馬拉巴栗之研究

A Study on Malabar Chestnut, Pachira Macrocarpa, Schlecht

蔡致謨(Chih-Mo Tsai) ； 傳文吾(Wen-Wu Fu)

《中華農業研究》 2卷4期 (1951/12) Pp. 89-102

https://doi.org/10.29951/JARC.195112.0007

並列摘要

1. The Malabar chestnut is a deciduous, tropical tree, which belongs to the family Bombacaceae. It is native to Mexico, Central America. It was introduced into the Chiayi Experiment Station of the Taiwan Agricultural Research Institute in 1931, and was found growing and fruiting very well at Chiayi.
2. A nine-years-old tree reaches a height of 5.61 meters, the crown of which spreads to a diameter of 5.28 meters. The bark is in bluish green. The leaf is palmately compound, about 21.28 cm. long by 31.08 cm. wide, with 4 to 7 leaflets and frequently 6 in number. Leaflets are oblong or obovate, and glabrous.
3. Flower solitary, petals up to 20 cm. long, lacinate or linear in shape, greenish pubescent without, white or pale yellow within. Calyx is stipitate, cuptike, and smooth or nearly so, 5 shallow-lobed and light green in color. Flowers those blooming in spring usually have 5 petals, scarcely 6 or 7 in number, while those blooming in sutumn frequently have 6 or 7 petals. During flowering time, petals revolute outward and a rosette of stamens with long and white filaments reveals, and this gives the tree an attractive appearance. Stamens are numerous, about 125 to 254 in number in one flower. Filaments are about 15.4 cm. long and one third of their lower part is united as a tube. Pistel is single, 17 cm. long and its stigma is 5 lobed.
4. Capsule is ovoid in shape, leathery, 8.5 cm. long by 6.2 cm. in diameter, and with 5 longitudinal sutures. When the fruit becomes ripe, the husk splits naturally along these sutures, and the seeds will scatter out over the ground. If the conditions are favourable all the seeds will germinate instantly.
5. The kernel is salmonish brown in color, covered with several yellowish white stripes. The raw kernels are edible by stewing them with sugar and water, and give a good taste. The sun dried kernels may also be roasted which give a delectable taste with good flavour and aroma.
6. According to the observation in 1949 the tree flowers four times a year. The first flowering period began from 20th. April to 22nd. May; the second period, from 29th July to 2nd September; the third period, from 24th September to 20th October, and the fourth period, from 14th November to 12th January of the next year. But the flowering periods in 1950 were different from those in 1949. The flowering periods were 5-9 days earlier respectively than the corresponding periods in 1949.
7. The flowers maturing into fruits reguired 50-85 days in the second period. But in the fourth period it prolonged to 118-177 days. And in both the first and the third periods 90 days were needed.
8. Although the blossoming dates of the Malabar chestnut in each period are as long as twenty four to sixty days, the fruits mature in uniformity, and may be harvested in a few days after the first one has splitted its husks.
9. The bolossoming duration of a single flower varies in different periods. Flowers of the Malabar chestnut always open early in the morning, but those of the first and the third periods wilt in the evening or the next morning of the blossoming day, those of the second period wilt in two or three hours after opening, and still those of the fourth period open for two to three days and then wilt. Obviously the blossoming duration is greatly influenced by the climatic conditions at that time.
10. In the years of 1949 and 1950 the trees gave highest yields in the first period, with averages of 155.88 fruits and 3.134 kilos of kernels, and 257.63 fruits-and 4.148 kilos of kernels per tree respectively.
11. As comparing the total yearly yields between the two years, the same eight trees produced more fruits and kernels in 1950 than they did in 1949, with an average of 191.76 fruits per tree in 1949 as against 310.64 fruits in 1950, and 3.738 kilos of kernels in 1949 as against 5.151 kilos in 1950. The cause of such a difference in yields between these two years is unknown. It needs further investigation to obtain more conclusive data.
12. The weight and the size of the fruit in 1950 are less than those in 1949. This may be due to the poor development of fruits in that year as a result of heavy bearing.
13. Fruits harvested in the second period are heavier with more kernels within them than those in the other periods, but the percentage of well-developed kernels is much lower. In this connection it must be mentioned that fruits harvested in the second period are not as good as those in the first period.
14. Fruits harvested in the third period also give a lower percentage of well-developed kernels, while fruits harvested in the fourth period not only small in size, but with fifty to eighty eight percent of poor-developed kernels, which are almost regarded as waste fruits. In addition, typhoons occurred frequently during the blossoming and the fruiting season of the second and the third periods, and thus decrease the setting percentage.
15. As regarding the growth habit and fruiting habit of the Malabar chestnut, records were taken in 1950. New shoots always grow from the terminal bud of branches, and flowers are located in the axils of its first to fourth leaves. Flower buds are, therefore, develoing only when the tree grows its new shoots. Only a few lateral shoots are produced in the growing season. If so, they are located on the lower part of the new shoot, growing simultaneously with the latter.
16. About 90.63 percent of the spring shoots (namely those growing in the first period) bears flowers among which 54.38 percent produces mature fruits. In summer and autumn a great number of branches are dormant and only 10 percent of the total branches flushes.
17. 208 out of 435 shoots bear one flower only; 141, two flowers; 63, three flowers; 15, four flowers; 6, five flowers. It scarcely happened that a shoot bears more than five flowers.
18. Similarly, a majority of shoots produces one fruit each. 219 out of 261 shoots hear one fruit; 36, two fruits; 6, three fruits. It is seldom that one shoot bears more than three fruits.
19. Flowers and fruits are mainly borne along the short shoots rather than the long ones. Shoots with 2-4 cm. in length and 7.5-12 mm. in diametr (the measurements were taken on 15th June, 1950, when three and half months after they started growing) are proved to bear fruit more satisfactory.
20. As it has mentioned above that lateral shoots are generally developed from the lower part of the new shoot, growing simultaneously with the latter, 17 out of 480 spring shoots have produced laterals, given a percentage of 3.54.
21. On each of these 17 spring shoots one to four laterals may be found, 2 being the popular number.
22. Spring shoots which have the ability of developing laterals are long and vigorous ones.