Table 6. Yield of sweet potato grown on sand, Sanford, 1981. Acknowledgements This paper reports results from a project that contributes 147 days 188 days to a cooperative program between the Institute of Food & Tons/acre rjry wt. Tons/acre Dry wt. Agricultural Sciences (IFAS) of the University of Florida. Cultivar fresh dry- fresh dry and the Gas Research Institute (GRI), entitled, "Methane from Biomass and Waste." W119 10.6 2.5 23.8 21.2 4.7 22.0 W149 7.0 1.5 21.9 18.3 3.8 21.0 Literature Cited Travis 5.5 0.9 15.7 14.4 2.1 14.9 W125 6.7 1.5 23.0 14.1 3.2 22.5 1. Bagby, M. O. 1981. Energy: Alternative sources for agriculture. Morado 3.0 0.8 25.1 12.9 3.3 25.6 Proc. Great Plains Agr. Council, p. 3-10. W115 7.5 1.5 19.9 12.1 2.1 17.5 2. Hall, D. O., G. W. Barnard, and P. A. Moss. 1982. Biomass for W154 8.1 1.5 17.9 — energy in the developing countries. Pergamon Press, New York. 220 p. 3. LeGrand, F. 1980. Producing ethanol by a community distillery for use asa fuel. Florida Agr. Expt. Sta. Cir. 482. 11 p. 4. Silva, J. G. da, G. E. Serra, J. R. Moreira, J. C. Concalves, and J. Goldenberg. 1978. Energy balance for ethyl alcohol production from crops. Science 201:903-906.

Proc. Fla. State Hort. Soc. 95:367-374. 1982.

