Push-pull Technology Research Articles

The economic, social, and environmental impact of ecologically centered integrated pest management practices in East Africa

Agricultural pest management faces mounting challenges with increasing pressure to reduce chemical pesticide use while ensuring food security, and environmental sustainability. Ecologically centered approaches, such as integrated pest management (IPM), offer promising sustainable agroecological crop protection alternative solutions to pesticides. This study assesses the investment viability and environmental sustainability of two IPM interventions—mango fruit fly IPM (FF-IPM) and push-pull technology (PPT) in Kenya and Uganda, using project investment and adoption data from 2007 to 2021. The study also evaluates these technologies contribution to food security and poverty reduction. FF-IPM integrates biological control, cultural practices, and targeted bait traps to manage fruit flies in mango production, while PPT employs Desmodium and Brachiaria grass to control stemborers and striga weed. The findings highlight that these IPM interventions achieved a combined net present value of $500 million, with a benefit-cost ratio of about 8:1, and an internal rate of return of 21%, comparable to returns from improved crop varieties. These technologies also improved food security for 641,000 people, lifted 445,349 people above the poverty line, representing 2% of the poor population in both countries, and generated an average income increase of $5 per capita in Kenya and Uganda annually. Environmentally, they sequestered 2.7 million tons of CO2 equivalent, valued at $12.2 million, and are reducing pesticide use by 86,000 to 204,000 L per year. These results demonstrate the potential of IPM approaches to simultaneously enhance livelihoods, local economies, and generate global environmental public goods, suggesting that addressing adoption barriers could further amplify these positive outcomes.

Push-Pull Intercropping Increases the Antiherbivore Benzoxazinoid Glycoside Content in Maize Leaf Tissue.

Push-pull technology refers to a promising mixed cropping practice for sustainable agricultural intensification, which uses properties of intercrop and border crop species to defend a focal crop against pests. Currently, the most widely practiced system uses Desmodium spp. as intercrop and Brachiaria or Napier grass as border crops to protect maize (Zea mays) against both insect pests and parasitic weeds. Several previous studies have demonstrated the efficacy of the push-pull system, but research on the underlying chemical mechanisms has mostly been limited to laboratory and glasshouse experiments that may not fully reproduce the complexity of the system under natural conditions. To address this limitation, we performed a large-scale study in farmer-operated push-pull maize fields in three east African countries. We compared maize leaf extracts from plants grown on push-pull fields with maize from fields employing conventional agricultural practices to assess the influence of push-pull cultivation on the maize metabolome. We identified two benzoxazinoid glycosides, which are known to have antiherbivore properties and were present in greater relative abundance in push-pull-cultivated maize leaves across three countries. Our data thus suggest that maize cultivated under push-pull has an increased resistance to herbivore attack compared to maize grown under conventional local agricultural practices.

Structure, tree diversity, and aboveground carbon stocks of smallholder farms with push-pull technology in western Kenya

Push-pull technology is a companion cropping system whose success in soil fertility improvement and management of agricultural pests has been established in cereal-based systems. Push-pull has also been proposed as a template for the sustainable intensification of agriculture in Africa. However, the application of the technology has remained on a field scale and is restricted to cereal-based systems. Trees in agricultural landscapes are considered a strategy for climate change mitigation by storing carbon in soils and woody biomass. However, their potential has not been quantified in push-pull systems. This study characterized 45 smallholder farms in western Kenya to establish the land use categories within which push-pull is integrated, the diversity and structure of perennials on the farms, and the aboveground carbon stored within those farms. The area of each land use category varied depending on the size of the land use category on each farm. The amount of carbon stored in aboveground biomass was estimated using an existing allometric equation. This study found that trees are integrated on farms with push-pull in homesteads (45), cropland (38), woodlots (26), boundaries (4), and grazing land (2) farms. A total of 9159 trees from 97 different species were recorded over 34 ha. Farms in Vihiga and Kisumu had more trees (38 % and 37 % of all trees recorded) than those in Siaya (25 %). There were more trees in woodlots (total=4518) and homesteads (total=3327), and the least in grazing land (total=18). Overall, the highest species richness, Shannon, and Simpson diversity were observed in the homestead (86 species, H’=2.52 and D = 0.86). Farms in Kisumu, Vihiga, and Siaya stocked an average of 12.1, 9.4, and 7.3 Mg C ha−1 in aboveground biomass respectively. Variations were observed in land use categories, where woodlots had the greatest amount of carbon (55.5 Mg C ha−1) while grazing land had the least (2.4 Mg C ha−1). Eucalyptus spp., Grevillea robusta, and Markhamia lutea were the most dominant trees in abundance at 50 %, 16 %, and 11 % respectively. Conservation of trees on farms should be encouraged, as they protect biodiversity and store carbon thus contributing to climate change mitigation. This study's findings contribute to knowledge valuable to farmers and policymakers in making decisions on tree species and land use categories that have a high potential to sequester carbon in agroforestry systems.

