Gezira Scheme Research Articles

Insecticide resistance in the cotton whitefly(Bemisia tabaciGenn.) in the Sudan Gezira

Abstract The results of a survey of insecticide resistance in the cotton whitefly (Bemisia tabaci Genn.) to some of the commonly used insecticides, or insecticide mixtures, in the Sudan Gezira Scheme, disclosed that high levels of resistance exist in the Scheme's whitefly populations. The resistance ratios of the scheme populations, relative to a susceptible strain, for the adults and nymphs, respectively were as follows: dimethoate, 454 × and 257 ×; endosulfan, 364 × and 5 ×; dimethoate/endosulfan mixture, 10 × and 7 ×; methomyl, 8 × and 8 ×; amitraz, 6 × and 2 ×; and amitraz/endosulfan mixture, 5 × and 3 ×. The adults of an out‐of‐season strain of the cotton whitefly exhibited moderate levels of resistance to amitraz (7 ×), amitraz/endosulfan mixture (3×), and endosulfan (3×). The nymphs of this strain showed resistance to dimethoate (25 ×), amitraz (8 ×) and dimethoate/endosulfan mixture (3 ×). Adult whiteflies were always found to be more susceptible than nymphs and the resistance ratio of the adults was generally higher than that of the nymphs.

Coping with Bureaucracy: Survival Strategies in Irrigated Agriculture

Small‐scale family farming and centralized bureaucratic management are in many ways incompatible, yet the two are often combined in modern irrigation systems. Bureaucrats and farmers cope by means of “informal adjustments.” The kinds of informal adjustments made by farmers vary with their differential access to resources, particularly labor, despite minimal variation in access to land and water. The effects of bureaucratic control and associated informal adjustments are illustrated by reference to three large‐scale irrigation systems noteworthy for their high degree of centralization and for their success in achieving high productivity by family farm operators: the Israeli cooperative farming sector, the Gezira Scheme in Sudan, and the Mwea Scheme in Kenya.

Wage labourers in the fragmented labour market of the Gezira, Sudan

Opening ParagraphThe Gezira scheme has been the focus of considerable attention in the literature of development in tropical Africa, especially during the colonial period. This was because the scheme represented one of the largest agricultural projects initiated by a colonial government. Views on the scheme have been divergent: Gaitskell (1959) describes it as a ‘story of development’ while Barnett (1977) calls it an ‘illusion of development'. The focus of the studies, which are extensive compared to other Sudanese studies, has largely concentrated on the relationship (or so-called partnership) between tenants and government, production requirements and output, as well as occasionally on various aspects of the tenants’ lives and activities. Wage labour, which is the main form of labour, has only been given scant consideration. Even so, the focus has been on its contribution to the total labour requisite and its supply and demand patterns. The social relations of wage labour, and especially relations between tenants and wage labourers as the essential core of production relations in the scheme, have been awarded very little attention. This is the main concern of this article. Compared with most labour-market studies, my intention is to go beyond a mere study of factors affecting supply and demand. In conditions of transition to capitalism and fragmented labour markets, the perception of the social and cultural aspects of labour is indispensable for an adequate understanding of the internal mechanisms of the labour market.

Effects of water velocity on snails and cercariae

Snail vectors of schistosomiasis occur in lakes and ponds, rivers and streams, and in the supply and drainage systems of irrigation schemes. The survival of snails and of schistosome cercariae in any localised system is greatly affected by water velocity, and this could be used to advantage, particularly in the design of new irrigation systems, to limit the spread of schistosomiasis and its vectors. Use of high velocity water in endemic areas could play a useful role in the focal control of schistosomiasis, whereas neglect of this factor by water development engineers may have contributed to the spread of schistosomiasis in some areas, for example in the S~o Francisco River development in Bahia, Brazil. Slow flow through field irrigation canals contributed substantially to the spread of schistosomiasis mansoni in the Gezira Scheme in the Sudan I, but in fiat areas such as this it may not always be practical to increase the flow rates due to high pumping costs. Most studies on the effect of water velocity on snails and cercariae have been carried out on Biomphalaria snails and cercariae of Schistasama mansoni, but there is no obvious reason to suggest that these results cannot be applied in general terms to Bulinus snails and cercariae of S. haematobium. Oncomelania snail vectors of S. ]aponicum, are amphibious and in their aquatic phase prefer very sluggish streams and swamps.