WETLAND : A NEGLECTED CROP FOR FOOD, FEED AND FUEL1

Stephen K. O'Hair Maoli' taro in a flooded Pahokee muck soil in Belle Glade, IFAS, University of Florida, Florida. Noticeable corm development began in July. A Agricultural Research and Education Center, maximum of 3404 kg dry weight/ha was recorded after 305 Homestead, FL 33031 days of growth in January. Maximum corm and cormel pro duction was recorded in December with a total of 9,317 kg George H. Snyder dry weight/ha. Top growth reach a plateau of 3300 kg dry IFAS, University of Florida, weight/ha by September, which was maintained unfif a Agricultural Research and Education Center, January frost. Belle Glade, FL 33440 Taro, Colocasia esculenta Schott (syns. C. antiquorum Julia F. Morton Morton Collectanea, University of Miami, var. esculenta Schott; Caladium esculentum Hort.), has, Coral Gables, FL 33124 historically, been the most prominent of the edible aroids (family Araceae), and it has acquired various regional names: coco (Jamaica), tannia or eddoe (Trinidad), eddo Additional key words. Colocasia esculenta. (Barbados), taya (French West Indies), oto (Panama), tiquisque (Nicaragua), nampi or nampy (Costa Rica), Abstract. Taro (Colocasia esculenta Schott) is an aroid with quequeisque, quiquisque (El Salvador), makal (Yucatan), large, heartshaped, peltate leaves arising from a starchy ashipa (Peru), inhame branco or inhame da costa (Brazil), main, cylindrical, tapered cormfrom which may develop gabi (Philippines), talo (Samoa), dalo (Fiji), kulkas (Egypt), numerous rounded side cormels. The species is highly vari kolocasi (Cyprus), kalo, keladi, or tales (Indonesia and able and it is claimed that there are more than 1,000 types Surinam). In Guatemala, Cuba and some other Spanish- or races varying in habit, degree of acridity, tenderness, color speaking areas, it is sometimes called "malanga", a term of plant and corm, and adaptability to dry or culture. better limited to Xanthosoma spp. (cocoyam) to avoid con Although it is grown commercially, most crop production and fusion (23). harvesting is done manually. For the past 50 yr, tropical agriculturists have tended to Origin and Distribution replace dryland taro plantings with cocoyam (Xanthosoma spp.) which gives a higher yield with less labor. Neverthe Believed native to India and neighboring regions of less, wetland taro has a place under conditions unsuitable for southeastern Asia, taro has been cultivated there and in the dryland crops. Machines are being developed to replace sev East Indies for more than 2,400 yr. Recent archaeological eral difficult and tedious manual operations. researchin Papua New Guinea indicates that taro was The corms can be peeled and boiled, fried, or dried and grown in the swamps of the Western Highlands Province as made into flour. Taro chip production is currently com much as 9,000 yr ago (42). mercialized. Both the tops and corms can be used to feed Taro was introduced into Egypt about 2,000 yr ago, and swine. All plant parts can be converted to carbon-based fuels. thereafter to Italy and Spain. From Spain it was carried to Monthly harvests were made of March planted 'Lehua the New World. Meanwhile, it spread to various parts of tropical Africa and throughout the Pacific Islands and be came a staple food long before the sweetpotato was known iFlorida Agricultural Experiment Stations Journal Series No. 4386. This paper reports results from a project that contributes to a coopera in Oceania. The northern and southern limits of taro's tive program between the Institute of Food and Agricultural Sciences range of cultivation are "upwards of 10 degrees beyond that ot the University of Florida and the Gas Research Institute, "Methane of the greater yam" (Dioscorea alata L.) (6). from Biomass and Waste". Mention of a chemical product does not Over the past 300 yr, taro has taken second place to the imply endorsement or registration in the U.S. for that use on taro. 367 Proc. Fla. State Hort. Soc. 95: 1982. sweetpotato, and some taro-producing swamplands have wide, on green, green-and-purple, or wholly purple, suc been abandoned in Papua New Guinea. Nevertheless, wet culent petioles 40 to 150 cm long. Leaf color varies from land taro is still important in the Cook Islands, Fiji, the light- or dark-green to more or less purple. The incon New Hebrides, and in New Caledonia where irrigated plant spicuous inflorescence which forms seasonally (1 or from ing declined for some years and then was revived (42). 2 to 5 together) is a cylindrical spadix about 10 cm long, Today, 99% of Hawaiian taro production is in flooded yellow or reddish above and green below. Male flowers fields similar to rice paddies (Fig. 1). Even in this case all of occupy 2.5 to 5 cm of the upper part and are separated by a the actual crop production and harvesting is done by hand. space from the female flowers which cover 2.5 to 5 cm of the lower part. The whole inflorescence is shielded by a yellow-and-green spathe about 24 cm long. Seeds are seldom set without hand-pollination although natural seed set oc curs in some cultivars (40, 44). Some forms never have stout corms or rhizomes (underground stems), but edible taro has a starchy main, cylindrical, tapered corm, ranging up to 50 cm long and 20 cm wide, from which may develop sev eral rounded lateral cormels. All are surrounded by a mass of thick, cordlike feeder roots. Externally, corms and cormels are brown-skinned, encircled by fibrous rings. Internally, the corms or cormels may be white, yellow, orange, red, brownish-red, or purple. Cut surfaces often discolor when exposed to air. There is great variation in the degree of acridity.

Varieties The species is highly variable and it is claimed that there are more than 1,000 types or races varying in habit, degree of acridity, tenderness, color of plant and corm, adaptability to dry or wetland culture, and suitability tor various food uses. Var. aquatilis Hassk., with long, slender stolons and with out a swollen corm, has levels of cold tolerance and is naturalized along bodies of in the southern United States (1). In 1903, O. F. Cook (9) reported that Californians of Chinese history had "recently" started raising Chinese taro, corms of which were being imported from Canton and Hong Kong. The French name, "Taro de Chine" in Indochina, was anglicized as "dasheen". This form which produces abundant small cormels, became popular in the West Indies. Dasheen is the botanical variety C. esculenta var. globulifera R. A. Young and includes the cultivars 'Globulifera' (per haps the same as 'Trinidad*), 'Sacramento', and 'Ventura'. In dasheen is called "Japanese" taro. Plants produc ing only a central corm are classed as "Chinese" taro (8). A taro collection started by O. W. Barrett in Puerto Rico was transferred to Brooksville, Florida, in 1906, and the United States Department of Agriculture made vigorous

