Estimating the impact of biological control of maize stemborers on productivity and poverty in Kenya: a continuous treatment approach

This study examines the farm-level effects of stemborers’ biological control (BC) using biological and household survey data collected in rural Kenya. The authors use a continuous treatment impact-evaluation method to estimate BC’s average and marginal treatment effects. Findings indicate that, on average, a one percent increase in the intensity of BC increases maize yield by 9.3 kg per hectare and reduces the poverty level of maize-growing farm households by 0.5%. Developing and promoting biological control can be seen as an additional tool in the fight against food insecurity and poverty in Africa through controlling important pests

Assessing the long-term welfare effects of the biological control of cereal stemborer pests in East and Southern Africa: Evidence from Kenya, Mozambique and Zambia

The International Centre of Insect Physiology and Ecology (icipe), undertook a biological control (BC) programme for control of stemborers from 1993 to 2008, to reduce cereal yield losses due to stemborer attack in East and Southern Africa. The programme released four biological control agents—the larval parasitoids Cotesia flavipes and Cotesia sesamiae, the egg parasitoid Telenomus isis and the pupal parasitoid Xanthopimpla stemmator—to control the economically important stemborer pests Busseola fusca, Chilo partellus and Sesamia calamistis. Two of the natural enemies that were released got established and spread to many localities in the region. This study adopted the economic surplus model based on production, market and GIS data to evaluate the economic benefits and cost-effectiveness of the programme in three countries—Kenya, Mozambique and Zambia. Findings show that the biological control intervention has contributed to an aggregate monetary surplus of US$1.4 billion to the economies of the three countries with 84$ 272 million for both crops and ranged from US$142 million for Kenya to US$ 39 million for Zambia. The attractive internal rate of return (IRR) of 67% compared to the considered discount rate of 10%, as well as the estimated benefit–cost ratio (BCR) of 33:1, illustrate the efficiency of investment in the BC research and intervention. The estimated number of people lifted out of poverty through the BC-programme was on average 57,400 persons (consumers and producers) per year in Kenya, 44,120 persons in Mozambique, and 36,170 persons in Zambia, representing an annual average reduction of poor populations, respectively of 0.35, 0.25 and 0.20% in each of the three countries. These findings underscore the need for increased investment in BC research to sustain cereal production and improve poor living conditions

An assessment of the magnitudes and factors associated with postharvest losses in off-farm grain stores in Kenya

Off-farm grain storage is an important postharvest undertaking by government, traders and processors in Kenya. A survey was conducted in 2014/2015 to assess the kinds and magnitudes of perceived losses experienced in off-farm stores, and the factors associated with them. Store supervisors or key personnel charged with grain storage in 39 public and 74 private stores, spread across the six maize growing agro-ecological zones, were interviewed using a structured questionnaire. Total perceived losses averaged 17.6± 2.3%, and were attributed to insects (7.2± 1.0%), molds (5.7± 2.1%), moisture loss (3.4± 0.5%), rodents (2.0± 0.5%), spillage (0.50 ± 0.0%) and birds (0.10± 0.0%). Total losses experienced in public and privately owned stores were not significantly different. The losses attributed to insect and the vertebrate pests, moisture loss and spillage, were also not significantly different in the two storage systems. However, losses due to molds were significantly higher in the private stores. From regression analysis, higher losses were associated with the use of residual insecticides, purchasing low quality maize for storage, reuse of storage bags, untimely control of storage pests, and the agro-climatic conditions of the moist transitional, moist mid-altitude and dry mid-altitude zones. Relying on infestation reports to initiate pest control had the highest marginal effect (21.7%). Lower loss magnitudes were associated with cleaning and drying grain before storage, early pest control and storage periods shorter than two months. These findings provide important reasons for appraising current off-farm storage techniques with a view to taking possible actions for improvements. It is recommended that innovations to mitigate maize postharvest losses should also target off-farm storage, as the losses incurred are significant

On-farm maize storage systems and rodent postharvest losses in six maize growing agro-ecological zones of Kenya

Rodents are one of the major postharvest pests that affect food security by impacting on both food availability and safety. However, knowledge of the impact of rodents in on-farm maize storage systems in Kenya is limited. A survey was conducted in 2014 to assess magnitudes of postharvest losses in on-farm maize storage systems in Kenya, and the contribution of rodents to the losses. A total of 630 farmers spread across six maize growing agro-ecological zones (AEZs) were interviewed. Insects, rodents and moulds were the main storage problems reported by farmers. Storage losses were highest in the moist transitional and moist mid-altitude zones, and lowest in the dry-transitional zone. Overall, rodents represented the second most important cause of storage losses after insects, and were ranked as the main storage problem in the lowland tropical zone, while insects were the main storage problem in the other AEZs. Where maize was stored on cobs, total farmer perceived (farmer estimation) storage weight losses were 11.1 ± 0.7 %, with rodents causing up to 43 % of these losses. Contrastingly, where maize was stored as shelled grain, the losses were 15.5 ± 0.6 % with rodents accounting for up to 30 %. Regression analysis showed that rodents contributed significantly to total storage losses (p < 0.0001), and identified rodent trapping as the main storage practice that significantly (p = 0.001) lowered the losses. Together with insecticides, rodent traps were found to significantly decrease total losses. Improved awareness and application of these practices could mitigate losses in on farm-stored maize

Determinants of diffusion and adoption of improved technology for rice parboiling in Benin

The widespread use of traditional rice-parboiling methods in Benin leads to poor quality of final rice. To address this problem, the national agricultural research institute of Benin and Africa Rice Center have developed improved rice parboiling technology. An educational video developed by AfricaRice was used for it diffusion. Women have expressed high interest in the use of the technology and have reported that it helps increase the quality of their final rice despite its' relatively high cost. This paper uses the Average Treatment Effect (ATE) framework and data collected from 200 women rice parboilers in central Benin to estimate the actual and potential adoption rates of this technology and the determinants of its diffusion and adoption. 85% of the sampled women were exposed to the technology in 2008. With this incomplete diffusion, the actual adoption rate is 67%, whereas the potential adoption rate is estimated to be 75%. "Being member of a parboilers association'' and "Participation in video training" are positively associated with knowledge and adoption of this technology. This indicates that support and promotion of women parboilers associations is a means to increase technology uptake and access and video-supported training is an extension tool to promote agricultural technology awareness and adoption