Farmers’ knowledge, experience and management of fall armyworm in a major maize producing municipality in Ghana

Abstract

Since its discovery in Ghana, the fall armyworm (FAW) has damaged maize farms resulting in yield losses. This study investigated farmers’ knowledge, practices and impact of the pest in a major maize growing municipality in Ghana. A structured questionnaire was used to obtain information from 200 randomly sampled farmers on their knowledge, practices, perceived effect and management of the FAW. FAW susceptibility to insecticides was also assessed. Although insecticide application was dominant (98%) and farmers experienced adverse health effects, application frequency and the resulting effects were not significantly related (p > 0.05). Usage of personal protective equipment (PPE) was low (45.7%) and only 2% of the farmers used complete PPE. Gender correlated positively with PPE usage with more females wearing PPE compared to males. Age, farming experience, education and farm size did not significantly impact on PPE usage. The FAW outbreak negatively affected farmers’ relationships (36.5%) and caused economic loss to many farmers (80%). FAW was susceptible to emamectin benzoate (1.9% w/v) and emamectin benzoate (48 g/L) + acetamiprid (64 g/L) but not Bacillus thuringiensis (55%) + monosultap (45%) under laboratory conditions. The findings and implications of the study on farmer safety and sustainable pest management are discussed.

Keywords:

• fall armyworm
• insecticide application
• maize farmers
• personal protective equipment
• Ghana

1. Background

Agriculture is a major source of livelihood in Ghana (Ministry of Food and Agriculture (MoFA), 2018) with maize being a widely cultivated staple crop in the country (Day et al., 2017). It is an important food crop in Ghana and vital for the attainment of the sustainable development goals (SDGs) of ending poverty (SDG 1) and ending hunger, achieving food security and improved nutrition and promoting sustainable agriculture (SDG 2). Maize production is negatively impacted by pests and diseases, thereby affecting stakeholders in the value and supply chain, the nation’s economy and food security.

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Insecta: Lepidoptera: Noctuidae), is an invasive pest that feeds on a variety of crops including maize, sorghum and Bermuda grass, causing huge economic losses in the process (Yu et al., 2003). It is a strong flier that is native to the tropical and sub-tropical regions of the Americas and disperses in the summer (Capinera, 2002; Sparks, 1979), with a flight capability of over 100 km (Chen et al., 2022). Since its arrival in Ghana in the Yilo Krobo Municipality in 2016, it has spread countrywide with presence in all the regions of the country. The Ministry of Food and Agriculture (MoFA) in Ghana embarked on several measures to control the pest during its outbreak such as the provision of insecticides, training of staff for early detection, surveillance and monitoring and sensitization and awareness creation among farmers. Furthermore, the ministry procured 72,774 litres of liquid pesticides and several powdered pesticides for use on farms (Tanko, 2017). FAW is estimated to have affected 500,000 tonnes of maize and sorghum and a total estimated cost of about US $163 million in 2017 due to yield loss and control of the pest (Godwin et al., 2017). The maize yield loss in Ghana in 2018 was estimated at $177 million (Rwomushana et al., 2018). Africa could also lose between 8.3 and 20.6 million tonnes of maize per year in the absence of FAW management practices (Day et al., 2017). Destruction of maize farms by FAW lowers the yield of farmers and affects the income generated from their produce. Implementation of control measures against FAW such as insecticide use also increases the production cost of farmers and is a financial burden on farmers. The loss of income may affect the welfare and livelihood of farmers and their ability to meet their household responsibilities, possibly putting a strain on their social interactions.

Farmers’ knowledge and ability to identify crop-damaging organisms is crucial for pest scouting and early detection. Their knowledge may influence their decision-making, attitude and practices including the use of pesticides and adherence to the requisite safety precautions. These could be affected by the demographic profile of farmers due to the heterogeneity of farmer populations (Abdulai et al., 2018; Asare-Nuamah, 2022; Bariw et al., 2020; Tambo et al., 2020; Wongnaa & Awunyo-Vitor, 2018). Hence, an understanding of farmers’ knowledge, management practices, coping and adaptation strategies informs the development of effective pest management strategies and farmer resilience and adaptive capacities (Awudzi et al., 2021; Obour et al., 2022; Tambo et al., 2020; Umeh et al., 2022).