Soil greenhouse gas fluxes and net global warming potential from two maize farming practices in the Bamenda highlands, Cameroon

Farming practices used in maize crop production are thought to modify greenhouse gas (GHG) emissions from the soil particularly methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). The quantities of these GHG fluxes have rarely been estimated from smallholder farms in Sub-Saharan Africa. We estimated the quantities of GHG fluxes and Global Warming Potential (GWP) from the Push-Pull Technology (PPT) and Tillage with the Formation of Ridges (TFR) farming systems at the University of Bamenda, Cameroon. Greenhouse gases were sampled bi-monthly from April to Early August 2020 using the static chamber technique. The experiment followed a split-plot randomized complete block design with two replicates and three planting distances (1 m, 1.5 m, and 2 m) used as treatments. Mean cumulative CH4 (5.39 kgCH4-Cha−1) and N2O (1.03 kgN2O-Nha−1) emissions under TFR were significantly higher (P < 0.05) than mean CH4 (3.59 kgCH4-Cha−1) and N2O (0.52 kgN2O-Nha−1) emissions under PPT system. Mean net-GWP under PPT followed the trend 2 m (−267.61 tCO2-eqha−1) < 1.5 m (−75.76 tCO2-eqha−1) < 1 m (−24.95 tCO2-eqha−1) while under TFR, net-GWP was ordered 1 m (0.38 tCO2-eq ha−1) < 1.5 m (85.29 tCO2-eq ha−1) < 2 m (288.41 tCO2-eq ha−1) with significant differences between them. Maize grain yields under PPT were in the trend 1 m (0.81 tha−1) < 2 m (0.85 tha−1) < 1.5 m (0.92 tha−1) with a significant difference (P < 0.05) between 1 m and 1,5 m treatments. While under TFR, the trend was 2 m (0.56 tha−1) < 1 m (0.77 tha−1) < 1.5 m (0.80 tha−1) with significant difference between 1.5 m and 2 m (P < 0.05). On average, PPT was a sink to GWP (−122.77 tCO2-eqha−1) and revealed higher (P < 0.05) yields (0.86 tha−1) than TFR (0.71 tha−1) which was a source of GWP (124.69 tCO2-eqha−1). Therefore, a PPT practice of 1.5 m planting distance is recommended in Sub-Saharan Africa to enhance food productivity while mitigating global warming by minimizing soil greenhouse gas emissions.

Comparative microbiome diversity in root-nodules of three Desmodium species used in push-pull cropping system.

