TREE SURVIVAL IN LONG-TERM CITRUS ROOTSTOCK FIELD TRIALS

Transcription

1 3,was ranked with Swingle as more tolerant. (Graham et al. I993). Few problems related to Phytophthora have has been reported in plantings of these rootstocks on well drained soils of the ridge. Citrus Blight has been reported in plantings of F/80-3 w hile F/80-8 has not sustained severe losses. (Youtsey and Ro enthal 986). It remains to be seen to what extent that CitBlight will occur in this trial.. From observations to date it would seem that few of these rootstocks are superior overall to Swingle, but citrumelo FI -8 and F/80-2 may be acceptable rootstocks for further trial plantings with Hamlin orange scions because of increased,delds offruit per tree and pounds soluble solids per acre. Citunelo F/80-3 should also be included due to the outstanding yield performance, however, care should be taken that :nursery stock should be free of Phytophthora and careful attention should be given to control of fire ants in the planting. rus Acknowledgments The authors wish to recognize Jim Baldwin for his valuable assistance with statistical analysis and Tommy Long for juice analysis. Literature Cited Bridges, G.D. and C. 0. Youtsey Yield variations among citrus nucellar seedling clones at the Florida State Foundation Grove., Proc. Florida State Hort. Soc Derrick, K. S., R. F. Lee, R. H. Brlansky, L. W. Timmer, B. G. Hewitt, and G. A. Barthe Proteins associated with citrus blight. Plant Dis. 74: Graham, J. H. and W. S. Castle Screening citrus genotypes for tolerance to phytophthora root-rot in chlamydospore-infested soil. IV World Congress of the International Soc. of Citrus Nurserymen. Lee, R. F., L.J. Marais, L. W. Timmer, andj. H. Graham Syringe injection of water into the trunk: a rapid diagnostic test for citrus blight. Plant Dis. 68:5-53. Norman G. G. 964, Old and nucellar lines in the foundation grove of the Div. of Plant Ind. Proc. Fla. State Hort. Soc. 77:7-76. Pieringer, A. P., G.D. Bridges, and C. 0. Youtsey. 978, Comparison of yield and internal quality of 25 navel orange selections, Proc., Fla. State Hort. Soc. 9: Wutscher, H.K., M. Cohen, and R.H. Young Zinc and water-soluble phenolic levels in the wood for the diagnosis of citrus blight. Plant Dis. Rptr. 6: Wutscher, H.K. and L. L. Hill Performance of 'Hamlin' orange on 6 Rootstocks in East Central Florida. Hort.Science 30():4-43. Wutscher, H. K. and F. W. Bistline Performance of 'Hamlin' orange on 30 citrus rootstocks in Southern Florida. J. Amer. Soc. for Hort. Soc. 3( 4): Youtsey, C. 0. and G. D. Bridges Yield and growth comparisons of one old-line and eight nucellar Washington navel budlines in a demonstration planting on ten rootstocks. Proc. Florida State Hort. Soc. 92: Youtsey, C. 0. and F.J. Rosenthal Incidence of citrus blight in Florida's. citrus budwood foundation grove. Florida State Hort. Soc. 99:7-73. Bridges, G.D The Florida citrus budwood program. Proc., st International Citrus Short Course, p Proc. Fla. State Hort. Soc. 08: TREE SURVIVAL IN LONG-TERM CITRUS ROOTSTOCK FIELD TRIALS S. CAsTLE AND JAMES C. BALDWIN University ofrorida,!fas Citrus Research and Education Center 700 Experiment Station Road Lake Alfred, FL WILLIAM Additional index words. Blight, citrus tristeza virus, Phytoph;thora. Abstract. Tree losses caused by blight, citrus tristeza virus (CTV) or Phytophthora foot rot were recorded periodically in four formal rootstock experiments and one grower trial. The five trials, located throughout Florida, were planted between 968 and 978. The scion cultivar was either 'Valencia' or 'Hamun sweet orange [Citrus sinensis (L.) Osb.] with rough,jemon ( C. jambhiri Lush.), Volkamer lemon ( C. volkameriana en. & Pasq.), sour orange ( C. aurantium L.), Cleopatra mandarin ( C. reshni Hort. ex Tan.), Carrizo citrange [ C. sinensis x Poncirus trifoliata(l.) Raf.], and Swingle citrumelo (C. paradisi Florida Agricultural Experiment Station Journal Series No. N-054. We gratefully acknowledge the support for these projects received from Becker