75 Years of USDA Research at Miami
|75 Years of USDA Research at Miami|
Abstract. In 1898, the U.S. Department of Agriculture established a research station in Miami on six acres of land leased from Mrs. Mary Brickell. Subsequently, the station was expanded by the addition of 25 acres of land at Buena Vista. Then in 1923, a Garden for the Propagation of Tropical and Subtropical Plants was established at Chapman Field Army Station, 12 miles south of Miami. Over 20,000 plant introductions have been registered at the Miami station since its establishment. Emphasis has been on rubber, cacao, coffee, mango, palm, avocado, lychee, and miscellaneous fruits, ornamentals, and other plants. The station provides materials to experiment stations and other organizations throughout the U.S. and abroad. Other activities at the station include storage of fruits and vegetables, control of the Caribbean fruit fly, Anastrepha suspensa (Loew), and State and Federal survey and detection programs against fruit flies. Reorganization of the Agricultural Research Service of the U.S. Department of Agriculture resulted in administrative changes but has not affected the research program.
The year 1973 is a landmark year for the United States Department of Agriculture in the Miami area. It was seventy-five years ago that the Department of Agriculture established its first introduction garden in the City of Miami. Also, it was fifty years ago that the Plant Introduction Station, now called the Subtropical Horticulture Research Unit, was established at Chapman Field. The original Miami facility was located on six acres rented from Mrs. Mary Brickell and an acre rented from Henry M. Flagler, and the garden was used as a site for research having to do with diseases of subtropical crops as well as a place for establishment of introduced new varieties of plants from foreign countries. Dr. David Fairchild visited the garden in 1898, soon after its beginning, and has written extensively about its history (2).
After fifteen years, the plant introduction garden at Brickell Avenue had become inadequate and Charles Deering deeded twenty-five acres at Buena Vista to the State Experiment Station for use as an introduction garden (4). This Buena Vista property was located about seven miles north of the Brickell property and was used for testing many different species of tropical plants. Dr. Fairchild and his associates at the Department of Agriculture traveled extensively during the early part of the twentieth century and were responsible for obtaining plant material from China, Java, the Philippines, Africa, and South and Central America. Varieties of mangos and avocados as well as many other trees and shrubs were among the hundreds of introductions sent to Miami each year.
However, both the Miami and the Buena Vista gardens suffered severe damage during the freeze of 1917. In his reminiscences (2), Dr. Fairchild reports that the temperature fell to 26.5 F. at Miami and slightly lower at Buena Vista and that many species of plants at both locations were severely damaged or killed by the cold. He realized that the land on which the gardens at Miami and Buena Vista were located was already crowded and that more land was required. Therefore, when the War Department was preparing to sell Chapman Field Military Reservation, he contacted the Secretary of War, John Weeks. Dr. Fairchild's notes concerning Chapman field filled a 150-page manuscript (1) and are fascinating reading to anyone interested in the early history of Dade County. The field had been established by the War Department as an aviation training field during World War I and was named after the first U.S. aviator shot down over France during that war.
Chapman Field consisted of over 800 acres of land of which approximately 200 acres were high enough above sea level to be protected from high water and floods. The mangrove swamp that was there originally was filled in 1917 with dredged marl soil to provide a level airfield. A variety of soil types were represented including the pineland, sand, and limestone rock of the elevated areas and marl areas of the lowland. It was located fifteen miles south of the City of Miami and three miles north of the Village of Cutler. Thus, among the other factors contributing to its suitability for research, was a tendency to somewhat warmer temperatures than those at Miami and Buena Vista. Low temperatures had been frequent at both these locations and had been especially damaging to some of the most tropical plant material. Also, Chapman Field was located on the bay and was therefore accessible directly from the ocean as well as from the land. Dr. Fairchild estimated that the field would not become overcrowded for at least twenty-five years. In addition, it included seven buildings that were suitable for use, as well as pumps and a water distribution system.
In late 1922, the Secretary of War agreed to give the Department of Agriculture a revocable permit to use 850 acres of the field for research. This permit was accepted by the Department on January 12, 1923, in a letter signed by Secretary of Agriculture, Henry G. Wallace.
