4080 P-03 9/17/03 11:04 AM Page 83 3 Red Bayberry: Botany and Horticulture* Kunsong Chen, Changjie Xu, and Bo Zhang Department of Horticulture Huajiachi Campus, Zhejiang University Hangzhou, 310029, P. R. China Ian B. Ferguson The Horticulture and Food Research Institute of New Zealand Private Bag 92 169 Auckland, New Zealand I. INTRODUCTION A. History B. Distribution C. Commercial Production II. BOTANY A. Taxonomy B. Morphology and Anatomy III. PHYSIOLOGY A. Vegetative Growth B. Flowering and Fruit Set C. Fruit Development IV. ENVIRONMENTAL REQUIREMENTS A. Temperature B. Water C. Soil D. Light E. Elevation and Exposure *This review was supported by the State Key Basic Research and Development Plan (G2000046806), the National Natural Science Foundation of China (30170660), and Zhe- jiang Natural Science Foundation (ZD0004), and was also a part of a cooperative program between The Horticulture & Food Research Institute of New Zealand and Zhejiang Uni- versity. We thank Dr. Grant Thorp for critically reading the manuscript. Horticultural Reviews, Volume 30 Edited by Jules Janick © 2004 John Wiley & Sons. ISBN: 978-0-471-35420-8 83 4080 P-03 9/17/03 11:04 AM Page 84 84 K. CHEN, C. XU, B. ZHANG, AND I. FERGUSON V. HORTICULTURE A. Propagation B. Field Cultivation C. Pests and Diseases D. Harvest and Handling E. Storage and Transportation F. Processing VI. CONCLUDING REMARKS LITERATURE CITED 1. INTRODUCTION Red bayberry (Myrica rubra Sieb. & Zucc., Myricaceae) is a subtropical fruit tree native to China and other Asian countries, bearing a delicious, berry-like fruit (Fig. 3.1). Gengmin Wu, founder of modern Chinese hor- ticulture, praised it as a “precious Southern Yangtze fruit of early sum- mer ” (Wu 1995). The fruit ripens in June and early July in the main Chinese production areas of Zhejiang and Jiangsu provinces, earlier than most other local fruits. The rich red colors and appealing flavor make this juicy fruit popular with consumers; it is eaten like a cherry. Fig. 3.1. Red bayberry (Myrica rubra) fruit and trees. A and B: mature fruit showing (B) the segmented juicy flesh and the hard stone. C: fruit growing on the outer space of the canopy. D: trees growing on hillsides, a common cultivation practice in China. Photos by Jiangguo Xu. 4080 P-03 9/17/03 11:04 AM Page 85 3. RED BAYBERRY: BOTANY AND HORTICULTURE 85 In addition to being consumed fresh, various products such as juice, canned fruit, jam, wine, sweets and salted fruit are produced. Present- day commercial cultivation is still largely restricted to China. The fruit and roots of red bayberry have been used as important com- ponents of traditional Chinese medicines for more than 2000 years (Li 1578), the fruit being beneficial for treating congestion, coughs, diges- tive problems, and diarrhoea. The root also has wound healing proper- ties. In recent years, a number of pharmaceutically active compounds have been identified from the various plant parts (Zhang et al. 1993; Chi et al. 2000; Yi and Liu 2000; Zhong et al. 2000). The evergreen tree has a bushy, round canopy and grows well in soils of low fertility, having an association with the nitrogen-fixing bacterium Actinomyces frankia. The tree is used in China to increase the organic matter content of soil, reduce soil erosion, and to enhance the landscape (Wang and Chen 1989). Red bayberry is often interplanted with existing vegetation such as pine or other natural forest trees (Wang et al. 2001). While the fruit is well known throughout China, where there is a con- siderable body of literature on various aspects of production, it is little known elsewhere. There is a short general review on red bayberry avail- able in English (Li et al. 1992), and a review of research progress in China has recently been published (Li et al. 1999). This review will cover the botany and horticulture of red bayberry, most of it based on Chinese publications. A. History In China, red bayberry has been known by a variety of names. Yangmei is the most common name in Chinese. Shizheng Li, in Compendium of Materia Medica (1578), wrote: “The shape of the tree is similar to poplar (Yang), and the taste of the fruit is somewhat like mume (Mei), thus it is named Yangmei.” Shumei (strawberry tree) is used in Taiwan. Zhuhong is a common name in Fujian province and, elsewhere in China, names such as Shanyangmei and Zhurong are used. The English names for this fruit include red bayberry, Chinese bayberry, and waxberry. The fruit has a very long history in Chinese civilization. The earliest records come from the Neolithic site at Hemudu, Zhejiang province, indi- cating that the fruit has existed as a foodstuff for more than 7,000 years (Yu 1979; Wu 1984). Red bayberry fruit and stones have also been found in the Mawangdui tumulus of the Western Han Dynasty (206 B.C.E.