LEDIN: NARANJILLA 187 fertilizer solution to the rate of 500 grains of the greenhouse and in pearls in the open. It the dry fertilizer to 115 liter of water. (Hy- is possible that technical deviations of the Gro). equipment as well as medium, are responsible It contained the following elements in per for the difference. cents of total: Summary

Total nitrogen 13 % Periodicity in Lychee as expressed by root Available phosphoric acid 26 % Water soluble potash 13 % ing response of branch-tip cuttings was de Chlorine 7.730 % termined. In April and May about 80% of Copper sulphate, as CuO 0.079 % Manganese sulphate, as MnO 0.094 % the cuttings rooted in different media. During Iron sulphate, as FesOs 0.250 % Calcium sulphate, as CaO 0.810 % the dormancy period in Nov., Dec, Jan. and Calcined magnesite, as MgO 4.250 % Febr., only callus formation could be noticed. Zinc sulphate, as ZnO 0.110 % Borax, as B2O3 0.090 % The rooted cuttings let themselves be easily 0.156 mg. per oz. 3- lhdolebutyric acid established when potted with the necessary

Per medium were tested 12 cuttings per care. month and the experiments were terminated LITERATURE after 8 weeks. Brandon, D., Seasonal variations of starch con tent in the genus Rosa, and their relation to Results propagation by stem cuttings, J. Pom and Hort. Sci., 17; 233-253. 1939. The dormant cuttings all formed profusely Co wart, F. F., and Savage, E. F., The effect of various treatments and methods of handling upon callus in all the media under the three ex rooting Muscadine grape cuttings, Proc. Am. Soc. Hort. Sci., 44 : 312-314. 1944. posures, but no roots. Gardner, F. E., The relationship between tree The flush cuttings in the greenhouse gave age and the rooting of cuttings, Proc. Am. Soc. 9 and 10 rooted and 4 and 2 callused ones in Hort. Sci., 26: 101-104. 1930. Garner, R. J., and Hatcher, E. S. J., Spacing as muck, 3 rooted and rest callused in grit. The a factor governing rooting and growth of hard wood cuttings of the Myrobalan B plum root- flush cuttings in the slathouse propagator were stock. J. Pom. and Hort. Sci., 23: 149-166. 1947. all callused in grit, but no roots were formed. Hitchcock,A. E., and Zimmerman, P. W., Root The flush cuttings in the sun exposed propa inducing substances effective on apple cuttings taken in May, Proc. Am. Soc. Hort. Sci., 40: gator with pearls rooted at a rate of 10 out 292-297. 1942. of 12 and the balance callused. Knight, R. C, The propagation of fruit tree stocks by stem cuttings, J. Pom. and Hort. Part of the rooted cuttings were transferred Sci., 5 s 248-266. 1926. Luckwill, L. C, Growth-inhibiting andgrowth- to pots and hardened by putting the pots in promoting substances in relation to the dormancy the open in the fog, and gradually moving and after-ripening of apple seeds. J. Hort. Sci., 27: 53-67. 1952. them out. The roots that are formed on the Ochse, J. J., and Reark, J. B. The propagation cuttings are very brittle and care should be of sub-tropicalplants by cuttings, Proc. Sixty- third Annual meeting Fla. State Hort. Sci, 248- taken to leave them intact. With normal care 251. 1950. ful handling, the potted soon establish Richards, D. A., Notes on the vegetative propaga tion of cacao cuttings, J. Hort. Sci., 24: 192-199. themselves. (The callused cuttings died when 1948. potted after longer or shorter period). 10 Rosen, H. R., Inducing root formation on dor mant rose cuttings, Am. Rose Mag., 2: 147-148. There are some points that cannot be ex 1938. plained without further experimentation. They 11 Snow, A. G., Variables affecting vegetative prop agation of red and sugar maple., J. Forestry, are the negative results of the flush cuttings 39: 395-404. 1941. in grit inside the greenhouse and under the 12 Stoutemeyer, V. T. Humidification and the rooting of greenwood cuttings of difficult plants, slathouse, and the equal success in muck in Proc. Am. Soc. Hort. Sci., 40: 301-304. 1942.

THE NARANJILLA ( QUITOENSE LAM.)