On April 26, 1923, the first trees were planted on the grounds of the new Chapman Field Plant Introduction Garden. Three species, Ficus racemosa L., F. sycomorus L., and Pongamia pinnata (L.) W.F. Wight, were planted that day. To this day, gigantic specimens of each of these introductions still stand as living memorials to those who foresaw the great importance of exploring the world for new plants to satisfy the needs of an expanding population for food, ornamental, medicinal, and industrial crops.
On June 23, 1925, 95 acres of Chapman Field were permanently assigned to the Department of Agriculture, and the balance of the land was returned to the War Department. Fortunately, this ninety-five acres consisted of the land that was most suitable for research. At the same time, the staff at the Plant Introduction Garden began the effort to transfer plant material from the Brickell Avenue and Buena Vista plots to Chapman Field, and by 1926, much of the most valuable plant material had been established at the new location. This timing was extremely fortunate since a devastating hurricane that hit Miami on September 19 of that year, wiped out the garden on Brickell Avenue. Since the Department's lease was scheduled to expire in four years, the remaining plant material was salvaged, and the station was abandoned.
Shortly after 1926, an additional sixty-five acres of land west of the ninety-five acre plot was made available on a 5-year extendable permit to the Department for the planting of rubber trees. Although this research was terminated many years ago, many of those trees still survive, confirming Dr. Fairchild's estimate of the site's potential. In 1947, Congress transferred title of the leased land as well as an additional 37 acres to give the Station a total of approximately 200 acres.
Plant Introduction Research. The station at Chapman Field is one of 8 U.S. Department of Agriculture Plant Introduction Station located in different climatic zones throughout the United States. At four of these stations, including Miami, scientists conduct preliminary evaluation of plants introduced from all parts of the world, the first step in the search for possible new crops for this country. At the other four stations, introductions of wild or cultivated forms of commercial crop plants are subjected to preliminary screening for selecting those with resistance to known diseases and insects or with improved plant characters needed for the development of better varieties of commercial crops.
By far the largest part of the garden is on what is known locally as "high pine land." This area is from three to 12 feet above the water table and is composed of very porous and rather soft oolitic limestone overlain by only a thin covering of sandy soil, though in pockets of varying size the sandy soil may extend down to the ground water. On the east side, the high land drops off to what was once the mangrove swamp. This combination of high, rocky, and sandy land and the low marl-filled area permits the testing of introduced plants at the extremes of soil conditions as they occur in the region.
New introductions are received and planted throughout the year, especially since transport has greatly facilitated movement of live plant material and seeds with periods of short viability. As accessions are obtained through the Department of Agriculture, a Plant Inventory number is assigned to each individual item. [ex., PI 247831, (an African forage plant)]. This number is the permanent designation for the particular plant, one by which it and its progeny always may be identified. For local use, a Miami Station number is also given [ex., MIA 20469, (a cacao clone from Brazil)]. Field labels attached to trees carry both identifying numbers but not the letters; they also show field position, and, if determined, the scientific name. An extensive file system on accessions and their disposition is maintained by PI numbers, Miami station numbers, and scientific names; thus, a ready cross reference is available. At the present time, approximately 125 acres are developed in plantings or are ready to receive them.
Since 1923, over 22,000 accessions have been received at the Station, and more than 3,000 are presently growing in plots where scientists, nurserymen, students, and laymen come to study them. Especially noteworthy are the collections Acacia (15 spp.), avocado (106 var.), bamboo (21 spp.), Bauhinia (20 spp.), Bougainvillea (28 var.), cacao (150 var.), Cassia (17 spp.), coffee (280 var. in 10 species), Cordia (16 spp.), Ficus (62 spp.), mango (over 90 var. ), palm (115 spp. in 51 genera), Passiflora (15 spp.), and Sansevieria (28 spp.). Most of these species and many more have been distributed by the Station in the form of seeds or plants to researchers and nurserymen all over the United States.