Hlding Corp., Alcoma Packing Co., Talquin Corp., Via Tropical Fruit Co., One Lee, C. Elton and Robert Crews and Gene Swearingen, Congen Inc. and Jack Neitzke, the Berry Corp., Florida growers through a Citrus Production,Research Advisory Council grant (Project ), and L. W. Timmer and R. F. Lee for disease assays. Proc. Fla. State Hort. Soc. 08: 995. Macf. x P. trifoliata) rootstocks common to most trials. A broad range of other rootstocks were included in the experiments. Early losses were caused by site conditions, cultural practices and Phytophthora foot rot. Overall, few trees were lost to the latter except for trees on sweet orange rootstock where generally < 50% survived. Blight was the primary cause of loss among older trees except for CTV decline in trees on sour orange. Trees on commercial stocks survived blight according to prior experience, i.e., high survival among those on Swingle citrumelo, sweet orange, and sour orange (> 80%) and lower survival (< 50%) for those on rough lemon with other rootstocks having intermediate losses. The survival results be.tween trials were sufficiently consistent to suggest that longterm field trials are, and continue to be, the only current means to conduct blight evaluations. Among non-commercial and new rootstocks, tree survival was > 75% for those on English Small trifoliate orange, C. amblycarpa, Koethen sweet orange x Rubidoux trifoliate orange, Chinotto, a pummelo, and 80-8 citrumelo. Blight, Phytophthora diseases, and citrus tristeza virus (CV) continue to be among the principal causes of tree loss in the Florida citrus industry. In searching for rootstocks tolerant or resistant to these diseases, new plant material is frequently screened in controlled tests before field evaluation. These tests function well to identify the usually small number of plants with desirable traits among the much larger original population; however, these tests also have certain disadvan73

2 j'f, tages. They may not represent normal field conditions, and they frequently involve juvenile plants that may behave differently when budded with a scion and observed over a longer time period. Therefore, following rootstock performance in a commercial setting over a time span of years is a valuable complement to preliminary screening tests and remains the critical source of information. For blight, it is virtually the only means of evaluating rootstocks be.cause the cause is unknown. We report herein the survival of 'Hamlin' and 'Valencia' sweet orange trees among five rootstock trials located throughout Florida. Materials and Methods Tree losses and their causes were recorded periodically in four rootstock experiments established on commercial property, and a grower trial (Table ). Data were obtained at - to 4-yr intervals with the exception of the Vero Beach trial in which there was about an 8-yr gap between the initial and most recent recordings of tree status. A tree loss is defined as death, or decline in productivity resulting in tree removal. Blight was generally diagnosed by visible symptoms and trunk water injection. When CTV was suspected, small bark pieces were removed across the budunion and examined for honeycombing, and young leaves collected for enzyme-linked immunosorbent assay (Castle et al., 993). In some instances, a tree was stunted by CTV (and recorded as a loss) but this was not apparent until several years after planting. For Phytophthora foot rot, only trees that died or were clearly rendered unproductive from foot rot were considered as losses. Soil samples were collected one to three times between planting and 995, generally from trees on rough lemon, Carrizo citrange, or Cleopatra mandarin, to assay for Phytophthora (Timmer et al., 988). The trees at each site were initially irrigated either by flooding or traveling gun. Field trials (T.), 4, and 5 were latr_ --J:cd to _Il!ic:rgsprinklers, and T.2 to drip irrigation, when the trees were mature; T.3 is irrigated with a volume gun. Nutritional and weed and pest control practices were