Desmodium species used as intercrops in push-pull cropping systems are known to repel insect-pests, suppress Striga species weeds, and shift soil microbiome. However, the mechanisms through which Desmodium species impact the soil microbiome, either through its root exudates, changes in soil nutrition, or shading microbes from its nodules into the rhizosphere, are less understood. Here, we investigated the diversity of root-nodule microbial communities of three Desmodium species- Desmodium uncinatum (SLD), Desmodium intortum (GLD), and Desmodium incanum (AID) which are currently used in smallholder maize push-pull technology (PPT). Desmodium species root-nodule samples were collected from selected smallholder farms in western Kenya, and genomic DNA was extracted from the root-nodules. The amplicons underwent paired-end Illumina sequencing to assess bacterial and fungal populations. We found no significant differences in composition and relative abundance of bacterial and fungal species within the root-nodules of the three Desmodium species. While a more pronounced shift was observed for fungal community compositions compared to bacteria, no significant differences were observed in the general diversity (evenness and richness) of fungal and bacterial populations among the three Desmodium species. Similarly, beta diversity was not significantly different among the three Desmodium species. The root-nodule microbiome of the three Desmodium species was dominated by Bradyrhizobium and Fusarium species. Nevertheless, there were significant differences in the proportion of marker gene sequences responsible for energy and amino acid biosynthesis among the three Desmodium species, with higher sequence proportions observed in SLD. There is no significant difference in the microbial community of the three Desmodium species used in PPT. However, root-nodule microbiome of SLD had significantly higher marker gene sequences responsible for energy and amino acid biosynthesis. Therefore, it is likely that the root-nodules of the three Desmodium species host similar microbiomes and influence soil health, consequently impacting plant growth and agroecosystem functioning.

Evaluation of push-pull technology for pest and soil fertility management on maize in north western Ethiopia

Maize (Zea mays L.) production in north western Ethiopia is severely constrained by the parasitic weed striga (Striga hermontica), the stemborer (Busseola fusca) pest, and poor soil fertility due to continuous mono cropping. An intercropping system known as push-pull technology is a novel soil and pest management strategy for improving soil fertility and controlling agricultural pests by using repellent "push" plants (such as desmodium, Desmodiumintortum)and trap "pull" plants (such as napier grass, Pennisetum purpureum). The aims of the study were (i) to evaluate the effectiveness of the push-pull technology against stemborer and striga infestation, (ii) to investigate the impact of the push-pull technology on improving grain yield, and (iii) to assess effect of the push-pull technology on soil fertility. The study was conducted in 2017 and 2018 cropping seasons in 3 districts in north western Ethiopia. Three farmers from each district, who practiced the technology, were randomly selected for the study. Each farmer had a set of two treatments (plots): a push-pull technology (PPT) and maize monocrop (MC) treatments. Data were collected on the percentage of maize plants damaged by stemborers, the number of striga plants that emerged, plant height, grain yield, available phosphorus (P), available potassium (K), total nitrogen (TN), organic carbon (OC), organic matter (OM) and bulk density (BD). There were significant reduction in stemborer damage (2.8 %) and striga count (4.1 Striga plants/m2) in the push-pull treatment compared to the maize monocrop plots (15.4 % and 21.8 striga plants/m2, respectively). Maize plant height (2.34 m) and grain yield (5.3 t ha−1) were significantly higher in the push-pull plots as compared to the sole crop (1.9 m and 3.0 t ha−1, respectively). Similarly, there were significantly higher P (20.06 mg/kg soil), K (406.86 mg/kg soil), TN (2.5 g/kg soil), OC (42.9 g/kg soil), OM (73.8 g/kg soil) levels considered to be moderate to high fertility status in the push-pull as compared to monocrop plots (11.17 mg/kg soil, 347.93 mg/kg soil, 1.6 g/kg soil, 29.8 g/kg soil, and 51.2 g/kg soil, respectively) which is rated from low to moderate soil fertility level. Moreover, bulk density was significantly lower in PPT (0.92 g/cm3) than in MC (0.95 g/cm3) plots. This suggests that push pull technology is effective in reducing striga and stemborer damage and improves soil fertility status which results in better grain yield.