Fig. 1. The Hanalei National Wildlife Refuge on the Hawaiian efforts to promote dasheen growing throughout the southern Island of , a major site of wetland taro production in the state. states (20). Nonetheless, taro has never competed success Taro production by private producers is encouraged in this wildlife fully with the potato and sweetpotato in this country (18). refuge because it helps reverse the state's trend toward reduced areas In 1939, Whitney et ah (49) described 56 dryland and 31 of , a trend that poses a threat to such wetland dependent as the Hawaiian gallinule. wetland cultivars in Hawaii. A collection of 154 cultivars (56 Hawaiian, 62 from other Polynesian sources, 28 Mela- For the past 50 years, tropical agriculturists have tended nesian, and 8 from other countries) is maintained under to replace dryland taro plantings with cocoyams (Xantho- dryland culture by the Harold L. Lyon Arboretum in the soma spp.) which give a higher yield with less labor. upper Manoa Valley near the University of Hawaii campus Filipinos have come to prefer the mealy, mucilaginous (2) (Fig. 2). texture and the flavor of cocoyams. In tropical Africa, taro Only 5 or 6 cultivars are grown commercially in Hawaii. and yams are giving place to cocoyams bacause the latter are 'Lehua', the main cultivar, produces a pinkish-fleshed corm. more suitable for manufacturing the staple pasty food Others are 'Piko uaua', 'Piko kea', and 'Uliuli' (mostly product, fufu. Yet, wetland taro obviously has a place under white-fleshed); and 'Maui Lehua' and 'Piialii' (reddish- conditions unsuitable for dryland crops. When grown under fleshed). The red-fleshed cultivars are preferred for poi (35). flooded conditions, adapted cultivars grow more rapidly The cultivar 'Sar kachu' is grown in Bengal as an aquatic, and mature more quickly than when grown as dryland taro, producing corms 15 to 30 cm long (48). and yields may far exceed those of dryland taro (11, 42). Cultivation Description In India, Oceania and parts of Africa, wetland taro is Taro is a perennial herb with erect, peltate, heart-shaped, often a fringe crop grown along rice paddy borders, ponds downward-pointing leaves 12 to 60 cm long, 7 to 50 cm and streams. Larger plantings may require field leveling and

368 Proc. Fla. State Hort. Soc. 95: 1982. istered for use on taro in Florida by the U.S. Environmental Protection Agency (EPA). The wetland crop should be ready for harvesting in 12 to 15 months from planting. Corms cannot be left in the ground as long as those in upland culture. The plants are considered to be mature when the newest fully expanded leaves are smaller than the older leaves. Corms taken from immature plants are edible, however they do not store as well as those from mature plants. At harvest the fields are generally re-flooded. It is usually necessary to cut through the feeder roots in a circle around the plant to facilitate harvesting. Laborers usually are equipped with a 1.5 to 2 m pipe with a sharp ened tip (35). The remaining roots are manually detached and the corms washed in the field, then put in mesh- bottomed buckets and rafted to dry land (Fig. 3), where they are further cleaned, bagged and then trucked to dealers and processors (35).

Fig. 2. Mr. Don Anderson, Curator of the Harold L. Lyon Arboretum taro variety collection pictured with a portion of the 150-plus selections he has maintained for many years. Mr. Anderson has been growing taro for over 60 yr.

