Serious Diseases of Tropical Fruits in Florida

thereafter, decay increased rapidly. Storage at 70° F re of polyethylene bags lost approximately 50% of their sulted in the least acceptable quality with a decay rating of weight between weeks one and two; the rate of weight loss 2.2-3.3 within 2 weeks. decreased by the 6th week (Fig. 4). After the first week of Twang Tung' had more decay at all times when storage both cultivars with and without polyethylene bags polyethylene bags were used (Fig. 1). 'Arkin', on the other lost significant percentages of water during the 3rd and hand, showed less decay 61.1% of the time when 5th weeks (Figs. 5, 6). polyuethylene bags were used (Fig. 2). 'Arkin' lost less overall weight when stored with a Percentage of water weight loss for both cultivars was polyethylene bag, whereas the Twang Tung' showed less significantly lower at 45° F than at 40°, 50°, or 70° F, (Fig. percentage of water weight loss when a polyethylene bag 3). On the average, both cultivars with and without the use was not used.

Proc. Fla. State Hort. Soc. 99:224-227. 1986.

SERIOUS DISEASES OF TROPICAL FRUITS IN FLORIDA

Robert T. McMillan, Jr. all of the foliar parts of the plant, but is rarely seen on the University of Florida, IFAS fruits in the field, except when the fruit is allowed to fully Tropical Research and Education Center ripen. Black rot is mainly a post-harvest problem since the Homestead, FL 33031 fungus generally enters through the cut stem at thebase of the fruit, or at the side of the fruit through harvest, Abstract. A wide variety of tropical and subtropical fruits can handling, and packing. In the early stages the disease is a flourish and produce fruit in Florida. In spite of the distance wet, soft decay of the pineapple core and tissues that takes between their new home and origin they are not without on a bright yellow color and has a characteristic smell of diseases. The pineapple fruit rot caused by Ceratocystis ethyl acetate. In the later stages of the disease symptom paradoxa, Erwinia ananas, Fusarium moniliforme, Penicil- development continues until the very soft fruit, almost lium funiculosum and Pseudomonas ananas results in seri liquefies, with the skin becoming a brittle shell. Ultimately ous fruit loss. Colletotrichum gloeosporioides which causes the liquids are entirely lost, leaving nothing but an empty cashew anthracnose, attacks leaves, stems, flower shoots, shell composed of blackened vascular fibers. On the bro fruits, and nuts. Annona anthracnose caused by C. gloeo ken surfaces of the decayed tissues a black crust composed sporioides is a serious preharvest and post harvest disease of of macrospores is formed. The macrospores also form in atemoya and sugar apple fruit. Rhizopus artocarpi, which the decayed tissues next to the core of the fruit, turning it causes Rhizopus fruit rot, reduces production by attacking black (5, 11,14, 24, 25, 26,27, 28, 29, 30, 35,36, 45). the male and female flowers. Colletotrichum gloeosporioides The moisture conditions in the field at time of harvest which causes carambola anthracnose is a serious post harvest are most important in rot development. The disease devel disease of the fruit. The most limiting factor in producing ops in the fruit very rapidly at temperatures between 21 Florida papayas is the ringspot virus. The most serious disease and 32°C, with little development below 10°C. Fruit should of loquat is fire blight, caused by Erwinia amylovora, noted not be harvested after prolonged rains. When harvesting by the large number of dead tree limbs. The Barbados cherry fruits the stems should be cut, not snapped (42). is attacked each spring by Cereospora bunehosiae causing a Brown rot (Erwinia ananas Serrano, Fusarium severe leaf spot disease. The mamey has very few diseases moniliforme Sheldon, Penicillium funiculosum Thorn, and but recently it was noted that Cephaleuros virescens attacks Pseudomonas ananas Serrano) is also called, in most of the resulted in bark cracks and stunted branches. The most serious pineapple production areas, fruitlet black rot, fruitlet disease of the jujube is Cereospora spot caused by Cereos brown rot, ripe fruit rot, fruitlet core rot, and exogenous pora jujubae. brown discoloration. The symptoms on the fruit vary, de pending upon whether bacteria, fungi, or both, are in This paper provides descriptions of the more com volved in the disease making it difficult to distinguish be monly found tropical fruit diseases in Florida. For each tween the rots by appearance. The organisms most com tropical fruit the reader will find its common name, scien monly associated with this disease are saprophytes on de tific name, disease common name, scientific name of the cayed vegetation in the field. They are also found on the pathogen, symptoms of the disease, and conditions neces senescing flower parts in the cavities under the eyes on the sary for disease development. fruit and enter through mechanical injuries, growth cracks, and insects feeding or ovipositing. The rot is not Pineapple (Ananas comosus L.) Merr. easily detected from the outside of the fruit, although pre mature ripening or an uneven color at ripening may occur. Black rot (Ceratocystis paradoxa (Dade) C. Moreau), also Eyes may become sunken and turn brown. Internal break known as water blister, soft rot, or water rot, is found down may be small light to dark brown, firm, moist, areas throughout most of the commercial pineapple production at the center of the eye or the fruitlet. Occasionally only areas of the world including Florida. The fungus attacks the style or the central part of the fruitlet is diseased. In the later stages of decay the disease progresses to the core Florida Agricultural Research Stations Journal Series No. 7890. of the fruit and involves all the tissues surrounding the

