Components for the management of two insect pests of pearl millet in Sahelian West Africa

Pearl millet, Pennisetum glaucum (L.) R. Br. is attacked by over 100 species of insect pests, but only a few of these are of economic importance. The two major ones, the millet stem borer, Coniesta ignefusalis Hampson and the earhead caterpillar Heliocheilus albipunctella de Joannis have been the subject of research in the Sahel during the last decade. The various methods that have been suggested for the control of these species are briefly discussed. Generally, the control strategy adopted by farmers involves the use of cultural operations that will reduce insect damage. There are no control measures that have been developed for farmers. The more scientific methods that have been suggested are the results from research trials and experiments. These have several limitations. Future perspectives and considerations for developing sound and practical farmer-oriented practices are discussed

National agricultural research programmes in Sahelian countries of West Africa: Problems and recommendations

Increasing food production in Africa through augmentation of the area of cultivated land is becoming less feasible thus emphasizing the need for increasing the productivity of the existing area to meet the objectives of national food security programmes. Several factors, however, negate the achievement of this goal. This paper focuses on the eight countries of the West African Sahel and discusses the implication of the lack of a critical mass of indigenous scientists in national programmes for conducting adaptive research on existing technologies or generating new ones for the particular situations of the region. The problems associated with these programmes are presented in the light of the number and calibre of personnel in agricultural research, the place of agriculture in national development, and the impact of foreign technical assistance. Measures for improving the domestic capacity of national programmes especially as they relate to training, are discussed. Regionalisation and networking programmes are also suggested as possible alternative

Sustainable Food Production In Africa: The Challenge To National Agricultural Research Systems (NARS)

In the years prior to independence, farmers had access to the international market through the production of export crops which at that time received considerable input from research. Access to export crops has dwindled, support for research by national governments is disappointing, human resource developing is inadequate, donor funding is uncoordinated, and the food crisis has taken on political dimensions. The assumption that direct importation of western technology can solve the problems of Africa is no longer valid in the face of several failures. The challenge to national agricultural research systems and the problems associated with the generation or adapting of farmer-oriented, location-specific technologies for sustaining agricultural production are discussed. Examples are drawn from India and an agenda for action, involving national governments, the international agricultural research centres and donors, in resolving these problems is presente

Some aspects of pest management and host plant resistance in pearl millet in the Sahel

Among several species of insect pests that attack the millet crop, the earhead caterpillar, Raghuva albipunctella de Joannis and Acigona ignefusalis Hmps., are considered the major pests. The constraints against the successful implementation of an integrated pest management programme of these insects are examined. The relative importance and significance of host plant resistance in such a programme is compared against other modalities. The use of insecticides is negated by lack of cash value returns, water supply, trained personnel and poor delivery system. Cultural practices, such as the synchronisation of early planting, destruction of harvest residues and end-of-season ploughing, have the potential for reducing carry-over populations. However, the difficulties in their implementation range from farmer education and efficiency to changes in traditional practices and introduction of new labour intensive practices after harvest. While it appears that natural enemies are taking a gradual toll on R. albipunctella, they appear inefficient in controlling A. ignefusalis. A range of plant characters have been identified: tillering in certain varieties as a form of tolerance to borers; maturity cycles that result in escape (pseudo-resistance) from Raghuva infestation, hairiness in relation to preference for oviposition and head compactness in deterring larval penetration into millet heads. Most of these characters are common in landrace types. The real problem appears to be one of incorporating and utilising the identified resistance into germplasm sources which possess other desirable agronomic characters that the farmer requires. This implies multi-disciplinary effort which is the basis for integrated pest management. In most of Africa, and in the Sahel in particular, this basis is remotely present

Stem-borers of cereals in Sahelian West Africa relative importance and control

A brief account of the distribution and relative importance of the major stem-borer species of cereals in the Sahel is given. The level of parasitism is usually low and populations of the major parasites: Apanteles sesamiae, Pedlobius furvus and Terasticus atriclavus increase only towards the end of the growing season. Further investigations on local natural enemies and of exotic species are suggested. Other control measures involving the use of resistant varieties and cultural practices are presented as modalities within the context of a viable integrated pest innagement progra

Assessment of On-Firm Losses in Millets Due to Insect Pests

Pearl millet Penmseium amencanum L occupies a large proportion of the area growing millets in Africa Consequently the insect pests that attack this species have received attention over other millets A list of the major species is presented Actual data on losses due to insect pests on pearl millet are not readily available Crop loss assessment methods using incidence and damage ratios are discussed Quantitative losses determined from insecticide trials at research station are also presented

Insect pests of pearl millet in Sahelian West Africa. I: Acigona ignefusalis (Pyralidae, Lepidoptera): distribution, population dynamics and assessment of crop damage

Pests were surveyed in farmers’ fields in Burkina Faso, Niger and northern Nigeria from 1980 to 1983, and field trials at research stations in Burkina Faso (1980 and 1981) and at the ICRISAT Sahelian Center in Niger (1984 and 1985). Acigona ignefusalis is widely distributed in West Africa but its predominance as the major stem borer of millet varies with location. There are two generations of the pest annually, with peaks in moth population in July and September. Diapausing larval population declines during the dry season from November to May. A progressive decline in borer infestation was recorded between 1983 and 1985 in Niger. Damage to early‐sown millet was usually low while late sowing resulted in severe stem tunnelling and unproductive tillers. However, under low levels of borer infestation an unprotected crop gave higher grain yield than one which was protected with insecticide

Panicle insect pests of sorghum and pearl millet:proceedings of an International Consultative Workshop 4-7 Oct 1993 ICRISAT Sahelian Center Niamey, Niger

This workshop brought together national and international scientists from 12 countries to assess the economic importance of panicle-feeding insect pests of sorghum and pearl millet worldwide and review existing knowledge; provide concise and up-to-date information on current research on management tactics; develop research themes and priorities for their management in various cropping systems and agroecologies; and develop/strengthen linkages and enhance collaboration and partnership between international agricultural research systems, universities, and NARS, in order to achieve more effective technology transfer, resulting in increased and sustained productivity on farmers' fields. The sessions covered bioecology and crop losses, and management strategies (including host-plant resistance, crop management and biological control, and integrated pest management). Regional reports were presented from western, eastern, and southern Africa, Asia, and the Western Hemisphere. Discussions of working groups and recommendations are included. Presentations are reproduced in the original language of submission (English/French), followed by an extended swnmary in French/English as the case may be. The opening session addresses, objectives, discussions at the end of each session, general discussion session, and recommendations are in both language

Insect pests of pearl millet in Sahelian West Africa—II. Raghuva albipunctella De Joannis (Noctuidae, Lepidoptera): Distribution, population dynamics and assessment of crop damage

Pest surveys in farmers’ fields were conducted for Raghuva albipunctella infestations on pearl millet in Burkina Faso, Niger and northern Nigeria in 1980–1983. Field studies on the seasonal fluctuations of moths and diapausing pupae, assessment of crop damage and grain yield loss were conducted in Niger. The results indicated that R. albipunctella occurred between latitudes 11° N and 15 ° N, within the Southern Sahel and Sudan bioclimatic zones. R. albipunctella is a univoltine species, and off‐season carryover is through diapausing pupae in the soil. The majority of diapausing pupae (51%) were found at 10–20 cm of soil depth. The onset and continuity of rains, favourable soil moisture and temperature conditions were key factors in diapause termination, duration of post‐diapause development and adult emergence. Crop damage and grain yield loss were a function of sowing date, time of panicle exsertion and the occurrence of critical numbers of adult moths. Percentage crop lost varied from 1% to 41% with a mean of 20%