Sudano-Sahelian Zone Of West Africa Research Articles

Characterizing sorghum (Sorghum bicolor [L.] Moench) varieties diversity to identify those with contrasting traits of interest for intercropping systems in the Sudano-Sahelian zone of West Africa

AbstractSorghum is an important staple crop in Sub-Saharan Africa. In the Sudano-Sahelian zone of West Africa, sorghum is mainly intercropped with cowpea, but these intercropping systems are facing low-productivity problems. The overall aim of this research was to identify sorghum varieties with different agro-morphological and physiological traits that could improve the performance of the intercropping systems. We followed a two-step methodology comprising (i) identification of varieties and plant traits of interest in intercropping systems, using participatory methods, and (ii) agro-morpho-physiological characterization of 50 sorghum varieties, to examine the range of variation in traits of interest. The results show that landraces are the varieties most widely used by farmers, and that 82.5% of farmers consider the variety type they choose for intercropping to be important. Farmers mentioned plant height, number of leaves and stem diameter as important traits to consider. Analysis of variance showed significant differences between varieties for half of the 24 agro-morpho-physiological traits studied. Hierarchical clustering identified three main groups of varieties, distinguished by morphological traits such as stem diameter, total number and size of leaves (group 1), root traits (depth, growth angle, dry matter) and relative chlorophyll content (groups 2 and 3). Based on this classification, we recommend several varieties from each of the three groups, exhibiting contrasting traits, for an assessment of their performances in intercropping systems.

Identification of a Representative Stationary Period for Rainfall Variability Description in the Sudano-Sahelian Zone of West Africa during the 1901–2018 Period

Many studies have been undertaken on climate variability in West Africa since the drastic drought of 1970s. These studies rely in many cases on different baseline periods chosen with regard to the reference periods defined by the World Meteorological Organization. A method is developed in this study to determine a stationary baseline period for rainfall variability analysis. The method is based on an application of three statistic tests (on deviation and trend) and a test of shifts detection in rainfall time series. The application of this method on six different gridded rainfall data and observations from 1901 to 2018 shows that the 1917–1946 period is the longest stationary period. An assessment of the significance of the difference between the mean annual rainfall amount during this baseline period and the annual rainfall amount during the other years shows that the “Normal” annual rainfall amount is defined by an interval delineated by ±the standard deviation (STD). With regard to this interval, a very wet/dry year is defined with a surplus/gap over/below the STD. Overall the 1901–2018 period, the 1950–1970 period presents the most important number of significant wet years and the 1971–1990 period presents the most important number of significant dry years.

Performance of Three Sorghum Cultivars under Excessive Rainfall and Waterlogged Conditions in the Sudano-Sahelian Zone of West Africa: A Case Study at the Climate-Smart Village of Cinzana in Mali

Recent climate analyses show trends for increasing precipitation variability with increasing precipitation sums in Mali. The increasing occurrence of temporary intra-seasonal droughts and waterlogging longer than a week demands climate-smart solutions. Research has focused on water deficits since the 1980s. However, besides droughts, waterlogging can restrict productivity of sensitive cash and staple crops as cotton and corn. The year 2019 offered the historically unique opportunity to monitor waterlogging effects with 1088 mm precipitation in the rural commune Cinzanawith an isohyet of 681 mm. Impacts of two extreme downpours on three sorghum cultivars were monitored in a farmers-field experiment with three replications. All sorghum cultivars performed well in 2019 with significantly higher grain and above ground biomass yields than in the reference year 2007, with well distributed rainfall in Cinzana. “Jakumbè” (CSM63E) produced significantly higher grain yields than the hybrid cultivar “PR3009B” bred for high harvest index. The local cultivar “Gnofing” selected by local farmers produced significantly higher above ground biomass. All cultivars tolerated without severe stress symptoms 20 days waterlogging and 72 h inundation. Further waterlogging resilience research of other crops and other sorghum cultivars is needed to strengthen food security in Mali with expected increasing precipitation variation in the future.

Which is more important to sorghum production systems in the Sudano-Sahelian zone of West Africa: Climate change or improved management practices?

