Determining smallholder farmers’ preferences for Push-Pull technology dissemination pathways in western Kenya

The push-pull technology (PPT) has widely been disseminated to control stemborer (Chilo partellus and Busseola fusca) and Striga weeds (Striga hermonthica and Striga asiatica) in maize fields in Kenya. This study examined farmers’ preferences for various dissemination pathways in order to proffer better targeting of resources in an optimal dissemination strategy. The pathways considered were public meetings (barazas), radio, farmer field schools (FFS), field days (FD), farmer teachers (FT), the fellow farmers (FF) and print materials. Using a weighted score index and ordered probit regression, the different pathways were sequentially ranked as FD, FT, FFS, FF, print materials, Radio, and barazas. Marginal effects from ordered probit showed that farmers had the least preferences for baraza and radio pathways. The farmer categories with the highest preference for particular pathways were: less educated farmers for FD, farmers with small land sizes for FT, farmers belonging to groups for FFS, and young educated farmers for the print materials. This information is extremely important for targeting the different segments of farmers.Push-pull technology, Stemborer, Striga, Dissemination pathways, preference, Research and Development/Tech Change/Emerging Technologies,

Ecological chemistry of pest control in push-pull intercropping systems: What we know, and where to go?

Push-pull technology (PPT) employs mixed cropping for sustainable intensification: an intercrop repels or suppresses pests of the focal crop (push), while a trap crop attracts pests out of the field (pull), where they may be targeted for control. Underlying chemical-ecological mechanisms have been demonstrated in controlled settings, primarily for some of the best-established cereal PPT systems developed in east Africa. Yet, many questions remain regarding mechanisms, and strategies to adapt PPT for different crops and locations. We conducted a systematic review of scientific literature on PPT and related practices for biological control of pests of food and fodder. Of 3335 results, we identified 45 reporting on chemistry of trap- or intercropping systems for pest control, of which 30 focused on cereals or African pests. Seven of these reported primary chemical data: measurements from glasshouse and laboratory studies (5), or of field-collected samples (2). From these 30, we provide a database of compounds, discussing degrees of evidence for their mediation of push-pull. We depict hypothesized spatial distributions of selected compounds in PPT fields from physical properties and emission/exudation rates, and design of the east African cereal PPT system, and discuss influences on activity in field settings likely to affect success

Participatory Evaluation of Integrated Pest and Soil Fertility Management Options Using Ordered Categorical Data Analysis

During participatory rural appraisals, farmers at the Lake Victoria basin of Kenya and Uganda identified Striga, stemborer and declining soil fertility as three major constraints to maize production To reduce food insecurity, several innovative integrated technologies to address these constraints have been developed, including push-pull (maize intercropped with Desmodium and surrounded by napier grass), maize-soybean and maize-crotalaria rotations, and Imazapyrresistant (IR) maize seed coated with the herbicide. To let farmers evaluate the new technologies, 12 demonstration trials, comparing the different technologies, were established in four villages in Siaya and Vihiga districts (Western Kenya) and two villages in Busia (Uganda). These evaluations, where farmers' appreciation and feedback on the technology are captured, are an important step in technology development. During field days at the end of short rainy seasons of 2003 and 2004, 504 farmers individually observed and rated each treatment under the different cropping systems, with and without IR maize, and with and without fertilizer, with a maize continuous monocrop as control. Farmers scored each of the 16 treatments on an ordered scale of five categories: very poor, poor, average, good, and very good. The treatments were scored for each of the criteria farmers has previously determined (including yield, resistance to Striga and stemborer, and improvement of soil fertility). Analysis of the evaluation, using ordinal regression, show significant differences in farmers' preference by year and site. There was, however, little effect of farm and farmer characteristics such as farm size and gender of the observer. Ordinal regression of farmers' scores are not as intuitive and also bit cumbersome to use, but they have a better theoretical foundation than other methods, in particular the use of means. This paper shows how the method can be used, and concludes that, with some effort, it is a convenient way to analyse farmers' ranking of a large number of options.farmers' preference, technologies, ordinal regression, Crop Production/Industries,

Ecological Chemistry of Pest Control in Push-Pull Intercropping Systems: What We Know, and Where to Go?

