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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease 2 Challenges to Citrus Production ECONOMIC IMPORTANCE OF CITRUS: WORLDWIDE, UNITED STATES, FLORIDA Commercial citrus fruit are produced in about 140 countries. The primary producers are Brazil, the Mediterranean Basin, the United States, and China. Citrus fruit ranks first internationally in trade value among all fruits (Norberg, 2008; UNCTAD, 2009). Sweet oranges are the major fruit grown and represent approximately 70 percent of the citrus output. According to the Food and Agriculture Organization of the United Nations (FAOSTAT, 2007), four countries account for about 60 percent of the worldwide orange production: Brazil (32 percent), United States (14 percent), India (6 percent), and Mexico (7 percent) (Figure 2-1). Four states, Florida (68.7 percent), California (27.5 percent), Texas (2.7 percent), and Arizona (1.1 percent), produce virtually the entire US commercial citrus crop. Sweet oranges dominate Florida’s citrus production (83.6 percent) followed by grapefruit (12.6 percent) and specialty fruit consisting of mostly tangerines and tangelos. Florida produces very few lemons. Two areas dominate the production of oranges for juice: São Paulo State, Brazil (50 percent) and Florida (35 percent) (Norberg, 2008). More than 95 percent of Florida’s orange production is processed into juice, accounting for essentially all of the US orange juice production. China is another major orange juice producer. Brazil exports about 90 percent of its juice production including a considerable amount to the United States, whereas only 10 percent of Florida’s production is exported internationally. Important producers of sweet oranges for fresh consumption are Spain, Turkey, South Africa, and California (United States). Fresh market oranges bring much higher returns per acre than juice processing oranges. Mandarin production is concentrated in China, Japan, and other Asian countries, but high quality export fruit is produced in South Africa, Spain, and other countries of the Mediterranean Basin. Lemons are produced in Argentina, California, Italy, Spain, and other Mediterranean countries. Florida grapefruit is grown predominately for fresh fruit but a considerable portion of the crop is processed for grapefruit juice as well. Florida is the largest US producer, commanding about two-thirds of the total. Florida produces about 30 percent of the world’s grapefruit with Mexico, Cuba, and Turkey contributing significantly to world production. Japan is the largest importer of fresh Florida grapefruit and Canada is the leading importer of Florida fresh oranges and specialty citrus fruit (USDA-APHIS, 2006; USDA-NASS, 2008, 2009).
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease FIGURE 2-1 Worldwide orange production, percent total production, 2005–2007. Source: FAOSTAT, 2007. The Florida citrus industry is estimated to have a $9.3 billion economic impact for the state. Approximately 80,000 full-time equivalent jobs (grove employees, seasonal pickers, haulers, processors, packers, and managers) are involved, earning a combined annual wage of $2.7 billion or about 1.5 percent of the state’s wage income. Most of the fruit is harvested by hand although harvesting machines have been developed and are used for harvest of about 5 percent of the processing fruit. Nearly all of the hand harvesters are transient labor, mostly from Mexico or Haiti. Citrus is a major segment of Florida’s agricultural industry, accounting for an estimated 21.1 percent of cash farm receipts in 2005 (Norberg, 2008). HISTORY AND EVOLUTION OF THE CITRUS INDUSTRY IN FLORIDA Cultivation of citrus is believed to have begun in Southeast Asia roughly 4,000 years ago. Trade and cultivation moved slowly west to Northern Africa, the Mediterranean, and then to southern Europe by the Middle Ages. Christopher Columbus is thought to have brought the first citrus seeds on his second voyage to the New World in 1493. The Spanish explorer, Ponce de Leon, is credited with planting the first orange trees near St. Augustine, Florida sometime between 1513 and 1565. French Count Odet Philippe first introduced grapefruit to Florida in 1806. He later planted the first grapefruit grove near Tampa in 1823 (Webber et al., 1967; Florida Citrus Mutual, 2009; UNCTAD, 2009).
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease Commercial farming of citrus in Florida began in the mid-1800s, motivated by favorable growing conditions in Florida and a growing demand for the attractive, healthful fruit. The fledgling industry’s growth was facilitated by improved commercial rail transportation systems along the east coast that opened the market for the fruit to northeastern United States. By the end of the Civil War, annual citrus production in Florida reached roughly one million boxes. By 1893, production was about 5 million boxes. Florida’s hot and humid climate has made the success of its citrus industry possible, but periodic winter freezes and hurricanes have shaped the industry’s development. The Great Freeze of 1894–1895 proved devastating. Orchards throughout the state were ruined and most production on the Gulf Coast of other states was discontinued. A trend to move groves further south in Florida followed this freeze. This gradual movement south has continued following subsequent severe freezes mainly in the 1930s, 1960s, and 1980s, resulting in larger acreages in south Florida and disappearance of most citrus from the more northerly counties. Hurricanes have had an immediate negative effect on orange production. From August 2004 to October 2005, Florida was hit by four significant hurricanes (Figure 2-2). Based on figures from the US Department of Agriculture- National Agricultural Statistical Service (USDA-NASS) (2005), the 2003–2004 season saw a near record orange crop of about 240 million boxes of fruit. But, following the string of hurricanes, the figure for the 2004–2005 season was down to about 150 million boxes. For oranges alone, the decline in yield after the hurricanes was 38 percent (Table 2-1). In contrast to California fruit, Florida oranges have a thinner skin, are more difficult to peel, are more subject to transit and handling damage, and are less attractive. These factors become irrelevant when the fruits are converted to juice. Processing into juice takes advantage of the characteristic “juiciness” of Florida fruit brought about by the state’s hot, humid climate. The earliest harvest of fresh market oranges begins in October, for Hamlin, Parson Brown, Ambersweet, and Navel varieties with some cosmetic packinghouse eliminations being processed for juice. The bulk of the early orange processing begins in December. Early and mid-season varieties are harvested throughout the winter and harvest of late Valencia oranges begins in early April and continues into June. Following World War II, commercially feasible methods to process and freeze fresh fruit into concentrated juice were invented. This was a major boon to the industry, especially in Florida. Frozen juice has an extended shelf life that permits the storage of inventory to smooth out variable seasonal