Ejura-Sekyedumase is a major farming municipality in the Ashanti Region of Ghana with about 140 farming communities grouped under 8 farming zones. As the leading producer of maize and yam in the region, over 60% of the inhabitants are farmers, and more than 80% of the land in Ejura-Sekyedumase is arable (Ministry of Food and Agriculture (MoFA), 2019). The FAW invasion in Ghana caused financial loss to the government and farmers and the en masse deployment of insecticides to control the pest exposes farmers and the environment to pesticide pollution (Godwin et al., 2017). Hence, it is prudent to minimise future outbreaks and mitigate their impact. Reducing the impact of the FAW on maize production will be contingent on farmers’ knowledge about the pest and the implementation of effective management strategies including surveillance and monitoring of the pest. Although studies on FAW infestation, impact and management have been conducted in several parts of Ghana (Abdulai et al., 2018; Ansah et al., 2021; Asare-Nuamah, 2022; Bariw et al., 2020; Koffi et al., 2020a; Tambo et al., 2020), studies focusing on this important production municipality are limited even though FAW infestation is one of the major contributors to maize production failure in the area (Obour et al., 2022). Different management practices including diverse insecticides such as formulations of synthetic insecticides and bio-insecticides like Bacillus thuringiensis are used in response to FAW attack (Koffi et al., 2020a; Obour et al., 2022; Rwomushana et al., 2018; Tanko, 2017). However, information on the efficacy and safe use of insecticides in the area is also limited in light of the widespread practice of agrochemical use and the reported ineffectiveness of market-available insecticides against FAW (Obour et al., 2022). Hence, this study assessed farmers’ knowledge, perceived effect and management practices regarding FAW in this major maize growing municipality in Ghana. Susceptibility of the FAW to some of the commonly used insecticides in the study area was also determined. Information on the impact of FAW outbreak on farmers will help in formulating well-suited policies for farmers including those who are disadvantaged due to pest management practices through health risks and socio-economic losses.

2. Methods

2.1. Study area

The study was conducted at the Ejura-Sekyedumase Municipality (7° 22^’ 30 N 1°22ʹ1.2”W), which is located in the northern part of the Ashanti Region of Ghana (Supplementary Material 1). It is at an altitude of about 228 meters with a relatively flat topography. It has a total land area of 1,250 km² and experiences both forest and savannah climatic conditions. It is in a warm climatic zone with a mean monthly temperature of 21 to 30° C, annual rainfall levels of 1,200 to 1,500 mm and relative humidity of 90% in the rainy season and 55% in the dry season (Ministry of Food and Agriculture (MoFA), 2019). It had a population of 85,446 people based on the 2010 Population and Housing Census (Ghana Statistical Service (GSS; 2013). The major occupations for inhabitants are crop production and livestock rearing. Some of the crops produced include maize, yam, cassava, cowpea, groundnut, plantain, rice and vegetables like okra, tomatoes, garden eggs and pepper. Livestock production includes the rearing of cattle, goat, sheep and poultry. The municipality is the leading producer of maize and yam in the Ashanti Region with estimated production values of 28,861 tonnes of maize and 33,034 tonnes of yam (Ministry of Food and Agriculture (MoFA), 2019).

2.2. Sampling

The study was conducted from August 2019 to January 2020. A questionnaire (Supplementary Material 2) was administered to 200 farmers in the 8 farming zones of the municipality via face-to-face interviews, with 25 farmers from each zone. The farmers were randomly selected during their community education sessions with Extension Officers. Although there were several repeat attendance by farmers at the community sessions, in total, an average of 357 different farmers were present in the sessions. This was used to compute the sample size (n = 189) using the formula of Yamane (1967); thus n = N/(1 + N(e²), with N (population size) = 357 and e (level of precision) = 0.05 at a 95% confidence level. Each farmer was interviewed only once and whenever clarity in response regarding farm practices was needed, a follow up farm visit was done. The questionnaire contained details of the farmer, knowledge on FAW, effect of FAW on farmer’ life, methods of FAW control and usage of personal protective equipment (PPE) (Supplementary Material 2). The interviews were conducted in the local language (Asante Twi) to elicit responses to the various sections of the questionnaire. Regarding farmers' knowledge of the identity of the pest, they were made to select the image of the pest (larvae or adult) from a cardboard containing the pictures of larvae and adults of different insect species after they had indicated that they can identify either the larvae or adult of FAW.

