5B-62.001. Definitions and Purpose

(1) For the purpose of this rule chapter, the definitions in Section 581.011, F.S., and the following definitions shall apply:

(a) African Citrus Psyllid. The insect known as African citrus psyllid, Trioza erytreae, classified in the order Hemiptera: family Psyllidae and all of its life stages. It is a vector of citrus greening.

(b) Approved Citrus Nursery Site. A defined area that meets the certification requirements as prescribed by the Department.

(c) Approved Soil Pit. A soil source used for fill purposes, highway or road construction, or as an ingredient in plant growing or potting media that meets the Department’s requirements as to the absence of injurious nematodes of citrus.

(d) Asian Citrus Psyllid. The insect known as Asian citrus psyllid, Diaphorina citri, classified in the order Hemiptera: family Psyllidae and all of its life stages. It is a vector of citrus greening.

(e) Australian Citrus Dieback. A disease from Australia similar to citrus greening, but for which neither the causal organism nor the vector has been characterized and identified.

(f) Brown Citrus Aphid. Toxoptera citricida, classified in the order Hemiptera: family Aphididae and all of its life stages.

(g) Budwood. A portion of a stem or branch with a vegetative bud(s) used in propagation for budding or grafting.

(h) Certified Citrus Nursery. A nursery that has been certified by the Department as meeting the requirements for production of citrus nursery stock free of pests of citrus.

(i) Certified Tree. A scion tree meeting all the requirements of Chapter 5B-62, F.A.C., but not yet having borne fruit or nursery trees propagated from a certified scion tree.

(j) Citrus. All members and any hybrids of the family Rutaceae, including any plants, plant parts, fruits, seeds and any other parts thereof.

(k) Citrus Blight. A root graft-transmissible disease of unknown etiology associated with xylem dysfunction which results in wilting and slow decline of trees.

(l) Citrus Canker. A bacterial disease of citrus incited by the organism Xanthomonas campestris subsp. citri.

(m) Citrus Cachexia Viroid. A graft- and mechanically-transmissible viroid incited by the organism Hop Stunt viroid in the Pospoviroidae family and Hostuviroid genus. Disease symptoms include phloem deterioration and blockage in many mandarin, mandarin hybrids, Citrus macrophylla, Rangpur lime and sweet lime. This disease causes decline, stunting and crop reduction.

(n) Citrus Chlorotic Dwarf. A graft-transmissible disease vectored by the bayberry whitefly, Parabemisia myricae, classified in the order Hemiptera and family Aleyrodidae. It is a disease of the Eastern Mediterranean causing chlorotic patterns and distortion in young leaves, stunting of young trees and reduced yields in lemon, mandarin, grapefruit and to a lesser degree sweet orange.

(o) Citrus Exocortis Viroid. The organism that incites a graft- and mechanically-transmissible pathogen in the Pospoviroidae family and Pospoviroid genus. Disease symptoms include tree decline, stunting of growth, scaling and shelling of the rootstock bark of Poncirus trifoliata and many P. trifoliata hybrids and Rangpur lime.

(p) Citrus Greening. A phloem-limited bacterial disease of citrus and citrus relatives incited by the organism Candidatus Liberibacter spp., (also known as huanglongbing or yellow dragon disease) that is vectored by Diaphorina citri and Trioza erytreae. Disease symptoms include mottled foliage, asymmetrical bitter fruit, and infected trees which become non-productive and die.

(q) Citrus Leaf Blotch Virus. Also known as Dweet Mottle, it is a wide-spread, graft-transmissible and seed-transmissible disease with no known vector. It is incited by a virus in the genus Citrivirus in the Betaflexiviridae. It may cause a bud-union disorder in certain varieties on specific rootstocks.

(r) Citrus Leprosis Virus. A non-systemic virus disease incited by a virus in the Cilevirus genus, is not currently assigned to a family, and is vectored by mites in the Brevipalpus genus. It is a problem in Brazil through upper Central America. It causes a non-systemic infection in citrus with local necrotic lesions on fruit and leaves with leaf and fruit drop, twig die back and where the vector is not controlled, death of the tree.

(s) Citrus Nursery Stock Certification Program. A mandatory program administered by the Division of Plant Industry whereby registered nurserymen, or other researchers, under permit, are propagating citrus, including all dooryard, own-use and commercial plantings, are required to propagate citrus in accordance with these rules.