The productivity of smallholder farming systems is held back by poor soil fertility, low input levels and erratic rainfall distribution in the sorghum-based cropping systems of the Sudano-Sahelian zone of West Africa. We assessed the sensitivity of current agricultural practices to climate change and to improved management practices: (i) increased fertilizer application combined with increased plant populations and (ii) use of improved sorghum varieties. We applied the Decision Support Systems for Agro-Technological Transfer (DSSAT) Cropping Systems Model, and the Agricultural Production Systems sIMulator (APSIM), for a multiple-farm assessment (i.e. diverse types of management and soils) in Koutiala (Mali) and Navrongo (Ghana), which are representative sites for West African sorghum production systems. Baseline climate data from observed weather (1980–2009) and future climates from five Global Circulation Models (GCMs: 2040–2069) in two Representative Concentration Pathways (RCP 4.5 and 8.5) were used as inputs for crop models. In Navrongo, under current management, sorghum yields either decreased or increased compared to the baseline, depending on the crop models and the GCMs; changes in management options induced a yield increase of up to 256%. The addition of genetic improvement resulted in further yield increases (24%). In Koutiala, sorghum yield changes for future climates ranged from −38 to +8% assuming current management. Shifting to an improved cultivar had a marginal effect on grain yields, while increased fertilizer rates resulted in grain yield increases ranging of 20% and 153% for DSSAT and APSIM, respectively, assuming the current climate. We conclude that in the Sudano-Sahelian zone of West Africa sorghum, as it is cultivated today, appears moderately vulnerable to climate change, while doubling fertilizer inputs with an adjusted planting density, in the current climate, would more than double yields. However, by exploring farm diversity we established that, under certain conditions, the effect of the future climate might be as important as the effect of management changes in the current climate, hinting at the importance of locally-relevant management practices.

Shoot and root responses of woody species to silvicultural management for afforestation of degraded croplands in the Sudano-Sahelian zone of Benin

In the Sudano-Sahelian zone of West Africa, where deforestation and cropland soil degradation occur at alarming rates, the (re-)introduction of trees on degraded lands can improve and sustain farming systems and landscapes. The shoot and root morphological traits of five woody species introduced to degraded cropland were assessed with a particular focus on the survival, early establishment and growth of saplings subjected to manuring (1kg per plant) and drip irrigation (0.5L of water per plant per day). Functional traits of the woody above- and belowground organs of field-grown plants were monitored for the first 15months after planting, covering two growing (rainy) seasons and one dry season. The high survival rate (>60%), combined with a very low incidence rate (<1%), for all species was evidence of successful establishment overall. The highest survival rates (94–100%) were observed in Jatropha curcas L., Leucaena leucocephala Lam. and Moringa oleifera Lam. The mortality rate of the most drought-sensitive species Parkia biglobosa Jacq. could be reduced ten-fold through supplemental irrigation during the dry season. The fast-growing L. leucocephala, M. oleifera and J. curcas had higher values for shoot-level traits than did the slow-growing Anacardium occidentale L. and P. biglobosa. Fertilization and irrigation enhanced the shoot growth of both the fast and slow growers during the dry and growing seasons. In contrast, belowground development was either increased or reduced by fertilization and irrigation during the growing and dry seasons, but the slow growers demonstrated a more plastic response to these treatments than did the fast growers. Among the studied traits, the relative growth rate of plant as a whole (i.e. shoots and roots combined) exhibited the greatest plastic response to resource availability, thus suggesting its application in screening candidate species for afforestation efforts. Overall, the five studied species were considered suitable for the afforestation of degraded croplands, while the early growth and establishment of saplings could be boosted by irrigation and a supply of manure.

Modelling cereal crops to assess future climate risk for family food self-sufficiency in southern Mali