supply due to adverse growing conditions caused by droughts and hurricanes. The use of frozen concentrate permits blending of juice stock to provide consumers with a consistent high quality product. The convenience of a juice form also increases consumption over what it would be if only fresh fruit were available. More recently, shipping and handling methods have improved and fresh juice can be transported without producing frozen concentrate and “not from concentrate” products have become a popular product in the United States (Brown, 1995). Brazil, specifically São Paulo State, is Florida’s key competitor in the juice market. The Brazilian coffee crisis of the 1930s led to the shift toward citrus production. The crisis was caused by a huge oversupply of coffee beans brought about by government price support programs that actually contributed to further cultivation of trees thereby exacerbating the oversupply. The worldwide Great Depression sharply reduced demand for coffee in the 1930s. Brazil entered into a period of political and economic instability that, in combination with
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease FIGURE 2-2 Path of hurricanes Charley (August 13, 2004), Frances (September 5, 2004), Jeanne (September 26, 2004), and Wilma (October 24, 2005). Source: NOAA-CSC, 2009. Table 2-1 Impact of 2004–2005 Hurricanes on Florida Citrus Crop Yield (Number of Boxes) Fruit 2003–2004 2004–2005 Percent Decline Orange 242,000,000 149,600,000 38 Grapefruit 40,900,000 12,800,000 69 Specialty 8,900,000 7,000,000 19 Source: USDA-NASS, 2005.
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease reduced demand, led to a collapse in coffee prices paid to growers. Growers shifted to citrus and this began a period of growth for this crop. Growth in the 1960s was particularly steep as Brazil ramped up production in response to freezes in Florida that destroyed orchards and seriously affected supply. Brazil set out to be a source of alternate supply to fill the existing demand for citrus products in the United States and Europe. By the 1980s, Brazil had become the largest supplier of citrus fruit and juice. Urbanization and diseases have been critical factors in the recent history of the Florida citrus industry. According to the 2000 US census, Florida ranks seventh in the US in population growth (23.5 percent) from 1990–2000, almost double the US average of 13 percent, and corresponds to a daily population growth in Florida of 830 (US Census Bureau, 2009). The housing boom over the past few decades, now a burst bubble, led to rapid residential development in the state especially near the coast. Developers purchased grove land at premium prices, by agricultural standards, in part because acreage was plentiful and still relatively inexpensive for real estate. Developed properties are taxed at a much higher rate than agricultural lands, so public officials are disinclined to oppose the conversion of groves to residential and commercial development. Urban encroachment means that many citrus-growing areas are no longer isolated. Current levels of production and citrus acreage are sharply lower than the levels of the mid-1990s through 2004 (Figure 2-3 and 2-4). The number of juice processors has also declined sharply. There were 37 processors in Florida in 2001, but only 15 remained in 2008 (Norberg, 2009). The agricultural alternatives for most citrus land are cattle pasture or pine forests, neither of which is highly profitable, so growers have few options. FIGURE 2-3 Florida citrus production in tons and dollar value. Source: USDA-NASS, 2008.
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease FIGURE 2-4 Acreage of existing commercial and bearing citrus groves. Source: USDA-NASS, 2009. Plant diseases such as citrus canker have had a negative effect on citrus production and economics. The eradication program for citrus canker was responsible for the loss of 70,000 acres of groves, and the regulations on the movement of fruit from areas with the disease have greatly affected the ability of the state to market fresh fruit. Over the last 20 years, Citrus tristeza virus (CTV) caused the decline and death of most trees on sour orange rootstock, which originally constituted 25–30 percent of the acreage in Florida, but most of that acreage was replanted gradually as trees were lost. The greatest immediate threat to both the processing and fresh fruit industries in Florida is the recently arrived disease known as citrus greening or huanglongbing (HLB). Developing measures for combating HLB is the principal topic of this report. The insect vector of the HLB-associated bacterium in the Americas is the Asian citrus psyllid (ACP), which was reported in Brazil in 1942, but was not reported in North America until it was found in 1998 in Florida. Although it cannot be known whether small, unetected populations of ACP predated discovery, it is clear that ACP was widely distributed by 2000, having been reported in 31 counties in the state, so that eradication was no longer conceivable. The ACP reportedly arrived in Texas in 2001 on potted Murraya plants that originated from Florida (Mead, 2009). HLB itself was discovered in Brazil in 2004 and in the Miami area of Florida in August of 2005. The origin of HLB in Florida is unknown but may have been from budwood imported from Asia. The exclusion of pests such as ACP and the HLB bacterium clearly would have been the most effective control measure. Improving current measures for excluding pests and pathogens would likely benefit Florida citrus, but pest exclusion is a topic beyond the scope of this report. HLB is now present in all 34 Florida counties that have commercial citrus fruit production (FDACS-DPI, 2009), but is most prevalent in the southern areas of the state (Figure 2-5). The spread of HLB in
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease Florida is considered to have occurred too rapidly to be accounted for by ACP flights, and it is likely that long-distance spread of ACP occurred due to commerce or hobbyist activities involving backyard and ornamental citrus. HLB is widespread in Brazil and many other citrus-producing regions. HLB represents a serious threat to the citrus industry worldwide. FIGURE 2-5 Distribution of HLB in Florida from October 2005 to October 2009. Source: FDACS-DPI, 2009. ECOLOGY, CLIMATE, WATER AND FLORIDA CITRUS Landscape Factors that Contribute to Pest Outbreaks in Florida It has been estimated that approximately 4,500 arthropod species have been introduced into the United States and of this total, approximately 1,000 insect and mites have become crop pests (Pimentel et al., 2000). Because of Florida’s geographic position in the United States, it is subject to intense pressure from invasive species. Florida’s 1,350 miles of coastline, second only to Alaska’s, provides easy access for pests that arrive by aerial movement or with humans from