(t) Citrus Psorosis Virus. A graft-transmissible virus thought to also be transmitted by a soil fungus in the Olpidium genus. Mild psorosis A and Severe psorosis B are caused by viruses in the Ophiovirus genus in the Ophioviridae family. Symptoms include bark-scaling, internal wood staining, ringspots or irregular chlorotic patterns in the foliage and/or eventual tree decline.

(u) Citrus Stubborn. A graft-transmissible disease that is incited by Spiroplasma citri and vectored by several species of leaf hopper (order Hemiptera: family Cicadellidae). Symptoms include buds on newly budded trees not sprouting, acorn-shaped fruit on diseased trees, small shoots and leaves, the presence of witches’ brooms and flowering out of season. It is present in California and Arizona.

(v) Citrus Sudden Death. A disease of unknown etiology thought to have an insect vector. Symptoms include rapid decline of trees budded on Rangpur lime and to a lesser extent on Volkamer lemon in Brazil.

(w) Citrus Tatter Leaf Virus. A graft- and mechanically-transmitted disease incited by a virus also called citrange stunt or apple stem grooving virus in the Capillovirus genus which is assigned to the virus family Flexiviridae. Symptoms include a severe bud-union crease, which affects trees on trifoliate orange or trifoliate orange hybrid rootstocks causing death of the tree.

(x) Citrus Tristeza Virus. A graft-transmissible Closterovirus in the Closteroviridae which is transmitted by aphids (primarily brown citrus aphid, Toxoptera citricida). Severe strains, as opposed to mild strains, of the virus cause severe stem pitting, seedling yellows or quick decline on sour orange rootstock, any of which can result in reduced crops or death of the trees.

(y) Citrus Variegated Cholorosis. A graft-transmissible disease incited by a strain of Xylella fastidiosa, a fastidious xylem-inhabiting bacterium which is vectored by many species of sharp shooters (order Hemiptera: family Cicadellidae). It is also seed-transmitted. It is found in Brazil and up into Central America. Affected trees are stunted with dieback and have fruit that are small and ripen early.

(z) Citrus Vein-Enation Virus. A graft-transmissible disease also called woody gall is transmitted in a persistent manner by aphid vectors including Toxoptera citricida, Myzus persicae and Aphis gossypii (order Hemiptera: family Aphididae). It is thought to be incited by a virus of unknown etiology possibly closely related to the Luteoviridae. It is widespread throughout the cooler citrus growing regions of the world and is present in California. It is symptomless in the majority of citrus cultivars and is not considered of major economic importance. Wood galls are formed on the trunks and branches of Rough and Volkamer lemons. Severe infection on these rootstocks has been reported to eventually cause tree decline.

(aa) Citrus Viroids. Viroids in the family Pospiviroidae and the genus Apscaviroid (Citrus bent leaf viroid, Citrus viroid I, Citrus viroid V), Citrus viroid III, the genus Cocaviroid (Citrus viroid IV), the genus Pospiviroid (Citrus exocortis viroid) and the genus Hostuviroid (Citrus cachexia viroid).

(bb) Citrus Yellow Mosaic Virus. A graft- and mechanically transmissible disease that is also vectored by the citrus mealybug, Planococcus citri (order Hempitera: family Pseudococcidae). It is incited by a Badnavirus in the Caulimoviridae family. Symptoms include yellow mosaic on leaves, reduced leaf size, stunted trees and fruit with elevated green areas and depressed yellow patches. It is known to be in India.

(cc) Clone. An asexually reproduced cultivar; a group of genetically uniform plants that have been propagated vegetatively from a single original plant.

(dd) Commercial citrus grove. A solid set plantings of 40 or more citrus trees.

(ee) Commercial Citrus Nursery Stock. Citrus nursery stock to be used in or for establishing a planting of 40 or more citrus trees.

(ff) Concave Gum/Blind Pocket. Graft-transmissible or seed transmitted pathogens causing infected trees to have concavities in the trunk and main branches. The disease is found in most citrus-growing areas where it reduces yield and tree vigor.

(gg) Cooperating Agencies. The University of Florida and the United States Department of Agriculture shall be regarded as cooperating agencies.

(hh) Decline. An unknown disorder that causes citrus trees to become unhealthy and show receding vigor, and/or a significant amount of dieback.

(ii) Dooryard Citrus Nursery Stock. Citrus plants to be used only in a residential setting or for establishing a planting of less than 40 citrus trees.

(jj) Florida Gummosis. A disease of unknown etiology characterized by bark cracks and gumming of scions. This disease is called Rio Grande gummosis in Texas and ferment gum disease in California.

(kk) Foundation Tree. A citrus tree owned and maintained by the department in accordance with Rule 5B-62.014, F.A.C., that is used to provide a source of budwood to nurserymen, primarily for establishing scion and increase trees.