2.3. Insecticide susceptibility test

2.3.1. Insect sample

Larvae of fall armyworm were randomly collected by brushing or handpicking into collection containers (height = 5.5 cm, bottom diameter = 3.5 cm, top circumference = 11.5 cm) from 4 randomly selected farms within the 2 different production zones (Ejura and Sekyedumase) of the municipality. The larvae were reared in the insectary at the Department of Theoretical and Applied Biology (DTAB), Kwame Nkrumah University of Science and Technology (KNUST) by placing them in plastic containers as described above, with netted covers for aeration. The larvae were provided with maize leaves on every other day basis until adult emergence. The temperature of the insectary ranged from 24 to 31 °C with a relative humidity of 60–75%, and 12 h daylight. A 0.06 acres maize farm was set up at DTAB, KNUST, to provide leaves for feeding the larvae.

2.3.2. Leaf dip test

The two most widely used insecticides in the study area based on the questionnaire responses were selected. These were Attack™ (1.9% w/v emamectin benzoate) and Ema Star™ (48 g/L emamectin benzoate + 64 g/L acetamiprid). The microbial insecticide Agoo™ (55% Bacillus thuringiensis + 45% monosultap) was included for comparison. This is due to the fact that Bacillus thuringiensis-formulated bio-insecticides are commonly used for the management of FAW (Koffi et al., 2020a; Rwomushana et al., 2018; Tanko, 2017). Five concentrations of each insecticide were prepared with reference to the recommended dose as the median concentration. The recommended concentrations were 50 g/15 L (0.33 g/100 mL) for Agoo^TM, 250 mL/15 L (1.67 mL/100 mL) for Ema Star^TM and 30 mL/15 L (0.2 g/100 mL) for Attack^TM. Pieces of fresh maize leaves (3 x 4 cm) were dipped into an insecticide concentration for 5 min and allowed to air-dry on the laboratory bench. Larvae were introduced to feed on the leaves in small plastic containers (top diameter = 3.5 cm, height = 2 cm, bottom circumference = 6 cm). Each test concentration used 2^nd instar larvae (30 individuals: 1 individual per container) in individual containers and this was replicated three times with a control set up which had leaves treated with distilled water. Larval mortality was observed at 24, 48 and 72 h. Fresh insecticide-free leaves were added when all the treated leaves were consumed. Larvae that were alive after 72 h were monitored for a further 48 h to observe if the insecticide had a delayed effect on the larvae after the 72 h period.

2.4. Statistical analysis

Questionnaire data was entered using Microsoft Excel 2013. Counts and percentages were calculated with Excel. R console was used to perform the linear regression and logit model analyses. Linear regression was used to examine the relationship between insecticide usage frequency and side (harmful) effects, insecticide usage frequency and effectiveness of insecticides, and use of protective equipment against side effects. The decision factor of farmers wearing protective equipment or not was also analysed with the logit model. The findings were reported in accordance with the Consolidated criteria for Reporting Qualitative research (COREQ) checklist for qualitative studies (Supplementary Material 3; Tong et al., 2007). Larval mortality at specific insecticide concentrations was determined as a percentage of the number of dead larvae to the total number of exposed larvae.

3. Results

3.1. Demographic characteristics of farmers

Out of the 200 questionnaires, 3 were non-responsive. There were more males (77.7%) than females (22.3%) among the interviewed farmers with most of the respondents within the age range of 20–49 years (70.1%). A greater percentage (61.9%) of the farmers had formal education with a higher proportion (56.9%) having pre-tertiary education (Primary School, Junior High School (JHS), Senior High School (SHS) and Vocational School). Most (67%) of the farmers had at least 11 years of farming experience. Farming was the sole occupation for 48.2% of the respondents while the others had other jobs in addition to farming (Table 1).