Why Do Gezira Tenants Withhold Their Households' Labour?

The Gezira Scheme which was established during British Colonial rule in Sudan was often viewed as a 'model of development' where small producers (tenants) are incorporated into a large-scale project. The low contribution of the tenants' household labour in the Scheme's farming was a matter which was not expected and which begged for explanation. Some officials and scholars seem to attribute this to the tenants 'negative attitudes' towards farm labour, an attitude caused by ideological norms, lifestyle and other factors. This paper attempts to situate the problem in its socio-economic and historical context. After exposing different 'technical factors' that may affect the tenants' household labour input, it goes on to search for answers in the effects of the uneven and non-linear development of capitalism. It contends that factors of uncertainty and obstacles for development created by the institution itself, as well as factors related to the wider socio-economic formation, have made Gezira tenants, who are not an undifferentiated stratum, and their household members tendencious towards finding alternative ways of livelihood.

Why Do Gezira Tenants Withhold Their Households' Labour?

The Gezira Scheme which was established during British Colonial rule in Sudan was often viewed as a 'model of development' where small producers (tenants) are incorporated into a large-scale project. The low contribution of the tenants' household labour in the Scheme's farming was a matter which was not expected and which begged for explanation. Some officials and scholars seem to attribute this to the tenants 'negative attitudes' towards farm labour, an attitude caused by ideological norms, lifestyle and other factors. This paper attempts to situate the problem in its socio-economic and historical context. After exposing different 'technical factors' that may affect the tenants' household labour input, it goes on to search for answers in the effects of the uneven and non-linear development of capitalism. It contends that factors of uncertainty and obstacles for development created by the institution itself, as well as factors related to the wider socio-economic formation, have made Gezira tenants, who are not an undifferentiated stratum, and their household members tendencious towards finding alternative ways of livelihood.

Incidence of peanut mottle virus in the Sudan Gezira and its effect on yield

Peanut mottle virus disease is widespread in the Sudan Gezira Scheme. The main symptom is a mild mottle without apparent reduction in shoot growth. Leaf necrosis and deformation are occasionally observed. Disease incidence in the field varied from 2% to 9% and from 3% to 92% in 1977 and 1978, respectively. In 1977, 82% of the fields had a disease incidence between 11% and 60% and in 1978, 84% of the fields had a disease incidence between 1% and 50%. The estimated losses in value were 2.3 and 1.0 million Sudanese pounds in 1977 and 1978, respectively. The results of the two seasons revealed that some fields had significantly less disease infection. These fields are potential sites for PMV‐free seed production in the Gezira.

Mineralogy of the Major Soils of the Gezira Scheme (Sudan)

AbstractThe major soil series comprising the Gezira scheme are Hosh, Suleimi, and Laota. These soils are calcareous, dark brown to grayish brown clays with low organic matter contents (< 1%). The mineralogical properties of these soils were studied by X‐ray diffraction (XRD), dissolution, and Ca/Mg and K/NH4 cation exchange capacities. Some complementary data were obtained using infrared (IR) spectroscopy. The results of the study reveal that these soils have similar sand, silt, and clay mineralogy. The sand fractions are composed of quartz, plagioclase, K feldspars, anatase, and amphiboles. The silt fractions contain, in addition to the above minerals, kaolinite, mica, and chlorite. The coarse clay is composed of chlorite, kaolinite, smectite, plagioclase and K‐feldspars, quartz, and mica. The fine clay is predominantly smectite (a mixture of montmorillonite and beidellite), kaolinite, and mica. Calcite is the dominant mineral in the gray hard nodules. The uniform physiographic position and similar mineralogy of these soils suggest that they have a common origin. The similarity in mineralogical composition to that of the recent sediments of the Blue Nile and its tributaries, supports the contention that the Gezira soils have inherited their mineralogical properties from the source area of the sediments in Ethiopia.