typical for commercial groves in the local area. Chemicals to control nematodes or Phytophthora were generally not applied but preplant methyl bromide was used in T.2 and T.4. Results and Discussion The objective fort.l was to evaluate various rootstocks for tree size control. The trees are located on three adjacent beds in the midst of a larger block of 'Valencia' trees on rough lemon. The soil in this block is unusually sandy for the immediate area which, combined with the flood irrigation used for several years after planting, made it difficult for many of the trees on the lower vigor stocks (Castle and Phillips, 977) to become established. As a result, many trees on Sunki x Swingle Table. Description of rootstock field trials used for long-term TF, Meyer lemon, and Hong K:ong kmquat did not live b: yond the first 5 yr; those that did sul"vlve were poor perfo it, ers and gr:dually died off for reasons not readily obvious... te: 2 yr, 70% or mor of the.trees on Cinotto, Yutz Willits cltrange, and K x R citrange m T. l sul"vlved (Table 2 The ren:iaining trees had < 50% survival with one exceptio:; Capuchm sweet orang..phytophthora counts ranged fro.rn 2 46 propagules/ cm 3 soil m 995. The high value was unusu JI; compared to previous samplings. Nevertheless, Phytophtho II was present and caused the loss of.th:ee trees on Capuch(i and four trees on rough lemon withm 2 yr after plantinil Thereafter, blight eliminated one tree on Capuchin but a? counted for a steady loss among trees on rough lemon. Bligfi\' apparently took a greater toll among trees on rough lemon ;I the trial than the surrounding grove based on occasional 0 servations of the extent of replanting. The trees on sour orange rootstock grew well initially arjil were among the largest in 995, but they began to decline {, about age 5 yr from CTV; likewise, the trees on Chinotto, i sour orange mutant, were large and fruitful, but survived be L\l!> ter despite CTV decline. There were no losses from blight trees on either rootstock. r; Blight eliminated most of the trees on Rusk and Savage di tranges, Sacaton citrumelo, and Rubidoux trifoliate orang'' but only a few of those on Willits and K x R citranges. The suit viving trees on the latter two rootstocks are medium-sized, iii excellent condition, and are still yielding well; in other triali trees on Rusk have survived well for 0 to 5 yr (Wheaton I al., 986). }t:, Little is known about citrangequats or pummelos as root'., stocks. Trees are medium-sized on the former with poor Sllli; vival, but large on the pummelo with < 20% tree los ;? Pummelo is monoembryonic. The trees on this rootstock ar '. uniform but there were three odd trees, noticeable from th ; beginning, that declined slowly, apparently from CTV. j\,,ji/, The trees m T.2 were planted at a flatwoods locat0n wit.:.': Pineda and Riviera soils. Each row was methyl bromide fumif.: gated prior to planting; however, that did not prevent Phy.t tophthora foot rot losses during the first 2 to 3 yr among treei on rough lemon and continuing losses among trees on sweei orange. Those losses were 0% and 50%, respectively, and ar :; not included in the data reported in Table 2 for this planting{li All trees were surveyed twice for CTV, the first time a. planting and then about 8 yr later. The mild strain present iq'.:. the budwood may have provided some degree of cross-proteo'\i tion as severe strains were rarely detected. Two trees "".erel stunted on sour orange, and one tree on Palestine sweet hme,:i, declined, and were removed. The major cause of tree decline and removal in T.2 w blight which affected all trees except those on sour orang; (Table 2). The general order of blight incidence betweeqj rootstocks followed the cumulativ: lorida experience, i.e:!i trees on rough lemon (45%) and similar rootstocks had a lolll t'i jj fol stdy of tree survival.' Trial Location Year planted Scion Vero Beach Indiantown St. Cloud Avon Park LaBelle Valencia Valencia Hughes nucellar: Valencia (mixed budlines) Valencia Hughes nucellar: Hamlin 8--4 Ii;:: Remarks Budwood infected with mild strain of CfV Budwood infected with mild strain of GTV '3 ' For additional background information, see Castle et al., 993; and Castle and Phillips, t.e Proc. Fla. State Hort. Soc. 08:

