of GA3 efficacy. Five tank mixes were tested along with a nonsprayed control. These included 1) GA3; 2) GA3 and Silwet; 3) GA3 and Kinetic; 4) GA3 Silwet, and fosetyl-Al; and 5) GA3, Silwet, avermectin, and oil. All compounds were applied at recommended concentrations. In September 1997 or October 1998, about 2.5 gal (9.5 L) of each tank mix was applied with a hand sprayer to 14- or 15-year-old `Hamlin' orange (Citrus sinensis) trees on sour orange (Citrus aurantium) rootstock. Peel puncture resistance (PPR), color, and juice yield (% juice weight) were evaluated monthly between December 1997 and March 1998, and December 1998 and January 1999. In both years, fruit of treated trees usually had higher PPR and were less yellow in color than fruit from control trees. There were tank mix effects on juice yield in January of both seasons and February 1998. Gibberellic acid was most effective at enhancing juice yield when applied singly or with avermectin and oil. In both seasons there were dates when GA3 applied singly was superior at enhancing juice yield than a tank mix of GA3, Silwet and fosetyl-Al, indicating that GA3 was incompatible with fosetyl-Al. Neither Kinetic nor Silwet adjuvants consistently enhanced GA3 effects on peel quality or juice yield over GA3 alone.
Matthew W. Fidelibus, Frederick S. Davies, and Craig A. Campbell
Gibberellic acid (GA3) increases juice yield of processing oranges, but results are inconsistent. Preliminary research suggested that this variability might be related to application timing. Therefore, we conducted an experiment to determine the optimal time to apply GA3 for increasing juice yield of `Hamlin', `Pineapple', and `Valencia' sweet oranges [Citrus sinensis (L.) Osb.]. Mature trees of each cultivar were sprayed with ≈10 L of a solution of GA3 (45 g·ha-1 a.i.) and organo-silicone surfactant (Silwet, 0.05%) between 2 Sept. and 9 Dec. 1998, and 25 Sept. and 9 Dec. 1999, or remained non-sprayed (control). Generally, the earliest application dates were most effective at maintaining peel puncture resistance above that of control fruit, while the latest application dates resulted in the most green peel color at harvest. Juice yield of `Hamlin' and `Valencia', but not `Pineapple', was increased by GA3 at some application timings and harvest dates in both years. The increase in juice yield was related to time between application and harvest; juice yield of `Hamlin' was greatest ≈2 months, and `Valencia' ≈5 months after GA3 application. Treated fruit often had lower juice Brix than non-sprayed fruit, a phenomenon that often paralleled treatment effects on peel color. When treatments did not increase juice yield but reduced juice Brix, then yield of solids was sometimes lower than for non-treated fruit. Treatments generally delayed flowering of `Pineapple' and `Valencia' but not `Hamlin'.
Nicole L. Waterland, Craig A. Campbell, John J. Finer, and Michelle L. Jones
Drought stress is a major cause of postproduction decline in bedding plants. The plant hormone abscisic acid (ABA) regulates drought stress responses by mediating stomatal closure, thereby reducing transpirational water loss. Exogenous ABA applications delay wilting and allow plants to survive short periods of severe drought. The effectiveness of the ABA biochemical, s-ABA (ConTego™; Valent BioSciences Corp., Libertyville, IL), at delaying wilting and extending shelf life during drought stress was evaluated in six bedding plant species. Spray and drench applications of 0 or 500 mg·L−1 s-ABA were applied to Impatiens walleriana (impatiens), Pelargonium ×hortorum (seed geranium), Petunia ×hybrida (petunia), Tagetes patula (marigold), Salvia splendens (salvia), and Viola ×wittrockiana (pansy). Water was subsequently withheld and wilting symptoms were compared between treated and control plants. s-ABA applications delayed wilting in all crops by 1.7 to 4.3 days. Leaf chlorosis was observed after s-ABA application in drought-stressed seed geraniums, marigolds, and pansies. In seed geraniums and marigolds, the drought stress itself resulted in leaf chlorosis that was equivalent to or more severe than the s-ABA application alone. In pansies, s-ABA applications induced leaf chlorosis that was more severe than the drought treatment. Overall, s-ABA was consistently effective at reducing water loss and extending shelf life for all species treated. Applications of s-ABA to bedding plants before shipping and retailing would allow plants to maintain marketability even under severe drought stress conditions.