COLBURN, GOLDWEBER: CERTIFIED LIME CLONES 305 The avocado maturity schedule issued by the decay, stylar-end breakdown, color, steins, scars, Avocado Administrative Committee for the 1971- discoloration, thorn damage, cuts, skin breakdown 72 season lists fifty seven varieties. In addition all and scale. unnamed varieties are classified as West Indian Pack regulations for avocados and limes are set Type or Guatemalan Type. Each variety or type up by the administrative committees. Only stand is considered to be mature when the individual ard size containers with specified dimension may fruit has reached a given size or weight on a given be used. All containers have requirements for date. It behooves the inspector to be able to recog minimum net weight and most have maximum net nize each variety or type of avocado to enable him weight requirements. In addition the fruits must self in the determination of maturity. be of fairly uniform size and packed according to Only one kind of lime, the seedless Persian good commercial practice. Type is of commercial importance in Florida. This Avocados and limes from foreign countries are lime is considered mature when it has reached a inspected at the port of entry. They are not sub given minimum size and minimum juice content. ject to a pack regulation but must meet the same These requirements are determined by the Florida minimum grade and maturity requirements as Lime Administrative Committee. The current regu Florida avocados and limes. When fruit are found lation requires limes to be at least 1-7/8 inches that fail to meet these requirements the receiver minimum diameter and to have a minimum aver has the option to recondition the fruit so that it age of 42 percent juice by volume. does meet requirements or the fruit is destroyed. For grade determination in avocados the in Through the use of federal regulations and spector looks for several defects. Different amounts insipection the Florida avocado and lime industries of a given defect are permitted in different grades. assure themselves of keeping inferior fruit, both Scarring, for instance, is one of the most common domestic and foreign, from the regular channels defects of avocados. The U.S. No. 1 grade allows of trade and in the end a higher monetary return 10 percent of the surface of the individual fruit to the grower. to be affected by light brown fairly smooth scars. The U.S. No. 2 grade permits 25 percent of the surface to be affected and U.S. No. 3 grade 50 Acknowledgments percent of the surface. Other defects to be con sidered in addition to scars include decay, anthrac- Grateful appreciation is expressed to Mr. R. D. nose, cercospora spot, color, shape, cleanness, stems, Williams for his help with the historical informa cuts, scab, sunburn and sunscald. tion and to the Florida Avocado and Lime Ad When inspecting limes the inspector looks for ministrative Committees for shipment figures. CERTIFIED LIME CLONE STATUS - GROWERS1 VIEW BURT COLBURN Producing grove trees were declining 5% to 8% per year. New plantings had mortality of 7% to South Florida Growers Association 50% in their first year. With the search and and development and propagation from a known source Seymour Goldweber to apparently virus free scion, tree mortality has been reduced to zero percent. Production has in IFAS Cooperation Extension Service creased from 250 bushels (or less) to 700 bushels Homestead or more per acre. Abstract Introduction Prior to 1957-58, growers of Persian limes in This paper is a resume of clonal lime develop Dade County faced decline in production. This was ments rather than a scientific report. due to the selection of budwood for propagation of Development of the lime and lemon industries new trees from virus infected "Old Lime" trees. follows a pattern from about 1150 A.D., when the 306 FLORIDA STATE HORTICULTURAL SOCIETY, 1971 Moors and Crusaders moved westerly from the commercial Persian limes. As these were coming eastern Mediterranean areas then on to the New from seed, a reasonable assumption would be that World with Columbus in 1492. What is now known they be virus free. A test planting on various root as West Indian or Key Limes were included with stocks was completed in 1962 (2). In 1965 U.S.