3 Table 2. Tree survival(%) as of 995 among sweet orange trees in five rootstock field trials.' Rootstock (2)' 2 (60) 3 4 (48) 5 (48) common name Scientific name 27yr 9 yr 9 yr 8 yr 7 yr med Alemow Citrus macrophylla Wester Capuchin sweet orange C. sinensis 67 Carrizo citrange C. sinensis x Poncirus trifoliata (L.) (8) 7 83 Raf. Chinotto sour orange C. myrtifolia Raf. 70 (0) Cleopatra mandarin C. reshni Hort. ex Tan (20) 7 79 Duncan grapefruit C. paradisi Macf. 65 English Small Flowered trifoliate P. trifoliata 88 orange Flying Dragon trifoliate orange 50 (24) Hong Kong kumquat F. hindsii (Champ.) Swing. 0 Meyer lemon C. meyeri Y. Tan. 0 Milam lemon C. jambhiri hybrid? 50 (34) 69 Morton citrange 64 Nasnaran C. amblycarpa Ochse 88 Orlando tangelo C. paradisi x C. reticulata Blanco Palestine sweet lime C. limettioides Tan (56) 67 Ponkan mandarin 33 Rangpur C. limonia Osb (72) 69 Ridge Pineapple sweet orange (24) Rough lemon C. jambhiri Lush. 9 (4) (76) 46 4 Rubidoux trifoliate orange 42 Rusk citrange 0 3 Sacaton citrumelo C. paradisi x P. trifoliata 7 Savage citrange 25 Smooth Flat Seville Natural hybrid of unknown origin 65 (20) Sour orange C. aurantium L (3) 00 7 Swingle citrumelo (48) Thomasville citrangequat Fortunella margarita (Lour.) Swing x Willits citrange Trifoliate orange Troyer citrange 67 (24) Volkamer lemon C. volkameriana Ten. & Pasq (60) Willits citrange 75 Yutze pummelo C. grandis (L.) Osb. 83 Yuzu C. ichangensis Swing. x C. reticulata 7 var. austera? Unnamed _..J:;.:65-69 Rangpur x Shekwasha mandarin 42 ( C. depressa Hayata) Citrumelo F (20) KxR F (20) Koe then sweet orange x Rubidoux 75 Rxs trifoliate orange Rangpur x Shekwasha mandarin 0 RxT Rangpur x Troyer citrange i$: x S C. sunki Hort. ex Tan. _x Swingle 0.., trifoliate orange :lank spaces indicate rootstocks not included in a particular planting.,,umbers in parenthesis are the original tree count for each rootstock in the trial except where noted otherwise within ;,e table. iee loss in these two trials was caused almost entirely by blight. -Tree age in 995. Trial i!f.,!val, Carrizo (73%) and Cleopatra (58%) were intermedi- ' >' and few trees on Swingle or sweet orange were missing,f:fom blight. Trial 3 trees were produced in a field nursery at the Citrus Budwood Registration Office Foundation Farm in Dundee. The -nursery site was methyl bromide fumigated. Extra µees of various 'Valencia' budlines on a series of rootstocks were transplanted to the St. Cloud site where they were set in adjacen rows by rootstock with the budline running across the block perpendicular to the rootstocks. Proc. Fla. State Hort. Soc. 08: 995. Only trees on sour orange ( 00%), F80-8 citrumelo (95%), and Swingle citrumelo (90%) survived well in this planting after 9 yr, attesting to their tolerance to blight, and the freezes that occurred during the 980s (Table 2). This planting was not assayed for CTV except for the trees on Smooth Flat Seville (Castle et al., 992); mild and severe strains were found. Nearly all trees (90%) on Smooth Flat Seville had survived in 992 but only 65% remained in 995. The trees removed exhibited blight-like visual symptoms. Their CTV status was not determined; however, in a nearby, 75