Push-pull technology (PPT) employs mixed cropping for sustainable intensification: an intercrop repels or suppresses pests of the focal crop (push), while a trap crop attracts pests out of the field (pull), where they may be targeted for control. Underlying chemical-ecological mechanisms have been demonstrated in controlled settings, primarily for some of the best-established cereal PPT systems developed in east Africa. Yet, many questions remain regarding mechanisms, and strategies to adapt PPT for different crops and locations. We conducted a systematic review of scientific literature on PPT and related practices for biological control of pests of food and fodder. Of 3335 results, we identified 45 reporting on chemistry of trap- or intercropping systems for pest control, of which 30 focused on cereals or African pests. Seven of these reported primary chemical data: measurements from glasshouse and laboratory studies (5), or of field-collected samples (2). From these 30, we provide a database of compounds, discussing degrees of evidence for their mediation of push-pull. We depict hypothesized spatial distributions of selected compounds in PPT fields from physical properties and emission/exudation rates, and design of the east African cereal PPT system, and discuss influences on activity in field settings likely to affect success

Push-Pull: Chemical ecology-based integrated pest management technology

Lepidopterous stemborers, and parasitic striga weeds belonging to the family Orobanchaceae, attack cereal crops in sub-Saharan Africa causing severe yield losses. The smallholder farmers are resource constrained and unable to afford expensive chemicals for crop protection. The push–pull technology, a chemical ecology- based cropping system, is developed for integrated pest and weed management in cereal–livestock farming systems. Appropriate plants were selected that naturally emit signaling chemicals (semiochemicals). Plants highly attractive for stemborer egg laying were selected and employed as trap crops (pull), to draw pests away from the main crop. Plants that repelled stemborer females were selected as intercrops (push). The stemborers are attracted to the trap plant, and are repelled from the main cereal crop using a repellent intercrop (push). Root exudates of leguminous repellent intercrops also effectively control the parasitic striga weed through an allelopathic mechanism. Their root exudates contain flavonoid compounds some of which stimulate germination of Striga hermonthica seeds, such as Uncinanone B, and others that dramatically inhibit their attachment to host roots, such as Uncinanone C and a number of di-C-glycosylflavones (di-CGFs), resulting in suicidal germination. The intercrop also improves soil fertility through nitrogen fixation, natural mulching, improved biomass, and control of erosion. Both companion plants provide high value animal fodder, facilitating milk production and diversifying farmers’ income sources. The technology is appropriate to smallholder mixed cropping systems in Africa. Adopted by about 125,000 farmers to date in eastern Africa, it effectively addresses major production constraints, significantly increases maize yields, and is economical as it is based on locally available plants, not expensive external inputs

Classification and influence of agricultural information on striga and stemborer control in Suba and Vihiga Districts, Kenya

This paper reports on findings of a study to examine the sources used by farmers in search of agricultural information on striga and/or stemborers control technologies and factors that influence acquisition of such information in Western Kenya region. A random sample of 476 households in Suba and Vihiga districts were interviewed and 15 information pathways were identified. Using principle component analysis (PCA) to derive few latent variables that encapsulate maximum variance in the pathways, two components (latent variables) proxying for ‘agricultural knowledge’ were extracted. Type I-knowledge (first component) loaded heavily with sources that had ‘group’ information searching. Type II-knowledge (second component) loaded heavily with sources requiring individual farmer search. Both types of knowledge positively and significantly influenced the likelihood of households using improved technology to control stemborer, while only Type-II knowledge and social economic factors were important in influencing the farmers’ likelihood of using an improved technology to control striga. This study shows that information is an important factor in the households’ likelihood of using improved technologies in the control of striga and stem borer in Vihiga and Suba, Kenya. Methods of individual interaction are important to striga control.Agricultural information, improved technology, striga, stemborers, control technologies, Kenya, Agricultural and Food Policy, Community/Rural/Urban Development, Demand and Price Analysis, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Institutional and Behavioral Economics, International Relations/Trade, Marketing, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy,

Drought-tolerant Desmodium species effectively suppress parasitic striga weed and improve cereal grain yields in western Kenya