Policies and prospects in Nigerian irrigation

In contrast to many parts of Asia, where large-scale formal irrigation schemes have a long history, organised irrigation projects in Africa are a relatively new concept. In Africa the Gezira scheme in the Sudan is perhaps the best known and similar large projects are now being planned and constructed in other countries including Nigeria. These schemes are seen as a means of ensuring food supplies in areas where rainfall is inadequate or unreliable for successful crop production. In Africa, Nigeria is unusual in having not only the desire to develop irrigation but also the financial resources from oil revenues to implement its ambitious plans. The implementation of policy has, however, encountered difficulties which should be heeded by other countries having similar plans.

Soil moisture influence on micronutrient cation availability under aerobic conditions

The three major soil series comprising the Gezira scheme (Sudan) are Hosh, Suleimi, and Laota. Surface soil samples from each soil series were employed to study the effect of soil moisture on the DTPA-extractable micronutrient cation under aerobic conditions. The study continued for 8 weeks using an incubation technique at two levels of soil moisture (continuously moist and moist/dry cycles). The DTPA-extractable Cu, Fe, Mn and Zn from air-dry soil samples were much higher compared to values from their incubated counterparts. For the three soils the CO2 production (microbial activity) reached the maximum in 5 weeks and then levelled off while the lowest values of micronutrient cation from the incubated soils were obtained between 2 to 8 weeks.

Disparities in the management of resources between farm and national levels in irrigation projects, example of the Sudan Gezira scheme

In closely supervised irrigation projects increasing participation by farmers in the decision-making process often leads to a greater manifestation of the disparities in resource use which exist between the micro- and macro-economic levels, subject to the different objectives pursued at those levels. This is analysed in this paper for the case of the Sudan Gezira Scheme. Within the limits of freedom attained under the existing situation, the tenant shifts resources—especially irrigation water—from cotton growing to the production of other crops which yield more returns to the scarce resources than cotton does at current prices. If, however, the tenant were completely free to decide, he would tend to grow no cotton and would increase the production of wheat and sorghum instead. This is in opposition to national efficiency criteria where cotton yields the highest returns to the scarce resources at economic prices. The contradiction between the micro- and macro-economic levels could be minimised if other price relationships prevail at the farm gate.

Pesticide‐microbial interaction in the soil

Soils collected from the Gezira irrigation scheme in Sudan were incubated with five pesticides (pyrolan, α‐and β‐endosulphan, γ‐HCH and dieldrin), using three independent methods (incubation of microbial culture with soil and leachates, with carbon‐based growth media and with carbon‐free mineral salt agar). Endosulphan isomers were degraded by soil micro‐organisms to a much greater extent than pyrolan, dieldrin or γ‐HCH. When applied at low concentration (280 ppm), α‐endosulphan was broken down by both bacteria and fungi; whereas, β‐endosulphan was degraded mostly by bacteria and dieldrin was utilized by fungi. However, at high concentration (4000 ppm), γ‐HCH increased the growth of micro‐organisms (gram positive bacilli); but at this high concentration, the other pesticides inhibited all micro‐organisms in the Gezira soil.

The Gezira Scheme: an illusion of development by Tony Barnett London, Frank Cass, 1977. Pp. 192.

The Gezira Scheme: an illusion of development by Tony Barnett London, Frank Cass, 1977. Pp. 192.