4 " younger rootstock experiment, the trees on Smo oth Flat pests and diseases, site conditions and management fact Seville assayed positive for severe CV strains, and blight is seemed to control tree growth and survival. Stage eve(} present but neither disease has visibly affected them. were largely responsible for the poor survival of trees on n Tree loss on all but three rootstocks was the result of tain (especially low vigor) rootstocks. Also, many of thee blight; however, substantial losses from freeze damage are in- same rootstocks could be described as particularly site Os; cluded in the data for trees on Palestine sweet lime (2 % ) management sensitive, i.e., when planted in relatively pa and Rangpur (4%) (Table 2). Blight began early and losses soil and without good care, they did poorly as young tr Orj accumulated steadily for trees on most rootstocks. By 990, Stage 2 is the remaining time, and was a generally unevenii there were < 60% remaining trees among those on rough period for several years after stage ended re CTV, Phyto lemon, Carrizo, Rx T, and Volkamer lemon. By 995, the sur- thora and blight. At about age 8 yr, blight appeared in rnos{ vival of trees on Milam was slightly greater than of those on the trials and was essetially the only cause of tree loss th er rough lemon. Blight eliminated all trees on Cleopatra with after other than CV m the trees on sour orange; thus, th':. most losses occurring in recent years which seems to be a following discussion and rootstock summary concern ont common pattern. Four trees on Cleopatra had been removed blight. Across the five trials, the general order of blight loss w' by 990 and the remaining 6 were removed in the following 4 yr. There was a large difference in blight incidence between rough lemon.and Volkamer lemon (highest; most susceptf, trees on 80-8 and 80-3 citrumelos. Both citrumelos have ble), Carizo cit:ange and Cleopatra mandarin (intenned shown promise as rootstocks but little is known about their ate), Swmgle ctrumelo, sour orange, and sweet oran ::. field tolerance to blight. (lowest; most tolerant). Moreover, the results were reasona' Trial 4 is located at a typical Ridge site. The trees are part consistent within rootstocks especially rough lemon whe{ of the same group used for T.2 only they were planted about the range in tree survival was only 35 % to 46 % in four similaf: 2 months later and one-half of the tree spaces were methyl ly aged trials (T.2-T.4); tree survival was l?wer (29%) in T.:, bromide-fumigated as an experimental treatment. Burrowing but those trees are 0-yr-older than those m the other trials,l nematodes invaded the site and by 992 had spread throughthe cause of blight is still unknown. The survival <la,:'' out the trial. The first Phytophthora sampling was conducted from the trials reported herein, and their consistency, pn). when the trees were 2-yr-old. The mean propagule count in vide evidence that such trials can serve as a means to conduki the summer was about 6/cm3 soil with differences between blight evaluations by including new roots tocks among ones a'-rootstocks but none between the fumigated and unfumigated known blight response. In the absence of any alternative; plots (Agostini et al., 99). Some foot rot losses occurred long-term field trials remain a valuable source of informatiort''; (about 0% for trees on rough lemon or sweet orange) in the first few years regardless of the fumigation treatment. ThereRootstock Summary: Blight after, only blight was a factor in tree survival as in T.2. The recommercial rootstocks. Most of these rootstocks are charac lationship among rootstocks was similar in both trials but the terized in the preceding discussion. Milam was included i blight incidence was lower at Avon Park (T.4) except for the only two trials but tree survival exceeded rough lemon trees on Carrizo citrange and rough lemon. Volkamer lemon. Four selections of trifoliate orange had re Soil variation cm:nined with the initial irrigation meth- -ods as well CV and blight determined tree survival at the atively low survival values (except for English Small Floweredf in agreement with the usual ranking of trifoliate orange$, LaBelle site (T.5). Within the planted area (a 2-row bed), susceptible. ':; there were spots of "weak soil," i.e., white sand. Seepage and Other rootstocks. Morton and Troyer citranges were only iq.. volume gun irrigation created establishment difficulties and eluded in T.5 and had similar tree survivals that were loweru; 0% to 30% of the trees on Rusk citrange, Rx T, Thomasville than those for the trees on Carrizo. Rusk citrange tree survivh..))