Table 1. Demographic characteristics of farmers interviewed on fall armyworm in Ejura-Sekyedumase Municipality, Ghana in 2019/2020

Variable	Description	Number of farmers	Frequency (%)
Sex	Male Female	153 44	77.7 22.3
Age (years)	20–29 30-39 40–49 50-59 60–69 Above 70	25 51 62 42 13 4	12.7 25.9 31.5 21.3 6.6 2.0
Level of education	No formal education Primary JHS SHS Vocational Training College University/ Polytechnic	75 42 35 34 1 5 5	38.1 21.3 17.8 17.3 0.5 2.5 2.5
Farming experience (years)	1–10 11-20 21–30 31-40 Above 40	65 68 40 19 5	33 34.5 20.3 9.6 2.5
Occupation	Only farming Farming and other job(s)	95 102	48.2 51.8

JHS: Junior High School; SHS: Senior High School

3.2. Farmers’ knowledge and socio-economic effect of fall outbreak armyworm

All the farmers knew of FAW and the source of their first information was mainly by MoFA/Extension Officers and the media (radio and television; Table 2). Almost 20% of the farmers who claimed to know the pest (adult or larva) could not identify it. According to 77.7% of the farmers, the leaves were the most attacked part and about 44% of the farmers stated that FAW attacks other crops such as beans, yam, rice, okra, cowpea, cotton, millet, soybean, tomato, garden eggs and groundnut although the damage was more severe on maize. Majority of the farmers knew that the pest is not indigenous to Ghana and attributed its presence in the country to international trade (importation of goods and planting materials including maize seeds), migration from neighbouring countries, natural occurrence and dispersal by wind. About 80% of the farmers experienced economic loss due to FAW attack on their maize farms (Table 3). Yield loss of the farmers ranged from 8–83.3%, with an average loss of almost 50% (Table 3). This made some farmers to resort to other means of meeting their needs such as doing other jobs, borrowing, benevolence of others and reliance on life partners (Table 4). About 36.5% of the farmers experienced a negative effect in their relationships while a greater proportion (63.5%) managed to maintain their relationships after the outbreak of FAW (Supplementary Material 4a). About 37% of farmers had no idea on what to do differently to control FAW infestation while 27% continued to apply insecticides (Supplementary Material 4b). Alternative FAW management approaches used by farmers included slashing and burning, waiting on government intervention through extension officers which is mainly awaiting the supply of chemical products from the government for application, early planting, farm sanitation, early control and non-farming related jobs (Supplementary Material 4b).

Table 2. Farmers’ knowledge on fall armyworm at Ejura-Sekyedumase municipality

Variable	Response	Number of farmers	Frequency (%)
Knowledge on FAW	Yes	197	100
Source of first information on FAW	Media	42	21.3
	Friends and family	37	18.8
	Other farmers	54	27.4
	Farmer group	2	1.0
	MoFA/Extension Officers	62	31.5
Can you identify FAW?	Yes	184	93.4
	No	13	6.6
Farmers who identified FAW correctly	Yes	149	81
	No	35	19
Can you identify adult FAW?	Yes	181	91.9
	No	16	8.1
Farmers who identified adult FAW correctly	Yes	145	80.1
	No	36	19.9
Part of maize plant attacked by FAW	Stem	44	22.3
	Leaves	153	77.7
	Flowers	0	0
Does this pest attack other crops apart from maize?	Yes	87	44.2
	No	110	55.8
Which of the crops is severely attacked?	Maize	76	87.4
	Non-maize	11	12.6
Is FAW indigenous to Ghana?	Yes	62	31.5
	No	135	68.5

Table 3. Farmers’ perception of yield loss due to fall armyworm infestation

Variable	Response	Number of farmers	Frequency (%)
Experience of loss	Yes	158	80
	No	39	20
Yield loss (%) [Range of 8.0 to 83.3%, with a mean of 49.5%]	0–20	9	5.7
	21–40	42	26.6
	41–60	66	41.8
	61–80	40	25.3
	81–100	1	0.6