puddling by plowing, disking, harrowing and grading along with the development of drainage ditches 12.5 to 15 cm deep around the inner field edges. Dike building is generally necessary to control water depth and flow. Constant water circulation is necessary to avoid root rot, to which most cultivars are susceptible in warm, stagnant water. Water depth should be maintained at 2.5 to 5 cm from planting until the plant is well anchored in the soil. There after water level is raised to fully cover the lower half of the plant. Additional culture includes a drainage period of a few days before and after the application of fertilizer (36), and before harvesting to weaken the root structure and facilitate removal of corms. Plantings can be made year round (35). Mechanized planting is being explored in Fig. 3. Windrowed taro corms and cormels with attached 'hulis' Hawaii and a tractor for planting dryland taro has been ready for separation and loading onto a raft which is winched by the developed in Fiji (39); nevertheless wetland culture is still tractor in the background to the dike roadway for transport from the largely manual. field. Setts (corm and cormel crown cuttings with 15 to 25 cm Hawaiian growers look forward to the day of mechanical of leaf petioles attached), called "hulis" in Hawaii, are harvesting. A horizontal auger tractor attachment has been pushed into the soil by hand. The base is submerged 5 to devised which can dig and windrow flooded taro (24, 35). 7.5 cm or until moist soil has been reached. The corm gives Compared to hand-digging, it takes 1/10 of the time. How a higher yield than the smaller cormel. Spacing may be ever, it lifts up the corms with a thick coating of mud which much closer than with dryland taro, ranging from 12,000 to handicaps the manual cleaning and collecting operations. 100,000 plants/ha (11). However, the wider the spacing, the Therefore, pickup and cleaning machines are under develop larger the corm size. Planting at average densities may re ment (21,41). quire 15 to 20 man hr/ha (35). It has been found that taro plants grown on mounds in flooded land are more produc Diseases and Pests tive than plants grown on the level. Adequate N is essential to taro. It is usually incorporated Leaf blight caused by Phytophthora colocasiae Rac. is a into the soil at the outset because the plant requires most common problem in taro paddies in Oceania and the Orient. of its N during the early stages of growth, and also to min Attempts at chemical control have been partially successful imize N losses through leaching and flooding. Wetland taro (16, 17). Some cultivars may be tolerant to this disease. Leaf has given good yields with application of 250 kg N and 250 spot caused by Cladosporium colocasiae Samada is most kg K/ha. Fertilizer trials with wetland taro in Hawaii evident on older leaves. Copper fungicides will control it. showed highest yields in plots given 1120 kg/ha N. Yields Soft rot or pythium rot of the corm resulting from infection in a soil with high P fixation capacity were increased by by several soil-borne species of Pythium has caused severe 1120 kg/ha P and delaying harvesting to 15 months. Appli losses (10-50 or even 100%) in Hawaii. Sanitary measures, cation of K gave no significant increase in corm yield (12, soil treatment with Captan 50W at 100 kg/ha and crop 13). Well fertilized paddies may yield 35,000 to 50,000 kg/ha, rotation are effective means of control in acid soils. In the twice the yield of sweetpotato (19). British Solomon Islands, Fusarium oxysporum Schlecht In wetland culture, weeds are largely controlled by water emend. Snyd. et Hans, has been found responsible for corm depth. Nevertheless some hand- or chemical-weeding is rot in actively growing taro (17). Dasheen mosaic virus is needed. Propanil, prometon, prometryne and nitrofen are the most common virus disease. Yield loss in taro as a result considered appropriate for weed control in wetland culture of this disease has not been documented. if necessary (3). However, no herbicide has yet been reg- Taro leaves are attacked by the taro leaf hopper (Taro- Proc. Fla. State Hort. Soc. 95: 1982. 369 phagus proserpina Kirkaldy. An effective predator, the Philippine sucking bug (Cyrtorhinus fulvus Knight) has provided adequate control of this pest in the Eastern Caro line Islands. Taro plants may be defoliated by the sweet- potato hawk moth caterpillar (Hippotion celerio L.) or by the small grasshopper, Gesonia sanguinolenta, and the cater pillar, Agrius convolvuli L. Injuries also result from attacks of other insects: striped mealybug (Ferrisia virgata Cockerell), thrip (Heliothrips indicus Bagn.), taro thrips (Organothrips bianchii Hood and Pseudobryocoris colo- casicus Carvalho) and aphid (Aphis gossypii Glov.). Taro beetles (Papuana laevipennis Arrow and P. huebneri Fairm) feed on the stems and roots but may be deterred by soil ap plications of dieldrin or aldrin (3, 23). The nematode Meloidogyne incognita (Kofoid k White) Chitwood, has been found on feeder roots of wetland taro in Trinidad (4).

