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

Abstract

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.

1. Introduction

With maize accounting for more than 24% of farming land and 35% of production [1], Ethiopia produces more maize than it does any other cereal crop. In nearly all agroecological zones, maize is widely produced using rain-based and irrigation farming systems. Although the crop contributes significantly to food security, its productivity is low—at an average yield of 4.2 tons/ha [1]—while the world average is 5.88 tons/ha [2]. This is often attributed to biotic and abiotic variables that limit the productivity of maize-growing farmers. Inefficient production techniques, declines in soil fertility, increased drought, and small landholdings are examples of abiotic variables, and diseases, weeds, and insect pests are examples of biotic variables [3]. In this regard, the push–pull technology (PPT) agroecological farming system is one of the methods used for controlling biotic factors, particularly insect pests in maize.

PPT applies ecological concepts and principles for the sustainable management of pests in farming systems. The PPT approach attempts to replace external inputs with natural processes such as natural soil fertility and biological control [4,5]. This agroecological farming system uses natural processes and advantageous on-farm interactions to reduce off-farm input use, and thereby improves the productivity of farming systems. Such an agroecological farming system maintains the biodiversity of agroecosystems, which is essential for the maintenance of immune, metabolic, and regulatory processes [4,6]. A key principle of agroecology farming is the diversification of farming systems; positive effects on biodiversity and productivity are derived from increased complementarity between different species of plants and animals (crop varieties, intercropping systems, agroforestry systems, and livestock), and this, in turn, leads to a more efficient use of natural resources (sunlight, water, and soil) and the natural regulation of pest populations [6].

The application of PPT in maize farming systems represents a novel cropping system that contributes to an agroecological approach to enhancing agricultural system resilience. PPT is a well-known agroecological technology in East Africa involving the intercropping of cereal crops with a forage legume, Desmodium, and planting Brachiaria species as border crops [7]. PPT regulates stem borer populations and improves soil fertility in cereal livestock farming systems [8]. Stemborers are drawn to Brachiaria (a pull plant), and a repellant legume intercrop, Desmodium, is used to keep them away from the main cereal crop. Desmodium seeds are planted by spreading them between maize rows. The semi-chemical odor that Desmodium emits repels stemborer moths, causing the stemborers to avoid maize. Furthermore, by causing abortive germination, Desmodium root exudates effectively suppress the parasitic striga weed [5,8]. Desmodium also enhances soil fertility by fixing nitrogen and improving moisture conservation through natural mulching. It also serves to improve biomass and reduce soil erosion [8]. Besides improving maize productivity, the two companion plants provide nutritious animal fodder, helping to improve milk production and increasing income sources for farmers. In general, PPT has multiple benefits in enhancing the livelihood of smallholder farmers, including minimizing pest and weed infestations, improving soil fertility, and increasing the availability of quality livestock feed. In the context of mixed-crop livestock farming systems, the PPT approach is therefore a logical pathway for improving smallholder farmers’ productivity as well as resilience to climate-related production shocks through the diversification of income sources [8,9].

The International Centre of Insect Physiology and Ecology (icipe) and its partners have promoted PPT using on-farm demonstrations and trainings with the objectives of improving soil fertility, enhancing biological pest control, improving livestock feed, and increasing the incomes of small-scale farmers. Most studies conducted on PPT thus far have emphasized the effectiveness of PPT in stem borer and striga control, in providing increased fodder for animal feed, and in introducing economic benefits through increased maize yield [9,10,11,12,13,14]. There are, however, limited empirical studies examining subsistence farmers’ perceptions and level of knowledge of PPT’s contributions to their farming system. Understanding farmers’ maize production constraints, their knowledge of PPT, and perceptions of PPT’s impact on soil fertility and pest control are critical steps in further expanding the adoption of the PPT approach by farmers and expanding its application to other parts of sub-Saharan Africa where the production of maize is hugely constrained by similar problems. In this regard, taking a broader approach to examining the PPT farming system by combining yield, soil fertility, and farmers’ perception can provide further insights into its potential relevance to other parts of Africa. In line with this, the current study is designed to draw insights from multiple data sources: soil analysis, yield results, pest control datasets, and information on farmers’ perceptions. Such multiple data sources allow us to provide a complete picture of the contributions and limitations of PPT in enhancing the productivity of smallholder farmers. Accordingly, this study aimed to address two main objectives: (1) to assess farmers’ perceptions of maize production constraints and the contribution of PPT’s pest control, and (2) to determine the effects of PPT on crop yield, pest control, and soil fertility.