–25 C.E.) in Hunan province and the Luobowan tumulus in Guangxi Zhuang Autonomous Region (Yu 1979). Nan Fang Cao Mu Zhuang, a book on the properties of various plants from southern China, written by Ji Han dur- ing the Jing Dynasty (265–420), recorded the cultivation of red bayberry 4080 P-03 9/17/03 11:04 AM Page 86 86 K. CHEN, C. XU, B. ZHANG, AND I. FERGUSON and its use in wine making (Ji 304). By the Song Dynasty (960–1279), the Wu-Yue area (Jiangsu and Zhejiang provinces today) was well known for red bayberry production and the fruit recognized for its quality and quan- tity; locations close to Ningbo and Taizhou in Zhejiang province are still the most important production areas. B. Distribution Red bayberry originated in southeastern China, where it is still found in the wild and is the source of seed for rootstocks. It is now distributed south of the Yangtze River and north of Hainan Island, approximately 97° to 122°E longitude, and 20° to 31° N latitude. This distribution is similar to that of citrus, loquat, tea, and bamboo, except that red bayberry can withstand lower temperatures (Maio and Wang 1987; Maio et al. 1995). The major commercial production area is concentrated in Zhe- jiang, Fujian, Jiangxi, Jiangsu, Guangdong, and Guizhou provinces. There is some production in Yunnan, Guangxi, Sichuan, Hunan, Shanxi, and Taiwan, from semi- or wholly wild trees (Wang 1995). Outside of China (Yu 1979; Wang 1987) the crop is grown in Thailand, although fruit quality is often poor and the area limited. In Japan, it is grown in Tokushima, Kochi, Ehime and the western part of Honshu. In Europe and America, red bayberry trees are used mainly for ornamen- tal purposes. There are a number of closely related species (described below) that are cultivated. Myrica integrifolia Roxb. is distributed in India, Sri Lanka, Burma, and Vietnam, where it is confined to home gar- dens, producing small and acid fruit, usually used for jam or medicine. Myrica esculenta Buch.-Ham. is found in India, Nepal, and Vietnam as well as in southwest China. Myrica faya Ait. has fruit suitable for fresh consumption and is grown in the Canary Islands. C. Commercial Production Production of red bayberry has increased dramatically; the cultivated area in China in 1995 was 130,000 ha. The crop has become one of the most important fruit tree crops in south China (Liu 2000; Wang et al. 2001). In Zhejiang province, the cultivated area and production were 4,400 ha and 26,500 tonnes (t) in 1959, 17,500 ha and 46,200 t in 1985, and 38,378 ha and 129,750 t in 2000 (Wang et al. 2001). As a result, red bayberry is second only to citrus among the fruit crops of the province, and the yield is expected to continue to increase. Most production is consumed locally, but an increasing proportion is being exported both within and outside of China. 4080 P-03 9/17/03 11:04 AM Page 87 3. RED BAYBERRY: BOTANY AND HORTICULTURE 87 II. BOTANY A. Taxonomy 1. Species. The Myricaceae are widespread in tropical, subtropical, and temperate areas of the world. They consist of two genera, Comptonia and Myrica, both of which are cultivated. The genus Myrica Linn contains more than 50 species of which six are found in China (Yu 1979; Maio and Wang 1987; Qu and Sun 1990; Wang 1995; Li et al. 1999). More recently, RAPD (Random Amplified Polymorphic DNA) markers have been successfully used in classification and identification of Myrica species (Lin et al. 1999). Myrica cerifera L. originating from North Amer- ica was clearly distinguished from three Chinese species (Myrica adenophora Hance, Myrica esculenta Buch. -Ham, and Myrica rubra Sieb. & Zucc.), which clustered together. Myrica rubra Sieb. & Zucc. Red bayberry (2n = 16) is an evergreen tree growing to a height of 5 to 10 m, distributed in southern China, but also found in Japan, South Korea, and The Philippines. The bark of young trees is smooth and yellow-green, while that of old trees is grey-brown with white spots and narrow cracks. The canopy is uniform and round or slightly flattened. The branches are frail and easily broken, and the leaves alternate and simple, with blades 5–14 cm long and 1–4 cm wide, usually with smooth margins, although sometimes serrated. The upper and lower leaf surfaces are smooth without hairs, the upper lustrous and dark green and the lower light green. The plant is dioecious, although occasionally monoecious, with the inflorescence forming in axillary buds. The staminate inflorescence is a compound catkin, 1–3 cm long, columnar, and yellow-red; the pistillate inflorescence is a simple catkin and shorter and thinner, filaceous, bright red, with two longitudinal grooves along the stigma.