Table 4. Coping strategies of farmers after experiencing fall armyworm infestation

Relief source	Number of farmers	Frequency (%)
Other jobs	86	45
Borrowing	70	37
Reliance on partner	24	12
Benevolence	11	6

3.3. Management practice against insect pests

Chemical control was the most dominant (98%) insect pest control practice and none of the farmers engaged in biological control such as the use of natural enemies (Table 5). Cultural methods such as crop rotation, slash and burn and other farm sanitation practices targeted against insect pests were used by very few farmers. Almost all the respondents (99%) used insecticides to manage insect pests on their farms. The insecticides contained active ingredients belonging to different insecticide classes (Supplementary Material 4c). Among the respondents who used insecticides, 49% experienced side effects due to the chemicals they applied (Table 6). These included eye irritation, nausea, headache, catarrh, skin irritation, body pains and body weakness. There was no significant relationship (p = 0.198) between insecticide usage frequency and the harmful effects on farmers (Table 7).

Table 5. Dominant pest management practice at Ejura-Sekyedumase

Variable	Response	Number of farmers	Frequency (%)
Dominant method	Chemical (including bio-insecticides) Cultural Biological Physical	193 4 0 0	98 2 0 0

Table 6. Insecticide usage and adverse side effect

Variable	Response	Number of farmers	Frequency (%)
Use of insecticide	Yes No	196 1	99 1
Experienced side effect	Yes No	96 100	49 51

Table 7. Insecticide usage frequency versus harmful effect

Variable	Estimate	Std. Error	z value	Pr(>|z|)
(Intercept)	−0.06354	0.45633	−0.139	0.889
Usage frequency	−0.41188	0.32012	−1.287	0.198

3.4. Farmers attitude towards the use of protective equipment

Only 45.7% of the farmers used PPE during insecticide application. However, only 2% of the respondents used complete PPE. A complete PPE in this study implied covering of the entire body of a farmer during insecticide application. This included the use of head cover/hat, goggles, nose mask/respirator, working gear/overall long coat, hand gloves and wellington boots. Compared to the other protective equipment, nose masks, wellington boots and hand gloves were worn by more farmers (Table 8). There was no positive relationship between wearing protective equipment and the effects of pesticide exposure (Table 9).

Table 8. Percentage of farmers who wear personal protective equipment

Use of PPE	Number of farmers	Frequency (%)
Yes	90	45.7
No	107	54.3
Type of PPE used
Head cover	6	3
Wellington boots	32	16.2
Hand gloves	22	11.2
Nose mask	53	26.9
Overall gear	16	8.1
Goggles	5	2.5
Long sleeves	16	8.1

Table 9. Use of personal protective equipment versus harmful effects

Variable	Estimate	Std. Error	z value	Pr(>|z|)
(Intercept)	−0.3594	0.2142	−1.678	0.0934
PPE	−0.5435	0.3045	−1.785	0.0743

Summary of the logit regression results on the factors influencing farmers’ decision to wear PPE during insecticide application showed that age (p = 0.8299), years of farming experience (p = 0.1447), educational level (p = 0.1054) and size of land (p = 0.5426) of farmers did not have a significant influence on farmers’ decision to use PPE (Table 10). Gender was the only factor that associated significantly (p = 0.0460) with farmers’ decision to wear PPE.

Table 10. Logit results on factors influencing farmers’ decision to wear protective equipment

Variable	Estimate	Std. Error	z value	Pr(>|z|)
(Intercept)	2.228955	0.937088	2.379	0.0174
Age	−0.003088	0.014376	−0.215	0.8299
Gender	−0.778704	0.390175	−1.996	0.0460
Experience	−0.157134	0.107740	−1.458	0.1447
Education	−0.173917	0.107418	−1.619	0.1054
Land size	−0.014458	0.023747	−0.609	0.5426

3.5. Mortality of fall armyworm to insecticides

Attack™ and Ema Star™ caused a larval mortality of 100% after 24 h of exposure. However, when exposed to Agoo^TM, there was no mortality after 72 h and even after the cumulative 120 h period. No mortality was observed in larvae exposed to concentrations of Agoo^TM exceeding the recommended rate (Table 11).

