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Vol.5, No. 1 Important Changes Being Considered for Producers of Nursery Trees in Florida Phil Rucks, President Today a nurseryman's survival depends on their ability to modify production practices while preserving quality at a competitive price. Unfortunately, many will sacrifice the quality for the competitive price. Ultimately this will tarnish a nurseryman's reputation. Sometimes things have to get a little worse before they turn for the better. I can't foresee the price of trees becoming any worse, however, the threats of newly introduced pests and diseases are on the rise. If there ever was a time for nurserymen to unite their efforts in organizing a program to address these threats, I think right now is the time. Within our own state, the florida citrus nurserymen have available many essential resources in research and education that can assist in developing a program for preservation of tree quality. How can we preserve our image and good intentions in producing a safe quality tree? Tree Registration. The production of trees, propagated from registered pathogen-free sources has been proven to lower the incidence of diseases and pests in other industry's around the world. The Florida Citrus Nurserymen's Association (FCNA) is dedicated in continuing the improvements of horticultural and ethical practices within the citrus nursery industry. The association has taken the initiative to create standards for citrus nursery tree quality. A Quality Tree Standards Committee has been formed consisting of nurserymen, growers, and researchers to develop standards for a quality tree. I urge all nurserymen members and non-members of FCNA to meet these challenges of diseases in becoming an advocate of the Quality Tree Program. I invite and urge all nurserymen to attend the Annual FCNA meeting on April 19th at Lake Alfred CREC, Ben Hill Griffin Auditorium. This program will allow nurserymen to voice their concerns and needs directed to the Quality Tree Program. The Quality Tree program will be debated and supported by panel members of this committee. I urge you to attend due to the effects this program could have in modifying your operation. DPI Update Charles Youtsey Revision of Psorosis Quarantine Law Revision of the psorosis quarantine law (Rule 5B-7) affecting citrus nursery stock found infected with Psorosis Virus Complex (Blind pocket/concave gum). Revision of Rule 5B-7 providing for quarantine of psorosis, blind pocket, concave gum virus became effective March 10, 1994. The rule has been amended to include all the major citrus varieties commonly grown in Florida, including recent varieties released through the IFAS/USDA Breeding programs since the rule was last revised in 1961. An additional important amendment includes seeds used for rootstock purposes. A complete copy of the rule may be obtained from Division of Plant Industry, Post Office Box 147100, Gainesville, Florida 32614-7100. SUMMARY OF RULE This rule chapter defines psorosis virus complex; declares psorosis virus complex to be a plant pest; provides for inspection procedures; lists regulated citrus varieties including seeds used in the production of citrus nursery stock; and provides penalties for violations. DETAILED STATEMENT OF FACTS AND CIRCUMSTANCES JUSTIFYING AMENDMENTS TO PROPOSED RULE CHAPTER Psorosis virus complex is a closely related group of seed and graft-transmissible agents known to cause tree decline and crop reduction in citrus trees. Since this rule chapter was implemented in 1961, the propagation of citrus nursery stock infected with psorosis, blind pocket, and concave gum, which are graft-transmissible diseases, has been reduced to infrequent detection in the commercial varieties identified in this rule. Since 1961, there have been additional clean-stock varieties made available for propagation in commercial quantities through the Citrus Budwood Registration and Citrus Research Breeding Programs that should be included under this rule chapter. There is no cure for this disease after infection. Prevention by use of clean stock is the only effective control. Therefore, it is necessary to test the trees used as seed sources to determine the presence of psorosis virus complex in order to assure growers of disease free nursery stock. Adoption of these rules amendments would preclude use of any trees to supply seed for nursery tree production except those known to be free of psorosis virus complex. 5B-7.004 Declaration of Psorosis Virus Complex as a Plant Pest. Pursuant to Section 581.031(6). Florida Statutes, the psorosis virus complex is declared to be a plant pest and a nuisance as well as any plant and plant product infected therewith or likely to communicate same. Specific Authority 570.07(23) FS. Law Implemented 581.031(6) FS. HISTORY - NEW 5B-7.005 Psorosis Regulations. (1) Regulated Articles
(2) Citrus nursery stock of varieties listed as regulated articles in Rule 5B-7.005(1) found to be infected with psorosis virus complex as determined by visual leaf symptoms will be refused certification for movement and addressed in the following manner:
(3) Citrus Seed.