(ll) Graft-Transmissible Pathogens. Disease agents spread by vegetative propagation including but not limited to budding, grafting, air-layering and cuttings. This general term includes known viruses, viroids, bacteria, spiroplasmas and other non-identified virus-like pathogens of citrus.

(mm) Horticulturally True-To-Type. A plant which conforms to the description of a particular cultivar and which is from the same genetic line of descent as that cultivar.

(nn) Increase Trees. Specially designated nursery propagations made to rapidly multiply supplies of propagative material for citrus nursery tree production and meeting all the requirements of Rule 5B-62.016, F.A.C.

(oo) Indian Citrus Ringspot Virus. A disease of mandarin in India incited by a Mandarivirus in the Alphaflexiviridae family.

(pp) Melon Aphid. Aphis gossypii, classified in the order Hemiptera: family Aphididae and all of its life stages that is also known as the cotton aphid. It is a vector of citrus tristeza virus.

(qq) Micropropagated – The use of a plant part to initiate the tissue culture process.

(rr) Parent Tree. A citrus tree of unique germplasm that has met all of the requirements of Rule 5B-62.013, F.A.C., and has been registered with the Department.

(ss) Polymerase Chain Reaction (PCR). A highly sensitive laboratory test that can detect small amounts of DNA or RNA in a plant tissue sample by amplification of a specific DNA or RNA segment.

(tt) Progeny Nursery Tree. A citrus nursery tree produced from budwood from a registered source tree in accordance with instructions outlined in this rule chapter.

(uu) Propagative Material. Any live plant material used to produce nursery stock, including cuttings, budwood, seeds, seedlings, air layers and tissue culture.

(vv) Registration. The process of certifying source trees as being virus-tested and meeting the requirements of these rules, including annual renewal by notification and fee payment.

(ww) Rootstock. A plant used as the recipient understock in budding or grafting.

(xx) Satsuma Dwarf Virus. A graft- and mechanically-transmissible disease which apparently also has a non-nematode soil vector. It is incited by a Nepovirus species which is assigned to the viral family Comoviridae. Satsuma trees infected with Satsuma Dwarf Virus will display a range of leaf symptoms including narrow, boat or spoon-shaped leaves, the surfaces of which are often distorted or crinkled. A severely affected tree has poor fruit-set, its fruit are small and irregularly shaped and tree vigor is reduced.

(yy) Scion Tree. A citrus tree grown in accordance with Rule 5B-62.015, F.A.C., from budwood taken from a registered foundation tree and registered with the Department as a source of budwood.

(zz) Seed Source Tree. A tree that originates from a foundation or parent tree source and is used to supply seed for nursery propagation; must be registered and tested by the department for the seed-transmitted diseases as listed in Rule 5B-62.003, F.A.C.

(aaa) Severe Strains of Citrus Tristeza Virus. Strains of Citrus Tristeza Virus that have been identified by the Department as being harmful to citrus production in Florida.

(bbb) Source Tree. A citrus tree that has met all of the requirements as a source of budwood or propagative material, i.e., a scion tree, increase tree, foundation tree or seed source tree.

(ccc) Tests. Standardized laboratory, biological greenhouse or field plot tests for certain graft-transmissible pathogens before trees are eligible for registration as source trees as contained in the Citrus Budwood Testing Manual, Revised 03/14, as incorporated in Rule 5B-62.004, F.A.C., or approved by the Citrus Budwood Technical Advisory Committee.

(ddd) Witches’ Broom Disease of Lime. A disease of Citrus aurantiifolia, small-fruited acid lime. It is found in Asia and is incited by a Candidatus aurantifolia phytoplasma and thought to be vectored by Hishimonous phycitis (order Hemiptera: family Cicadellidae).

(2) The purpose of this rule chapter is to minimize the spread of serious graft-transmissible diseases and certain other pathogens as well as nematodes of citrus by requiring all nurserymen propagating citrus to participate in a mandatory citrus nursery stock certification program. The requirements for program participation are established in this chapter. It is intended that there shall be no propagation of citrus nursery stock except as provided in this chapter and it shall be unlawful to plant citrus nursery stock in Florida unless that citrus nursery stock has been propagated pursuant to this chapter.

Rulemaking Authority 570.07(23), 581.031(1), (3), (8) FS. Law Implemented 570.07(2), (13), 581.031(1), (14), (17), (23), 581.1843(3), (4) FS. History–New 12-26-06, Amended 2-25-15.