Abstracts The parasitic weed Striga hermonthica Benth. (Orobanchaceae), commonly known as striga, is an increasingly important constraint to cereal production in sub-Saharan Africa (SSA), often resulting in total yield losses in maize (Zea mays L.) and substantial losses in sorghum (Sorghum bicolor (L.) Moench). This is further aggravated by soil degradation and drought conditions that are gradually becoming widespread in SSA. Forage legumes in the genus Desmodium (Fabaceae), mainly D. uncinatum and D. intortum, effectively control striga and improve crop productivity in SSA. However, negative effects of climate change such as drought stress is affecting the functioning of these systems. There is thus a need to identify and characterize new plants possessing the required ecological chemistry to protect crops against the biotic stress of striga under such environmental conditions. 17 accessions comprising 10 species of Desmodium were screened for their drought stress tolerance and ability to suppress striga. Desmodium incanum and D. ramosissimum were selected as the most promising species as they retained their leaves and maintained leaf function for longer periods during their exposure to drought stress conditions. They also had desirable phenotypes with more above ground biomass. The two species suppressed striga infestation, both under controlled and field conditions, and resulted in significant grain yield increases, demonstrating the incremental capability of Desmodium species in striga suppression. These results demonstrate beneficial effects of Desmodium species in enhancing cereal productivity in dry areas

A climate-adapted push-pull system effectively controls fall armyworm, Spodoptera frugiperda (J E Smith), in maize in East Africa

Fall armyworm, Spodoptera frugiperda (J E Smith), an economically important pest native to tropical and subtropical America has recently invaded Africa, causing substantial damage to maize and other crops. We evaluated functionality of a companion cropping system, ‘climate-adapted push-pull’, developed for control of cereal stemborers in drier agro-ecologies, as an added tool for the management of fall armyworm. The technology comprises intercropping maize with drought-tolerant greenleaf desmodium, Desmodium intortum (Mill.) Urb., and planting Brachiaria cv Mulato II as a border crop around this intercrop. Protection to maize is provided by semiochemicals that are emitted by the intercrop that repel (push) stemborer moths while those released by the border crop attract (pull) them. 250 farmers who had adopted the technology in drier areas of Kenya, Uganda and Tanzania were randomly selected for the study during the long rainy season (March-August) of 2017. Each farmer had a set of two plots, a climate-adapted push–pull and a maize monocrop. Data were collected in each plot on the number of fall armyworm larvae on maize, percentage of maize plants damaged by the larvae and maize grain yields. Similarly, farmers' perceptions of the impact of the technology on the pest were assessed using a semi-structured questionnaire. Reductions of 82.7% in average number of larvae per plant and 86.7% in plant damage per plot were observed in climate-adapted push-pull compared to maize monocrop plots. Similarly, maize grain yields were significantly higher, 2.7 times, in the climate-adapted push-pull plots. Farmers rated the technology significantly superior in reducing fall armyworm infestation and plant damage rates. These results demonstrate that the technology is effective in controlling fall armyworm with concomitant maize grain yield increases, and represent the first documentation of a technology that can be immediately deployed for management of the pest in East Africa and beyond

Farmers' perception and evaluation of brachiaria Grass (brachiaria spp.) genotypes for smallholder cereal-livestock production in East Africa

Brachiaria (Urochloa) is a genus, common name brachiaria, of forage grasses that is increasingly transforming integrated crop-livestock production systems in East Africa. A study was undertaken to (i) assess smallholder farmers’ perception on benefits of brachiaria in cereal-livestock production, (ii) identify brachiaria production constraints, and (iii) identify farmer preferred brachiaria genotypes. A multi-stage sampling technique was adopted for sample selection. Data were collected through semi-structured individual questionnaire and focus group discussions (FGDs). The study areas included Bondo, Siaya, Homabay and Mbita sub-counties in Western Kenya and the Lake zone of Tanzania. A total of 223 farmers participated in individual response questionnaires while 80 farmers participated in the FGDs. The respondents considered brachiaria mainly important in management of cereal pests (70.4% of respondents) and as an important fodder (60.8%). The major production constraint perceived by both male and female respondents is attacks by arthropods pests (49.2% and 63%, respectively). Spider smites had been observed on own farms by 50.8% of men and 63.1% of women, while sorghum shoot flies had been observed by 58.1% of men and 67.9% of women. These pests were rated as a moderate to severe problem. Xaraes was the most preferred genotype, followed by Mulato II and Piata. These genotypes are important in developing new crop pest management strategies, such as push-pull, and for relatively rapid improvements in crop management and yield increases, particularly in developing countries