Storage Fig. 4. Ready mixed poi (jar in center) and several brands of taro Corms and cormels can be kept in storage at 10°C with chips are widely available in Hawaiian markets. adequate ventilation for over 5 months (36). Shelf life at ambient (ca. 25 °C) temperatures can be several months (22). and is used either alone or mixed with other flours to make pancakes, rolls, cookies and bread (28, 48). The dough can Food Uses be kept for a long time in sealed metal boxes (28). Young leaves and petioles of "luau" types, low in acrid All parts of the taro plant contain irritant crystals of ity, are commonly eaten as greens (27, 34) after boiling calcium oxalate and/or an acid sapotoxin with definite twice or adding baking soda, lime or lemon juice, milk, seasonal variation, the concentration being highest at the butter or other fat when cooking to reduce or eliminate the end of the dry season (32, 38, 46). Other factors besides acrid properties. As a safeguard, it is best to peel the petioles calcium oxalate have been associated with the acridity (31). since the cuticle contains most of the irritant (10). Thorough 'None o£ the plant parts can be eaten raw. Most of the ir cooking may take 30 to 45 min (29). The leaves are an im ritant is in or near the skin and therefore is largely removed portant ingredient in calalu soup in Trinidad (19). They by peeling (45). To reduce irritation of the hands, peeling are prepared as a creamed soup in Hawaii (27). In Samoa, can be done underwater (6) or plastic gloves can be worn. after removing the midribs, taro leaves are stacked on a In Hawaii, taro is often pre-peeled for sale, being kept in breadfruit-leaf "platter", filled with coconut cream, rolled water to avoid discoloration (8). Thorough cooking elimi up and cooked on hot stones. In Tahiti, leaves and peeled nates the irritant in most cultivars. petioles are layered with chicken or pork, topped with In Oceania, whole taro is commonly roasted on stones or coconut cream and lemon juice, rolled up and cooked in an baked in ovens. The corm may be peeled, sliced or diced oven (28). and steamed, boiled or baked. In New Caledonia, peeled, Very young blanched shoots are obtained by mounding sliced corms with chicken or fish and coconut cream are up mature corms with soil or sphagnum moss in a dark wrapped in leaves and roasted (28). Corms are less place, or in raised greenhouse beds with bottom heat and mucilaginous than the cormels, mealier and richer in flavor heavy shading (50). Long, slim, white or white-and-purple (48), and are better for making chips. Taro chips are made shoots will emerge. When 20 to 30 cm long, they are cut off, like potato chips but absorb less fat and have a distinctive bundled and sold in the market. They are cooked till tender flavor (Fig. 4) (20, 33). Boiled corms are sometimes formed in salted water. Japanese farmers in Hawaii produce these into patties or fritters and fried, and are often added to shoots on a commerical basis as "asparagus taro top" (Fig. stews. In the Philippines, the boiled, sliced corms are sprin 5) (8). kled with sugar and coconut (5). Japanese in Hawaii boil peeled, cut-up corms for 7 min, drain, add sugar and soy sauce and boil again till tender. They also fry and then Food Value simmer diced corms with sliced meat, onion and a little soy Where a population is dependent on wetlands for a sauce, or slice the corm and then cook it with chopped starchy food staple, taro may be a better choice than rice pork and ham or bacon and diced shrimp. The mixture is from the standpoint of human nutrition (14). In fact, it folded into batter, and steamed (8). equals potato for amino acid content (Table 1). Dr. David In Hawaii and Polynesia poi is a slightly fermented Fairchild, in commenting on Hawaiian dietary studies, paste of boiled and mashed taro which is easily digested and wrote that "Japanese babies and children brought up on a considered beneficial to invalids and infants (Fig. 4). As a rice diet in this tropical climate develop serious dental dif part of the main meal, the paste may be eaten as such or ficulties. When fed on a diet of poi [made from taro], they made into patties and baked or toasted. Poi is even added to have strong teeth and far better health" (15). He was re chocolate ice cream mix. There are several commercial ferring to the results of an investigation by Dr. Nils P. Lar processors in Hawaii. The Julliard Fancy Foods Company son of Honolulu who conducted his nutritional experiiueut of San Francisco sells "Ready-mixed poi" through grocery with the people on a plantation of the Hawaiian Sugar stores at $1.19/0.45 kg net weight jar. In southeast Asia, taro Planters* Association (18). is often preserved by salting and drying for future use (19). Corms contain about 64% moisture, 32% carbohydrate Solar drying is a potential alternative where salt is not and 2% protein (Table 2). Leaves of certain cultivars are a available (30). good source of calcium, phosphorus, carotene and vitamin Flour can be made from fresh or pre-cooked corms. Much C, if the cooking water is not discarded (27). The starch like potato flour, it is used in soups, gruels, puddings, gravies grains contain 28% amylase (46), are among the smallest of

