fruit may be transplanted at 100 days or later, as long as the should be deep enough to reach the cambium. The flap of root system is healthy and unrestricted. As a grafted plant, bark created by the three cuts is then lifted from the bottom jackfruit may be planted after the graft has established and up revealing the weak tree's cambium layer. The top of the produced three to four new leaves. In both cases the nursery seedling rootstock is then cut off and removed. This cut is grown jackfruit is planted 2.5 cm above the ground level to al done at a 45 degree angle. The cut seedling is then slipped un low feeder roots to grow from the planting hole and establish der the flap of bark on the weak tree and taped or waxed into in the mulch layer. The roots of the jackfruit are checked for place. This may be done at several points around the weak root binding before the tree is planted into the field. If the tree. When the approach graft heals, the weak jackfruit will be root system is severely bound, the plant should be culled or able to use the healthy roots of the seedling. the bound roots should be cut away to allow new, unrestricted roots to develop. The newly planted jackfruit is mulched to a Conclusions depth of 10 to 15 cm. If necessary, the jackfruit is staked with bamboo poles. The soil is not amended with fertilizer until The jackfruit is highly susceptible to root-binding and suf the jackfruit has established itself and developed a proper fers a major loss of vigor and productivity when its roots are root system. Fertilization within the first few months of plant restricted. Root restriction can be avoided in jackfruit by us ing horticultural practices both in the nursery and in the ing can damage the newly developing root system. If a root-bound jackfruit is planted in the field and allowed field. In the nursery, timely transplanting, the cutting of re to establish, it will be a weak, non-productive tree. Root-bound stricted tap roots and the use of deep nursery containers will jackfruit growing in the field should be removed or repaired avert root restrictions. In the field, applying techniques such by using approach grafting. Approach grafting is a technique as direct seeding and approach grafting can help to avoid or that relies on the new healthy root system of seedling jackfruit. correct root restrictions. By practicing the above horticultural When a tree is approach-grafted, seeds or seedlings are plant methods, root binding and the ensuing low vigor and poor ed 7.6 to 10 cm from the base of the tree and grown to a graft- growth can be successfully managed. able size (pencil diameter). The seedling jackfruit is then grafted into the trunk of the weak field-grown jackfruit which Literature Cited allows the weakened tree to use the healthy roots of the seed Campbell, R. J., S. F. El-Sawa and R. Eck. 1998. The Jackfruit. Fairchild Hor ling jackfruit. The seedlings are grafted by first making two ticultural Series. Vol. 2. Fairchild Tropical Garden, Miami, FL. parallel, vertical (5 cm long) cuts in the weakened tree's Nakasone, H. Y. and R. E. Paull. 1998. Tropical Fruits. CAB International. trunk. The distance between the two cuts should match the di New York. ameter of the healthy seedlings. A third horizontal cut is made Popenoe, W. 1934. Manual of Tropical and Subtropical Fruits. Macmillan connecting the bases of the two parallel, vertical cuts. The cuts Company. New York. Proc. Ha. State Hort. Soc. 111:314-315. 1998. GENERAL OBSERVATIONS ON HYBRIDIZING ANNONA SPECIES Gary E. Zill and Har Mahdeem color to far more offspring than do others, especially with An Zill High Performance Plants, Inc. nona squamosa. Including A. squamosa in a hybrid's parent age is conducive to precocity. Hybrids that are one-half Boynton Beach, Florida Annona reticulata usually produce fruits which resemble it more than they do the other parent. Hybrids that are one-half Additional index words. Atemoya, crosses, pollination, metaxe- A. diversifolia usually are not healthy in our field and have nev nia; A. squamosa, sugar apple; A. reticulata, custard apple; A. er fruited here. Some pollen sources degrade fruit quality in diversifolia, ilama; A. cherimola, cherimoya; A. glabra, pond the immediate fruit. Hybrids with A. reticulata extend the har apple. vest season 1-2 months past the main atemoya harvest. Abstract. In the early 1980's, we started a project to develop An Highly colorful varieties of Annona squamosa, A. reticulata, nona varieties that would be more productive and more color and A. diversifolia were crossed with each other or with A. cher- fully attractive than those then available. We searched for imola or with "atemoya" to develop Annona hybrids with ex superior