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I. The production of Dura (Sorghum vulgare) in Sudan and the Parasite Buda (Striga hermonthica)
Dura and Buda
I.2. Livestock and Buda
F. F. Bebawi, G. A. El-Hag, and M. M. Khogali
Dura (Sorghum Vulgare) is the staple food of most of the population of arid and semi-arid Sudan and constitutes on average two-thirds by weight of the cereal production in the country. It does well on the clays in the desert margin, while its rivel dukhn (Pennisetum typhoideum) surpasses it in importance only on the sandy qoz of western Sudan. Dugan accounts for 15 per cent of Sudan's cereal production. Wheat, the other important cereal, accounting for another 15 per cent, is a crop of the riverain lands of the far north, with significant quantities now being grown also in Khashm el Girba and the Gezira.
Buda (Striga hermonthica; English: witch weed) is a parasite or semi-parasite, Sudan's varieties of which attack millet, sugarcane, and possibly maize and rice as well as aura (Parker and Reid 1979). Varieties of buda seem to be specific to aura or Duhkn, and possibly some strains of buda specific to aura flourish most successfully on some varietes of aura rather than on others (Bebawi 1981a). The effect of an attack by buda on a aura crop can be devastating- certainly much more serious than that of non-parasitic weeds. Bebawi and Farah (1981) conclude that a serious attack of buda will reduce yields by up to 65 per cent Farmers often claim much more severe damage, but buda infestation is often allied to other factors such as soil exhaustion and rainfall fluctuations. El-Hiweris (1979) suggests that buda causes a drastic reduction of growth in aura, akin to the effect of growing the crop under unfavorable environmental conditions, in particular of a shortage of water.
Buda attacks aura throughout the whole of the semi-arid region of the Sudan in varying degrees. It is important, therefore, that buda should be controlled. However, although methods for control are known - the use of trap crops, chemical sprays, and various husbandry methods such as early and constant weeding and intercropping with groundnuts-certain key problems remain. Firstly, movement of people and animals is a potentially serious source of reinfestation, secondly, the methods so far developed are really more suited to advanced societies and experimental stations than to peasant cultivation; thirdly, the methods are expensive in labour and material inputs and therefore are hardly feasible under current conditions; and, fourthly, one of the reasons for the increase in buda infestation is soil exhaustion due to a reduction in fallows caused by a rising population. Some of these difficulties might be overcome by the wider use of nitrogenous fertilizers, but Bebawi (1981b) has shown that, unless you get the applications right, you are likely to stimulate buda as much as the aura. Fisyunov (1977) concludes that the only really satisfactory way to control Striga hermonthica and its associates is to keep them out!
If buda then presents problems very difficult for a durabased peasant society to solve by conventional control methods, the question arises whether some use of it within the peasants' purview can be found. Livestock and their feeding is a source of perennial difficulty in northern and central Sudan, and the possibility therefore exists of using buda for this purpose.
The first part of this paper deals in more detail with the interaction of aura, livestock, and buda in people's lives in Sudan, and the second part deals with the possibility of using buda as a livestock feed, bearing in mind that livestock are also potential agents for the dispersal of buda both via their coats and through their faeces.
H. R. J. Davies
I.1. Dura and Buda
The importance of Dura in Sudan
Systems of Dura production and Buda infestation
Nearly 80 per cent of Sudan's working population is engaged primarily in either crop production or livestock rearing. The two activities are not necessarily incompatible since most of the settled cultivators raise some animals whenever that is possible, while the nomads always like to cultivate some crops, mainly grains for their subsistence. Although traditionally competition and conflict between cultivators and nomads over land use may take place, some co-operation between the two groups also occurs. Some settlers send part of their livestock with the nomads to graze in distant grazing areas, and some nomads buy aura stalks (gassab) from the cultivators as feed for their animals. In the Gezira the cultivators, as an incentive to the seasonal cotton pickers, allow their livestock to graze the cotton plant residues after picking is completed. In fact throughout Sudan, though the livestock of both the settled and nomadic population subsist mainly on natural grazing, they also derive a substantial part of their feed from crop residues, including the grazing of crop remains in the field after harvesting. It is not surprising therefore that a relation often exists between grazing and movement and the dispersal of certain agricultural weeds that adhere to the skin of the animals or pass through their digestive systems: buda (Striga hermonthica) seems to be a good example of this.
The main aim of the present study is to assess how far success or failure in the campaign to control the spread of buda may be hindered or enhanced by the prevailing socioeconomic conditions in Sudan.
The material is based not only on previous research and field work in Sudan and on library studies but also on field work specific to the purpose between November 1980 and February 1981 in four distinct areas in the country
TABLE 1. Field-work survey
|Location||Number of villages||Number of persons interviewed|
|Singa and Abu Na'ama (Blue Nile Province)||3||97|
|Gezia Scheme (Gezira)||2||86|
|South ana south-west of El Obeid (Northern Kordofan)||3||91|
(table 1). Surveys were taken in 13 randomly chosen villages, and 383 interviews were held.
The study concentrates on the central zone of Sudan, the area where most aura is cultivated within the remit of the UNU Arid Lands Sub-programme.
The importance of Dura in Sudan
Dura is the staple diet for most Sudanese (table 21. It is the staple in the rural areas in the central zone, being only challenged for supremacy on the sandy qoz lands of western Sudan by dukhn, and among urban areas it is challenged in some of the large towns where wheat bread is consumed. Furthermore, aura production takes up more land than any other crop (table 3).
The importance of aura in Sudan can hardly be overstressed. Ever since the establishment of the Anglo - Egyptian Condominium in 1898 it has been considered a strategic crop by all governments, and expansion of production and the maintenance of a sufficient supply to meet the needs of a rising population has been a primary consideration in all government policy and action in the agricultural sector. The Gezira Scheme when it was opened in 1925 was seen as a great step forward in Sudan development, not only because of the incomes to be derived from cotton export but also because of its contribution to home food production through the more secure aura production made possible by irrigation. The most important single development, however, took place after the Second World War when the mechanical crop production schemes (MCPSs) were started in Gedaref. Today, MCPSs account for over half the total area under aura. (Table 4 indicates the relative significance of the various modes of production in various parts of Sudan today, and table 5.shows the expansion of the areas under aura during this century.)
TABLE 2. Cereal consumption in Sudan
|Total supply ('000 metric tons)||Share of each cereal (%)|
Source: Sudan Government 1979
TABLE 3. Major crops in Sudan (thousands of feddans)
|Other subsistence crops|
|Horse beans (ful masri)||43||38||42||31|
|Haricot beans (fasulia)||13||5||5||6|
|Essentially cash crops|
Source: Sudan Government 1979
*Area under sugar-cane has since increased dramatically due to the opening of four new major sugar schemes since 1978.
Despite the great expansion of the area under aura, the situation of the crop, as compared to the needs of population, is not yet fully secured. Usually the local production meets domestic demand with a small surplus for export (table 6). However, with a population increasing at the rate of at least 2.8 per cent per year and the possibility of an increased demand as a feeding stuff with the expansion of the livestock industry, more aura will certainly be needed in the future. This can be met by an increased area under the crop and by increasing yields per hectare. One step in the latter direction, besides control of insect pests, vermin, and diseases, is to combat weeds, the most serious of which is buda. On the other hand, if satisfactory control of buda is not possible, then it may possible to use buda as animal fodder in one way or another to produce more animal protein.
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