370 Proc. Fla. State Hort. Soc. 95: 1982. Table 2. Average nutritional value of taro (nutrients in 100 g edible portion).

Young Conns Leaves shoots Petioles

Calories 137.0z 34.0y 33.0* 29.0* Moisture (%) 64.4 89.9 89.5 93.0 Protein (g) 2.2 2.5 3.1 0.9 Fat (g) ' 0.2 1.0 0.6 0.2 Carbohydrates (g) 32.0 5.3 5.7 3.8 Fiber (g) 1.0 2.1 3.2 1.0 Ash (g) 1.2 1.3 1.1 1.3 Calcium (mg) 16.0 95.0 49.0 25.0 Phosphorus (mg) 47.0 328.0 80.0 12.0 Iron (mg) 0.9 2.0 0.3 0.5 B-Carotene eq. (mg) tr. 3300.0 — 180.0 Ascorbic acid (mg) 8.0 37.0 82.0 13.0 Thiamine (mg) 0.1 0.1 — tr. Riboflavin (mg) 0.1 0.3 - tr. Niacin (mg) 1.2 1.5 — 0.4

zfrom references 25, 26, 47. yfroin references 25, 26 sfrom references 8, 25, 26 wfrom references 7, 8, 25, 26

suggest that it may be a crop that could be readily adapted to Florida wetlands with final use as food, feed or fuel. To observe taro growth and development on a flooded muck soil an experimental planting was made at Belle Glade Fig. 5. Taro shoots (petioles) grown in the dark for use as "asparagus (Fig. 6). taro top".

Table 1. Amino acid content of taro corms in comparison with potato (mg in 100 g edible portion).

Taro Potato

Isoleucine 77 Leucine 160 125 Lysine 128 106 Methionine 58 22 Cystine 21 19 Phenylalanine 153 67 Tyrosine 64 54 Threonine 129 77 Tryptophan 24 21 Valine 141 115 Arginine 119 105 Histidine 42 35 Alanine 49 80 Aspartic acid 217 262 Glutamic acid 95 352 Glycine 81 70 Fig. 6. An experimental planting of 'Lehua Maoli' taro grown in Proline 74 77 flooded Pahokee muck soil at the University of Florida, IFAS, Agricul Serine 137 70 tural Research and Education Center in Belle Glade as part of a taro production study conducted in 1981. zfrom reference 37 Setts of 'Lehua Maoli' taro received from Dr. Ramon any plant and are more easily digested than those in other de a Pena, University of Hawaii, were planted in 0.5 m foods (48). spacings in unflooded Pahokee muck soil at the AREC-Belle Glade on March 5, 1981. The plot area had been cropped Other Uses to rice in 1979. Triple superphosphate was applied prior to the taro planting to provide 30 kg P/ha. The field was Taro can be employed as feed for domestic stock (43). In addition there is much interest in the potential of taro as flooded so that the bottom half of the plants was covered, once the plants were established. raw material for the production of bio-fuels. For this pur pose taro has value in that it is well adapted to lowland At 1-month intervals, 6 randomly selected whole plants were harvested and divided into their constituent parts soils that are not of value for most other crops. It currently is not of great economic importance in the United States for (leaves, petioles, corms, cormels, roots and unidentifiable food or export and its concentrated carbohydrates can be senescent material). Fresh and dry weight yields were de readily converted to carbon based fuels. termined for each part, and the harvested material was analyzed for starch and glucose. The monthly harvests were made through March, 1982, and a final harvest was taken in Experimental Florida Planting June, 1982. A severe freeze (—6°C) occurred on January 12, The versatility of taro along with its potential yields 1982. Taro leaves and petioles above the water line were