Future climate change will have far reaching consequences for smallholder farmers in sub-Saharan Africa, the majority of whom depend on agriculture for their livelihoods. Here we assessed the farm-level impact of climate change on family food self-sufficiency and evaluated potential adaptation options of crop management. Using three years of experimental data on maize and millet from an area in southern Mali representing the Sudano-Sahelian zone of West Africa we calibrated and tested the Agricultural Production Systems sIMulator (APSIM) model. Changes in future rainfall, maximum and minimum temperature and their simulated effects on maize and millet yield were analysed for climate change predictions of five Global Circulation Models (GCMs) for the 4.5Wm−2 and 8.5Wm−2 radiative forcing scenario (rcp4.5 and rcp8.5).In southern Mali, annual maximum and minimum temperatures will increase by 2.9°C and 3.3°C by the mid-century (2040–2069) as compared with the baseline (1980–2009) under the rcp4.5 and rcp8.5 scenario respectively. Predicted changes in the total seasonal rainfall differed between the GCMs, but on average, seasonal rainfall was predicted not to change. By mid-century maize grain yields were predicted to decrease by 51% and 57% under current farmer’s fertilizer practices in the rcp4.5 and rcp8.5 scenarios respectively. APSIM model predictions indicated that the use of mineral fertilizer at recommended rates cannot fully offset the impact of climate change but can buffer the losses in maize yield up to 46% and 51% of the baseline yield. Millet yield losses were predicted to be less severe under current farmer’s fertilizer practices by mid-century i.e. 7% and 12% in the rcp4.5 and rcp8.5 scenario respectively. Use of mineral fertilizer on millet can offset the predicted yield losses resulting in yield increases under both emission scenarios.Under future climate and current cropping practices, food availability is expected to reduce for all farm types in southern Mali. However, large and medium-sized farms can still achieve food self–sufficiency if early planting and recommended rates of fertilizer are applied. Small farms, which are already food insecure, will experience a further decrease in food self-sufficiency, with adaptive measures of early planting and fertilizer use unable to help them achieve food self-sufficiency. By taking into account the diversity in farm households that is typical for the region, we illustrated that crop management strategies must be tailored to the capacity and resource endowment of local farmers. Our place-based findings can support decision making by extension and development agents and policy makers in the Sudano-Sahelian zone of West Africa.

GF-120 effects on fruit fly species (Diptera: Tephritidae) in Sahelian agroforestry-based horticultural cropping systems

Introduction. In the water-saving and income-generating agroforestry cropping systems developed and promoted by the ICRISAT in the Sudano-Sahelian zone of West Africa, particularly in Niger, fruits of domesticated Ziziphus mauritiana (apples of the Sahel) are severely damaged by fruit flies(Carpomya incompleta), and chemical pesticide application poses economic, environmental and human health problems. In the Bio-reclamation of Degraded Lands (BDL) system, apple of the Sahel is the main high-value crop, while in the Dryland Eco-Farm (DEF), it is grown alongside watermelon. Sclerocarya birrea (marula plum) is presently being investigated as a dryland tree species for fruit and oil production, either in orchards or such systems as BDL. Materials and methods. To complete preliminary results of earlier studies published elsewhere, we collected and incubated in 2010 ripe fruits of marula plum and water- melon in Sadore, Niger, where the above-mentioned agroforestry systems are developed, and we recorded emerging fruit flies. We also conducted a spot-spraying experiment (using GF-120) in an apple of the Sahel orchard in Niamey in 2010; we recorded undamaged and damaged fruits and incubated the latter. In the same orchard, we set up in 2011 a fruit fly trapping survey targeting the invasive species Bactrocera invadens (Chempac ® traps using methyl eugenol as the attractant). Results and discussion. The results showed that only Ceratitis cosyra emerged from marula plums, and only Dacus spp. from watermelon. The GF-120 spot-spraying experiment showed that C. incompleta was not attracted / intoxicated, contrary to Ceratitis spp. and Dacus spp.; the sprayed trees yielded significantly more mar- ketable fruits than unsprayed ones; only C. incompleta emerged from damaged fruit. Detection trapping revealed for the first time the presence of B. invadens in the Sahelian zone of Niger, including at the time of apple of the Sahel fruit production. Conclusion. This, alongside results of earlier studies, suggests a repellent effect of GF-120 on the monophagous C. incompleta species (Trypetinae), while it is attractive to oligophagous/polyphagous Dacinae fruit flies; some of them (e.g., Dacus spp.) damage watermelon, which is part of the DEF system, and produce fruit at the same time as the jujube tree. The prospects for harnessing these two opposite regulation pathways are discussed. Niger / Ziziphus mauritiana / Citrullus lanatus / pest control / Carpomya incompleta / Bactrocera invadens / Ceratitis / Dacus / control methods / integrated control / attractants / repellents

Acacia communities and species responses to soil and climate gradients in the Sudano-Sahelian zone of West Africa