Mangos, avocados, and lychees are of primary interest among the fruits because of their economic importance. Some of the present objectives include: fruit with fine flavor and commercial acceptability; extension of the crop, i.e., earlier and later seasons than at present; regular and productive cropping; cold hardiness (especially of avocados); and disease resistance. Miscellaneous fruits such as Dovyalis, carambola, Eugenia, etc., also have potential commercial interest as well as an existing interest among home gardeners.
Department of Agriculture Plant Introductions have played an important role in the horticultural, economic, and cultural development of the United States. For example, Florida's mango industry was founded on early introductions. ‘Mulgoba', which had been introduced from India by USDA pomologist H.E. Van Deman in 1889, was the parent of ‘Haden', which in turn produced ‘Springfels', ‘Zill', ‘Edward', ‘Lippens', and other named varieties. ‘Sandersha', introduced from India in 1901, gave rise to 'Brooks', and from this cultivar have come ‘Fascell' and ‘Kent'. A recent computer-based study applied techniques of numerical taxonomy to mango cultivars and uncovered a group designated the "Sandersha-Haden complex." Among the ten cultivars placed in this group were ‘Irwin', ‘Tommy Atkins', ‘Keitt', and ‘Palmer' (5). The Saigon type derived from ‘Cambodiana', introduced in 1902 by Lathrop and Fairchild, is a parent of ‘Florigon' and of station experimental selections MIA 4329 and MIA 13269; seedling populations from these selections and their offspring are being planted for the evaluation and selection of new varieties. Thus, mango germplasm introduced by USDA obviously entered into the genetic make-up of all commercially important Florida cultivars.
Avocado introductions prior to 1923 that have contributed to the industry or to the home gardener are ‘Family' (introduced in 1905), ‘Taylor, ‘Collinson', and ‘Simmonds'. We seek avocados that have more cold-hardiness than these cultivars, and also plants that produce early-season and late-season fruits. ‘Arue', introduced from Tahiti in 1932, is an early variety and ‘Itzamna', from Guatemala in 1916, is late; neither is of major commercial importance, but because of these traits they are among the parents used in the current avocado selection program. The latter is a commercial variety in South Africa. M-18686 is another introduction used as a source of cold-hardiness and earliness in our program. ‘Kosel-Lowe', an early ripening seedling of ‘Capac' (PI 53895), has recently interested some growers.
A hybrid Dovyalis, resulting from open pollination between two plants growing on the Station, Dovyalis abyssinica (A. Rich.) Warb., and Dovyalis hebecarpa (Gardn) Warb., has been widely distributed because of fruit quality and productivity.
The ‘Bengal' and ‘Sweet Cliff' lychees are USDA introductions. The latter has been observed for many years throughout the lychee-producing area of south Florida and is presently being looked at for commercial production, although its fruit color is a drawback. A few outstanding seedlings of ‘Sweet Cliff' are also under observation. The lychee cultivar named for W.N. Brewster was sent to us in 1906 from Fukien Province, China.
A new hybrid, Passiflora ‘Incense', (MIA 21470) was developed at the Station by crossing the wild maypop from Tennessee with a species from Argentina. ‘Incense' has large, colorful, fragrant flowers on dark green vines. The juice is an effective addition to other fruit drinks and can be used in jellies and pies. Present breeding research is to develop additional cold-hardy passionvine cultivars.
As noted, the extensive collections of avocado and mango at the Station are based on clones transferred from those that were at the Miami and Buena Vista gardens, and on additional introductions. The first rubber plantings were established in 1923. In 1940, additional introductions provided an excellent source for studies of the physiology of the plant and the chemical aspects of rubber production. In 1954, the collections of germplasm of coffee and cacao were started. Rubber, coffee, and cacao planting can be maintained at the Station, free of the major diseases affecting these crops in producing countries since commercial plantings do not occur in the area (3).
In 1950, the first plants of Strophanthus were introduced at the Station, and a 15-year project was begun to study a group of plants as sources of steroids used in production of cortisone. The next year, a number of Dioscorea species, and later Agave species, were introduced and tested in this program. The Dioscorea were promising, and subsequent tests revealed that good yields could be obtained if the plants were grown in the muck soils of the Everglades region instead of in the rocky soils of the Station.
