Proc. Fla. State Hort. Soc. 95:119-121. 1982. INTERGENERIC AND INTERSPECIFIC ROOTSTOCK TRIALS FOR JABOTICABA (MYRCIARIA CAULIFLORA (MART.) BERG)1 Mary Ann H. Ogden since grafting knives were too large and cumbersome. Para- Fruit Crops Department, film was used to bind the small wounds because it is more University of Florida, IFAS, adhesive and pliable than grafting tape (2). Small seedling Gainesville, FL 32611 tops and young terminal scions were used as scions in order to closely match the diameter of the stocks. Carl W. Campbell In many of the replications, plastic bags were placed Agricultural Research and Education Center, over the entire plant which was then put in the shade to University of Florida, IFAS, prevent moisture loss. In other tests the micro-grafts were Homestead, FL 33031 put under the mist with and without plastic bags. The use of the mist was for cooling since the heat in the summer Additional index words. Myrtaceae, Eugenia, Calyptranthes, months caused the plants to wilt rapidly. Plants in plastic Myrcianthes, Syzygium, native plants, propagation, bud bags not in the mist had to be put in the shade to prevent union. a build-up of heat. Veneer and approach graft wounds were made in the Abstract. Jaboticaba is a slow growing tree and it would standard way but again using scalpels because of the small be advantageous to graft jaboticaba scions onto vigorous size of the stock plants. Parafilm was used to bind graft native or edaphically adapted rootstocks to induce precocity unions on the smaller stocks, and grafting tape split to 5 mm and scion vigor. Six genera and 10 species of native and in width was used on the larger diameter stocks. exotic relatives were evaluated as potential rootstocks for Budwood was prepared on the tree for the veneer grafts jaboticaba. No satisfactory alternative rootstock was identi by using material from mature trees. Terminal buds were fied. Although several species formed unions, none survived cut off and the leaves were removed leaving the petioles at for more than one year. A micro-cleft grafting technique is tached. When the petioles abscised, the buds were starting also described for jaboticaba. to swell and the budsticks were then collected. When pre paring the budsticks for the graft, a shallow longitudinal Myrciaria cauliflora is native to Brazil and widely cut was made removing only 1/4 of the diameter of the bud- planted in southern Florida (4, 6, 8). The tree blooms in wood leaving the scion 3/4 of its original diameter. This Florida 5-6 times yearly with fruit ripening in 20-30 days. retained as much food reserves as possible for the small scion The fruits are similar in appearance and flavor to a grape to utilize while the graft union was forming. and are 2-3 cm in diameter with a tough black skin (4, 7, 8). Approach grafts were made by planting the stock and Most members of the family Myrtaceae are difficult to scion plants in the same pot, and waiting for 2 wk for the graft. Propagation of Myrciaria cauli flora is usually by plants to recover from the effects of transplanting. After the seedage. The seeds are polyembryonic and usually come grafts were made the wounds were bound with parafilm for true to type (1, 3, 7). Because of slow growth of the seedlings the smaller diameter combinations and for the larger ones, and the long time it takes them to come into bearing, it standard grafting tape was split to 5 mm in width. In the would be advantageous to graft M. cauliflora to impart second year of the experiments standard 10 mm width graft scion vigor and to induce precociousness (1, 8). Seedling ing tape was used since the plants were larger. trees under very good cultural conditions bear in 6-8 yr; Nine rootstocks were selected from available native and however, under poor growing conditions take up to 16 yr to naturalized plants. The native species were: Calyptranthes come into bearing (8). When grafted they are usually pallens Griseb. (spicewood), C. zuzygium (L.) Sw. (myrtle- inarched (1,7, 8), or veneer grafted (8). of-the-river), Eugenia axillaris (Sw.) Willd. (white stopper), E. confusa DC (redberry stopper), E. foetida Pers. (Spanish stopper), Myrcianthes fragrans (Sw.) McVaugh (Simpson Materials and Methods stopper). Exotic species include: E. uniflora L. (Surinam After a review of the taxonomic literature for potential cherry), Pimenta dioica (L.) Merr. (allspice), and Syzygium rootstocks, several possibilities were found among the native cumini (L.) Skeels (Jambolan plum). and naturalized species (5). Final determination of which In the first year, there were 4 experiments (Table 1) and rootstock to use for experimentation was made by the avail in the second year there were 2 experiments (Table 2). The ability of these