varieties of several species, and produced interspe ceptional color. Most of the varieties used were also of cific hybrids by cross pollination of each variety of each spe exceptionally good flavor and texture, as we had started this cies with each variety of the other species, reciprocally. As we project with considerable efforts to select good breeding conclude our evaluations of the first generation of hybrids (147 crosses) and start to evaluate the second generation, we have stock. L.H. Zill and Gary Zill selected many varieties of A. re some observations to offer. It has been easier to make hybrids ticulata in Belize and northeastern Guatemala and two variet with beautiful color than ones with high productivity and great ies of A. squamosa in Yucatan, Mexico. Har Mahdeem and eating quality. Some varieties of each colorful species transmit Gary Zill selected several varieties of A. diversifolia in south- 314 Proc. Fla. State Hort. Soc. Ill: 1998. western Guatemala (Mahdeem, 1989, 1990). From Fairchild for two or three seasons. Most hybrids produce sparsely. A few Tropical Garden (Miami, Florida) we got the A. reticulata hybrids occasionally produce so many fruits by open pollination 'Fairchild Purple', the A. diversifolia 'Fairchild' and 'Imery'; that they require severe fruit thinning to maintain the health from Lessard Nursery (Homestead, Florida) we got A. squamo of the trees, (examples: '48-26' & '47-18') sa 'Lessard Thai' and 'Red Sugar'; from nurseries in Califor Tree Vigor. A. cherimola X A. reticulata hybrids are the most nia came several varieties of A. cherimola and atemoya; from vigorous. The other extreme was A. squamosa x A. diversifolia, Israel came the 'Gefner' atemoya. After planting our first gen which germinated by the hundreds and then all died at a eration of interspecific hybrid seedlings from 147 crosses into height of two inches. the field, and after observing fruiting seedlings of 70 of those Sterility. Some trees had flowers that were deformed, or crosses, with approximately 600 seedlings fruiting, we can brittle, or never receptive, or didn't open when receptive. De make some generalizations. formities included petals too short to protect the developing Color. It is possible to obtain good flesh and skin color by sexual parts from the elements, and brittle petals that looked breeding atemoyas with any of the colorful A. reticulata variet like tiny leaves. All hybrids containing A. diversifolia as a par ies—relatively easily when the A. reticulata used is either 'Fair- ent have failed to fruit. We planted out nearly four hundred child Purple' or 'Canul'. The hybrids' flesh colors can be as seedlings, of which approximately fifty survived long enough intense as in the A. reticulata parent (example: '4-5', whose to flower. The flowers were similar to those of A. diversifolia, parents were 'Priestley' atemoya, seed parent, and A. reticulata with no obvious defects. They were hand-pollinated with dif var. 'Fairchild Purple', pollen parent). Skin colors can be ferent pollens repeatedly over several years, but only five set even more intense than in the A. reticulata parent (example: fruit, and none held to maturity. (In Queensland, Alan '47-18' = 'Gefner' atemoya x A. reticulata var. 'San Pablo'). George has also made hybrids using A. diversifolia var. 'Imery', Transmission of flesh color to A. cherimola x A. reticulata hy and has not had any problems getting fruit to set. Their soil is brids (example: '75-9' = A. cherimola var. 'Spain' x A. reticulata rich, deep, and well drained, and their field is well tended.) var. 'Canul') is also good, but decent skin color is rare. We sususpected that our A. diversifolia hybrids' sterility was When bred with A. cherimola, skin color transmission from caused by our less than optimal growing conditions. We dug different colorful A. squamosa varieties differs markedly, from up and returned to containers many of our declining trees. a very high rate with *M-2' to a very low rate with 'Red Sugar'. We also grafted several of these onto seedlings of A. diversifo Though the 'M-2' has a nice red-purple color, most of its col lia, A. reticulata, and A. glabra. Though all of these measures orful offspring are too dark a purple to be attractive (almost resulted in healthier looking plants, they did not set any fruit. black—a mix of green and red pigments?), while some off After 18 years of trying, we have given up on using A. diversifo spring have a nicer reddish color, and others are attractively lia as a parent. speckled. The few offspring of 'Red Sugar' with any color oth Inconsistency. Fruits from the same tree can be wonderful er than green are light pink (example: '48-26' = A. cherimola or disgusting.