Proc. Fla. State Hort. Soc. 95: 1982. 371

vegetables in Hawaii. Univ. Hawaii Agr. Expt. Sta. Bui. 97, drawn dalo {Colocasia esculenta) planter in Fiji. Fiji Agr. J. 40: Honolulu 110 p. 101-103. 28. Massal, E. and J. Barrau. 1956. Food plants of the South Sea 40. Shaw, D. E. 1975. Illustrated notes on flowering, flowers, seed and Islands. Tech. Paper #94. South Pacific Cornm., Noumea, New germination in taro (Colocasia esculenta). Dept. Agr., Stk., Fish, Caledonia. 52 p. Port Moresby Res. Bui. 13:39-59. 29. Miller, C. D., L. Luis and K. Yanazawa. 1946. Food used by Filipinos 41. Smith, M. R. 1972. Taro harvest mechanization—flooded and up in Hawaii. Univ. Hawaii. Agr. Expt. Sta. Bui. 98, Honolulu. 80 p. land culture. J. Ser. #1410. Int. Conf. Trop. Agr. pp. 252-256. 30. Moy, J. H., W. Bachman and W. J. Tsai. 1980. Solar drying of taro 42. Spriggs, M. 1980. Taro irrigation in the Pacific: a call for more roots. Trans. Amer. Soc. Agr. Eng. 23:242-246. research. South Pacific Bui. 1st quarter 1980:15-18. 31. Moy, J. H., B. Shadbolt, G. S. Stoewsand and T. O. M. Nakayama. 43. Steinke, W. E., J. R. Carpenter, Jaw-Kai Wang and R. S. de la 1979. The acridity factor in taro processing. J. Food Process. Pena. 1982. Taro silage—A new feed for the humid tropics. Trans. Preserv. 3:139-144. Amer. Soc. Agr. Eng. 25:1034-1040. 32. Munsell, H. E., L. O. Williams, L. P. Guild, L. T. Kelley, A. M. 44. Strauss, M. S., G. C. Stephens, C. J. Gonzales and J. Arditti. 1980. McNally and R. S. Harris. 1950. Composition of food plants of Genetic variability in taro, Colocasia esculenta (L.) Schott (Araceae). Central America VI. Costa Rica. Food Res. 15:379-404. Ann. Bot. 45:429-437. 33. Murray, B. K. 1977. Taro emerges as a new commercial crop. Food 45. Sunell, L. A. and P. L. Healey. 1979. Distribution of calcium oxalate Prod. Dev. 11:30. crystal idioblasts in conns of taro (Colocasia esculenta). Amer. J. 34. Ochse, J. J. and R. C. Bakhuizen van den Brink. 1931. Vegetables Bot. 66:1029-1032. of the Dutch East Indies. Dept. Agr., Industry & Commerce Neth. 46. Watt, J. M. and M. G. Breyer-Brandwijk. 1962. Medicinal and E. Indies, Buitenzorg, Java. 1004 p. poisonous plants of Southern and Eastern Africa. E. & S. Living 35. Plucknett, D. L. and R. S. de la Pena. 1971. Taro production in stone, Ltd., Edinburgh. 1457 p. Hawaii. World Crops 23:244-249. 47. Vieth, G. R., B. W. Begley and W. Y. Huang. 1980. The economics 36. Plucknett, D. L., R. S. de la Pena and F. Obrero. 1970. Taro of wetland taro production in Hawaii. Hawaii Agr. Expt. Sta., Agr. (Colocasia esculenta). Field Crop Abstr. 23:411-426. Econ. Dept. Paper 51, 16 p. 37. Rao, M. N. and W. Polacchi. 1972. Food composition table for use 48. Wealth of India: Raw Materials. 1950. Vol. II. Council Sci. Indus in East Asia. Part II. Amino acid, fatty acid, certain B-vitamin trial Res., New Delhi, pp. 310-312. and trace mineral content of some Asian foods. U.S. Dept. Health, 49. Whitney, L. D., F. A. I. Bowers, and M. Takahashi. 1939. Taro Educ, & Welfare No. (NIH) 75-465. Bethesda, MD 334 p. varieties in Hawaii. Univ. Hawaii Agr. Expt. Sta. Bui. 84, Honolulu. 38. Rashid, M. M. and H. J. Daunicht. 1979. Chemical composition of 86 p. nine edible aroid cultivars of Bangladesh. Sci. Hort. 10:127-134. 50. Young, R. A. 1920. Forcing and blanching dasheen shoots. U.S. 39. Sharma, A. P. 1978. Design, development and evolution of a tractor Dept. Agr. Cir. 125. 6 p.