2. Materials and Methods

2.1. Description of the Study Sites

The study primarily focused on three study sites: Botor Tolay, Gurage, and Halaba (Figure 1). Botor Tolay is located at 8°19′60.00″ N latitude and 36°14′60.00″ E longitude; its altitude ranges from 1100 to 1600 m above sea level; its mean temperature ranges from 21 °C to 30 °C; and its mean annual rainfall varies from 400 to 900 mm/year. Gurage zone is located at 7°76′ 8°45″ N latitude and 37°46′ 38°71″ E longitude, with altitudes ranging from 1600 to 3600 m above sea level, mean temperatures ranging from 13 °C to 30 °C, and mean annual rainfall varying from 600 to 1600 mm/year. The Halaba zone is located at 7°24′59.99″ N latitude and 38°14′60.00″ E longitude, with altitudes ranging from 1554 to 2149 m above sea level, mean temperatures ranging from 17 °C to 20 °C, and mean annual rainfall varying from 857 to 1085 mm/year. The dominant soil type in all places is black clay loam to black. According to information from the respective offices of agriculture, farmers in the study area follow cereal based mixed-crop livestock (mainly cattle) farming. Major cereal crops grown in Abeshgie district based on the area allocated are maize (77%), teff (18%), and sorghum (6%), out of the total 32,405 ha of land covered by cereals. In Halaba, maize stands first in area coverage (59%) followed by teff (19%) and finger millet (11%), while the remaining land is covered by wheat and sorghum. Maize is the dominant cereal crop produced in Abeshgie and Halaba. Unlike Abeshgie and Halaba, teff is the dominant crop in Cheha district, followed by wheat and maize in order of importance.

2.2. Data Sources

There are two datasets used in this study. The first dataset comes from a farmers’ perceptions survey, and the second dataset comes from on-farm demonstrations, as described below.

2.2.1. Survey on Farmers’ Perceptions

This survey intends to understand farmers’ perceptions about PPT and maize production constraints. Survey data were collected from three districts: Atote Ulo, in the Halaba zone, and Abeshgie and Cheha, which are in the Guragie zone. Six kebeles (the lowest administrative unit) where PPT demonstrations were established in 2019 and 2020 were selected purposively (

Table 1. Sample distribution by district and kebeles.

Administrative Zones	Districts	Kebeles	Number of Respondents N
Halaba	Atote Ulo	Felka	34 (16.04)
		Yeye	36 (16.98)
		Sinkilie Bitena	28 (13.21)
Gurage	Abeshgie	Boketa Soriety	34 (16.04)
		Gibie Yibarie	51(24.06)
	Cheha	Gasorie	29 13.68)
Total			212 (100)

Note: numbers in parentheses represent percentages.

). Finally, in total, 212 household heads were selected randomly using the probability proportional to size (PPS) sampling procedure. Out of the interviewed households, 33% of households participated in on-farm demonstrations of PPT. A structured questionnaire was prepared and pretested for further modification to ensure the validity of all questions. Farmers’ perceptions of pests, maize production constraints, and the effects of PPT on pest control and soil health were included in the questionnaire. Constraints included in the questionnaire were identified prior to the interview using key informants and a focus group discussion. Experienced enumerators were identified and trained for data collection. Thorough data cleaning was conducted before the analysis.

2.2.2. On-Farm Demonstrations of PPT

In total, 45 farmers in Botor Tolay, 48 farmers in Gurage, and 36 farmers in Halaba were selected for on-farm PPT demonstrations. In Botor Tolay, on-farm demonstrations were conducted from 2014 to 2016, while they were conducted in 2020 in Gurage and Halaba. The on-farm demonstrations were fully implemented and managed by farmers with technical backstopping by extension agents. These farmers were selected according to their willingness to adopt the PPT technology as a selection criterion. Accordingly, their willingness to provide land for the application of PPT technology, and their experience in maize cultivation and livestock ownership were considered selection criteria. After enrollment, all important participants in the farming system including the selected farmers, their spouses, and local extension agents were trained on the practical application of the PPT plots. After acquiring enough knowledge on the management of PPT plots, the farmers planted the demonstration plots and control plots with an average area of 900 square meters on their lands. In the demonstration plots, maize was planted on average in areas of 30 m by 30 m with 28 total rows, with a 40 cm spacing between maize plants, and with a 80 cm spacing between the rows. The two companion plants, Desmodium and Brachiaria, were planted along with the maize crop for the control of maize stemborers. Brachiaria was planted in 3 rows surrounding the maize plots (40 cm between plants and 40 cm between rows) as a trap plant to attract stemborer moths.

