Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. LH ARS 34-37-4 C ‘ cuew.tue March 1967 aa, Ghorll AGO JUN 30) 1857 U.S. Department of Agriculture CACAO CLONE COLLECTION Agricultural Research Service U.S. DEPARTMENT OF AGRICULTURE PREFACE The purpose of this publication is to provide a brief description of the cacao clones being held at the U.S. Plant Introduction Station, Miami, Fla. This information should be of value to cacao workers whe are in need of disease-free, documented clonal stock. The material is available in small quantities for research purposes. Requests sent to the Miami station will be honored on an availability basis. It is not intended to duplicate in any way the more complete catalog being published by the Instituto Inter- americano de Ciencias Agricolas (IICA) de la Organizacion Estados Americanos, Turrialba, Costa Rica. ACKNOWLEDGMENT The authors are grateful to Jorge Soria V., IICA, Turrialba, Costa Rica, who furnished much of the information for this publication. Many of the clones in the collection were also obtained through Dr. Soria's efforts. E. P. Imle, American Cocoa Research Institute, Washington, D.C., and USDA collaborator, provided invaluable assistance in contributing to the collection itself by recommending clones for inclusion in it and personally carrying budwood to Miami from other countries. Credit is also due those institutions in other countries that have contributed to the collection, CONTENTS Page INtroductlonesceccescccevaverevssceesecrsseeesesceseseseseseesne 3 Virus indexing programesesssecerecsrnvessssnececstevevesseesss 4 Indexing proceduressssercccceneccsesesssesscescccvescsesccsees 4 Cultural and sanitary practiceScsssseccrerrerceccrsssccsesesese 9 Identification of cacao CloneSsreseccccccecssevsessecsessesese 6 Background data for Selected CloneSesessecscccccsssevsecesvees 8 Selected referenceSssesccccccescececcesensccsevesceceveesdseens 26 U.S. DEPARTMENT OF AGRICULTURE CACAO CLONE COLLECTION 1/ 2/ By H. He Fisher, P, Ke Soderholm,~ and R., P. Kahn™ INTRODUCTION In 1954, the Foreign Operations Administration, a predecessor organization of the Agency for Inter- national Development (AID), formulated a special agreement with the Agricultural Research Service (ARS) of the United States Department of Agriculture (USDA) ",...to provide continuing technical assistance facilities and coordination for the securing, propagation, maintenance, packing, inspection, and shipping of plant and seed materials for experimental use in other countries...." Within the ARS, the New Crops Research Branch of the Crops Research Division (present designation) was named to implement this agreement. Among the specific activities outlined, one was to ",,,assemble, maintain in quarantine, and distribute, living research collections of crops, such as coffee, cacao and rubber..." The U.S. Plant Introduction Station, Miami, Fla., was chosen for the location of a germ=plasm collection of cacao because it is isolated from commercial cacao producing areas and cacao relatives. It is conveniently located for the movement of propagating material by air transportation. The collection, begun in 1955, includes 220 accessions assembled largely through exchange with other countries, The clones are maintained under cone trolled phytosanitary conditions as a source of small amounts of budwood for cooperating countries with cacao breeding programs. A secondary collection, with similar quarantine controls, has been assembled in cooperation with the American Cacao Research Institute, at the Federal Experiment Station, Mayaguez, Puerto Rico. This collection will consist of one to three mature trees of each clone and will provide material for continued breeding research and will serve as a source for large-scale distribution of special clones not easily procurable elsewhere, The Mayaguez collection provides an isolated, tropical counterpart to the Miami collection as insurance against loss of valuable clones in the event of natural disasters. 1/ Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture. 2/ Plant Quarantine Division, Agricultural Research Service, U.S. Department of Agriculture. VIRUS Cacgo investigators originally believed that careful selection of material for inclusion in collections, combined with periodic inspections, and a regular pest and pathogen control program would assure reliably disease-free stocks for dis- tribution. However, with the detection of cacao viruses in widely separated cacao producing areas, INDEXING PROGRAM plants already in the collection have been indexed for swollen shoot virus. New material must undergo virus screening at the U.S. Plant Introduction Station at Glenn Dale, Md., or in isolation at the Miami station, before it may be included in the collections. such international bodies as the Food and Agriculture To initiate the virus indexing program, the Organization and the