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease tropical areas in the Caribbean, Central and South America where arthropods may reproduce continuously without a winter break. Florida’s population of 18.3 million people places it 4th among US states and with about 6 percent of the US total. This population receives shipments of agricultural produce from around the world through the state’s large airports and seaports. Despite surveillance by the US Department of Agriculture- Animal and Plant Health Inspection Service (USDA-APHIS), these ports remain major entry points for new pests that threaten Florida’s agriculture. Once in Florida, pests can be transported intra- and inter-state by movement of propagative materials, foliage or soil and become established. The 600,000 acres of commercial citrus in Florida currently is confined to the southern two-thirds of the peninsula exclusive of the urban Miami area and the Everglades (Figure 2-6). The highest point in Florida is only 345 ft in elevation. The flatness of Florida’s landscape facilitates planting, harvest, and transport of agricultural produce but also results in a lack of natural barriers to the movement of ACP and HLB, e.g., in storms. In the Central Ridge area, citrus is planted on deep sandy soils. Citrus in southwestern and coastal areas is planted on “flatwoods” which also have sandy soils, but are often very shallow with rooting depths of no more than 1 meter and contain some organic matter. In such areas, citrus is planted on raised, two-row beds with ditching to avoid flooding in the summer rainy season. Displacement of citrus from urbanized coastal areas has resulted in a larger proportion of the crop being at risk from frost damage. Urban encroachment on production areas means that even if commercial citrus producers use effective management practices to control ACP in their groves, nearby residential plantings may serve as a reservoir for ACP and HLB. Abandoned orchards and those that receive minimal care serve as major sources of pests and diseases that may infest commercial orchards or nursery stock. The slowing of home building recently has resulted in groves purchased for housing being left undeveloped and becoming potential sources of ACP and HLB. Climatic Conditions that Contribute to Pest Outbreaks in Florida Generally speaking, Florida’s sub-tropical climate and year round vegetation in and around citrus groves allows a larger number of generations of insects to be produced and leads to more frequent application of management practices, such as insecticides, than would be found in temperate areas. This situation has potential negative consequences for farm workers and the general environment. Accordingly, Florida also has cases of insect resistance to insecticides (Omoto et al., 1995). Although resistance may originate in one particular location due to the local management practices, such resistant insects may be able to move long distances. In Florida, such long-distance movement occurs regularly because of hurricanes and summer thunderstorms. From 1851 to 2008, there were 96 category-3 to 5 hurricanes that made landfall on the eastern US coast (Texas to Maine). Thirty nine percent of these landfall events occurred in Florida (AOML, 2009). Water Use, Groundwater Protection, and Citrus Production Water, once a cheap and plentiful resource in Florida, is becoming a precious and valuable commodity for all sectors of Florida’s economy, including agriculture and tourism. Florida relies on groundwater pumped from permeable aquifers underground to supply drinking water to more
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease FIGURE 2-6 Citrus production areas in Florida. Source: FGDL, 2007. than 90 percent of its population (FDEP, 2009). Water consumption continues to rise and the water levels in the aquifers continue to drop, sometimes leading to geological disturbances such as sinkholes and saltwater intrusion into city wells (Hutson et al., 2004; Barnett, 2007). Much of this increased consumption is due to urban activities such as the irrigation of lawns and golf courses associated with the fast-growing housing developments throughout the state. However, farms are also large water consumers, using nearly half of Florida's public supply (Barnett, 2007). Citrus is a tropical/subtropical crop; therefore it requires substantial irrigation when grown in drier climes. Unlike other evergreen fruit trees such as avocado and mango, citrus trees continuously replace their leaves as they grow. Further, citrus trees have a relatively shallow root system as compared to deciduous fruit trees such as apple and walnut. In Florida, depending on soil type, root depths range from 18 inches in the coastal flatwoods to 11 feet in central Florida (Boman and Parsons, 1999). Studies in Australia have shown that mature citrus may require 7–8 mega liters (ML) of water per hectare while young citrus plantings may require 2–5 ML per
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease hectare annually (Falivene et al., 2003). Reducing irrigation by 20 percent or more resulted in significant citrus crop losses. Citrus water requirements may be less in Florida than in Australia due to Florida’s lower temperatures and higher humidity, but the requirements nevertheless are substantial. Despite relatively high rainfall, virtually all Florida commercial citrus has microsprinkler irrigation systems installed to meet the crop water needs in the state’s soils, which are up to 95 percent sand (Reddy et al., 1992). Microsprinklers consume less water that the older overhead irrigation systems they replaced. Drip irrigation is not effective in Florida’s very sandy soils, except for young trees (Parsons and Morgan, 2004). Rainfall in Florida is confined largely to the summer season and irrigation is most needed in the dry spring. In the summer months, citrus grown in “flatwoods” groves has the opposite problem and requires good drainage to avoid flooding. The Florida Department of Environmental Protection (FDEP) has the primary role of regulating public water systems and its responsibility for ground water is divided into two individual programs—ground water protection and ground water regulatory (FDEP, 2009). Citrus production is impacted by both programs. The FDEP requires permits to pump ground water and controls the volumes that can be pumped at any time. The water is controlled by five management districts that may impose restrictions as needed on residential, industrial, or agricultural use. For groundwater protection, the FDEP has the responsibility for monitoring fertilizer and pesticide levels in the water to make sure that they do not exceed the Environmental Protection Agency (EPA) standards. Use of agricultural products, especially pesticides, in sandy soils is particularly contentious, and is likely to become even more so now that ACP and HLB are threats to the citrus industry. Some of the management practices in place are of concern for water quality. As is stated in the University of Florida 2010 Florida Citrus Pest Management Guide, “the only soil-applied insecticide that has been shown to provide any reduction in psyllid numbers on large trees is aldicarb” (Rogers and Dewdney, 2010). Studies conducted in the 1980s in the central sands area of Wisconsin demonstrated that aldicarb can be found in wells (Rothschild et al., 1982) and follow-up studies suggested a health risk from consumption of aldicarb-contaminated