The demonstration plots were planted in June every year; the plots were maintained every year. PPT plots are recommended to be maintained for 5 to 6 consecutive years without replacing them. The continuous maintenance of PPT plots would improve soil fertility. Maize was harvested at maturity every year and planted again in the same plot every year. Desmodium and Brachiaria are perennials and mowed 3 to 4 times a year by farmers for animal feed. In the same way, the control plots were also planted near PPT plots using the farmers’ conventional practices; maize crop was planted without the two companion plants. The control plots allowed us to examine the marginal changes in the outcome variables by comparing them between the PPT plots with those of the conventional plots. In both the PPT and the control plots, maize hybrid and agronomic practices were applied per the recommendations for the area. Neither PPT nor control plots were sprayed with pesticides.

2.2.3. Data Collection

Eight weeks after planting, a stemborer damage assessment was conducted for each plot, and each plant in a plot was inspected for damage symptoms due to stemborers. Plants showing symptoms of stemborer infestation were expressed as the proportion of total plants in a plot. The leaf damage score was recorded based on a rating scale described in [15,16]. The percentage of maize plants infested by stemborers was calculated using the following formula:

Infestation percentage = (number of infested plants/total number of plants assessed) × 100

We collected data on soil parameters in each production season of 2014, 2015, and 2016 for Botor Tolay and in 2020 for Gurage. Data were not collected in Halaba due to budget shortages. Soil samples were taken from the control and PPT plots both at planting and at harvest every year using an augur sampler at a sampling depth of 20 cm. To form a composite sample, five subsamples from each field were collected randomly. From the composited sample, one kilogram (kg) of soil was taken with a labeled soil sample bag. Soil sample preparation (drying, grinding, and sieving) was conducted at the National Soil Testing Laboratory in Wolkitie, Ethiopia. Soil pH was measured using a pH meter with a ratio of 1:2.5 of soil to water [17]. The concentrations of available phosphorous (P) and exchangeable basic cations were determined using the Mehlich-III multi-nutrient extraction method. The concentration of elements in the supernatant was measured using an inductively coupled plasma (ICP) spectrometer [18]. The total N content was measured using the dry combustion method (Sumigraph NC-95A, Sumika Chem. Anal. Service, Osaka, Japan) using finely ground samples following the procedure in [19]. The EC of the H₂O₂ solutions used as extractants was measured with an EC sensor attached to a graphite electrode (Handy SC meter TCX-999i attached to CX90CS, Toko Chemical Laboratories, Co., Ltd., Tokyo, Japan). The difference between the total carbon and inorganic carbon contents was used to calculate the organic carbon content of the soil. By multiplying the concentration of organic carbon by the ratio of organic matter to organic carbon present in the soils, the organic matter content of the soil was indirectly determined [20].

Each plot’s maize plants were picked when they reached physiological maturity, and the cobs were sun-dried individually for each plot. After that, the cobs were manually shelled, maize grains were sun-dried to 12% moisture content, and the grain weights for each plot were measured individually. The grain weights were translated to tons per hectare, and the grain weights were computed per harvested plot areas.

2.3. Data Analysis

Survey data on farmers’ perceptions of maize production constraints (e.g., drought, stemborer, FAW, etc.) were summarized, and descriptive data analysis was carried out using percentages and means. A 5-point Likert scale (1 = most important problem; 5 = least important problem) was used for ranking the constraints. The results are presented in tables and figures. Data on stemborer infestation, soil parameter, and grain yields of maize were averaged for each farm (each farm was considered a replicate for PPT and monocrop plots) and analyzed using a t-test to compare them between PPT and maize monocrop farms. The significance level was determined to be p < 0.05. Data analyses were conducted using Stata 15.1 software [21].

