Vavilov wrote of the need to “reveal the genius of the people and to tear down the Chinese wall of isolation”. The Western scholar who best came to embody that idea was Joseph Needham, with his massive project Science and Civilisation in China. The volume on Agriculture, published in 1984, contains much on kaoliang, extracted below. [1]
Cultivated sorghum (S. bicolor or Andropogon sorghum) is an African domesticate. Archaeological evidence suggests that it reached India soon after -2000, but the date of its introduction to China remains uncertain. Remains of sorghum have been reported from several neolithic, Chou and Han sites in North China, but their identification as sorghum is not universally accepted, and possible references in early texts are far from unambiguous.
Chinese sorghum is nowadays generally referred to as kao liang, literally ‘tall millet’; this name appears for the first time in the Wang Chen Nung Shu of +1313, but the plant was more commonly known in pre-modern times as shu shu, ‘Szechwan millet’ (Fig. 220), a name still in common use today in the South and West of China. The term shu shu first appears in the +3rd-century Po Wu Chih, which reads: “If a field is planted with shu shu for three years, then for seven years after there will be many snakes (ti san nien chung shu shu, chhi hou chhi nien to she)”. But even if the text is authentic (the Po Wu Chih has long since been lost except in quotation, and is full of later interpolations), the identification of shu shu with sorghum is not certain. The Chhi Min Yao Shu, in its section on exotic plants, quotes the late +3rd-century Kuang Chih which refers to a cereal called ta ho, ‘great millet’, introduced to China from Su-the-kuo (probably Sogdiana), over ten feet tall and with seeds like mung beans, as well as to a cereal called ‘willow millet’ (yang ho), as tall as rushes, which it says was the same as the ‘Szechwan millet’ (pa ho) or ‘tree millet’ (moo chi) of the Central States. These plants do sound similar to kaoliang, which is characterised by its tall stems ten feet high, huge panicles and comparatively large seeds. In Wang Chen’s description of shu shu, written in 1313, which definitely refers to sorghum, he says: “the stalks are over ten feet high and have panicles as large as a broom. The grain is black as lacquer and like frogs’ eyes.” Sorghum was known in both India and the Arab world well before its introduction to China, and coming from either place Szechwan would be a likely point of entry; the name shu shu means ‘Szechwan millet’, as does the term pa ho given in the Kuang Chih, which adds some weight to Wang Yü-Hu’s proposal that yang ho and pa ho be identified with sorghum. Even Hagerty, who doubts any introduction of sorghum into China proper before the Southern Sung, concedes that it may have been known in parts of Szechwan at a much earlier period.
Hagerty says that the earliest unambiguous references to sorghum are to be found in the Yuan texts, though he believes on linguistic grounds that the grain may have been introduced into Northern China during the Southern Sung, while Ping-Ti Ho says that the first unmistakable botanical description is given in the +1175 edition of the Hsi-An Chih, the history of Hui-Chou prefecture in Southern Anhui written by the famous natural historian Lo Yuan. On the other hand, both Amano and Wang Yü-Hu refer to a Northern Sung text, the Pei Meng So Yen, which describes the general Chu Wen on campaign in North China in c. +910, coming with his troops to a deep channel. They thought that their way forward was barred until they saw that shu shu stems had been piled up in the channel to make a passage (hu chien kou nei shu shu kan chi i wei tao), which Chu and his troops were able to cross on horseback. The shu shu in this passage almost certainly refers to kaoliang, the stems of which were often used for such purposes, and Wang deduces that kaoliang was already cultivated in North China in the early +10th century. A still earlier introduction into China or its border regions is suggested by the fact that the kaoliangs are morphologically related to Sorghum bicolor, the most primitive and least specialised of the early major races of sorghum, and appear to represent a Chinese variant of some early bicolor race.
Be that as it may, whenever sorghum was introduced into China proper, we can say for certain that it was reasonably familiar to Yuan and Ming writers. Wang Chen describes its uses as follows:
The grain can be hulled and eaten, and anything left over fed to livestock. It is a famine food. The tips of the stems can be made into brooms and the straw woven into trays, plaited to make fences or used to provide fuel No part of the plant need be thrown away.
However, we have already seen that Wang Chen described the grain as being ‘black as lacquer’, and in modern China the dark varieties of sorghum, red, brown or black, are considered too bitter for human consumption and are used only for fodder. White and Yellow sorghum, on the other hand, are considered reasonably palatable and sweet. Although sorghum is mentioned in the Wang Chen Nung Shu, Nung Cheng Chhuan Shu and other post-Yuan treatises, it is not until 1760 that the San Nung Chi, a Szechwanese work, gives a detailed account of its cultivation techniques, which are generally very similar to those of millets, and one suspects that sorghum occupied only a very small fraction of the cultivated area until population pressure mounled n the 18th and 19th centuries. Sorghum gives good yields on poor soils and was therefore usually grown on land not suitable for wheat and millet. Hsü Kuang-Chhi remarked on its flood-resistant qualities and its suitability for low-lying land, saying that once autumn had begun, even if the water rose in the fields to a height of ten feet the crop remained undamaged. Sorghum is therefore an ideal crop for marginal land, providing a coarse but edible staple as well as abundant supplies of straw for fodder, fuel and handicrafts. The grain can also be used to distil wine and a fierce spirit, and Wagner claims that up in 90% of the kaoliang crop was used for this purpose in Yunnan and Szechwan. Grain yields are comparable to those of Chinese millets, in the region of 800 to 1000 kg/ha, though the early 18th-century Nung Tshan Ching claimed yields of 2 shih/mu, equivalent to approximately 1900 kg/ha, but the yields of straw are double those of millet, varying from 1500 to 3000 kg/ha, a very important consideration in impoverished areas.
It seems probable, then, that sorghum was a relatively uncommon crop in China in the Yuan and Ming, but that as population pressure mounted during the Chhing it came to occupy an increasingly large proportion of the cultivated area. Not only could it be used to reclaim areas of marginal land too poor for millets or wheat, but eventually it even replaced millet in many areas, for although it was less esteemed as food, its straw was more abundant and extremely valuable; Wu Chhi-Chün was already deploring the replacement of millet by kaoliang in the Northwestern provinces in the mid-19th century. Kaoliang was cultivated principally in the Northeastern provinces, where marshy areas were common and the climate was less severe than in the Northwest; there millets could best withstand the aridity and low temperatures. Even so, when Buck [2] carried out his agricultural surveys in the 1920s and 1930s, kaoliang occupied only 4.7% of the cultivated area of China, whereas 9.4% was planted with millet. In recent years, particularly in the period 1960-76, kaoliang has replaced traditional Chinese millets in large areas of North China, presumably as a result of policies emphasising the expansion of rice cultivation for human consumption and that of kaoliangs and maize for animal fodder, but already there is a visible tendency to revert to the cultivation of millet, which the Northern Chinese much prefer as food to kaoliang.
That sets Vavilov straight. Kaoliang is not a millet, at least not taxonomically. But with the recent publication of the full sorghum DNA sequence, is it too much to hope that a definitive family tree for the economically important sorghums of the world will soon emerge?
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