224 Proc. Fla. State Hort. Soc. 99: 1986. floral cavity. The rot usually does not spread from one fall. When infestation becomes severe, the leaves turn yel fruit to another (4, 11, 14, 19, 20, 22, 24, 25, 26, 27, 35, low and fall. The disease is recognized by the numerous 36, 38, 39, 40, 41, 43, 44, 46). small, raised, yellow spots covered with 2 golden-yellow mass of spores, which are on the under surface of the Cashew (Anacardium occidentals L.) leaves. On the upper surfaces of the leaves, the small spots are yellow and more or less smooth (14, 16, 17). Anthracnose (Colletotrichum gloeosporioides Penz.) occurs in most of the tropical areas where the host is grown (14). The young lesions are red-brown water-soaked areas on Jackfruit (Artocarpus heterophyllus Lam.) leaves, stems, flower shoots, fruits, and nuts. The affected Rhizopus rot of jackfruit (Rhizopus artocarpi Rac.) has leaves become necrotic and die, flowers turn black and fall, been reported in Florida, India, and the Philippines. In all fruit and nuts shrivel and decay. The young trees affected cases the fungus attacks the male and female flowers. The by successive and progressive dieback of terminal shoots early stages of the disease on infected male inflorescence for several years may die. and young fruit first appear as a water soaked area, then The fungus can survive on dead plant material, and as the fungus develops, a greyish mass appears, gradually serve as a source of inoculum under more favorable en becoming denser, forming a black growth with black vironmental conditions. The conidiospores are spread eas sporangia. The young sporangiophores form a whitish ily by water and wind during periods of high humidity fringe on the edge of the black growth. The mycelium such as rain or overhead irrigation and attack the new eventually covers the entire male inflorescence and fruit. growth (42). The infected fruit rot slowly, mummify and eventually fall from the tree (9, 10, 15, 31). Annona (Atemoya cherimola x A. squamosa) and (sugar apple A. squamosa L.) Carambola (Averrhoa carambolal.) Anthracnose (Colletotrichum gloeosporioides Penz.) is Anthracnose (Colletotrichum gloeosporioides Penz.) is the probably the most common and widespread disease of the most serious disease affecting carambola. The loss results annona. The fungus is one of the most widely distributed from the rotting of the ripe fruit before and after harvest. in Florida as well as in other tropical and subtropical areas In the early stages the lesions appear as small, circular, of the world and if not controlled causes severe production slightly sunken spots in the skin. As these spots increase in losses. size the central portion becomes dark because of the pres The various manifestations of the disease on the an ence of the mycelium just beneath the skin. Eventually the nona include blossom blight, fruit russeting or staining, entire fruit becomes infected, often developing a watery fruit rot, and mummified fruit. Damage from the disease rot when invaded by other organisms. The fruit has 4 or is influenced greatly by relative humidity. However, even 5 prominent longitudinal ribs which are easily damaged in in relatively dry seasons considerable latent infection may high winds, allowing easy access for C. qloeosporioides. occur. The fungus grows saprophytically and sporulates Examination of the pulp beneath spots reveals the pres abundantly on twigs and mummified fruits. ence of many spores of the fungus. Green fruit will become Blossom blight may vary in severity from slight to com infected, but the lesions do not develop until ripening be plete, according to prevailing weather conditions. The in gins. When the fruit is ripe and the weather favorable, fected petals show dark-colored lesions, which often en spots develop on the ripe fruit and the spores are splashed large, turn black and cause flower drop. The young in onto other fruit. fected fruits either fall or mummify. On nearly mature to Cercospora leaf spot disease (Cercospora averrhoae Petch.) ripe fruits in the early stages of disease development, the has been found in Florida and other tropical areas where lesions are small and relatively inconspicuous with a plug occurrence is associated with high humidity. The lesion is of hardened tissue underneath, with no external rotting. roughly circular, slightly depressed, reddish, with gray to In the later stages the small spots enlarge, blacken and white centers (2). may coalesce to cover large areas. These infections gener ally penetrate deep within the fruit and cause pulp prehar- Corynespora leaf spot (Corynespora cassiicola Berk. & vest or postharvest decay of the fruit. Surface russeting or Curt.) probably occurs in most of the production areas of staining results from spores being washed down upon the the tropical world. In Florida the lesions are primarily fruit from an infected flower, fruit or twig. Infections on found on the leaves, and occasionally on the petioles and young leaves start as small, light green, angular to irregular the larger branches of the male inflorescences. Young in spots which enlarge, causing scorching and premature fall fections first appear as a faint yellow spot which develops (3,6, 14,21,33). with a small necrotic speck in the center. The developing lesions are tan or light brown. The mature lesions are sub- Botryodiolodia theobromae Pat. which causes Diplodia rot circular to irregular in shape and range from 1 to 2 mm on fruits of Annona reticulata, was described in Australia in in size. On the upper leaf surface the lesions are usually 1953. In Florida the disease manifests itself by mummify grayish to off-white, with the necrotic area depressed as to ing the fruit. The early symptoms are small brownish to appear as a brownish ring. The necrotic lesions on the black lesions that rapidly enlarge over half or more of the lower surface appear as a tan spot. The necrotic area is fruit (14, 33, 37). slightly depressed with a narrow light reddish-brown bor Leaves of the atemoya, cherimoya, custard-apple, der. The lesions occur on both upper and lower surfaces ilama, and sugar-apple are commonly attacked by this rust of the leaf. In the lesions dark reddish-brown con- fungus Phokospsora cherimoliae Cumm. in the summer and diophores with conidia are found in abundance (13).