Table 11. Mortality (%) of second instar fall armyworm larvae after exposure to different insecticides

Attack™ [1.9% w/v emamectin benzoate] (24 h of exposure)			Ema Star™ [48 g/L emamectin benzoate + 64 g/L acetamiprid] (24 h of exposure)			Agoo™ [55% Bacillus thuringiensis + 45% monosultap] (120 h of exposure)
Conc. (mL/L)	Ejura	Sekyedumase	Conc. (mL/L)	Ejura	Sekyedumase	Conc. (g/L)	Ejura	Sekyedumase
0.06	100	100	0.43	100	100	0.03	0	0
0.13	100	100	0.83	100	100	0.16	0	0
0.22*	100	100	1.67*	100	100	0.33*	0	0
0.27	100	100	2.50	100	100	0.50	0	0
0.33	100	100	3.30	100	100	0.57	0	0
Control	3.33	0	Control	4.6	0	Control	0	0

Conc: Concentration; *: Recommended rate

4. Discussion

A majority of the maize farmers in our study were males. This differs from studies in other parts of Africa such as the work of Makgoba et al. (2021) in South Africa where most of the maize farmers were females. Predominance of male farmers in this study could be attributed to the traditional role of males as breadwinners in the Ghanaian cultural setting, entrusted with the management of family properties (Anang et al., 2013; Okoffo et al., 2016; Wongnaa et al., 2019). Although low compared to males, the female farmers constituted nearly a quarter of the maize farmers in the study area. This could be due to an increase in female-headed households as a result of the migration of husbands, single parenting and other factors (Codjoe, 2010). The age distribution of the maize farmers differs from Codjoe (2010) where about a quarter of the farmers in the study area were at least 60 years old. This study found that about 70% of the maize farmers were aged below 50 years and hence indicates an increase in the youthful farming population with little likelihood of a decline in maize production due to an ageing farmer population. The relatively high proportion of farmers with formal education aligns with Wongnaa et al. (2019) and Koffi et al. (2020a) but contrasts Codjoe (2010) and Abdulai et al. (2018). Farmers with formal education may be able to access better pesticide information and have a higher awareness of safety precautions associated with pesticide use. Tambo et al. (2020) found a significant positive relationship between secondary education and pesticide application compared to other management methods like handpicking of larvae and adduced that since pesticide application is knowledge-intensive, educated farmers are well-positioned to have better information regarding pesticides to control FAW. Also, in a study by Asare-Nuamah (2022) in Adansi North District in Ghana, farmers with no education were less likely to use pesticides. However, Abdulai et al. (2018) observed that maize farmers without formal education in some districts in the northern part of Ghana could be more technically efficient than those with formal education. An inverse relationship also existed between the technical efficiency of smallholder maize farmers and their years of formal education in a district in northern Ghana (Anang et al., 2020). Hence, although important, educational status may not necessarily be an indicator of technical efficiency in maize cultivation since knowledge on pesticide handling, usage and safety precautions and other production practices could be acquired by observation or peer learning from other farmers or extension agents (Abdulai et al., 2018). The years of farming experience may help in farmer efficiency and productivity and compensate for the little or no educational background (Okoffo et al., 2016). Almost 52% of the farmers had other jobs and this could be due to a variety of factors such as inadequate income from farming or enough assistance on their farms and hence they had time to engage in other jobs. Also, since many of the farmers have formal education, they might have acquired some skills or qualifications via their education that could be used to engage in alternative income-generation activities. Hence, they may already be either gainfully employed or engaged in other jobs as their primary occupation. Equally, farmers without formal education but with some skills (e.g., artisanal) could also be engaged in other job activities.