Reviews on the Strategies Employed in Implementing the 'Push-Pull' Approach to Integrated Pest Management

Abstract: For small-holder maize farmers in Africa, the push-pull strategy is outlined as an alternate ecological management technique to traditional insecticide-based integrated pest management for the control of the spotted stem borer Chilo partellus and the autumn armyworm Spodoptera frugiperda. Push-Pull Technology (abbreviated PPT) is a unique integrated pest management method developed by the International Centre of Insect Physiology and Ecology (ICIPE) and its partners. This tactic involves influencing the behavior of natural enemies and insect pests by strategically deploying stimuli that make the resource under protection unappealing or inappropriate for the pests (the "push"). Additionally, the pests are drawn to an alluring source the pull, from which they are then eliminated

Long-term push–pull cropping system shifts soil and maize-root microbiome diversity paving way to resilient farming system

BackgroundThe soil biota consists of a complex assembly of microbial communities and other organisms that vary significantly across farming systems, impacting soil health and plant productivity. Despite its importance, there has been limited exploration of how different cropping systems influence soil and plant root microbiomes. In this study, we investigated soil physicochemical properties, along with soil and maize-root microbiomes, in an agroecological cereal-legume companion cropping system known as push–pull technology (PPT). This system has been used in agriculture for over two decades for insect-pest management, soil health improvement, and weed control in sub-Saharan Africa. We compared the results with those obtained from maize-monoculture (Mono) cropping system.ResultsThe PPT cropping system changed the composition and diversity of soil and maize-root microbial communities, and led to notable improvements in soil physicochemical characteristics compared to that of the Mono cropping system. Distinct bacterial and fungal genera played a crucial role in influencing the variation in microbial diversity within these cropping systems. The relative abundance of fungal genera Trichoderma, Mortierella, and Bionectria and bacterial genera Streptomyces, RB41, and Nitrospira were more enriched in PPT. These microbial communities are associated with essential ecosystem services such as plant protection, decomposition, carbon utilization, bioinsecticides production, nitrogen fixation, nematode suppression, phytohormone production, and bioremediation. Conversely, pathogenic associated bacterial genus including Bryobacter were more enriched in Mono-root. Additionally, the Mono system exhibited a high relative abundance of fungal genera such as Gibberella, Neocosmospora, and Aspergillus, which are linked to plant diseases and food contamination. Significant differences were observed in the relative abundance of the inferred metabiome functional protein pathways including syringate degradation, L-methionine biosynthesis I, and inosine 5'-phosphate degradation.ConclusionPush–pull cropping system positively influences soil and maize-root microbiomes and enhances soil physicochemical properties. This highlights its potential for agricultural and environmental sustainability. These findings contribute to our understanding of the diverse ecosystem services offered by this cropping system where it is practiced regarding the system's resilience and functional redundancy. Future research should focus on whether PPT affects the soil and maize-root microbial communities through the release of plant metabolites from the intercrop root exudates or through the alteration of the soil's nutritional status, which affects microbial enzymatic activities.

Farmers’ Perceptions of Maize Production Constraints and the Effects of Push–Pull Technology on Soil Fertility, Pest Infestation, and Maize Yield in Southwest Ethiopia

This study aimed to analyze farmers’ perceptions of maize production constraints and determine the effects of push–pull technology (PPT) on crop yield, pest control, and improving soil fertility status. Increasing fertilizer prices and pesticide prices, FAWs (fall armyworms) and stemborers, declining soil fertility, and drought are the main maize production constraints in the area. Seventy percent of the respondents indicated that an increase in input prices such as those of fertilizer and seeds is the major constraint in the area, while FAWs (55%) and stemborers (44.3%) were ranked the third and fourth major constraints. About 67% of farmers reported that stemborer damage to maize in PPT plots was either minimal or non-existent. Fifty-five percent of farmers stated that the damage caused to maize by FAWs was low or that there was no damage in PPT plots. PPT reduced stem borer infestation from 83% to 44%. The yield gained from PPT plots ranged from 18% to 31%. Soil samples taken from PPT plots showed improved soil organic carbon, organic matter, total nitrogen, and cation exchange capacity.