Proc. Fla. State Hort. Soc. 99: 1986. 225 Papaya (Carica papaya L) twigs. The bark becomes shrunken, dark to purplish, with cankers forming in the affected areas. The dead leaves Anthracnose {Colletotrichum gloeosporioides Penz.) fruit hang on over an extended period giving the tree a and foliar infections occur wherever papaya is grown. scorched appearance (14, 34). The bacterium over-winters Foliage symptoms are known to occur or have been re in the live tissue on the edge of the cankers. At the onset ported from the Bahamas, Florida, Caribbean Islands, of the spring rains the bacterium begins to ooze from in Central America, Hawaii, India, and Surinam. Early fected tissue. Insects are attracted to the exudate and carry symptoms on the leaves appear as small water-soaked spots the bacterium to the flowers and leaves. The rain or irriga of irregular shape. The spots continue to enlarge and turn tion splashes the bacteria to the flowers, tender shoots, and light brown in color, occasionally coalesing. The centers of suckers. The bacteria is also spread mechanically, mainly the older lesions turn gray white in color and occasionally through pruning (18, 34). drop out, giving a shot hole appearance. Imbedded in the necrotic centers of the older lesions are numerous acervuli, Barbados Cherry ( Malpighia glabra L.) appearing as small black specks (14). The fungus infects the young green fruit but symptoms Cercospora leaf spot (Cercospora bunchosiae Chupp and do not develop until the fruit matures. Symptoms on fruit Muller) has been reported from Florida and Hawaii. The first appear as water-soaked spots that develop into sunken occurrence of this disease is associated with the high lesions in which tan to pink spore masses appear in acer humidity in the summer months. The leaf spots are brown, vuli. Lesions generally enlarge to 5 mm in diameter and roughly circular, slightly depressed, with gray centers, turn dark in color. The infection extends into the flesh of which may vary in size up to 10 mm in diameter. The the fruit usually giving the appearance of a plug (14). lesions are surrounded by yellow halos and appear on both Disease severity is increased under conditions of exces surfaces. The lesions on the young tender leaves are larger sive moisture and high temperatures. The pathogen is eas than those on mature leaves (7, 14, 23). ily spread by rain or irrigation with wind. Ringspot virus is the most limiting factor to papaya pro Mamey ( Caloearpum sapota (Jacq.) Merr. duction in Florida. The disease has been reported from Africa, Australia, the Caribbean area, China, Hawaii, India Algal leaf spot (Cephaleuros virescens Kunze) disease on and South America (12, 14). The earliest symptoms appear mamey has only been reported from Florida, but does as a chlorosis in the topmost young leaves, which is fol occur on many genera and species of plants in South Flor lowed by vein clearing, rugosity, and a mottling of the ida. The lesions on the leaves, twigs, and small branches laminae. Leaf malformation and reduction of the laminae, are generally covered with a thin gray-green to reddish- which becomes extremely filiform, resembling phenoxy in gray velvety layer of algal growth during most of the year. jury, appears in the later stages. Occasionally, elongated During the rainy season this growth turns a dark red color dark green streaks develop on the petioles and the upper because of the fruiting bodies, which appear as an out half of the stem. The infected plants become stunted, growth of dense, fine hairs with tiny globular heads at the petioles are shortened, and fruit set is reduced. The fruits tips. The lesions on the leaves are mostly circular, on the on infected plants occasionally exhibit green or dark brown twigs and branches they coalesce to cover the surface for rings. The virus is easily transmitted mechanically and by some 30 to 50 mm. The new growth and large branches the aphids Aphis spiraecola, A. gossypii, A. ucraccivora, A. are affected. The infected branches are stunted with bark rumicis and Myzus persicae (14). cracked and scaly and foliage is sparse (32). Control of ringspot through applications of insecticides for the control of aphids has not been successful since the Jujube (Ziziphus jujuba Mill.) aphids do not colonize the papaya. Resistant cultivars have shown some promise in Florida, Hawaii, and Taiwan. The Cercospora spot (Cercospora jujubae Chowdhury), which most promising method of control is cross protection, causes Cercospora leaf spot is known in India and Florida. where the young seedlings are inoculated with a mild strain Cercospora jujubae and disease it causes are different from of the virus. other Cercospora species that are known to Florida. The mycelium of the fungus grows inside the leaf tissues and Loquat ( Eriobotryae japonica Lindl.) also on the outside on the under surface of the leaf giving the appearance of a sooty mold. The early symptoms first Leaf Spot (Entomosporium mepili (DC. ex Duby) Sacc. [E. appear as tiny dark brownish black irregular areas of fun Maculatum Lev., E. thuemenii (Cke.) Sacc; Diplocarpon mes- gus mycelium and spores on the underside of the leaf. The pili (Sauer) Sutton, perfect state, non Fabraea maculata Atk.] top of the leaf turns a light yellow. The individual areas spot was reported from Brazil in 1930, and is known to continue to enlarge, eventually coalescing and cover the occur in Australia and Florida. Leaf spots are dark colored, underside of the leaf (8). circular, up to 3 mm in diameter with a distinct halo. The spots on the leaves, young twigs and fruits occasionally coalesce and become misshapen. The conidial stage is the Literature Cited only form which attacks the loquat. Black acervuli are pro 1. Alencar, J. 1941. Notas sobre a entomosporiose na ameixa amarela duced below the epidermis in the leaf spot, which ruptures (Eriobotrya japonica Lindl.) Ceres 3:117-120. to release large masses of conidia (1, 14, 18). 2. Alfieri, S. A., K. R. Langdon, C. Wehlburg, and J. W. Kinbrough. 1984. Index of plant diseases in Florida. Fla. Dept. Agr. and Con Fire Blight (Erwinia amylovora (Burr.) Winslow et al.) is sumer Serv. Bui. 11. 389 pp. the most serious disease of loquat. The bacterium causes 3. Arruda, S. C. 1940. Anthracnose e cancro das Annonaceas. Biologico browning of the blossoms, leaves, and blackening of the 6:224-225.