3. Results

3.1. Farmers’ Perceptions of Maize Production Constraints

Increasing fertilizer prices, input prices, and pesticide prices, fall armyworms (FAWs) and stemborers, declining soil fertility, and drought are the main maize production constraints in the area in terms of the number of times they are mentioned as constraints (Figure 2). In terms of the severity of the impacts, about 70% of the respondents reported the increase in fertilizer price as the major constraint, while the increase in seed price was reported as a major limiting factor by 66.5% of respondents. FAWs and stemborers were reported by 55% and 44.3% of respondents as major maize production constraints, respectively (Figure 2). Increasing pesticide prices and frequent occurrences of drought were also reported the prevailing production constraints by 34.4, 29.7, and 27.8% of the respondents, respectively.

Table 2. Ranking of maize production constraints based on level of severity (n = 212).

Variable	Observation	Mean Score	Std. Dev.	Rank of the Problem
Drought	57	3.5	1.0	6
Stemborer	92	2.9	1.0	5
FAW	117	2.8	1.1	4
Soil fertility	63	3.5	1.0	6
Pesticide price	73	2.3	1.1	3
Fertilizer price	149	1.9	1.0	2
Seed price	142	1.8	0.9	1

Note on mean score: 1 = most important problem; 5 = least important problem.

shows that the high seed price was ranked as the most important constraint for maize production, with an average score of 1.8, followed by the fertilizer price (1.9) (Table 2). The increase in the price of pesticides was ranked as the third on the list, implying that the use of chemicals as a control option could result in high production costs, low profitability, and, more importantly, a negative impact on humans and other life forms. According to the survey results, 6.52% of the respondents reported that the effect of stemborers was very severe, while 28.26% and 39.13% of farmers rated the effects as severe and moderate, respectively.

3.2. Farmers’ Perceptions of the Effects of PPT

PPT adopters were asked to rate the level of stemborer and FAW infestation based on experience and observations of the trials. Of the 70 PPT adopters, 67% of farmers reported that the damage caused to maize due to stemborers in the PPT plot was either low or that there was no damage; however, less than 5% of the farmers reported that they observed stemborer damage in their PPT plots. Similarly, 55% of farmers stated that the damage caused to maize by FAWs was low or that there was no damage in the PPT plots. On the other hand, 30% of the respondents reported that they did not know the level of damage caused by the pest since they were establishing the PPT plot for the first time. In general, farmers believe that the level of damage caused by pests can be minimized if PPT is widely adopted.

3.3. Effects of PPT on Maize Yield, Pest Infestation, and Soil Fertility

Thus far, we have shown that farmers believe that stemborers and fall armyworms are the two important production constraints. Farmers also believe that PPT could help to reduce the impact of pests on maize production. In this subsection, we present the key findings associated with PPT’s effects on key soil quality indicators. There were significant differences between PPT and control (monocrop) plots in maize yields and stemborer infestations (

Table 3. Mean stemborer infestation and maize yields in push–pull technology (PPT) and monocrop plots (control) in maize in Botor Tolay district of Ethiopia from 2014 to 2016.

Cropping Season	Treatment	Stem Borer Infestation (%)	Infestation Reduction via PPT in Monocrop Plots (%)	Yield (t/h)	Yield Gain due to PPT in Monocrop Plots (%)
2014	PPT	4.81 a *	43.5%	9.62 a	17.8%
	Monocrop	8.52 b		7.91 b	-
2015	PPT	2.90 a	53.6%	10.79 a	26.5%
	Monocrop	6.25 b		7.94 b	-
2016	PPT	4.08 a	83.5%	11.93 a	30.8%
	Monocrop	24.68 b		8.25 b	-

* Means with the same letters in a column are not statistically significant, as determined via a t-test (p < 0.05).

). Stemborer infestation was substantially lower in the PPT plots than in the plots. As a result, the yield was higher in the PPT plots than in the monocrop plots. Compared to the control plots, lower stemborer infestation was observed in the PPT plots. PPT reduced stemborer infestation by 44% in 2014 to 84% in 2016. The yield gains from PPT were from 18% in 2014 to 31% in 2016 (Table 3).

The total percentage of nitrogen content revealed via the analysis showed that there was a significant difference between the PPT and monocrop plots (

Table 4. Average percentage of total nitrogen content in PPT and monocrop plots in maize in Botor Tolay district of Ethiopia from 2014 to 2016.