In 1959, the genus Dombeya was recognized for its qualities as an ornamental, and a program of introduction and breeding was launched with the goal of providing new flowering shrubs for subtropical landscaping. Five new cultivars have resulted from this continuing program.
Over the years, many other groups of plant collections have been studied at the Station or sent to cooperators for study, for example, the exotic fruits: carambola, lychee, passionfruit, longan, annona, guava; the oil producing plants Aleurites, African oil palm, and Licania; the latex-producing plants: Castilla, Cryptostegia, Ficus and Hevea; and ornamentals too numerous to mention.
At present, studies are being conducted by Station horticulturists including avocado, mango, lychee, longan, Passiflora, Dombeya, Cordia, Lagerstroemia, and coffee. As a result of these efforts, new cultivars of both the fruits and the ornamentals have been developed, named and distributed.
In 1961, the Miami Station began to furnish plant material from its vast collection for the screening of natural chemicals that might have potential value in cancer chemotherapy in man. Small samples of dried leaves, twigs, bark, roots, fruit, or bulbs receive preliminary screening by USDA scientists in the Beltsville, Maryland, laboratories. Then if potentially useful substances are found, larger working samples are furnished upon request. This program is continuing in cooperation with the National Cancer Institute, National Institutes of Health, Public Health Service, Department of Health, Education, and Welfare.
In recent years, emphasis at the Station has shifted from plant introduction per se to research concerning specific groups of plants. The older introductions are being re-evaluated, and if they are considered worthy of further study and improvement, seedling populations are grown and new selections are made whenever possible, from the segregating populations.
The Station also contributes toward research and education, by providing tropical and subtropical plant materials to research organizations and universities throughout the country. In addition, the field collections and physical facilities are made available to qualifying students and researchers. Many public gardens and conservatories, in their educational programs, are stressing the economic and cultural importance of tropical and subtropical agriculture in relation to the ever increasing food and health requirements. The Station has been able to add these worthwhile programs by providing them with plants of major economic crops such as cacao, coffee, and rubber as well as with spices and various tropical fruits not obtainable elsewhere in the continental United States.
Much of the plant material received from abroad is the result of reciprocal exchange. In this way, our opportunities for obtaining new and interesting plants are enhanced, and we can make horticultural contributions to foreign countries.
Market Quality Research. Market Quality Research by the Department of Agriculture in Homestead, Florida, was begun in May, 1955. The function of that first laboratory was to develop ways to improve the quality of subtropical fruits and to maintain that quality after harvest. The Station was moved to its present location at the Subtropical Horticulture Research Station in Miami in October, 1956. Major emphasis has since been placed on the development of standards of maturity for avocados and a determination of the conditions most conducive to ripening and satisfactory storage of harvested avocados and mangos. As a result, the standards developed for judging maturity of avocados are now in general use by the Florida avocado industry under a Federal Marketing Agreement. Also, the studies initiated in 1965 to examine the effect of a controlled atmosphere (CA) on storage have been successful. The method had been successfully developed for commercial storage of apples and offered promise for storage of avocados, mangos, limes or papayas. Tests with these fruits suggested that it was most promising for avocados. Also, in 1971, the scope of the work was increased to include postharvest problems with vegetables. Recently the investigation of CA showed direct application of research results with completion of the first commercial facility for CA storage of avocados in the United States.
Tropical Fruit Fly Research. In April of 1965, larvae and adults of the Caribbean fruit fly, Anastepha suspensa (Loew), were found in Miami. Soon thereafter, Federal and State entomologists undertook a research program to establish the importance of this pest and methods of control. As a result, in 1968, the Subtropical Horticulture Research Station was selected as the location for work with tropical fruit flies on the mainland United States. The initial studies were concerned with methods of mass rearing the Caribbean fruit flies, with attractants for fruit flies, and with sterilization of fruit flies with gamma irradiation. Results of this work demonstrated that populations of Caribbean fruit flies can be suppressed or eradicated using sterilization techniques. Also, we have recently established that some synthetic chemicals are effective as attractants for this pest and have developed improved diets for mass rearing of the larvae. Studies are now being initiated of fumigation and irradiation as commodity treatments to eliminate larval infestations in fruit subject to quarantine restrictions.