226 Proc. Fla. State Hort. Soc. 99: 1986. 4. Barker H. C. 1926. Fruitlet black rot disease of pineapple. Phytopath. 25. Johnson, M. O. 1935. The pineapple. 306 pp., Honolulu, Hawaii. 16:359-363. 26. Larsen, L. D. 1910. Diseases of pineapple. Hawaii Sugar Planters' 5. Bratley, C. O., and J. S. Wiant. 1938. Diseases of fruits and vegetables Assoc. Expt. Sta. Div. Path, and Physiol., Bui. 10. on the New York market during 1937. U.S. Dept. Agr. Plant Dis. 27. Linford, M. B. 1952. Pineapple diseases and pests in Mexico. F.A.O. Rptr. Sup. 106:74-82. Plant Protect. Bui. 1:21-25. 6. Burger, 0. F. 1921. Variations in Colletotrichum gloeosporioides Penz. J. 28. Matthews, W. H. 1959. Pineapples in Florida. Fla. Agr. Ext. Cir. 195. Agr. Res. 20:723-737. 29. McKnight, T. 1941. Water blister disease of pineapples. Queensland 7. Burnett, H. C, and J. R. McFarlin. 1960. Cercospora bunchosiae; a new Agr. Jour. 55:182-189. leaf spot disease of Barbados cherry. Plant Dis. Reptr. 44:505. 30. McKnight, T. 1946. Water blister disease of pineapples. Queensland 8. Burnett, C. 1966. Leafspot, Cercospora jujubae Chowdhury, on Jujube, Agr. J. 62:278. Ziziphys mauritiana Lam. Fla. Dept. of Agr. Div. of Plant Industry. 31. McMillan, Jr., R. T. 1974. Rhizpous artocarpi rot of jackfruit (Artocarpus Plant Path. Cir. No. 44. heterophyllus). Proc. Fla. State Hort. Soc. 87:392-293. 9. Chaudhuri, S. D. 1948. Appendix II. Annual Report of the Economic 32. McMillan, Jr., R. T. 1986. Cephaleuros virescens; a new branch and twig Botanist. Assam, for the year 1945-46. Rep. Dept. Agric. Assam. blight of Calocarpum sapota. Plant Disease (In press). 1945-46, pp. 85-170. 33. Mowry, H., L. R. Toy, and H. S. Wolfe. 1967. Miscellaneous tropical 10. Chaudhuri, S. 1949. Some studies in the Rhizopus rot of jackfruit. J. and subtropical Florida fruits. Fla. Agr. Ext. Serv. Bui. 156A. Indian Bot. Soc. 18:42-50. 34. Okabe, N. 1955. Bacterial plant diseases in Japan. V. A study of 11. Collins, J. L. 1960. The pineapple. New York, N.Y. loquat bacteriosis, canker and bud blight, caused by Pseudomonas 12. Conover, R. A. 1964. Distortion ringspot, a severe virus disease of eriobotryae (Takimoto) Dowson. Rept. Fac. Agr. Shizuoka Univ. 5:100- papaya in Florida. Proc. Fla. State Hort. Soc. 77:440-444. 106. 13. Conover, R. A. 1978. Corynespora leaf spot, a disease of Florida 35. Oxenham, B. L. 1953. Notes on two pineapple diseases in Queens papayas. Proc. Fla. State Hort. Soc. 91:184-185. land. Agr. Sci. 10:237-245. 