Integrating vegetables in push-pull technology systems: gendered preferences of smallholder farmers in western Kenya

Transformative rural smallholder agriculture addressing biophysical constraints requires farmer-led innovations for increased technology adoption. Following the need to further intensify the cereal push-pull technology (PPT) for pest and weed control through integration with vegetables, we conducted surveys to determine suitable vegetables across three different counties in Kenya namely Homabay, Siaya, and Trans-Nzoia. Farming in these areas is predominantly maize based and introducing vegetables to the system will improve household food and nutritional security, together with income. A systematic random sampling method was used to sample a total of 124 smallholder farmers who were interviewed during field days where farmer awareness of technology was mobilised. Descriptive results showed kale (47%) and black nightshade (30%) were the most preferred high-value vegetables for integration into push-pull plots in these regions. This was followed by cowpea (15%), onion (6%) and tomato (2%) underlying the wide range of farmer preferences and priorities. There were also gender differences in vegetable preferences with men preferring capital intensive and high value vegetables, while women preferred traditional vegetables. Results from multinomial logit model revealed that age of the farmer, education level, gender, and farming experience were determinants of smallholder farmers’ vegetable preferences for integration into the PPT plots. The contribution of these determinants to farmer preferences varied across different vegetables where the contribution of the market value of the vegetable in selection diminished with while the effect of farmers’ age. Overall, male farmers preferred capital-intensive and market-oriented vegetables in compared to their female counterparts. We conclude that gender and geographic location play a pivotal role in farmers` crop selection for integration in the PPT. Targeted awareness creation pathways accounting for these factors will be critical for wider adoption of the PPT. Key words: Food security, Multinomial Logistic Regression Model, Participatory rural appraisal, Sustainable agricultural intensification, Technology adoption

Integrating Entomopathogenic Fungi into Different Crop Management Practices for Fall Armyworm Management

The study was carried out to identify crop management practices favouring entomopathogenic fungi of fall armyworm (Spodoptera frugiperda J. E. Smith). An experiment was set up with 24 maize plots measuring 6 m x 5 m in Siaya, JOOUST Campus field during the September to December 2021 short rain season for identification of crop management practices favouring entomopathogenic fungi of fall armyworm. Morphological and Molecular characterization was done to estimate the diversity of entomopathogenic fungi offal armyworm larvae specimens from the treatment plots. Each plot was separated by 2 m occupied with Brachiaria CV Mulato to counter the possibility of fall armyworm migration from one treatment plot to another as recommended by the ICIPE’s fall armyworm push-pull technology. The results showed that weeding was statistically significant (0.044) on fall armyworm larvae collected while only 2 species of entomopathogenic fungi were isolated for this crop management practice. The case was different with intercropping, though not statistically significant, over 50% of the isolated species were from this management practice. This could mean that intercropping is likely to reduce FAW larvae infestation whilst increasing fungal activity. This study therefore concludes that the threat that S. frugiperda poses also calls for the need for the development and adoption of good crop management practices such as intercropping, adequate fertilization, and weeding

Determining the efficacy of push-pull for management of Eldana saccharina (Walker (Lepidoptera: Pyralidae) in sugarcane through on-farm field trials in KwaZulu-Natal.

An area-wide integrated pest management (AW-IPM) programme was developed to improve management of Eldana saccharina Walker (Lepidoptera: Pyralidae), a major pest of South African sugarcane. Push-pull technology is an important component of this AW-IPM approach. The sugarcane push-pull programme uses plants which are both repellent (Melinis minutiflora P. Beauv. (Cyperales: Poaceae)) and attractive (Cyperus dives Delile and Cyperus papyrus L. (both Cyperales: Cyperaceae) to E. saccharina. Previous research demonstrated the efficacy of push-pull in the Midlands North region of KwaZulu-Natal (KZN), South Africa. To date, little research has been conducted in coastal sugarcane growing areas. The aim of this study was to assess the feasibility of using push-pull for management of E. saccharina in coastal KZN, using large-scale on-farm field trials conducted on five model farms. On each farm, wetland habitats were rehabilitated with pull plants (C. dives and C. papyrus) and fields were intercropped with the repellent grass M. minutiflora. Eldana saccharina damage and infestation levels were recorded to assess the efficacy of push-pull, using a multiple before-after-control-impact (mBACI) design. Push-pull treatment sites showed a significant reduction in mean percentage stalk damage and E. saccharina abundance relative to control sites. Furthermore, stemborer surveys in wetland habitats revealed higher numbers of E. saccharina within Cyperus spp. stands. Pull plants were therefore effective at attracting E. saccharina away from sugarcane. The success of the push-pull trials in this study indicates that it is a useful tool for managing E. saccharina populations in coastal sugarcane, especially in conjunction with other management practices.