Agricultural Research Service. In April 1972, T.W. Edminster, Administrator of the Agricultural Research Service, announced the establishment in ARS of four regional headquarters, each to be headed by a Deputy Administrator. The Miami Station is thus now under jurisdiction of A.W. Cooper, Deputy Administrator for the Southern Region, with headquarters in New Orleans, Louisiana. Each of the regions was further divided into a number of areas. Dean Davis is Area Director for the Florida-Antilles area with headquarters in Gainesville, Florida. Therefore, as a result of the reorganization, the five scientists at the Miami Station now have a single Location and Research Leader at Miami. He reports to an Area Director at Gainesville, who reports, in turn, to a Deputy Administrator in New Orleans. Under the old organizational structure, these scientists reported to three separate Branch Chiefs and Division Directors, who reported to Deputy Administrators in Washington, D.C.
Pest Control Cooperative Programs. The Subtropical Horticulture Research Station also serves as headquarters for Federal and State regulatory pest control programs. Thus, it houses a District Office for Plant Protection and Quarantine Programs of the U.S. Department of Agriculture Animal and Plant Health Inspection Service, as well as offices for the Bureau of Pest Eradication and Control and the Bureau of Plant Inspection of the Division of Plant Industry, Florida Department of Agriculture and Consumer Services. In 1959, these State and Federal regulatory agencies established headquarters for their fruit fly inspection teams at the Station. These inspectors are responsible for continuous survey and detection of species of fruit flies not found on the mainland United States. Their work resulted in the discovery of infestations of Mediterranean fruit flies, Ceratitis capitata (Wiedemann), in Miami in 1962 and 1963 and discovery of the Caribbean fruit fly in 1965. In 1962, a joint program for eradication of the Mediterranean fruit fly was undertaken by State and Federal regulatory agencies in cooperation with their research counterparts. This campaign was being concluded successfully in 1963 when a new infestation was found and the campaign had to be expanded. The result was the eradication of the Mediterranean fruit fly within a few months. The pink bollworm, Pectinophora gossypiella (Saunders), a pest of cotton in the Southwest, is an indigenous population that has existed for many years on wild cotton and hibiscus in the Everglades. After many efforts to eliminate the host plants, the agencies at this Station are now releasing sterilized pink bollworm moths to mate with the native moth population. The technique is the same one that is being used in the Southwest to prevent the establishment of screwworms, Cochliomyia hominivorax (Coquerel), and Mexican fruit flies, Anastrepha ludens (Loew), and in California to prevent establishment of the pink bollworm in the San Joaquin Valley.
The giant African snail was inadvertently brought into the Miami area in 1966. However, State and Federal agencies now quartered at the station have been successful in controlling this snail. Surveys and treatments are now being continued with the cooperation of the general public to find any that may have escaped detection so as to complete the eradication.
A recent introduction into the Miami area is the lethal yellowing disease of the coconut and other palms. The State Division of Plant Industry, Bureau of Pest Eradication and Control, is responsible for the efforts to control this disease. Inspectors maintain a constant search for infected trees. Surveys for many other pests also are maintained by Federal and State Regulatory staff at the Station.
Fairchild, David. 1923. Chapman field garden. Unpublished manuscrpt. 151 pp.
Fairchild, David. 1938. Reminiscences of early plant introduction work in South Florida. Proc. Fla. State Hort. Soc. 51:11-33.
Hodge, W.H., Loomis, H.F., Joley, L.E., and Creech, J.L. 1956. Federal plant introduction gardens. National Horticultural Magazine. 35 (2):86-106.
Popenoe, W. 1923. Progress report of the Office of Foreign Seed and Plant Introduction. Bureau of Plant Industry -- 1922. 55 pp.
Rhodes, A.M., Campbell, C., Malo, S.E., and Carmer, S.G. 1970. A numerical taxonomic study of the mango Mangifera indica L. J. Hort. Soc. 95 (2):252-256