Crop Season	Treatment	Total Nitrogen Content (%)
2014	PPT	0.27367 a *
	Monocrop	0.17044 b
2015	PPT	0.30778 a
	Monocrop	0.17867 b
2016	PPT	0.48400 a
	Monocrop	0.17733 b

* Means with the same letters in a column are not statistically significant, as determined via a t-test (p < 0.05).

). Soil samples taken from PPT plots showed high N concentrations of 0.27367 to 0.48400% compared to samples from monocrop plots, which had low N concentrations. A high total nitrogen content percentage was recorded in 2016 in the PPT plots. Significant differences were observed in the PPT plots in terms of improving soil organic carbon, organic matter, total nitrogen, and cation exchange capacity in the 2019/20 cropping season in the area (

Table 5. Mean soil PH, electronic conductivity (EC), organic carbon (OC), organic matter (OM), total nitrogen (N), cation exchange capacity (CEC), and available phosphorus (P) in PPT vs. control plots in 2020 crop season, in Gurage, Ethiopia.

Soil Parameters	PPT vs. Monocrop	2020
		Mean ± SE
Soil PH	PPT	6.9 ± 0.1 a *
	Monocrop	6.6 ± 0.1 a
Electronic conductivity	PPT	124.3 ± 18 a
	Monocrop	114.2 ± 13 a
Organic carbon	PPT	2.7 ± 0.2 a
	Monocrop	2.2 ± 0.1 b
Organic matter	PPT	4.5 ± 0.3 a
	Monocrop	3.7 ± 0.3 b
Total nitrogen	PPT	0.2 ± 0.1 a
	Monocrop	0.1 ± 0.1 b
Cation exchange capacity	PPT	67.0 ± 2.1 a
	Monocrop	57.4 ± 2.7 b
Available phosphorus	PPT	19.2 ± 6.0 a
	Monocrop	12.7 ± 4.8 a

* Means with the same letters in a column are not statistically significant, as determined using a t-test (p < 0.05).

). PPT improved maize yield and reduced stemborer infestation in the same cropping season (Figure 3a,b).

4. Discussion

This study examines the role of PPT in promoting smallholder maize farmer productivity. Diversified farming systems use synergies from mixed farming systems that improve soil fertility and pest control [5,22]. Moreover, laboratory analysis demonstrated that PPT improves maize yield and soil fertility and reduces pest damage. This result is in line with farmers’ perceptions about the benefits of PPT. The current study implies that integrating PPT into farming systems can therefore help improve to productivity [8,10,23,24,25]. PPT is an integral component of agroecology, which has been developed at icipe to increase and diversify production, tackle pest pressure including that from stemborers and parasitic striga weeds, and improve soil fertility through integrated pest management [6,8,10]. In addition, recent studies demonstrated that PPT controls infestations from fall armyworm, a recently discovered invasive pest in Africa [26]. In the present study, PPT showed promising results in managing FAWs and stemborers. Farmers who are not using PPT rely on pesticide applications for pest control. The application of pesticides has adverse effects on human health and the environment [27]. The findings of the present study corroborate those from previous studies conducted on the impacts of PPT technology in various African countries. For example, a recent study using long-term data in Kenya showed a decline in insect pests and parasitic weeds, while it showed improved yields in PPT fields [28]. Similarly, the researchers in [29] discovered reduced infestation from FAWs, stemborers, and Striga in PPT plots compared to that in maize monocrop plots in Uganda. In addition to controlling pests, various studies demonstrated that PPT provides multiple ecosystem services including improvements in soil fertility and carbon sequestration [30,31]. This makes the on-farm implementation and promotion of PPT in the area a novel, cost-effective agroecological approach to enhancing the resilience of smallholders against pests and other constraints. As chemical fertilizers and most chemicals that are used to control pest infestations (by FAWs and stemborers) are imported, often they are not available in time and in the required quantity, while their price is often prohibitively high. This increases the production costs or minimizes the benefits obtained from maize production. In this regard, PPT might help to cut this expense (which involves Ethiopian farmers paying foreign businesses) if it is scaled up to a larger farming community.

Soaring input prices (of seeds and fertilizer), pest damage, drought, and limited access to credit were the major maize production constraints for small-scale farmers in the study area. PPT can help these farmers transition to more resilient agriculture, allowing them to produce enough food to feed their families while also rehabilitating the soil. In a region where the effects of climate change are already being felt, it is critical to preserve farms and farmers by developing a more resilient and sustainable agricultural system.