Although many of the farmers could identify FAW, this was lower compared to studies in Zambia (91%) and South Africa (100%) (Kansiime et al., 2019; Makgoba et al., 2021), hence the need to intensify education on FAW identification for early detection and management. FAW infestation affected economic activities of the farmers and this extended to their social relations. The estimated yield loss due to FAW attack on maize farms was higher compared to Kansiime et al. (2019) but within the national average of Ghana (mean of 45%, range of 22–67%) and Zambia (mean of 40%, range of 25–50%) in 2017 (Day et al., 2017). When farmers suffer yield loss, they lose income and are confronted with the challenge of not being able to cater for their families’ upkeep and welfare. Furthermore, they have to look for additional sources of funding to be able to secure insecticides to control the invasion of their farms. This puts an economic strain on those who are already struggling to meet their basic needs. This aligns with Bariw et al. (2020) that FAW did not only affect the physical environment but also affected the livelihoods of maize farming-dependent households. To cushion against the economic and social effects, farmers engaged in diverse livelihood activities including alternative sources of income as well as dependency on social safety nets. This is similar to the mitigation strategies of farmers against the social and economic impacts of maize production failure in the area (Obour et al., 2022).

Chemical usage was the dominant control method and the farmers considered it as effective, readily available, easier to apply and cheaper (insecticides) compared to the other methods. The farmers relied on insecticide usage to control FAW and mitigate losses compared to cultural methods such as slash and burn, early planting and farm sanitation. This practice is similar to Tambo et al. (2020), who reported insecticide usage as the preferred FAW control option of most farmers. Cultural practices like weeding can reduce pest damage because the weeds may be graminaceous and host of the pest, thus, contributing to its continuous survival (Baudron et al., 2019). Another strategy is the push-pull method using a repellent plant (Hruska, 2019), although this was not practiced by farmers in this study. However, intercropping maize with a legume as a trap crop in the push-pull system has varying degrees of success depending on the type of legume used (Baudron et al., 2019; Harrison et al., 2019). Insecticide use was widespread and preferred by the farmers due to its ability to control insect pests (Bariw et al., 2020; Belay et al., 2012), although adverse health effects were reported (Adekunle et al., 2017; Miah et al., 2014). The non-significant (p = 0.198) relationship between insecticide usage frequency and reported harmful effects in this study implies farmers could experience an adverse health effect even if they applied insecticides less often. This is possible since farmers who applied insecticides frequently in this study were better protected (wore more protective equipment) than those who did so less frequently. Since they knew they were at a greater risk due to the frequent contact hours with chemicals during application, they ensured that they were more protected from exposure to minimise body contact with the chemicals. This could account for the non-significant relationship observed, in addition to the fact that the adverse effects were self-reported and some farmers who applied insecticides frequently also reported no adverse health effects. The absence of a significant relationship between PPE usage and adverse health effects could be due to the fact that even though some of the farmers used PPE, they were not fully protected since they used incomplete PPE. The farmers in the study area mostly used their casual farm clothes and complemented them with one or two of the protective equipment, thus exposing them to the chemicals and the harmful effects. Hence it is important that a complete PPE is worn at all times during insecticide application to minimise occupational exposure. The adverse health effects experienced by farmers is a financial strain on them since they will incur costs in being treated. This will further burden the health system and increase public expenditure on health. Farm productivity may also be negatively affected since man hours will be lost if the farmer is sick and unable to work. Insecticide use can also leave contaminants in the environment and Akoto et al. (2013) observed pesticide residues in maize samples in Ejura. Hence, dietary exposure to pesticides has severe consequences for the health of consumers. Unintended consequences of pesticides in the air, soil and water also include negative impact on edaphic and aquatic biota and non-target organisms like natural enemies (Aktar et al., 2009) thereby affecting ecosystem functioning. The use of PPE was low among the maize farmers, similar to Kansiime et al. (2019) who reported non-PPE usage in more than 50% of their study respondents. With the exception of gender (p = 0.0460), factors such as age (p = 0.8299), years of farming experience (p = 0.1447), educational level (p = 0.1054) and land size (p = 0.5426) did not significantly influence farmer’s decision to use PPE. In this study, female farmers were more concerned about their health (pesticide exposure) and hence likely to use PPE during insecticide application. Although majority of the farmers had formal education and hence it was presumed that they would have better appreciated the risks associated with insecticide exposure and thus be appropriately clothed with complete PPE during insecticide application, this was not the case in the study. The non-compliance is consistent with other studies (Adekunle et al., 2017; Okoffo et al., 2016) with the refusal to use PPE during pesticide application a common practice in some African countries (Avicor et al., 2011; Williamson et al., 2008).