plants from local sources. number and size of available stock plants determined com Seedling stocks were obtained from native plant nurseries binations of species and the number of replications per ex in south Florida, the U.S.D.A. Subtropical Horticulture Re periment. M. cauliflora grows very slowly and takes 6 months search Station in Miami, Florida, and some were grown at to a year to reach 3-6 mm in diameter. Some of the natives the University of Florida Agricultural Research and Educa used as rootstocks grew faster than M. cauliflora and the tion Center in Homestead, Florida. Some of the plants at exotic rootstocks grew much faster than M. cauliflora or the 1-yr-old were quite small with stems of 3-6 mm in diameter. native species. Three types of grafts were used depending on the size and condition of the stock plants: 1) micro-cleft for the very Results small stocks (3-6 mm), 2) veneer for the larger stocks, and 3) approach for the general test of compatibility. All species tested as rootstocks showed some degree of Micro-cleft grafts were made with scalpels and forceps tissue mingling or graft unions. Some species demonstrated better healing and sprouting of buds than other species. The relative performance of the stocks is summarized in Table 3. ^Florida Agricultural Experiment Stations Journal Series No. 4251. Even though all species showed sufficient affinity to permit This work sponsored in part by the Rare Fruit Council International, Inc., Sam Mauro Fellowship and the Dade County Agri-Council—Dennis mingling of tissues, none tested showed sufficient longevity Carpenter Memorial Fellowship. to be considered as a rootstock for M. cauliflora. Proc. Fla. State Hort. Soc. 95: 1982. 119 Table 1. Summary of stock trials for Myrciaria cauliflora, 1979. Reps. Comments Expt. Stock Date (no.) Graft 1 month 2 months Later observations Calyptranthes pollens 6/27 5* micro-cleft 4 alive all dead dead Griseb. Eugenia axillaris 6/27 4 " 1 alive died 4 months (Sw.) Willd. E. uniflora L. 7/6 approach 2 " all dead dead C. pollens 8/12 tt all alive alive wilted and died 4 unions C. zuzygtum 8/12 5XW tt wilted and died (L.) Sw. 5xw n 4 unions E. axillaris 8/12 5yw it wilted and died 5xw tt 3 unions E. confusa DC 8/12 5yw micro-cleft all alive alive wilted and died 5xw tt tt 1 union E. uniflora 8/12 5yw tt wilted and died 5xw ft rr 3 unions Myrciaria cauliflora 8/12 5yw n tt wilted and died (Mart.) Berg 10* it tt tt 10 unions and growing E. axillaris 12/24 10w veneer dead dead dead 10w tt it // E. uniflora 12/24 10v veneer dead dead dead 10v it tt M. cauliflora 12/24 10w 10v rt it C. p 12/28 lw approach alive died tissue mingled E. axillaris 12/28 lw tt tt // it £. foetida Pers. 12/29 it pushed, tissues mingled Myrcianthes fragrans 12/29 it (Sw.) McVaugh Syzygium cumini 12/30 pushing stock outgrew the scion (L.) Skeels in 3 months zShade with bag. yMist without bag. xMist with bag. wWith parafilm. ▼With grafting tape. Because M. cauliflora is considered quite difficult to graft, conservative use of propagating material. The controls that it is commonly grown from seed, although approach grafts were grafted with this method in 1979 were still growing in and veneer grafts are possible (3, 4, 8). One method not the fall of 1982. mentioned in the literature was micro-cleft grafting. It was All species were micro-cleft grafted and placed under found with the controls (M. cauliflora/M. cauliflora) in ex mist with and without bags, including the controls. Those periment 3 (Table 1) that by putting the grafted plants in without bags including the controls, wilted and died. The a plastic bag under the mist that the grafts were uniformly bagged micro-cleft grafts placed under the mist lived longer successful. The plastic bag kept the plants from getting after removal. Living plants were sectioned free hand and waterlogged, while the mist kept the plants cooler and not graft unions were examined visually under a dissecting transpiring rapidly. The plants without the plastic bag be microscope. Some of the bagged micro-cleft grafts placed came waterlogged and when removed from the mist wilted under mist had successful unions. and died. The larger approach grafts in the second year were suc Micro-cleft grafting techniques can be used on much cessful only with the controls. None of the other species younger plants than can approach grafting, and it is a more tested grew and thrived after they were separated. The Table 2. Summary of stock trials for Myrciaria cauliflora, 1980. Reps, Comments Expt. Stock Date (no.) Graft 1 month 2 months Later observations Syzygium cumini 3/27 10 veneer all pushing 9 of 10 3 months stock outgrew (L.) Skeels alive scion all died Calyptranthes pallens 7/26 10 approach wilt died dead Griseb.