R. Bruce Ledin One of the most interesting fruit plants of South America is the naranjilla (Fig. 1). Al Florida Agricultural Experiment Stations though it has been tried many times in South Sub-Tropical Experiment Station Florida, only recently has the culture of this Homestead been successful here. The naranjilla is a native of the countries Florida Agricultural Experiment Station Journal of northern South America, especially Series. No. 106. 188 FLORIDA STATE HORTICULTURAL SOCIETY, 1952

and Colombia, and is cultivated there at ele vations of 4,000 to 7,000 feet on well drained slopes of humid valleys where the rainfall is at least 60 inches a year. The fruits are used to make a freshly squeezed juice called "Sor- bete" which is often served in restaurants and hotels; it is as popular as and tomato juice in the United States. Other uses are for flavoring ice creams and ices, and in mak ing jelly, preserves, puddings, pastries, pies and cakes. The dark-green juice (Fig. 2) of this fruit makes a very refreshing drink that has been well received by many people of South Flor ida. The taste is rather unusual, suggesting Fig. 2. The tomato-like fruits of the naranjilla and a combination of orange and tomato juice with a glass of the dark-green, juice. (Photo graph by J.^ C. Noonan.) a pineapple or strawberry flavor; also flavors of lemon, lime, plum, banana, green guava, Numerous introductions of the naranjilla and even passion fruit, have been detected. to the United States have been made in the It is sweet, yet possesses a certain amount of past. Seeds germinated readily but when the tartness. It is reported to be rich in vitamins, plants were set in the field they lived for a proteins, pepsin, and minerals such as lime, short time only; rarely did they reach flower phosphate, and magnesium. ing and fruiting stage. Because of this, it was believed that the climate and soils of The common name, which is pronounced South Florida were not suitable for this plant. "nahr-an-heeT-lyah" means "little orange." In However, in recent test plantings at the Sub- deed, this "golden fruit of the Andes" does Tropical Experiment Station at Homestead, it resemble a small orange. But the resemblance was found that the plant is extremely suscepti is only superficial, for the plant is a member ble to nematode infestation (Fig. 3), and this of the and is thus related to the is probably the main reason the naranjilla has potato, eggplant, tomato, etc. In fact, one never been grown successfully in this coun author suggested that "tomatillo," little to try. mato, would be a more appropriate name. The It is apparent, then, that the successful scientific name is Solarium quitoense, the spe growing of the naranjilla in Florida will de cies referring to the city of Quito, the capital pend upon overcoming the nematode problem. of Ecuador. One method of accomplishing this is to graft the plant on a root-knot resistant species of Solanum. This was first done by Milton Cobin in 1949 while he was with the Sub- Tropical Experiment Station, and the grafted plants were grown in the field to the fruiting stage (Fig. 1). The naranjilla is an herbaceous-like shrub, developing stout, spreading stems that become only slightly woody—that is, the stems form only one layer or ring of woody tissue. The naranjilla is a quick-growing but short-lived plant. Growth is so rapid the plants will flower when only a few months old and ma ture fruit will be produced within six months. Plants can rarely be expected to live for more Fig. 1. One year-old naranjilla plant grafted on Sol than two and one-half or, at most, three years. atium macranthum. Flowers are borne at the tips of the stems while mature fruit is be The fruiting period lasts for two years. It ing produced on the older portion of the stems. (Photograph by Geo. D. Ruehle.) might be possible to extend the life of this LEDIN: NARANJ1LLA 189 plant by cutting back the long branches during the second year of growth; new branches would then be produced on the lower part of the plant. Pruning experiments to increase the productive life of the plant are now be ing conducted. A suitable rootstock for the naranjilla must not only be root-knot resistant but also possess a stem structure similar to that of the naran jilla. Four species which meet these require ments have been successfully used as under stock. Three of these are species of Solanum, while the fourth belongs to another genus. The original graft that Cobin made was on Solanum macranthum Dun., the Brazilian po tato tree. This species is grown to a limited extent as an ornamental in South Florida. It is a shrub or small tree growing to about eight Fig. 4. Cleft grafts of naranjilla. Left, naranjilla feet and has large attractive blue flowers. This grafted on Solanum macranthum, six weeks after grafting. Right, naranjilla grafted on species will, in time, become quite woody, Solanum hirsutissimum, two and one-half but during its early life will grow rapidly and weeks after grafting. (Photograph by J. C. Noonan.) form large, semi-woody stems that are suit able for grafting with naranjilla. Grafted jilla. Field plantings, however, have not as plants which were set in the field in 1949 yet been tested. Perhaps the most ideal stock grew and fruited successfully until the early for the naranjilla is Cyphomandra betacea part of the summer of 1952. A second species Sendt, the tree tomato of South America. The that has been tried is Solanum verbascifolium growth, stem anatomy, and life expectancy of L., the mullein-leaf nightshade, a shrubby spe this species is more nearly like that of the cies native to South Florida. Test plantings naranjilla than the other three species. The set out in November of 1951 have grown well few test grafts made recently show that the and the plants produced fruit by April, 1952. naranjilla and tree tomato are compatible, but A third species, Sclanum hirsutissimum Standl., field plantings have not been made. a spiny shrub native to , introduced Grafting of the naranjilla is easily accom into this country by the USDA in 1942, also plished by using the cleft graft (Fig. 4). The has proved to be compatible with the naran- young plants that are to be used as stock are grown from seed. When these plants are about two feet tall, have developed a stem one-half to three-fourths inch in diameter, and are still soft and herbaceous, they are ready for graft ing. The stock is cut off leaving about a four- to six-inch stem. This is then split down the middle with a grafting knife for one to two inches. A three- to four-inch terminal scion from a naranjilla seedling is selected to match the diameter of the stock plant. This scion is cut at the lower end to make a long V- shaped base which can then be inserted in the cleft of the stock. The herbaceous stems are easily fitted and pulled together into a tight union when wrapped securely with a rubber budding strip. Melted paraffin and beeswax mixture is then applied with a brush to all exposed cut surfaces. In about two to three Fig. 3. A non-grafted naranjilla. The large swell weeks the union should be completed and ings on the roots are a result of nematode infestation. (Photograph by J. C. Noonan.) the rubber bands removed. When the grafted 190 FLORIDA STATE HORTICULTURAL SOCIETY, 1952