14. Cook, A. A. 1975. Diseases of tropical and subtropical fruits and 36. Oxenham, B. L. 1957. Diseases of the pineapple. Queensland Agr. nuts. Hafner Press. New York. J. 83:13-26. 15. Crisanto, J. 1924. Rhizopus artocarpi: its cultural characters and its 37. Purss, G. S. 1953. The fruit rots of the custard apple. Queensland J. relation to Rhizpous nigricans. The Philippine Agr. 12:465-468. Agr. Sci. 10:247-265. 16. Cummins, G. B. 1941. Descriptions of tropical rusts. IV. Bull. Torrey 38. Rose, D. H., C. Brooks, C. O. Bratley, and J. R. Winston. 1943. Bot. Club 68:466-472. Market diseases of fruits and vegetables, citrus and other subtropical 17. Cummins, G. B. 1956. Nomenclatural changes for some North Amer fruits. U.S. Dept. Agr. Misc. Pub. 498. ican Uredinales. Mycologia 48:601-608. 39. Seerano, F. B. 1928. Bacterial fruitlet brown rot of pineapple. Phil. 18. Doepel, R. F. 1966. Loquat diseases—black s ot and fleck. Western J. Sci. 36:271-3-5. Australia Dept. Agr. J., Ser. 4, 7:225-227. 40. Seerano, F. B. 1934. Fruitlet black-rot of pineapple in the Philippines. 19. Edmonstone-Sammons, C. P. 1957. Pineapples. Black spot: Phil. J. Sci. 55:337-362. symptoms and control. Farming in So. Africa 32:22-23, 25. 41. Sideris, C. P., and G. C. Walsron. 1930. Diseases of the pineapple 20. Edmonstone-Sammons, C. P. 1958. Some aspects of black spot in fruit. Pineapple News 4:79-93. pineapple. So. African J. Agr. Sci. 1:111-120. 42. Singh, S, H. S. Sehgal, P. C. Pandey, and B. K. Bakshi. 1967. Anthrac 21. Garcia, L. A. A. 1949. Anthracnose of the Annonaceae in Puerto nose disease of cashew (Anacardium occidentale Linn.) its cause, Rico. J. Agr. Univ. Puerto Rico. 33:27-43. epidemiology and control. Indian Forest. 93:374-376. 22. Hepton, A. and E. J. Anderson. 1968. Interfruitlet corking of pineap 43. Smith, M. A., and G. B. Ramsey. 1950. Bacterial fruitlet brown rot ple fruit, a new disease in Hawaii. Phytopath. 58:74-78. of Mexican pineapple. Phytopath. 40:1132-1135. 23. Holtzmann, O. V., and M. Aragaki. 1966. Susceptibility of acerola to 44. Smoot, J. J., L. G. Houck, and H. B.Johnson. 1971. Market diseases Cercospora leaf spot. Phytopath. 56:1114-1115. of citrus and other subtropical fruits. U.S. Dept. Agr. Handbook 398. 24. Johansson, N. 1934. A contribution to the knowledge of the etiology 45. Thompson, A. 1937. Pineapple fruit rots in Malaya. Malayan Agr. J. of fruitlet black rot diseases of pineapple. Svensk. Bot. Tidska. 25:407-420. 283:384-404. 46. Tryon, H. 1898. Fruitlet core-rot of pineapple. Queensland Agr. J. 3:458-467.