Farmers benefit from increased harvest security through multiple cropping systems, which enable crop diversification and have an impact on ground cover, soil erosion, soil chemical properties, pest infestation, and carbon sequestration potential [8]. This implies that decisions on crops and cropping systems are important factors with implications on farmers’ strategies to adapt to climate change [23,24,25]. Given the scarcity of farmland in the study area, maize–legume (e.g., maize–common bean) intercropping is one of the most important practices to improve household food security. Hence, PPT promotion complements farmers’ local practices. A study conducted in Kenya showed that PPT helps smallholder farmers diversify their income, improves livestock and crop productivity, and improves nutrition and soil fertility in the long run [10]. A recent study in Kenya and Tanzania showed a positive impact on the income of PPT-adopting farmers [32]. PPT promotes farm diversification instead of focusing on one crop. Diversified farms produce more food and animal feed using the same limited land available for farmers. The more diverse an agricultural system is, the greater its ability, on average, to adapt to climate change. Farm diversification provides the most evidence for positive effects on climate change adaptation, including positive effects on crop productivity, pollination, insect control, nutrient cycling, water regulation, and soil fertility [8].

PPT maintains plant cover by incorporating perennials such as Desmodium and Brachiaria to provide a habitat for predators and parasitoids of stemborers and FAWs (that is, PPT allows for plots that are ecologically self-regulating). PPT is a polyculture that deals with maize–legume (Desmodium) intercropping; crops planted in polycultures encourage symbiosis. For example, symbiotic nitrogen fixation is one of the major sources of N for crop production, and symbiotic bacteria of the genus Rhizobium have been associated with Desmodium roots (appropriately connected). PPT enhances the heterogeneity of features on a farm due to the combination of three crops, which will have an impact on the diversity of inputs, income sources, and pest control. Desmodium in PPT helps to maintain soil organic matter, recharge water, and import nutrients.

Commercial companies do not produce the seeds of forage crops, and seed availability is a limiting factor for smallholders in the area. This can be addressed through farmers’ involvement (community-based forage seed producer groups) and encouraging private companies to engage in forage seed production. In this regard, interventions in capacity building and extension service systems (demand assessment and information supply systems) on forage (Desmodium and Brachiaria) seed production technologies (pre- and post-harvest) are important. Practical training should be organized to improve farmers’ skills in PPT management and seed production businesses. Efforts need to be made to facilitate information exchange and linkages between producers, farmers, and seed businesses. Revisiting intervention approaches (e.g., using farmer field schools/farmer research groups where farmers implement, evaluate, and disseminate the technology in groups) is important. Exposure visits among the groups and across regions can also be used to boost farmers’ confidence in the performance of PPT.

5. Conclusions

Agroecological approaches such as PPT that encourage natural pest control for sustainable agriculture, with an emphasis on the incorporation of ecological principles while ensuring high productivity and profitable harvests without causing harm to the environment, should be promoted. There are multiple benefits of PPT, such as the regulation of pest populations, improvements in soil fertility, natural mulching, the control of erosion, the provision of high-value animal feed, and the diversification of farmers’ income sources in cereal-livestock farming systems [10]. The findings of the present study can be applicable to similar agroecological areas of cereal cropping systems. As stated by ICIPE [33] “The push–pull technology is flexible and can be successfully adapted and introduced to new cropping systems and agro-ecologies. Push–pull strategies can be developed and adapted for a range of cereal crops and farming systems”. Hence, for the broader applicability of the findings of this study on PPT, more effort is required to create awareness for the community regarding the multiple benefits of the technology. In addition, economic performance (cost–benefit) analysis of the technology needs to be conducted under specific agroecology systems to justify investments in the technology and boost stakeholders’ confidence in scaling up the technology. Data envelopment analysis (DEA) has been used assess efficiency performance in various agricultural technologies to assess the efficiency performance in forestry firms [34], and to assess the efficiency of chemical-free farming systems, for example [35]. DEA can also be used to assess the efficiency of PPT dissemination pathways, which is crucial in scaling up PPT.

This study is, however, limited to the assessment of farmers’ perceptions of maize production constraints and the effectiveness of PPT in controlling pests in maize production. Further rigorous analysis is needed to be undertaken for level adoption and barriers as well as farmers’ willingness to pay for PPT.