!, citrangequat or Flying Dragon trifoliate orange were lost in was very low in each of two tnals because of poor young-tre; the initial years with most losses occurring in those weak survival and a decline (unthriftiness) of unknown cause thi spots; the trees that did survive often grew poorly and deaffected older trees on Rusk. Trees on Willits citrange wer clined later. Neither CV nor blight had a major effect on the notable for excellent long-term survival. They are small, witl)'.;. survival of trees on 'Ridge Pineapple' sweet orange but Phyexcellent appearance, and are still yielding well for their sizj tophthora killed many trees on this rootstock. The trees on Pummelo and Kx R citrange also showed excellent survival af Duncan grapefruit also struggled after planting and never ter 27 yr (T. l). The trees on pummelo rootstock are relatively;$ achieved the large size expected. Budunion bark samples large and have produced good crops consistently althoug!w from those trees were routinely pitted or honeycombed sugjuice quality is comparable to fruit from trees on rough le gesting CV was affecting their growth. The trees on sour oron. K x R has been under study in Florida since 968 and h, ange clearly declined from a severe CV strain but tree loss been included in many trials along with Rx T. Trees on K.:ji did not begin until the trees were about 0 to 2 yr old. They Rare medium-sized with yield and juice quality characterisu' were not stunted. of most citrange rootstocks. Both K x R and Willits citrange The survival rates for trees on English Small Flowered trimerit further evaluation, particularly in higher density plan; foliate orange, Swingle citrumelo, Cleopatra mandarin, C. in gs. amblycarpa or Carrizo citrange were nearly 80% or higher (Table 2). Blight caused the losses among those trees and the Literature Cited larger losses for those on Troyer or Morton citranges, rough ' Agostini,J. P., L. W. Timmer, W. S. Castle, and D.J. Mitchell. 99. Effect i! or Volkamer lemon, or Milam. citrus rootstocks on soil populations of Phytophthora parasitica. Plant D Overall, a comparison of the results from Trials to 5 in75: Jtj dicates that tree survival was essentially a two-stage process. Stage was the first few years after planting when soil-borne Castle, ida W. citrus. Proc. Int.Phillips. Soc. Citriculture 2: \!.. S. and R. L Potentially dwarfing rootstocks for flo : r..., 9 andl as Ii,.,. :.l.... {: 76 Proc. Fla. State Hort. Soc. 08: }995'i, ;;;-f, ;. }

5 ()l5cje. w. S., R.R. Pelosi, C. 0. Youtsey, F. G. Gmitter,Jr., R. F. Lee, C. A. Pow, ell, and X. Hu Rootstocks similar to sour orange for Florida citrus trees. Proc. Fla. State Hort. Soc. 05: eastle. W. S., D. P. H. Tucker, A. H. Krezdom, and C. 0. Youtsey Root. stocks for Florida citrus, second edition. Fla. Coop. Ext. Serv. Pub. SP-42. Tmmer, L. W., H. A. Sandler,]. H. Graham, and S. E. Zitko Sampling citrtis orchards in Florida to estimate populations of Phytophthora parasitica. Phytopathology 78: Vasconcellos, L.A. B. C. and W. S. Castle Trunk xylem anatomy of mature healthy and blighted grapefruit trees on several rootstocks. J. Amer. Soc. Hort. Sci. 9: Wheaton, T. A.,J. D. Whitney, W. S. Castle, and D. P.H. Tucker Tree spacing and rootstock affect growth, yield, fruit quality, and freeze damage on young 'Hamlin' and 'Valencia' trees. Proc. Fla. State Hort. Soc. 99: Proc. Fla. State Hort. Soc. 08: COORDINATION AND QUALITY OF CITRUS RESEARCH WALTER]. KENDER University offlorida,!fas Citrus Research and Education Center 700 Experiment Station Road Lake Alfred, FL Abstract. University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) citrus research is conducted by scientists located at four Research and Education Centers (Lake Alfred, Ft. Pierce, lmmokalee and Homestead) and also in seven UF/ IFAS departments on campus in Gainesville. Citrus research,9rs have made important contributions to science and to the citrus industry. Numerous individual and multidisciplinary team projects have addressed emerging problems in the