groundwater (Rothschild et al., 1982). Under Florida conditions, aldicarb degrades relatively rapidly, but nevertheless has been found in some shallow water wells (Jones and Back, 1984; Forrest and Chris, 1986). Thus, aldicarb is limited to applications only in the dry season (November–April) and cannot be applied within 1000 ft of a drinking water well. Although aldicarb use under the indicated conditions is regarded as safe, it is desirable to rely on other methods and other insecticides for long-term control of ACP and HLB, to minimize risks to human health and the general environment. Other Environmental and Landscape Management Issues Commercial citrus production is close to being a monoculture crop. However, herbicides are applied only under the trees, leaving grasses and other plants in row middles and ditches with considerable vegetation surrounding most blocks in flatwoods groves. Crop monocultures facilitate mechanization of production and harvesting activities and allow specialization in marketing. However, monocultures generally provide less biological diversity and thus tend to be less ecologically stable than polycultures. Generalist natural enemies, primarily predators, are usually less abundant in monocultures since they have fewer alternative hosts to sustain them before the pests on which they can feed build up to damaging levels on the cash crop (Landis et
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease al., 2000; Bianchi et al., 2006). Thoughtful habitat management and introduction of plant diversity into a cropping system can help reduce pest populations and their damage on the cash crop by providing natural pest enemies with resources such as nectar, pollen, physical refugia and alternative hosts. There are many examples of “ecological engineering” tactics in annual crops and a few in perennial crops as well (Gurr et al., 2004). Three examples are summarized below, and described in more detail in Chapter 3.. Growers and researchers in Vietnam have noted that interplanting citrus with guava almost entirely negated infestations by citrus psyllids and, as a consequence, the citrus trees remained free of HLB (Stover et al., 2008; L. Stelinski citing unpublished report from Vietnam). Florida scientists are exploring the use of guava and the underlying biochemistry of guava’s putative capacity to limit or prevent infestations of citrus psyllids. In New Zealand, buckwheat ground cover has been used to enhance the parasitism of a leafroller insect, a major pest of grapes. Apart from enhanced biological control, mixed plantings of crops may disrupt an insect's ability to locate or establish on a plant species (Price, 1984). Trap cropping is the use of plant stands that are, per se or via manipulation, deployed to attract, distract, intercept, retain, and/or reduce targeted insects or the pathogens they transmit in order to reduce damage to the main crop (Shelton and Badenes-Perez, 2006). The trap crop may be treated to suppress the “trapped” insect population. DISEASES AND PESTS THAT THREATEN CITRUS PRODUCTION HLB (Citrus Greening): Impact, History, and Disease Spread Impact of HLB HLB is a destructive disease, and probably is the most serious disease of sweet orange, mandarin and grapefruit trees. It is destructive irrespective of rootstocks or whether the trees are grafted or are seedling trees. The yield of affected trees is not only reduced considerably by continuous fruit drop, dieback, and tree stunting, but also by the poor quality of fruits that remain on the trees. HLB epidemics take several years to reach high incidence levels. The temporal progress of HLB incidence is dependent on (i) vector populations, (ii) extent of the inoculum reservoir, and (iii) age of the grove at first infection. The disease progress in the orchard can be relatively fast, reaching more than 95 percent incidence in 3 to 13 years after onset of the first symptoms (Catling and Atkinson, 1974; Aubert et al., 1984; Gottwald et al., 1991; Gatineau et al., 2006; Gottwald et al., 2007a; Gottwald et al., 2009). Severe symptoms have been observed 1 to 5 years after onset of the first symptoms, depending on the age of the tree at infection time and on the multiplicity of infection (Lin, 1963; Schwarz et al., 1973; Aubert, 1992). As the disease severity increases, the yield is reduced and makes the orchard production uneconomical in 7 to 10 years after planting (Aubert et al., 1984; Aubert, 1990; Gottwald et al., 1991; Roistacher, 1996). It is estimated that close to 100 million trees are affected by HLB worldwide. In the northern and eastern regions of Thailand, 95 percent of trees were affected as of 1981. In the Philippines, HLB reduced the citrus acreage by 60 percent between 1961 and 1970. In Java and Sumatra, 3 million trees were destroyed from 1960 to 1970, and Bali lost 3.6 million trees from 1984 to 1987. In the southwestern oases of Saudi Arabia, HLB had killed most sweet orange and
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease dormant and produce no flush. These sprays target adult, overwintering psyllids. Similar to the situation with young trees, by eliminating these adults, psyllid populations will be greatly reduced on the following spring flushes. Application Methods Traditionally, foliar applications to Florida citrus have been made with airblast sprayers using spray volumes of 100 to 250 gal/acre. Some sprays are made with the Curtec sprayer utilizing 30 gal/acre, but they are not effective for some pests and diseases and not all products are registered for low-volume applications. Reducing spray volume and increasing the velocity at which applications are made greatly reduce the cost of insecticide applications. Recent research indicates that low volume and aerial applications of insecticides are effective for psyllid control. Most of the above products are registered for low-volume and aerial application butonly malathion is registered for aerial application at ultralow volume. It is important to control psyllids on an area-wide basis so that psyllid populations cannot build up between applications and move between groves so readily. SIGNIFICANT CITRUS DISEASES AND INSECT PESTS OTHER THAN HUANGLONGBING In addition to HLB, many other diseases can produce serious problems with citrus production. Systemic (graft-transmissible) diseases are often more serious in the sense that they may kill or completely debilitate trees and reduce production, but many foliar fungal and bacterial diseases may also reduce yield as well as blemish fruit. Many diseases are already widespread and most citrus areas have to deal with them. All of the important diseases are described in some general references such as the Compendium of Citrus Diseases (Timmer et al., 2000) and various other books and book chapters (Roistacher, 1991; Timmer and Duncan, 1999; Timmer et al., 2003; Timmer et al., 2004) and on the website of the International Organization of Citrus Virologists (http://www.ivia.es/iocv/). Many insect and mite pests are also described in publications such as the Florida Citrus Pest Management Guide (http://www.crec.ifas.ufl.edu/extension/pest/index.htm) and other local publications in different citrus areas. Many diseases and insect pests are not uniformly distributed, and those that pose threats if introduced into new areas are given in Appendices D and E respectively. Several vector species are listed which are minor pests alone but become important once the pathogen they transmit is introduced. ECONOMICS OF CITRUS PRODUCTION IN THE PRESENCE OF HLB Effect of HLB on Yields and Costs of Production HLB is a devastating disease and even if it can be managed, costs of production will increase dramatically. The disease is controlled by a combination of methods: 1) the use of disease-free nursery stock; 2) survey, detection, and removal of symptomatic trees; and 3) control of the psyllid vector. The costs to citrus production include:
