The effects of night temperature and photoperiod on the growth and development of Adelphia and Amsoy soybeans : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Agricultural Science in the University of Canterbury [Lincoln College]

Abstract

The origin of the soybean (Glycine max (L.) Merrill) is obscure, but there are indications that it came from north and central China (Manchuria). This plant has been important in China since the reign of Emperor Bhen-Nung about 2,838 B.C. About this time the Chinese described more than 300 remedies based on soybeans for the cure of human ills.

The first published account of soybeans in United States appeared in1804. At that time there were no more than eight varieties in that country. The soybean is classified in the family: Leguminosae and sub-family: Papilionoideae. Many commercial crops are varieties of Glycine max (2n=40). Its progenitor is G. Ussuriensis, a species that has been traced back to North China.

The germination of soybean seed is epigeal, and a tap-rooted summer annual of either determinate or indeterminate form develops. A single trifoliate leaf is borne on each node except the first from the base of the main stem which is a cotyledonary node, and the second node which bears two unifoliate leaves. In each axil there is an axillary bud which may develop into a new branch or flower cluster. Flowers develop first nearest the base of the main stem and then progressively upwards. The flowers may be white, purple or intermediate between these colours. Fertilization occurs within the unopened flower (Cleistogamy). Most leaves turn brown and drop off at maturity. Mature pods are concentrated on the upper parts of the axes.

The uses of soybean are many and varied. Branched and bushy varieties were originally used for hay and as green feed for stock in United States. Oil and protein are the most valuable components of the beans. Linoleic acid constitutes about 50% of soybean oil. In the home the oil is used as margarine and salad oil, in cooking and in sundry edible products. It is used in industry in the manufacture of paints, varnishes and linoleum, rubber fabric, soap, etc. The protein is mostly glycinin. Glutamic acid is a major amino acid while methionine may be deficient. As a protein supplement, soybean oil meal is used in manufacture of adhesives. Soybean flour is used for human nutrition in bread and other bakery products, in spaghetti, baby foods and high protein beverages. “Soy milks”, soybean protein extracts (Abdo and King, 1967) are valuable for infants and patients unable to metabolize human and bovine milk as a result of genetic block. The soybean grain is an important food item, complementary with rice in the Orient, especially China and Japan, This versatile bean is also expected to play on important part in synthetic meat industry.

The soybean crop became third in value ahead of wheat in 1964 (Hinson, 1967). United States produced 70 of the estimated world production in 1966 of 1.3 billion bushels of beans, or 929 million bushels (Judd 1966). Soy bean production in mainland China was second and Brazil third. Indonesia and Japan are also important producers.