Current Swedish Development Co‐operation Policy

Book reviewed in this article:Sverijs Samardete med U‐landema. Ministry of Foreign Affairs, Stockholm. Review 6, 1973 and M. Radetzki, Aid and Development. Income Distribution Policy in Developing Countries. A Case Study of Korea. By Irma Adelman and Sherman Robinson. India – Population, Economy, Society. By Robert Cassen. Commodity Conflict: The Political Economy of International Commodity Negotiations. By L. N. Rangarajan. Oil Companies in the International System. By Louis Turner. Europe and Africa: from Association to Partnership. By Carol Cosgrove Twitchett.The Renegotiation of the Lomé Convention. A Collection of Papers. Urbanization and Labor Markets in Developing Countries. By Stuart W. Sinclair. The Gezira Scheme. An Illusion of Development. By Tony Barnett. Malawi. The Politics of Despair. By T. David Williams. Planning the Future of Saudi Arabia. By R. D. Crane.

Beyond the sociology of development: Economy and society in Latin America and Africa : (SSC) I. Oxaal, T. Barnett, and D. Booth, eds. Routledge & Kegan Paul Ltd. (39 Store Street, London WCIE 700, United Kingdom), ISBN 0-7100-8050-6, 1975, 295 pp. $9.75 (paper) and $21.75 (cloth).

1. Editor's Introduction: Beyond the Sociology of Development 2. A Critique of Latin American Theories of Dependency 3. The Dependency Economist as Grassroots Politician in the Caribbean 4. Andre Gunder Frank: An Introduction and Appreciation 5. Imbalance Between the Centre and Periphery and the 'Employment Crisis' in Kenya 6. African Peasants and Resistance to Change: A Reconsideration of Sociological Approaches 7. Rice, Politics and Development in Guyana 8. Rural Social Differentiation and Political Goals in Tanzania 9. The Gezira Scheme: Production of Cotton and the Reproduction of Underdevelopment 10. Economic Anthropology and the Sociology of Underdevelopment: 'Liberal' Anthropology and its French Critics 11. The Theory of Internal Colonialism: The South African Case 12. Structural Dependency, Modes of Production and Economic Brokerage in Rural Peru

The Gezira Scheme: An Illusion of Development

The Gezira Scheme: An Illusion of Development

The Gezira Scheme: An Illusion of Development

The Gezira Scheme: An Illusion of Development

Reviews*

Book reviewed in this article:A Survey of Agricultural Economics Literature. Volume 1. Traditional Fields of Agricultural Economics, 1940s to 1970s. Edited by Lee R. Martin.An Economic Analysis of Agriculture. By B. E. Hill and K. A. Ingersent.The Economics of Futures Trading. Edited by B. A. Goss and B. S. Yamey.U.K. Agricultural Policy within the European Community. By J. S. MARSSpecial Interests and Policy making: Agricultural Policies and Politics in Britain and the United States of America. By G. K. Wilson. John Wiley,Soviet Agriculture: An Assessment of its Contribution to Economic Development. Edited by H. G. Shaffer.Agriculture in the People's Republic of China: Structural Changes and Technical Transformation. By Leslie T. C. Kuo.The Gezira Scheme: An Illusion of Development. By Tony Barnett.Growing Out of Poverty. Edited by ElizabethStamp.

The Gezira Scheme: An Illusion of Development

The Gezira Scheme: An Illusion of Development

Cultural and insecticidal control of Thrips tabaci on onions in the Sudan

SUMMARYOnion thrips (Thrips tabaci) is the major pest of onions in the Sudan. In the Gezira Scheme onions are normally transplanted between October and January when the thrips population is very low. Later, thrips commence to breed. Early transplanted onions were well established before infestations became severe and, without the need for insecticidal control, produced significantly higher yields. Onions transplanted later, when thrips began to multiply, produced lower yields.Depending on the duration and intensity of infestation three to five sprays applied at fortnightly intervals were required to control thrips on the late transplanted crop. The effect of spray frequency on the development and yield of onions was investigated and the response found to be solely due to the extent of thrips control achieved. The toxicant itself had no effect on growth. Although the leaves were unaffected by the various treatments, spraying when most thrips were present increased fresh and dry leaf weights, bulb weight and, in the Hudeiba cultivar, the proportion of flowering plants.With the late‐transplanted crop, light infestations led to yield losses of at least 39% whilst severe thrips attacks reduced the crop by 57%.