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease decline in yield and fruit quality of affected trees. survey for detection of infected trees. removal of the HLB-affected trees. soil-applied and foliar insecticides for psyllid control. increased cost of production of disease-free nursery trees. cost of replacement tree, care of replant, loss of production until replant becomes actively bearing (3 years). Yield Loss The effects of yield losses and the rapidity with which they occur are uncertain since there is little experience to date in Brazil or Florida. However, any young trees that become infected will never produce a commercial crop of fruit. The rate of decline of older trees depends largely on the number of infections that occur. If a tree has only a single infection, it is likely that the tree will remain productive for several years. However, if multiple infections occur in a single year to cause a systemically wider disease within a tree, its remaining productive life may be as short as two years. Even under the best of circumstances, grove life is likely to be shorter than it has been in the past. It is very difficult to quantify the cost of declines in yield and loss of entire groves that are likely to occur in Florida over the next few years. Direct Control Costs Nursery Trees The January 2008 requirement for production of citrus nursery stock in screened enclosures has doubled the cost of nursery trees from $4–5 to $8–10 per tree. Prices have begun to decline recently as supply is beginning to catch up with demand, but nursery tree prices remain high and a significant cost of replanting citrus groves. Those costs may be especially significant if growers choose higher density plantings anticipating losses of trees to HLB. Inspections and Tree Removal At the present time, four inspections per year are recommended (Brlansky et al., 2009). Each inspection is estimated to cost about $25–30/acre or $100–120 per acre per year (Morris et al., 2008). Tree removal costs vary considerably depending on the number of trees to be removed and the method used. Muraro (2008b) estimated the cost of tree removal at $34/acre/year, assuming that six trees per acre would need to be removed each year. The average grove in Florida has about 145 trees per acre and thus, six trees would represent about a 4 percent loss per year. That cost could be considerably higher in many situations. Tree removal costs are expected to be high initially for removal of already-infected trees and then decline and stabilize if the disease is brought under control. Morris et al. (2008) analyzed two approaches to dealing with HLB: 1) remove affected trees and replant with young trees immediately and 2) leave affected trees and remove the entire block
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease when production was no longer economically viable. They concluded that there was little difference economically between the two scenarios. The most desirable approach depends on the situation. Since young trees are very attractive to psyllids and readily infected by HLB, replanting of individual trees is probably only reasonable if HLB incidence in the area and the likelihood of infection are very low. Young trees can be effectively protected by soil applications of imidacloprid, but application costs are very high (about $0.50/tree/year) and higher where there are only a few trees per acre to be treated. In one large planting in southwest Florida, nursery trees are grown to 3 years old in pots in a protected area and treated with imidacloprid at maximum rates and frequencies prior to planting in the field to avoid numerous trips through the grove to apply the insecticide. From an operational point of view, it would probably be simpler to wait until the grove was no longer economically productive and then remove the entire block. However, that leaves large numbers of HLB-infected trees in the planting that serve as sources of inoculum for healthy trees. Thus, it is probably advisable and advantageous to remove infected trees promptly and then remove the entire block when too few trees remain to be economically viable. Insecticide Applications Morris et al. (2008) estimated that for the average grove of mature trees, a soil application of aldicarb and three applications of foliar insecticides would be needed for psyllid control in the presence of HLB in addition to normal sprays for control of other pests and diseases. Such a program would be similar to the possible control approaches that are recommended by the University of Florida (Rogers et al., 2010). The cost for those products and their application was estimated to be $288 per acre per year (Morris et al., 2008). Costs can vary considerably depending on the situation. They could be reduced by using a dormant foliar insecticide application rather than aldicarb in the winter, but could be substantially higher if more applications are needed to control psyllid populations. Effect on Returns and Profits The costs and returns on Florida citrus vary greatly depending on the variety of citrus grown, its destination (fresh or processing), and the yields attained. Citrus fruit is often sold on the tree and the purchaser is responsible for harvesting and transport of the fruit. Growers are paid for processing fruit on a pounds-solids basis (the sugar content of the fruit) as assessed upon delivery. Yields are usually expressed as the number of 90-lb boxes per acre and the average sugar content in Florida is about 6.5 lb per 90-lb box but varies considerably depending on the variety, rootstock, soil conditions, and management practices. Processing fruit is harvested by hand or occasionally mechanically and transported in bulk in open trucks to the processing plant. Muraro (2008b) estimates the cost of production for Valencia oranges in Central Florida at $1657 per acre including management and interest on investment for a grove assuming no costs for HLB or canker control. Harvesting, delivery and assessment costs are estimated to be $1226 per acre for a total delivered-in cost of $2883 per acre for an average grove. The break-even price for a grove with no HLB or canker would range from $1.19 to $0.80 per pound solids if yields ranged from 300 to 600 90-lb boxes of fruit per acre assuming no resetting of the trees removed. In the presence of HLB and canker, the break-even price would be $1.38 to $0.89 in groves with yields ranging from 300- to 600-box yields.