industry. With greater budget restrictions, eroding facilities and competition for extramural funding, the need for greater effici ency in the management of research funds and consolidation of research activities is needed. This paper addresses the importance of coordination of research personnel and programs with emphasis on communications, research efficiency and strategic planning. A discussion9f th quality c;._ f reearch and how scientists evaluated research follows.. The 980's brought dramatic change to Florida's citrus industry (Kender, 987). The devastating freezes of the 980s redued both citrus production and acreage. Although growers experienced higher returns, international competition, especially from Brazil intensified. In Florida, new plantings _;\Vere established in the Gulf citrus production region with :.corporate agri-business firms becoming more dominant and hifting citrus management philosophy. In the 990s, the 'Florida citrus industry faces different challenges. Expanded citrus acreage planted in both Florida and Brazil is now in full ;/.production resulting in an oversupply of citrus, lower fruit :':(/'J,?rices and diminishing profits to the grower. In addition, gov>% rnment regulations and environmental issues which restrict :ater, labor, fertilizer and pesticide use have escalated. These _.trends emphasize the importance of production efficiency for <lorida to remain competitive. It is imperative that research and extension programs in the State supply answers to growers' problems based on economic inputs. :og-. Historically, the mission of IFAS citrus scientists has been "to conduct research to solve short- and long-term problems " Florida Agricultural Experiment Station Journal Series No. N-06. Proc. Fla. State Hort. Soc. 08: 995. facing the industry as well as to add to fundamental knowledge to agriculture. As industry changed iri the last decade, IFAS has also changed, particularly in relation to the resources available for research. As budgets, personnel and infrastructure have eroded, all scientists were required to compete for extramural funding to support their research programs. As funds for maintaining research facilities decreased, the need for greater efficiency and accountability in the management of available resources was apparent. The need to consolidate activities by coordinating people and programs is evident and must be continued ififas is to continue to serve its customers in Florida, the nation and abroad. It is critical to use limited assets more wisely and productively. To insure a cohesive and efficient research plan statewide, UF-IFAS must: () enhance communication between scientists, extension personnel, administrators, regulators and the industry, (2) improve efficiency of UF /IFAS citrus research and extension programs, including more efficient use of its assets in the future, (3) identify and encourage the development of new and innovative high priority citrus research projects, and (4) maintain effective relationships with appropriate local, state and federal research and regulatory agencies. UF-IFAS Research on Citrus UF /IFAS citrus research is currently conducted by scientists located at Research and Education Centers in Lake Alfred (CREC), Ft. Pierce (IRREC), Immokalee (SWFREC), Homestead (TREC), Leesburg (CFREC) and Ft. Lauderdale (FLREC) and seven UF-IFAS. Departments in Gainesville (Horticultural Sciences, Entomology/Nematology, Plant Pathology, Soil and Water Science, Agricultural and Biological Engineering, Food and Resource Economics and Agronomy). Citrus researchers have made important contributions to world-wide science and to the citrus industry. Many examples of successful individual research programs and multidisciplinary team efforts are documented in the scientific literature. Resources Available for Citrus Research What resources are available to carry on a significant statewide citrus research program? Are they sufficient for researchers to solve the problems facing the Florida citrus industry in 996? In 2006? 77