plants have become one to two feet high they Hodge, W. H., 1947. El Lulo, una fructa Andina poco conocida. Rev. Facultad Nacional de Agron- can be set in the ground. omica 7 (26) :147-154. Medellin, Colombia. Hodge, W. H. 1947. Naranjilla or "little oranges" REFERENCES TO NARANJILLA of the Andean highlands. Journal New York Botanical Garden, 48 (571) :155-159. Anonymous. 1945. Naranjilla growing in Guatemala. Ledin. R. Bruce. 1952. Naranjilla (little orange), a Note in Agriculture in the Americas, 5 (11):217. new fruit for Florida. Florida Grower (Tampa), Camp, W. H. 1947. Some additional comments on October, 1952, page 20. the naranjilla. Journal New York Botanical Gar McCann, Lewis, P. 1947. Ecuador's Naranjilla — a den, 48:(571) :159-160. reluctant guest. Agriculture in the Americas, 7 Chalons, Manuel E. R. 1944. Naranjillas — the gold (12) :146-149. en fruit of the Andes. Agri. in the Americas, Popenoe, Wilson, 1924. Economic fruit bearing plants of Ecuador. Bulletin U. S. National Museum. Cheney, Ralph H. 1947. The biology and economics Vol. 24, part 5:133-134. of the beverage industry. Economic Botany, 1(3): Smiley, Nixon. 1952. Article in the Miami Sunday 272-273, plates 28, 29, 31. Herald, May 11. Gattoni, Luis, 1935. La Industria del jugo de naran University of Florida Sub-Tropical Experiment Sta jilla ecutatoriana. Direccion General de Agri tion annual report, 1948, page 249; 1949, page culture de Ecuador. 245; 1950, page 232.

GRAFTING STUDIES ON MACADAMIA AND SAPODILLA IN RELATION TO CARBOHYDRATES, USING PRE-GIRDLED SCIONS*

Ibrahim Fahmy. * * macadamia from certain parent trees was low, even though the scions were selected from Metabolic activity in plants is known to be branches which had been ringed to force car most intense in meristematic regions. No such bohydrate storage. This carbohydrate accu activity can efficiently take place without the mulation had been reported to be intimately presence of an adequate source of energy. related to the problem of asexual propagation. Carbohydrates being the main known source of energy in plants, their abundance would Preliminary investigations showed that branch es from various trees ringed for the same then be considered a major criterion of activity length of time differed in the amount of starch in such regions of cell division and differentia accumulation. Unringed branches on both tion, consequently of utmost importance in low- and high-starch trees had little or no healing of wounds in plants. Considering that the graft union is essentially a healed wound, starch (as indicated by the iodine test). The the quantity of carbohydrates would be ex percentage of "take" was found to be in ap pected to influence greatly the healing of graft proximate proportion to the relative amount wounds. of starch in the scions. Thus, emphasis was placed on the importance of carbohydrate It should be fully understood that the suc storage in scions for better "take." Also, the cessful control of graftage involves the inter suggestion was made that mature seedling play between the external environment and macadamia trees would vary in the rate at the internal conditions of the plant or part of which carbohydrate material accumulates after the plant used. Shippy (5) stated that for ringing. , general callusing purposes, temperature below The following experiment was undertaken 68°F have been found more satisfactory than in an attempt to understand the significance higher ones, on apple grafts. Also, air mois of pre-girdling the scions on their "take" in tures below saturation are generally inhibiting grafting. in their effect on callus formation, since be low this point desiccation of the tissues occurs. Two different species were used in this In 1941, a report from Hawaii (3) indi study: Macadamia ternifolia F. Muell, com cated that the percentage of "take" in grafting monly known as macadamia or Queensland nut, and Achras zapota L., commonly known ♦ Extract from a part of a Ph.D. dissertation, to be presented to the Graduate Council of the Uni as sapodilla. Branches of both plants were gir versity of Florida. dled at different times in late winter, spring ** On a study-leave from Fouad 1 University, Giza, Egypt. and summer for a certain length of time.