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease Fresh fruit is harvested in 10-box tubs (~ 900 lb total) and growers are paid on a per box basis. With the same assumptions as above, the total delivered-in cost for production of white grapefruit in the Indian River area would be $3,195 per acre without canker or HLB and $3,600 in the presence of both (Muraro, 2008a). Break-even prices would range from $8.37 to $5.82 per box for yields ranging from 350 to 650 boxes per acre in the absence of HLB and canker and $10.03 to $6.71 in the presence of both diseases. Morris et al. (2008) conclude that production of citrus for processing can be profitable in the presence of HLB, but production costs would increase by about 41 percent. That assumes that tree loss rates and costs for inspections and psyllid sprays are in the ranges indicated above and the value of orange juice is $1.25 to $1.50 per pound solid. In the past season (2008–2009), juice prices ranged from $0.75 to $0.85 for early and midseason varieties and $0.80 to $1.25 per pound solid for Valencia oranges (http://www.flcitrusmutual.com/market_info/citrusprices.aspx). Early and mid-season oranges generally have a lower price than Valencias, but some of the differential is due to increasing prices late in the season. Average delivered-in prices for Valencias have ranged from a low of $0.77 per pound solid in 2003–2004 to a high of $2.23 in 2006–2007 (Morris et al., 2009). Processing grapefruit prices are very depressed due to large inventories and ranged from only $0.25 to 0.80 per pound solid, but good quality fresh grapefruit still demands a high price and is a profitable crop. Morris et al. (2008) suggested that higher planting densities could be used to partially offset the increase in production costs per acre. Orange Juice Production, Consumption, and the Competitiveness of the Florida Industry Most of the orange juice consumed in the world is produced by Brazil (50 percent) and Florida (35 percent). Total world consumption of orange juice is about 3.3 billion gallons of single-strength equivalents (SSE) and the United States and the European Union consume about 1.3 billon SSEs each (Spreen et al., 2008). Florida supplies most of the orange juice consumed in the United States (77 percent) (USDA-NASS, 2009) and Brazil supplies most of the juice consumed in Europe and elsewhere in the world or about 1.25 billion gallons (USDA-FAS, 2008). The per capita consumption in the United States declined from 5.8 to 3.9 gallons per year from 1997–1998 to 2007–2008 and continues to decline and inventories are still high (Morris et al., 2009). That may be attributable to popular low-carbohydrate diets, the availability of other juices and beverages, and increased cost or other factors. China produces some juice currently and has the potential to become a major player in the juice market as their production has increased significantly in recent years. There are several factors that affect the ability of Florida citrus growers to compete for the market for citrus juice. There is currently a tariff on juice imported from Brazil of $0.29 per pound solids which is equivalent to about $0.17 per gallon of single strength juice. Elimination of the tariff for Brazil is estimated to reduce the price of juice in the United States by $0.22 per gallon (Brown et al., 2004). Elimination of all tariffs in the United States, Europe, and Japan is estimated to reduce the price of juice in the United States by $0.13 per gallon. Juice imported from Mexico and Central America is not subject to tariffs. Thus, if tariffs are eliminated, production in Florida would have to become more efficient to compete. Production costs do not differ greatly between São Paulo and Florida. Generally, labor costs are lower in São Paulo, but costs for machinery, pesticides, and fertilizers are higher in Brazil than in the United States. However, the cost of harvesting, which involves a great deal of labor, is significantly lower in Brazil than in Florida and thus, the total cost for production of juice is
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease greater in the United States. HLB will increase costs of production in São Paulo as well as in Florida. However, survey costs for HLB detection are estimated to be only $4 per acre in São Paulo compared to about $25–30 per acre in Florida. Other costs of control would be similar in the two locations. Other potential producers of orange juice either already have HLB or face the prospect of having it in the near future. Thus, it is unlikely that any area would have a competitive advantage over São Paulo or Florida long term because of the absence of the disease. Thus, São Paulo would be the main competitor for Florida in the foreseeable future. At current prices, processing orange production is not highly profitable for most growers. However, large vertically integrated companies that grow, harvest, process, and sell their own products are in a much better position to deal with price fluctuations. Profitability of citrus in Brazil is also affected by the value of the dollar since most of their returns are received in US $ and most of their expenses are paid in Brazilian reis. Thus, a high value for the dollar is beneficial to Brazilian producers. It is likely that the large Brazilian production companies, Citrovita, Citrosuco, and Cutrale, will control a significant portion of the production in both São Paulo and Florida in the future. In both locations, large companies with extensive land holdings will have an advantage over small growers who cannot control the actions of their neighbors. Small growers probably can only survive by forming cooperative arrangements with their neighbors for HLB control. There is adequate land available for citrus production in Florida despite considerable urban growth and development. Much of the land devoted to citrus is not suitable for other crops. Large acreages are available in São Paulo and citrus competes primarily with sugarcane (Spreen et al., 2008). Due to considerable utilization of sugarcane for ethanol production, prices of sugar have increased in recent years. Many of the groves severely affected by HLB have been converted to sugar production. Competitiveness in Florida may depend on reducing harvesting costs. Mechanical harvesting is already used to some extent and, if an abscission chemical can be registered, a large portion of the processing oranges could be harvested in that fashion. Thus, if HLB control can be achieved, production of processing oranges should continue in the foreseeable future, although the acreage is likely to be lower than in the past. FEDERAL, STATE, AND LOCAL REGULATORY AGENCIES AND INDUSTRY ORGANIZATIONS AND THEIR IMPACT ON THE CITRUS INDUSTRY There remains an urgent need to maintain speed and focus of research aimed at finding an effective solution for HLB. New technologies intended to combat HLB may include new early detection technology, new chemicals, transgenic plants and psyllid control by means of biological tools. A strong public-private partnership and commitment will be required to move any new technologies forward through regulatory agencies, to public acceptance and, ultimately, to commercial implementation. As is indicated below, many organizations are concerned with research related to citrus production and processing. This diversity of agencies presents both an advantage, by allowing many points of view to be developed, and a challenge, because of the need to channel efforts to combat HLB. In order to develop a picture of the Florida citrus industry’s many moving parts, we provide Table 2-4 which arranges the various agencies with influence over citrus production, processing and marketing or advocacy according to their status (university, government, non-government) and the type of benefit provided. Any attempt to pigeon-hole the many private and public agencies whose actions impinge on citrus production, processing and marketing will inevitably