Emamectin benzoate, acetamiprid and Bacillus thuringiensis are among the active ingredients recommended for FAW control (Babendreier et al., 2020; Day et al., 2017; Nboyine et al., 2022). In this study, emamectin benzoate-based products were effective against FAW larvae even at low concentrations while the B. thuringiensis product was not. This finding contrasts with Buntin et al. (2004) where B. thuringiensis-treated maize plants were more resistant to FAW destruction. Since the insecticide needs to be ingested by the larvae to act, there may be a delayed mortality effect beyond the observation period in this study, hence, the absence of mortality in the larvae. Koffi et al. (2021) also observed a protective effect of emamectin benzoate and B. thuringiensis against FAW on maize plants in some fields in Ghana. Although an effective insecticide, resistance to B. thuringiensis insecticide and transgenic maize has been reported in FAW populations in some parts of the world (Farias et al., 2014; Huang et al., 2014; Storer et al., 2010; Yainna et al., 2021). The non-sensitivity of FAW to B. thuringiensis in the present study could be an indicator of resistance development in the pest populations. Larval susceptibility to lower concentrations of emamectin benzoate and emamectin benzoate + acetamiprid indicates their effectiveness in managing the pest. It is however important to evaluate the efficacy of these concentrations under field conditions in the study area. A combination of methods is recommended to control FAW (Day et al., 2017), since relying solely on one method may not give the desired result. Several natural enemies of FAW with different control potentials have been reported (Agboyi et al., 2020; Koffi et al., 2020b) and their inclusion in an integrated manner may bode well for a sustainable management of the pest.

5. Conclusion

The farmers sampled in this study were mostly males, youthful, formally-educated and with at least a decade of farming experience. Although all the farmers knew of FAW, about 20% of those who claimed to be able to identify the pest (larvae or adult) failed to do so correctly. FAW outbreak caused economic loss and negatively affected the social interaction of farmers, resulting in the engagement of diverse livelihood activities and safety nets to mitigate the effect. Synthetic insecticide usage is the most common management practice for FAW in Ejura-Sekyedumase Municipality in Ghana. However, this was usually done with inadequate PPE use and adverse health effects were reported. While gender was significantly associated with PPE use, other factors such as age, farming experience, education and land size were not. Field populations of FAW larvae were susceptible to Attack^TM (1.9% w/v emamectin benzoate) and Ema Star™ (48 g/L emamectin benzoate + 64 g/L acetamiprid) but not to Agoo™ (55% Bacillus thuringiensis + 45% monosultap). The study indicates the need to sensitise farmers on integrated FAW management such as planting resistant varieties, early scouting of the pest and exploring the use of natural enemies and botanicals to avoid dependency on synthetic insecticides and also on complete PPE usage during insecticide application to protect their health. Efficacy of lower concentrations of the emamectin benzoate-based products should be evaluated in the study area under field conditions to inform FAW management and minimise insecticide usage.

Ethical approval and consent to participate

Ethical approval (ECBAS 013/18-19) was obtained from the University of Ghana, Legon.

Acknowledgements

The authors acknowledge the funding support of the University of Ghana (UGRF/11/MDG-019/2018-2019). The authors are also grateful to the Biotechnology and Nuclear Agriculture Research Institute of the Ghana Atomic Energy Commission, the Department of Theoretical and Applied Biology of the Kwame Nkrumah University of Science and Technology and the Department of Agriculture (Ministry of Food and Agriculture) at Ejura-Sekyedumase for the various logistical support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used and/or analysed during the current study are included in this published article apart from data containing information that could compromise the identity and privacy of research participants which are available on request from the corresponding author.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/23311932.2023.2184006

Additional information

Funding

This work was supported by the University of Ghana Research Fund under grant UGRF/11/MDG-019/2018-2019. The funding body had no role in the design of the study, collection, analysis and interpretation of data and writing the manuscript.