(4) Materials. The preceding report is hereby incorporated by reference. It may be obtained from the Division of Plant Industry, P.O. Box 147100, Gainesville, Florida 32614-7100. Improving Citrus Nursery Tree Standards Bob Rouse The Florida Citrus Nurseryman's Association has organized a committee of citrus nursery managers and invited grove managers from the Florida Citrus Production Managers Association to develop needed guidelines to better protect the Florida citrus industry from diseases and pests. Although the ultimate benefactors will be grove owners, the focus for control is the nursery at the time of propagating new trees. The Citrus Budwood Registration Program has benefited the Florida citrus industry since its establishment in 1952. The program has continued to provide improved budlines of all the commercial varieties, selected and maintained true-to-type selections, and eliminated psorosis virus and exocortis viroids from registered budlines. In the past the Florida program has been a model for clonal protection programs around the world. We no longer enjoy that prestige. We have allowed ourselves to become complacent with our own propaganda that Florida is way out ahead of the rest of the world because of our scientific knowledge and technology. Although we are at the leading edge in many areas of citrus production technology, we have lagged behind in implementation of that technology into our clonal protection of propagated nursery trees. Today many agree that the premiere citrus clonal protection programs are in Spain and South Africa. The aggressive initiatives taken in recent years by the California Citrus Nursery Association has allowed them to be viewed by the rest of the world as being in the forefront in North America. Our budwood program has served us well in the past, but we are facing new challenges. Citrus tristeza virus (CTV) has existed in Florida as mild strains for many years without major loss of trees on sour orange rootstock. But during the 1980s increasing spread of severe decline strains virtually eliminated the continued propagation of trees on sour orange. We stand braced for the introduction of the brown citrus aphid and spread of severe scion stem pitting CTV strains that threaten all citrus trees, especially grapefruit, irrespective of rootstock. The brown citrus aphid, found this past summer in Cuba, has island-hopped from South America, to Puerto Rico and now Cuba. The next expected stop could be the Florida Keys and then the Florida mainland. The ease with which there can be an introduction of a new pest was made real by the finding of the citrus leafminer less than a year ago. One concern that needs to be addressed is that under the current law, a registered parent budwood tree in the field that received registration status in the 1970s is still considered a viable registered parent tree even if no testing has been done since its original registration. Our knowledge of disease spread and technology provide the wherewithal to correct such an oversight. This and other anticipated future situations that could occur in today's world are the challenges being addressed by the quality tree committee. So what safeguards do we have in our budwood program to prevent the spread of a disease like CTV? Obviously not good enough safeguards or we would not continue to propagate severe CTV. We have known about sour orange decline CTV for several years and had the MCA 13 test for detection, yet we have not developed mandatory guidelines to prevent continued propagation of trees with severe CTV. As a result we have increased the rate of natural spread many times over by allowing planting with infected trees throughout our industry. What will stop the propagation of trees infected with stem pitting in the same manner? - Nothing as the guidelines now read. What do we do if tatter leaf or other graft-transmissible diseases of the world reach our industry? Many pathologists believe stem pitting CTV and tatter leaf viruses should be of primary concern to the Florida citrus growers. Many people may believe that most nursery trees trace back to a registered tree source. An interesting statistic recently put together at the Budwood Office is that 16 million citrus nursery trees were produced from July 1992 through June 1993. Only 2.8 million (17%) of the trees were registered. There is no such thing as "just as good as" when it comes to registered trees. The fact that many trees do trace back to a registered tree is credit to our nursery growers and the success of the budwood program. However, we still find non-registered trees less that 20-years-old with psorosis and many younger trees with exocortis. There should be no trees propagated with either of these diseases. There are diseases of citrus throughout the world which could totally destroy or cause serious damage to our industry, and we do not have adequate guidelines in place to prevent them from spreading in Florida. The question of over regulation of our industry is on everyone's mind. If the proposed quality tree program is made mandatory, and it won't be effective unless it is mandatory, everyone would be playing on a level field. The regulatory agency in our industry is the Florida Department of Agriculture & Consumer Services (FDACS). The budwood program is already in place and any changes to it will have to be requested by the citrus industry. This quality tree program would be a self imposed regulation to maintain quality of our nursery tree product. The law now states that it is unlawful to propagate for sale trees with psorosis. In the case for severe tristeza or anything else, it may be as easy as a wording change to include strains of severe CTV and/or other diseases of major concern. There has been some concern that since grove managers do not insist on registered trees, there is no general dissatisfaction with the trees they have been receiving. Although grove owners and managers should insist on registered trees, there is often dissatisfaction with trees. To the grove manager, I repeat, there is no such thing as "just as good as" a registered tree. From one point-of-view perhaps it is the responsibility of the grove managers making the decision on what trees to buy and not the responsibility of government to protect these individuals. Buyer-be-ware has always been a part of the free enterprise system, but so has consumer protection and the issue here is one of industry pride and standards. We in the Florida citrus industry are all part of one family, so to speak. We must work together because as the citrus industry of Florida benefits we all benefit individually. Besides, we all expect consumer protection in the food products we buy, restaurants we visit, and other consumer products we purchase. There are still many questions to be answered in developing a stronger nursery program resulting in a stronger citrus industry. Many concerns focus on what to test and which tests to use, how to test, how often to test, who will do the testing, and who will bear the costs of testing. Since it seems improbable to test every nursery tree, what confidence level are we willing to accept? Should the program be mandatory for everyone producing citrus nursery trees in Florida? I suggest everyone read the special insert article titled "Arguments for establishing a mandatory certification program for citrus" by Chet Roistacher in the October, 1993 issue of "Citrus Industry" magazine. One fact rings loud and clear, industry leaders in the Florida Citrus Nurseryman's Association and Production Managers Association, along with IFAS, and FDACS are dedicated to the future of our industry. All members need to attend the April 19 annual meeting to get details and voice views on the proposed quality tree program discussed in the above article. |
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