- seedling lemons and citron. These were widely D.A. No. 1 and U.S.D.A No. 2 were released to planted as colonization took place until about 1874. nurserymen. It was soon discovered that U.S.D.A The Tahiti or Persian lime was then introduced #1 clone had developed wood pocket or blotch. from Tahiti into Australia, from there to California Production records for U.S.D.A. #2 were taken between 1850 and 1880 and into Florida in 1883. in 1969 and 1971. These were comparable to those The Bearss clone, favored in California because of 38-10 and 11-14, but still no grove planting of of its roundness, was introduced into Florida in U.S.D.A. #2 clone has been used. 1912, with 12-14 trees by Glen St. Mary's Nursery To date, blotch (wood pocket) has not been of Dunedin. By the year 1954 only three of these found in any block of registered 38-10 and 11-14 trees remained. What caused their decline is un trees (Figure 2). However, this author has known. observed many blotch infected trees in groves The lime industry in Florida has developed since planted from nursery trees bought with the as the early 1920s. By the 1954-55 period there were sumption that they were "as good as registered" about 6000 acres in the state, 90% were in Dade trees. A grower planting a new grove should be County. more particular in selecting his source of nursery Up to the 1954-55 period, the lime industry trees. faced problems in tree decline, with the top pro Yield records of seven to ten year old blocks of duction about 250-300 fifty-five pound bushels per 38-10 and 11-14 registered trees have been noted acre. A new clone or sport, Idemore, was found as being over 700 bushels per acre. However, these and patented as #444 in 1934 by Mr. George Polk. trees are spaced at 20' x 10' and are now decreas Later investigations proved that this variant was ing in production. This decrease is associated with a result of a combination of viruses and the de management programs and not with budwood selec cline of the trees over a period of five years was tion. 100%. Tree decline of old line propagated trees During the seasons of 1970 and 1971 there have had reached 7% to 8% per year with new plantings been indications of more decline in production and reaching 50% mortality in their first year. (Figure tree growth in some of the registered blocks reach #1). ing the age of eight to twelve years. There may By 1954 the lime industry was in distress when be an indication of a new virus and because of tree the F.S.H.S., implemented a resolution from the decline and an over abundance of dead wood, Dr. Citrus Production Managers Association for the J. F. Childs of U.S.D.A., has observed these dis whole citrus industry for a registered budwood orders and has taken indexing material, with no program. In 1955 the lime industry requested help report to date. This may be the result of manage from the Plant Board's Budwood Program. After ment practices, such as close planting (20' x 10' - an intensive search by research workers covering 21' x 12%'); increasing root competition as well hundreds of man hours, and searching through as bearing surface competition; increasing inside about 100,000 possible candidate trees, the final wood death and not removing this dead wood. result was ten trees free of wood pocket (blotch). Another practice necessary because of this close Seven of these were ultimately lost because of planting program is mechanical hedging and Tristeza or Psorosis, resulting in three parents for topping. If this is practiced at the time the trees registration, free of Tristeza and Psorosis. Two of are dormant (our winter), the cut off limbs do not these, 38-10-14 and 38-11-14 have later been in flush out. Also, what prevents inoculation or the dexed as carrying weak indication of Xyloporosis spread of virus from an old grove to a virus free and Exocortis. The third, known as the Landrum grove when virus can be spread with an undisin- lime has not been extensively propagated. fected budding knife (3) ? Still hunting for a virus free clone of Persian Studies of the above problems are partially on lime, Phillip Reece, W. C. Long, and J. F. L. the way as well as renewed interest in post harvest Childs (1), in 1952 planted about 140 seedlings ing problems, especially "stylar-end" and rind grown from variable lime seeds recovered at a breakdown. Lake Wales processing plant. Two of these seed The 1970-71 Summary of the Federal-State lings were selected as being indistinguishable from Market News reports an acreage on limes as 3670 MITCHELL: MANGO PRODUCTION MARKETING 307 producing acres, 882 non-bearing acres, a yield of gative work is needed to develop the lime growing 1,408,000 bushels (55 pounds), or a per acre yield industry to withstand the economy of the present of 383.5 bushels. This increase over the produc mechanical methods of growing, producing and tion of the 1945-55 era is substantial. It is par harvesting the crop.