Abiotic environmental factors have a major impact on the distribution and performance of plant species. In order to assess two major species–environmental relations in Sudano-Sahelian Acacia woodlands, we tested the relationship of soil and climate variables on plant diversity as well as on species responses.The indicator species values clustered in five vegetation units characterized by three to ten diagnostic species with woody species richness means varying from three to seven species per 0.09 ha. The NMS ordination explained 65% of the variation in species composition and revealed that soil properties, annual precipitations and temperature range structured the diversity of Acacia communities. Along the annual precipitations gradient, the response of Acacia polyacantha and Acacia hockii showed maxima in the wettest zone of our study area (more than 850 mm/year) whilst Acacia laeta showed a maximum response in the driest zone (below 500 mm/year). The unimodal response of A. hockii, Acacia gourmaensis and Acacia seyal to the soil available water gradient spanned their central borders, respectively from 13 to 18% (optimum 16%), 11–20% (optimum 15%) and 4–12% (optimum 7.5%).The response of Acacia communities and species to soil and climate gradients, makes them performant afforestation species in specific habitats of the Sudano-Sahelian zone.

Building hazard maps of extreme daily rainy events from PDF ensemble, via REA method, on Senegal River Basin

Abstract. The Sudano-Sahelian zone of West Africa, one of the poorest of the Earth, is characterized by high rainfall variability and rapid population growth. In this region, heavy storm events frequently cause extensive damage. Nonetheless, the projections for change in extreme rainfall values have shown a great divergence between Regional Climate Models (RCM), increasing the forecast uncertainty. Novel methodologies should be applied, taking into account both the variability provided by different RCMs, as well as the non-stationary nature of time series for the building of hazard maps of extreme rainfall events. The present work focuses on the probability density functions (PDFs)-based evaluation and a simple quantitative measure of how well each RCM considered can capture the observed annual maximum daily rainfall (AMDR) series on the Senegal River basin. Since meaningful trends have been detected in historical rainfall time series for the region, non-stationary probabilistic models were used to fit the PDF parameters to the AMDR time series. In the development of PDF ensemble by bootstrapping techniques, Reliability Ensemble Averaging (REA) maps were applied to score the RCMs. The REA factors were computed using a metric to evaluate the agreement between observed -or best estimated- PDFs, and that simulated with each RCM. The assessment of plausible regional trends associated to the return period, from the hazard maps of AMDR, showed a general rise, owing to an increase in the mean and the variability of extreme precipitation. These spatial-temporal distributions could be considered by Organization for the Development of the Senegal River (Organisation pour la mise en valeur du fleuve Sénégal, OMVS), in such a way as to reach a better balance between mitigation and adaptation.

Evidence for important genetic differentiation between provenances of Parkia biglobosa from the Sudano-Sahelian zone of West Africa

Parkia biglobosa is a traditional economic tree legume of considerable multipurpose importance in the sudano-sahelian region in Africa. The species grows in multiple climatic zones with precipitation ranging from 600 to 2,500 mm a year and its natural distribution extends from Senegal and Guinea in West Africa to Uganda in Central Africa. In the present paper, a range wide sample of 25 provenances of P. biglobosa was tested in Burkina Faso, West Africa at two sites; Gonse (latitude 12°25′N; longitude 1°20′W; altitude 280 m) in the north-sudanian zone and at Dinderesso (latitude 11°18′N; longitude 4°35′W; altitude 425 m) in the south-sudanian zone. Based on analysis of survival and growth traits, we provide evidence of substantial genetic differentiation between P. biglobosa populations within West Africa. Height growth was best at Gonse, while the survival rate was higher at Dinderesso (61%) compared to Gonse (35%). Links between geographical parameters and the provenances performance were significant, and interesting geographic patterns were observed. Our results point towards superior fitness of the local Burkina Faso populations, and we speculate that presence of a continuum of locally adapted populations can be a part of the explanation for the species’ ability to thrive under quite different climatic conditions across West Africa. Based on the findings, we suggest recommendations for seed deployment and conservation strategies of the species in the West African Sahel. This is particularly important when considering the on-going climate change.