Proc. Fla. State Hort. Soc. 99:227-230. 1986.

STATUS OF PESTS OF MINOR TROPICAL FRUIT CROPS IN SOUTH FLORIDA

J. E. Pena of insect and mite species attacking papaya ( Carica papaya University of Florida, IFAS L), annonas (A. squamosa), carambola (Averrhoa cara Tropical Research and Education Center mbola L), mamey sapote ( Colocarpum sapota Jacq. Merrill), 18905 S. W. 280 St. and Barbados cherry (Malphighia glabra L.) is presented as Homestead, FL 33031 well as recent advances in entomological research.

Additional index words, papaya, Toxotrypana, Tetranychus, An- Minor fruit crops such as papaya (Carica papaya L.), nona, seed borer, Mamey, Cuban May beetle, carambola, mamey sapote (Calocarpum sapota [Jacq.] Merrill), annonas Barbados cherry, Caribbean fruit fly. (A. squamosa L., A. squamosa x A. cherimola Miller), caram bola (Averrhoa carambola L.) have increased in importance during the last years in south Florida (8, 16); whereas, Abstract. The recent increase in the acreage of minor tropical others such as Barbados cherry (Malphighia glabra) have fruit crops in south Florida has produced new pest problems been grown in more or less unchanging quantities (16). and increasing problems with established pests. An overview The acreage increase of these fruit crops and the in creased reliance on pesticides as control tactics have been Florida Agricultural Experiment Stations Journal Series No. 7768. largely responsible for the build up of pest problems in Chemicals used for research purposes only. No endorsements or registra some of these crops. In general, insect pest management tion implied herein. programs have not been developed for minor fruit crops

Proc. Fla. State Hort. Soc. 99: 1986. 227