Proc. Fla. State Hort. Soc. 95:374-376. 1982.

ABSORPTION AND TRANSLOCATION OF SOME GROWTH REGULATORS BY TOMATO PLANTS GROWING UNDER UV-B RADIATION AND THEIR EFFECTS ON FRUIT QUALITY AND YIELD Agustin Prudot and Fouad M. Basiouny1 stratosphere could cause a reduction of atmospheric ozone Department of Agricultural Sciences, (1, 4, 9). This would result in a concomitant increase in Tuskegee Institute, penetration of solar ultraviolet radiation to the earth's sur Tuskegee Institute, Alabama 36088 face with possible biological consequences (5). Simulating various atmospheric ozone concentrations, many investi Additional index words. Carotenoids, ascorbic acid, total gators showed reduction in many aspects of plant growth soluble solids. and development due to the exposure of plants to the UV-B irradiation. The use of growth regulators to accelerate, re Abstract. An experiment was conducted in the green tard, or modify plant growth and development is now com house to study the effects of UV-B irradiation on the absorp monly accepted. Absorption and translocation of these com tion and translocation of indoleacetic acid, gibberellic acid, pounds depend on many internal as well as environmental 2,3,5-triiodobenzoic acid, 6-benzylamino purine, kinetin, conditions. Light quality has been reported to affect the and ethylene by tomato plants. UV-B induced variable effects uptake of many organic and inorganic substances (8). This on the absorption and translocation of different growth regu experiment was conducted to evaluate the absorption and lators. Regardless, of the growth regulator treatments plant translocation of several growth regulators by tomato plants height, yield, total soluble solids, pH, carotenoids and growing under UV-B conditions and their effect on fruit ascorbic acid were slightly reduced under UV-B enriched quality and yield. conditions which indicated a direct effect of UV-B on different morphological and physiological processes of the tomato Materials and Methods plants. Tomato (Lycopersicon esculentum Mill cv. 'Walter') seeds were planted in the greenhouse in a mixture of ver- Plants growing in their natural habitat are constantly miculite, peat moss, and fine sand (1:1:1 by volume). Seeds exposed to radiant energy of all wavelengths from the sun were germinated under ultraviolet light UV-B ( + UV-B) or which reaches the surface of the earth. An important por without UV-B (-UV-B) (UV-B = 280-310 nm,) in a ran tion of this electromagnetic radiation is the ultraviolet. domized block design. When the plants reahed the second- There has been a growing concern that effluents from super leaved stage, they were sprayed with six different growth sonic and other highflying crafts, chlorofluoromethane, re regulators (Table 1). UV-B irradiance was supplied by frigerants and aerosol propellants, that diffuse to the twelve Westinghouse FS40 Sun Lamps filtered through either cellulose acetate for (+ UV-B) or mylar film for

iGraduate Student and Professor of Plant and Soil Sciences, respec (-UV-B). The plants received a total of 872 hr of UV-B tively. irradiation during the growing season. The temperature of

374 Proc. Fla. State Hort. Soc. 95: 1982.