Factors influencing the adoption of climate smart agriculture practices among smallholder farmers in Kakamega County, Kenya

Most of Kenya’s population’s livelihoods and agri-food systems rely on rain-fed agriculture making them vulnerable to climate change. The adverse effects of climate change on agricultural production have necessitated the promotion of Climate-Smart Agriculture (CSA) technologies. Climate-Smart Agriculture (CSA) technologies help guide actions needed to transform and reorient agricultural systems to effectively support development and ensure food security by increasing farmers’ resilience to climate change. This study sought to ascertain the current state of CSA practices among Kakamega County's smallholder farmers to identify the main drivers of CSA adoption. Stratified sampling was used to select six sub-counties to represent the county's various agroecological zones and regions for the research sample. A combination of purposive and snowball sampling was used to select 428 smallholder CSA farmers of which 182 were adopters while 246 were dis-adopters. Primary data were collected using interview guides developed through the Kobo Collect Application. Microsoft Excel and Statistical Package for Social Sciences (SPSS) statistical packages were used to process and analyze the data. This study established that CSA technologies in Kakamega are mainly promoted by international development partners, non-governmental organizations and research organizations. In addition, the most adopted CSA technologies were agroforestry, composting, and soil and water conservation structures, while push-pull technology, conservation agriculture, and vermiculture were the least adopted. This study, further, established that smallholder farmers’ level of education, membership to a farmers’ group, interaction with extension officers and farming experience influenced adoption of CSA technologies. Other factors are those that increase household productive resources, such as land ownership, household income, and access to agricultural credit. The results of this study suggest that those who promote CSA technologies, policymakers, extension service providers, and other stakeholders should take smallholder farmers' socioeconomic and bio-physical factors into account when doing so. Key words: Climate-smart agriculture, CSA practices, CSA adoption, CSA dis-adoption, smallholder farmers

Are agricultural extension systems ready to scale up ecological intensification in East Africa? A literature review with particular attention to the Push-Pull Technology (PPT)

AbstractAgricultural extension, or advisory services, have a key role to play in supporting farmers’ learning and adoption of new practices and technologies. This paper analyses gaps and needs which require addressing in order for extension systems to more effectively contribute to the upscaling of ecological intensification approaches in East African smallholder agriculture. Our starting point is the push-pull technology (PPT), a promising approach. PPT originated in East Africa and is being continuously improved through cycles of interdisciplinary and participatory experimentation. Despite well-documented benefits to farmers and the environment, more institutional support from agricultural extension systems (AES) is needed for PPT to realise significant impact on poverty reduction, food security, and sustainability. Departing from this assessment, we review literature on AES in five East African countries. After clarifying the AES characteristics that ecological intensification requires, emphasising the capacity to embrace complexity, we identify four thematic areas that are in urgent need of attention: first, widely recognised problems with access and inclusiveness have seen welcome innovation but remain substantial. Second, information and communication technologies provide many benefits and new possibilities, but expectations must be tempered. Third, pluralistic AES present coordination challenges that risk undermining and misdirecting extension. Finally, the political-economic underpinnings of extension require critical scrutiny and strategic interventions. While many challenges threaten extension effectiveness broadly, we highlight implications for ecological intensification approaches like PPT. Our insights thus speak to the broader question of how to design and implement extension for sustainable agricultural development in East Africa.