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease be inexact and subject to challenge. Nevertheless, we find the Table 2-4 distribution of agencies to be useful, even though some are of hybrid type and some have functions that are overlapping. Appendix G presents short mission statements for each of the agencies. The concern and sense of urgency over the HLB situation in the Florida citrus industry prompted the awarding of unprecedented amounts of funding for research aimed at developing short-, intermediate- and long-term approaches to mitigating the disease. Some in the industry and the research community are advocating a “Manhattan Project” type of dedicated and integrated research program on HLB mitigation. There is no road map for such an unprecedented undertaking in agricultural research, but whether a more or less focused course is taken for research and development on citrus, there will be possible organizational overlap and redundant responsibilities and funding mechanisms. Some industry leaders have expressed apprehension about the apparent fragmentation of research effort in the past and hope for a more integrated approach in the future. There is general recognition that investments into an insightful, focused, sustained and stable research funding program provide the best hope for survival of the citrus industry. Moreover, coordination of efforts in controlling HLB likely will lay the groundwork for dealing with future challenges to the profitability of the citrus industry. RELATIONSHIPS OF FEDERAL, STATE, AND INDUSTRY ENTITIES IN FLORIDA AND HOW THEY ADDRESS CITRUS DISEASES Intra-Industry Relations The citrus industry of Florida is not a unified force with similar interests. Rather it is a composite of many interests. The two large processing corporations, Tropicana and Minute Maid, do not grow citrus, but instead buy the fruit on the open market or via contracts with growers in addition to purchasing juice from Brazil and other countries. They have generally been opposed to a box tax for marketing purposes and prefer to advertise their own products rather than pay for generic advertising for Florida orange juice and other products. Most growers prefer generic advertising to compete with Brazilian and other producers of juice and fresh fruit. The growers of processing and fresh fruit also have different interests. While production of processed oranges represents the majority of the acreage in Florida, both are economically important because fresh fruit provides far greater income per acre. The main fresh fruit product in Florida is grapefruit, but some tangerines and navel oranges are also produced. The Indian River Citrus League was formed primarily to support the interests of growers of “Indian River Grapefruit”. Most of the industry-wide committees have members representing the processing and the fresh industries and include representatives from various areas of the state. Government Organizations The responsibility of the USDA-ARS is research, that of the University of Florida (UF) is research, extension, and education, and that of DPI is regulatory, with each of those entities restricting their efforts to those ascribed areas for the most part. The relationship between the principal government organizations dealing with HLB have generally been cordial although occasional conflicts have arisen where the boundaries of these areas blur. There has been some competition and infighting among them, as well as among research and extension stations within
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease UF. This competition has sometimes been detrimental to the development of a consistent policy and message to growers on dealing with HLB. However, most of the competition has been among agency and department heads for funds and influence, and probably has not greatly affected cooperation among individual investigators. Cooperation among investigators from the different agencies has often been very good. Since most of the agencies are not organized along disciplinary lines, there are few boundaries to research among the various areas of investigation. Entomologists, pathologists, and horticulturists cooperate readily and as needed to achieve specific goals. Table 2-4 Government, University and Non-Government Agencies with Responsibilities Related to Citrus Production and Marketinga, b, c University Federal, state or local government Non-government Citrus research UF-IFAS ARS (USDA) FCPRAC FDOC CRDF FCIRCC Citrus protection UF-IFAS-Extension APHIS (USDA) DPI (FDACS) US Sugar Commercial pesticide suppliers Citrus production and processing CAC (US) CHRP (APHIS/DPI) County governments DEP (FDACS) FCP FCPA FCPMA FFSP FGFSA FNGLA NVDMC Regional grower associations Water management districts Citrus promotion and marketing FDOC FCM aSeveral agencies are multifunctional. Placement in the table indicates the agency’s main function or functions bAcronym List: APHIS: Animal and Plant Health Inspection Service (USDA) ARS: Agricultural Research Service (USDA) CAC: Citrus Administrative Committee CHRP: Citrus Health Response Program CRDF: Citrus Research and Development Foundation DPI: Division of Plant Industry (FDACS) FCIRCC: Florida Citrus Industry Research Coordinating Council FCM: Florida Citrus Mutual