Climate Change Impact on Water Resources at the Transboundary Level in West Africa: The Cases of the Senegal, Niger and Volta Basins

The series of droughts of the past three decades that affected the Sudano-Sahelian zone of West Africa, particu- larly Niger, Volta and Senegal basins impacted the water resources, ecosystems and the fragile economies of at least 13 of the 16 countries of the region. Declining rainfall, highly variable in time and space has resulted in more than proportionate decrease in river discharges, and declining level of freshwater bodies. This situation translated into falling groundwater levels and accelerated desertification process, hence major crises of food insecurity and massive migration, which often leads to conflicts. The challenges and uncertainties associated with the impacts of future climate changes on water re- sources in West Africa are further compounded by many other factors, including regional demographic factors, non- existing or inadequate water policies, inefficient management strategies and lack of reliable and adequate data. This paper synthesizes the state of art research regarding climate change impact on water resources in West Africa economies of Senegal, Niger and Volta Basins while also making prescriptions on what can be done in terms of adaptation strategies, rather than mitigation, to reduce the severity of the expected impacts on the already stressed and poverty-stricken econo- mies of West Africa,

Identifying the global potential for baobab tree cultivation using ecological niche modelling

The benefits provided by underutilised fruit tree species such as baobab (Adansonia digitata L.) in combating increasing malnutrition and poverty become more apparent as awareness grows regarding concerns of climate change and food security. Due to its multiple uses, its high nutritional and medicinal value, drought tolerance and relatively easy cultivation, baobab has been identified as one of the most important edible forest trees to be conserved, domesticated and valued in Africa. In order to contribute towards the cultivation of the species, suitability of sites in Africa and worldwide was evaluated for potential cultivation using species’ locality data and spatial environmental data in MAXENT modelling framework. A total of 450 geo-referenced records of the baobab tree were assembled from herbarium records, commercial firm’s databases and fieldwork for modelling site suitability for global cultivation of the baobab tree. Climatic and topographic data were acquired from the Worldclim data while soil data was obtained from the Harmonized World Soil Database. MAXENT was found to be a successful modelling method for studying cultivation potential. The main variables that contributed towards predicting baobab’s global cultivation potential were annual precipitation and temperature seasonality. Results suggest that baobab tree could be widely cultivated in most countries in southern Africa and in the Sudano-Sahelian zone of West Africa from Senegal to Sudan. Angola and Somalia were found to be highly suitable for cultivating baobab in Africa. Model suggests, India, where the baobab tree already exists and is used, to be the most suitable country for baobab cultivation outside Africa. North-west Australia, Madagascar, north-east Brazil and Mexico resulted to be other suitable places for cultivating the tree species. Although it is recommended model results be validated with in situ seedling experiments, there seems to be a great potential for the cultivation of this species globally.

Climate Factors Play a Limited Role for Past Adaptation Strategies in West Africa

The Sudano-Sahelian zone of West Africa has experienced recurrent droughts since the mid-1970s and today there is considerable concern for how this region will be able to adapt to future climate change. To develop well targeted adaptation strategies, the relative importance of climate factors as drivers of land use and livelihood change need to be better understood. Based on the perceptions of 1249 households in five countries across an annual rainfall gradient of 400-900 mm, we provide an estimate of the relative weight of climate factors as drivers of changes in rural households during the past 20 years. Climate factors, mainly inadequate rainfall, are perceived by 30-50% of households to be a cause of decreasing rainfed crop production, whereas a wide range of other factors explains the remaining 50-70%. Climate factors are much less important for decreasing livestock production and pasture areas. Increases in pasture are also observed and caused by improved tenure in the driest zone. Adaptation strategies to declining crop production include 'prayer' and migration in the 400-500 mm zone; reforestation, migration, and government support in the 500-700 mm zone; and soil improvement in the 700-900 mm zone. Declining livestock holdings are countered by improved fodder resources and veterinary services. It is concluded that although rainfed crop production is mainly constrained by climate factors, livestock and pasture are less climate sensitive in all rainfall zones. This needs to be reflected in national adaptation strategies in the region. (Resume d'auteur)

Root-induced increases in soil pH and nutrient availability to field-grown cereals and legumes on acid sandy soils of Sudano-Sahelian West Africa.