Inter-American Cacao Conference Crops Research Division enlisted the assistance of have called for the imposition of stringent quarantine R. P. Kahny virologist, Plant Quarantine Division, measures to govern the international movement of cacao to set up the quarantine procedures under which the breeding stocks. To meet these recommendations, the INDE A desirable feature of the virus indexing procedure is that the indicator stock be forced to express symptoms of a virus that might be present in the clone (scion) either above or below the point of union of the scion with the stock. For some unex=- plained reason, the conventional patch=bud graft is unsuccessful at the Glenn Dale, Md., station and only ‘limited success can be achieved at the Miami, Eases station. Consequently, Soderholm and Shaw (31)2/ developed a modified side graft technique which is highly successful in establishing the clone on the stock, This calls for a variation in the indexing procedure recommended by T. W. Tinsley of 3/ Underlined numbers in parentheses refer to clonal collections would be maintained and to make periodic inspections and recommendations. XING PROCEDURES the West African Cocoa Research Institute. The procedure currently used at the U.S. Plant Intro- duction Stations consists of three steps: (a) Side-graft the clone onto an Amelonado (indicator) seedling grown from seed from virus-free trees, (b) Observe flushes of Amelonado growth for 6 to 12 months. (c) Bud=graft Amelonado onto grown-out clone scion and observe Amelonado scion for symptoms. the Selected References at end of publication. If the budwood is of too large caliper to fit the stock on hand for side grafting, the patch-bud is used. Twenty-one days after patch-budding, the stock is bent above the union to force the scion bud, This precludes observation of foliage on the stock for virus symptoms above the union until the CULTURAL AND SANITARY In the beginning, viruslike symptoms produced by nutritional deficiencies complicated the indexing program. This situation is most likely to occur in a lathhouse where the plants are grown in containers and the necessarily frequent watering tends to leach the soil. Frequent applications of soluble fertilizer eliminate the deficiencies and facilitate the release of the clones from quarantine. Rigid adherence to a spray program assures the control of fungi and insects. It is particularly important to control scion is large enough to be grafted with Amelonado. The length of time required to index a clone for virus symptoms is largely dependent upon how rapidly flushes of indicator growth can be induced both above and below the union of the clone-scion with the stock. PRACTICES mealy bugs, which can be virus vectors, and ants, which can transport mealy bugs. The initial grafting and subsequent manipulation of the stock and scion are done in an isolated lath- house or greenhouse, When the material indexes negatively for virus, it is released from quarantine and moved to a distant outdoor area for propagation and continued observation. It is from the latter area that propagating material is taken for distri- bution, Clone Significance Country Originator APA Amazonico Palmira Colombia “-- cc Cacao Center Costa Rica Soria and Paredes. Catongo Catongo Brazil --- DR Djati Roenggo Indonesia --- BE Estacion Experimental Tropical, Ecuador Varios. Pichilinque G Getas ? Indonesia ? -=-- GA Grand Anse Bay Haiti B, de Verteuil, GS Granada Selection Granada Cope. GW -<-- Netherlands Wageningen. NCS Imperial College Selections Trinidad Pound. IMC Iquitos Maranon Clones ? Amazonia, Peru Do. Lafi Lafi Samoa Jones» M --- Indonesia Wageningen, P (suffix) --- Mexico Muguerza. Pa Parinari Amazonia, Peru Pound. IDENTIFICATION OF CACAO CLONES [? = uncertain] Clone Significance Country Originator Pound or P,. Pound Amazonia, Peru Pound. R Rosario-Izapa Mexico Spencer and Del Arco. Ss -<-- Netherlands Wageningen. sc Seleccion Colombia Colombia -<-- SCA Scavina Ecuador Pound. SGU Seleccion Guatemala Guatemala Anleu. SIAL Selecao Instituto Agronomico Lesto Brazil Magalhaes,. Sic Selecao Instituto de Cacao Do. “== Silecia Hacienda Silecia Ecuador Desrosiers and Doak, SM % Brazil ? SNK Station N'Koemvone Cameroon --- SPA Seleccion Palmira Colombia --- TSAN Trinidad Selection Trinidad Freeman. TSH Trinidad Selection, Hybrid Do. Do. UF United Fruit Co. Costa Rica Grieve and Bowman. EO a a SED NEAT EOE IE NOSE POT REC EE LICE I Pa A OT" BL EC LE IE EG ER OE IT IE ITE OE EE EE TE OE SE i ee ce neta eee BACKGROUND DATA FOR SELECTED CLONES ily/ Clone PI No. Source Year Description APA 4 315233 IICA, Turrialba, 1964 Amelonado, medium, greenish red, Costa Rica. APA 5 315234 <- = =do- = = 1964 Amelonado, medium, greenish white. C 40 307747 WACRI, Ibadan, Nigeria, 1965 ~=- (fe) 315236 IICA, Turrialba, 1964 Cundeamor, green. Pod index 12.1, Costa Rica. Beans small, purple. Ce 10 315237 «| ~