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease FCP: Florida Citrus Packers FCPA: Florida Citrus Processors Association FCPMA: Florida Citrus Production Managers Association FCPRAC: Florida Citrus Production Research Advisory council FDA: US Food and Drug Administration FDACS: Florida Department of Agriculture and Consumer Services FDOC: Florida Department of Citrus/Florida Citrus Commission FFSP: Florida Foundation Seed Producers, Inc. FGFSA: Florida Gift Fruit Shippers Association FNGLA: Florida Nursery, Growers and Landscape Association NVDMC: New Varieties Development and Management Corporation UF-IFAS: University of Florida-Institute of Food and Agricultural Sciences USDA: US Department of Agriculture cSeveral agencies of the US federal government have authority to regulate aspects of citrus production and processing but are not specific to the citrus industry. These are the following: DOL: US.Department of Labor EPA: US Environmental Protection Agency FDEP: Florida Department of Environmental Protection ICE: US Immigration and Customs Enforcement OSHA: US Occupational Safety and Health Administration Government-Industry Relationships Relations between the USDA-ARS and industry have been cordial. USDA research efforts have contributed significantly to the understanding of HLB, and USDA-organized research conferences, to which growers have been invited, have been valuable. The University of Florida (UF) has the primary responsibility for extension and providing information to growers in addition to its leadership role in research and education. A serious effort has been made by UF to inform growers about HLB and the best management practices. HLB has been the primary topic for every grower meeting for the last few years. Speakers from the USDA and DPI are often on the program and cooperation has generally been good among the agencies in providing current information to growers. Local meetings have been organized primarily by DPI, UF and Florida Citrus Mutual to bring the latest information on canker and HLB to growers in each area of the state. Attendance at such meetings has been excellent, and growers have had numerous opportunities to become current on the HLB and canker situation and the recommended practices. However, individual extension agents hold differing views on the best management practices for HLB and have not always followed the consensus approach of prompt tree removal and intense psyllid control. This situation has left some growers confused about what recommendations to follow. Within UF, the Citrus Research and Education Center is the primary agency for research and education for citrus in the state, but the UF Southwest Florida Research and. Education Center and UF Indian River Research and Education Center, as well as faculty in various departments on the main campus, contribute significantly to the effort. To some extent, the experiment stations in southwest Florida and the Indian River reflect the interests of the industries in their areas, and industry jealousies and competition carry over into research and extension.
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease The FDACS-DPI and USDA-APHIS have the primary responsibility for regulatory matters. Those agencies were responsible for all of the citrus canker eradication programs (see Appendix H). In the 1980s, an eradication program was conducted for a disease, thought to be canker, which turned out to be citrus bacterial spot, another bacterial disease of relatively minor importance. However, citrus canker was discovered as well and infected trees were eradicated. Many nurseries were destroyed, many probably unnecessarily, during that time and many nurserymen still resent actions taken by DPI during that period. The canker eradication program conducted during the late 1990s and early 2000s was generally supported by growers and most nurserymen. Growers and nurserymen were mostly well-compensated for the losses during that program. However, at the end of the program, growers were losing confidence, felt that eradication was continued long after it was apparent that it could not succeed, and compensation for losses was greatly delayed. Thus, there is some resentment among growers toward DPI and USDA-APHIS due to those programs. Many lawsuits are still pending between DPI and a few nurserymen and a homeowners group, who do not believe that they were adequately compensated. The potential impact of the discovery of the ACPin Florida in 1998 was ignored because of the focus on the Citrus Canker Eradication Program. The disease was not known in Florida at this time, and the ACP was not causing much economic loss. When HLB was detected in 2005, DPI chose not to conduct an eradication program or even an inoculum suppression program for the disease. This decision was reached primarily because HLB was already widespread at first detection but also because of reticence by DPI about getting involved in another widespread and problematic suppression program even though HLB was listed as a select agent (SA) under Agricultural Bioterrorism Protection Act of 2002 (CFR Part 331). The SA designation limited research on HLB to a few registered quarantine/diagnostic laboratories in the US and was a serious impediment to research progress. HLB was subsequently removed from the SA list in late 2008. The FCPRAC has served to focus research efforts and has been forced to decide on the priorities for investigation that met the needs of all segments of the industry. The Council has greatly improved contacts between industry and the research community and has furthered mutual understanding. Since FCPRAC has provided much of the funding for citrus research at UF and the USDA in Fort. Pierce, they have greatly influenced research priorities and directions. Initially, they funded mostly research to fulfil immediate needs, but with time have seen the need for supporting more basic, long-term work. Currently, most of the funds have been directed toward HLB with small amounts dedicated to canker research. The need to develop regulations that met the needs of the entire industry and did not excessively burden any segment has brought together many diverse interests. The Citrus Health Response Program was initiated by the USDA-APHIS and DPI with considerable input from the USDA-ARS and UF and industry groups in an attempt to provide some regulations that would benefit the entire industry. Many aspects of those regulations were onerous especially for the nursery industry and there were many hard-fought battles waged in developing a satisfactory system. However, the current system of production of all citrus trees in screened enclosures has benefited everyone in the industry. The incursion of HLB has brought the industry and government agencies together as never before, and cooperation among all agencies has generally been good, if not always effective. Since the detection of ACP in Florida in 1998 and HLB in 2005, the various agencies and entities have been involved in activities geared towards finding ways to manage the vector and the
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Strategic Planning for the Florida Citrus Industry: Addressing Citrus Greening Disease disease (see Appendix H). Recently developed organizations such as Florida Citrus Industry Research Coordinating Council and the Citrus Research and Development Foundation represent significant attempts by the industry to coordinate all efforts focused on HLB. The array of organizations (federal, state, university, local, or grower or producer) which impinges on citrus production and processing is large and diverse. Table 4-1 in Chapter 4 presents, in brief, five recommendations for changes in organizations and organizational activities that we believe will advance HLB mitigation. Table 4-1 is followed by notes on the five recommendations.
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