A field experiment with millet (Pennisetum glaucum L.), sorghum [Sorghum bicolor (L.) Moench], cowpea (Vigna unguiculata L.) and groundnut (Arachnis hypogeae L.) was conducted on severely P-deficient acid sandy soils of Niger, Mali and Burkina Faso to measure changes in pH and nutrient availability as affected by distance from the root surface and by mineral fertiliser application. Treatments included three rates of phosphorus (P) and four levels of nitrogen (N) application. Bulk, rhizosphere and rhizoplane soils were sampled at 35, 45 and 75 DAS in 1997 and at 55 and 65 DAS in 1998. Regardless of the cropping system and level of mineral fertiliser applied, soil pH consistently increased between 0.7 and two units from the bulk soil to the rhizoplane of millet. Similar pH gradients were observed in cowpea, but pH changes were much smaller in sorghum with a difference of only 0.3 units. Shifts in pH led to large increases in nutrient availability close to the roots. Compared with the bulk soil, available P in the rhizoplane was between 190 and 270% higher for P-Bray and between 360 and 600% higher for P-water. Exchangeable calcium (Ca) and magnesium (Mg) levels were also higher in the millet rhizoplane than in the bulk soil, whereas exchangeable aluminium (Al) levels decreased with increasing pH close to the root surface. The results suggest an important role of root-induced pH increases for crops to cope with acidity-induced nutrient deficiency and Al stress of soils in the Sudano-Sahelian zone of West Africa.

Effects of seasonal variation in temperature and cultivar on yield and yield determination of irrigated groundnut (Arachis hypogaea) during the dry season in the Sahel of West Africa

In the Sudano-Sahelian zone of West Africa there is potential for groundnut (Arachis hypogaea L.) to be grown as a dry-season crop where irrigation is available. However, there are substantial variations in the temperatures during the post-rainy season that can be expected to influence growth and yield. An experiment at the ICRISAT Sahelian Centre was done in order to study the effect of sowing date on phenology, yield and the processes of yield determination for four groundnut cultivars under irrigation in the dry seasons of 1990/91 and 1991/92. Starting on 15 November, eight sowing dates at 2-weekly intervals were tested. Sowing date significantly affected phenology (time to emergence, flowering and maturity) with groundnut sown in November/December taking the longest time to reach these phenological stages. November and December sowings gave the highest pod yield within each year, despite the lowest crop growth rates (B), and yield declined progressively as sowing occurred later (50% decrease by March) despite increasing B. The observed responses appear to have been due to the effect of temperature differences during the pod-filling phase on partitioning. Partitioning (p) to pods was optimized at c. 30 C, with some indication of cultivar differences in partitioning response to temperature. Across all the environments, cultivars displayed substantial differences in yield stability. When sown late, yields were low and lines with high partitioning were the best. When sown early in the post-rainy season, cultivars with a high B value were the better choices. Plant habit differences and B suggest that radiation interception was a limitation to yield, particularly when the crops were sown in the cool months of the year. However, haulm yield and crop growth rates were not consistently affected by sowing date across the years, and cultivars demonstrated different degrees of stability for B. It is concluded that where pod has a price advantage over fodder, irrigated groundnut for the dry season should be sown in November to allow the crop to develop under the relatively cool temperatures that maximize pod yield. Further agronomic research is suggested to maximize B for individual cultivars for given sowing dates.

Rooting systems of western and southern African Faidherbia albida (Del.) A. Chev. (syn. Acacia albida Del.) —a comparative analysis with biogeographic implications

Faidherbia albida is a well-known and widespread agroforestry species of the Sudano-Sahelian zone of West Africa. Recent collection and testing efforts have included attempts to introduce seed origins from eastern and southern Africa into the Sahel. These have generally met with failure. Despite superior early growth, mortality is severe by the first or second year. Trials conducted at the ICRISAT Sahelian Center in Niger have demonstrated that this is probably due to differences in rooting patterns between southern and western Africa origins. A separation of the species into two ecotypes, i.e., upland (western Africa) and riparian (eastern, southern and southwestern Africa) is proposed. Based on this argument, the Sudan/Ethiopia region is identified as a possible center of origin for the species.

Population Ecology of Acigona ignefusalis (Lepidoptera: Pyralidae) in Senegal

Ecology of Acigona ignefusalis Hampson, which is an important insect pest of pearl millet in the Sudano-Sahelian zone of West Africa, was studied in Senegal. The pest had two or three generations in a crop season with maximum activity in August–October. Pearl millet and a grass, Pennisetum purpureum Schum., supported a higher population of borers than sorghums. Vertical distribution of borers in the millet plant was influenced by insect feeding site, plant height, stalk thickness, internodes, and stalk condition. Millet stalks and stubble left in the field after harvest and stalks used for housing harbored the diapaused borers during off-seasons. Partial burning of infested green stalks proved to be effective and practical in checking carry-over of the pest.