Farmers’ perceived pathways for further intensification of push-pull systems in Western Kenya

Push-pull technology provides farmers in East Africa with an eco-friendly strategy that increases crop yield and household income in smallholder cereal systems by controlling pests and improving soil health. Though promising for a sustainably intensified production, push-pull has been used at limited scale, primarily in maize-and sorghum-based production systems. Expanding the scope, applicability and acceptance of the practice in smallholder farming systems, will leverage the full potential of push-pull as a widely applicable sustainable farming practice. Using key informant interviews and focus group discussions, we explored farmers’ needs and perceived pathways for integrating push-pull and other sustainable intensification practices in synergy with existing cropping systems in Kisumu, Vihiga and Siaya Counties in Western Kenya. We found that farmers in the region typically grow and intercrop a variety of crops, with maize being the most common crop. Farmers commonly practice crop-livestock farming, intercropping, crop rotation, manure and fertilizer use, and use improved varieties to increase maize production. Across the counties, integration of food legumes, agroforestry and crop-livestock farming, were identified as fundamental pathways for stretching the benefits of push-pull. Limitations to farmers’ aspirations and key enablers for facilitating spontaneous adoption of identified sustainable intensification practices for push-pull farming systems are discussed.

Bridging the gap in agricultural innovation research: a systematic review of push–pull biocontrol technology in sub-Saharan Africa

ABSTRACTBiological control for sustainable plant protection in sub-Saharan Africa (SSA) is gaining attention due to low crop productivity caused by pests, increasing costs of agrochemicals, and their harmful impact on health and the environment. A valuable case is the Push–pull technology (PPT) developed by the International Centre of Insect Physiology and Ecology (ICIPE). However, evidence for the success of PPT in reducing pest prevalence has not translated from experimentation and demonstration to wider-scale on-farm uptake. A systematic review was conducted to explore the research gaps, benefits of PPT, adoption determinants, barriers to uptake, and how farmers choose to adopt and adapt the technology. The study found a large body of evidence on the biophysical benefits of PPT, which comes from a relatively narrow set of ICIPE-led or managed experiments in Western Kenya. Besides, evidence of its social and economic benefits is less robust. Documented barriers to adoption include initial establishment costs, labour intensiveness, risk averseness of farmers, socio-cultural rigidity, and inadequate access to information and inputs. The review highlights the need for qualitative research, an in-depth examination of the social dynamics of innovation and decision-making processes on farms, and institutions’ role in shaping innovation for sustainable agricultural development.

Push-pull technology enhances resilience to climate change and prevents land degradation: Perceptions of adopters in western Kenya

Climate change and land degradation adversely affect food security in sub-Saharan Africa (SSA). Smallholder farmers are the most affected. Therefore, it is imperative to identify technologies that boost resilience to climate change, and restore lands. Push-pull technology is among proposed solutions. This technology controls stem borers, fall armyworm, striga, mycotoxins; improves availability of nitrogen and phosphorus, and stores increased carbon in biomass and soils. Though much has been published about push-pull technology, there is a lean in publications about how this technology can help smallholder farmers to cope with climate change and variability. Here, we present perceptions of adopters of push-pull technology in western Kenya with regard to climate change and land degradation, and discuss reasons it should be adopted widely. We compared push-pull and other maize-based cropping systems in western Kenya, through interviews. Push-pull technology produces 0.3–1.1 ​t more maize ha−1 compared to maize-bean intercrop, and maize monocrop when the season is drier than normal. Additionally, push-pull provides 3.6–9.8 ​t more fodder during drought-stricken seasons. Push-pull technology covers 70% of the soil surface compared to 20% cover found in maize-bean intercrop and maize monocrop. In push-pull farms, 150–280 ​kg nitrogen, 13–24 ​kg phosphorus and 370–470 ​kg potassium can be recycled through biomass and this is five times greater than the potential for maize-bean intercrop and maize monocrop. There is need for wide adoption of push-pull technology to increase resilience of farmers to climate change and restore degraded lands.

Climate change and ecological intensification of agriculture in sub-Saharan Africa – A systems approach to predict maize yield under push-pull technology

Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. ‘Push-pull’ technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant–insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species- and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests’ natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops.

Push-Pull Technology in Climate-Smart Agriculture: A Strategy for Sustainable Agriculture

Push-Pull Technology in Climate-Smart Agriculture: A Strategy for Sustainable Agriculture

Maize From Push-Pull Technology (PPT): Can the Produce Be Differentiated?

Maize From Push-Pull Technology (PPT): Can the Produce Be Differentiated?