Barriers to Hermetic Bag Adoption Among Smallholder Farmers in Malawi

Abstract

Hermetic grain storage bags are an airtight technology that protects stored grain from environmental factors, pests, and pathogens, with proven feasibility for smallholder farmer use. We examined the determinants and barriers to the use of these bags by smallholder farmers in Malawi and found that 83% of farmers were aware of hermetic bags for grain storage, but only 11–20% had ever used them, with half of the farmers who used the bags receiving them through donations. Furthermore, only 7.2% of farmers used the bags more than once. There was no association between their receipt of donated bags and their continued use and purchase of additional bags. There were, however, strong correlations between use of hermetic bags and the age of the head of household, distance to farmer groups’ meeting points, household size, and participation in a CIP-sponsored project. Focus group discussions identified key barriers to adopting hermetic bags, including local unavailability, perceived high cost, limited knowledge of the technology, low yields, and misconceptions about the utility of the bags. Thus, while donations play a central role in introducing hermetic bags, donations alone are insufficient in ensuring their long-term adoption. Addressing the identified barriers through improved availability, reduced costs, local manufacturing, and policy interventions such as microfinancing options and better distribution networks are essential to increasing the uptake of hermetic bags by smallholder farmers in Malawi and elsewhere in sub-Saharan Africa.

1. Introduction

Postharvest grain losses are a critical issue across sub-Saharan Africa, where smallholder farmers depend heavily on home-grown staple crops such as maize, sorghum, and millet for subsistence and income. The losses may occur in the field, during processing, or in storage. Approximately one third of food is lost or wasted during postharvest. Estimates further show that the quantity of maize, the main staple crop in the SSA region, decreases by 26% due to postharvest losses (PHLs) [1]. These losses threaten food security for and the economic stability of rural agricultural communities.

Limited access to reliable and affordable methods of reducing postharvest grain losses trap farmers into “sell low, buy high” behavior. Smallholder farmers commonly sell their produce soon after harvest at a low price only to buy it back later when prices are high during the lean period. Smallholder farmers are unable to store their commodities between harvests due to poor storage availability and management and a lack of financial resources to meet household expenditures. Thus, reducing PHL to allow producers to store commodities between harvests themselves would have multiple benefits.

Agricultural policies that enhance sustainable crop productivity without proper PHL reducing strategies are not enough. In Malawi, the promotion of several technologies that could reduce PHL are in progress. Such technologies include storage chemicals, metallic silos, and hermetic storage bags, e.g., Purdue Improved Crop Storage (PICS) bags [2].

Hermetic storage bags have emerged as an effective alternative to conventional storage bags to reduce postharvest grain losses [3,4,5,6,7,8]. Hermetic storage bags are made of special plastics and when sealed are impermeable to air or water. As respiration of a grain, an insect, or a microbial contaminant occurs within these bags, O₂ is depleted and replaced with CO₂, creating an anaerobic environment in which no growth occurs. This atmosphere preserves properly dried grain and other agricultural produce as it is unsuitable for pests or molds [9].

Non-governmental organizations (NGOs) across sub-Saharan Africa, including Malawi, have been promoting hermetic bags by donating trial bags and demonstrating their proper use. Despite these efforts, smallholder farmers’ adoption of this technology in Malawi has been limited.

The objectives of this study were threefold as the following: (i) to assess the level of adoption of hermetic bags by smallholder grain farmers in Malawi; (ii) to examine factors that influence adoption, such as cost, availability, and misconceptions about the technology; and (iii) to evaluate the effectiveness of current promotional efforts. One-time subsidies for grain storage bags increased the adoption of hermetic bags in Uganda, so we hypothesized that the promotional strategies in place are effective, that key barriers to adoption have been addressed, and that high levels of adoption can be expected [10]. The data we generated will inform strategies to enhance the use of hermetic bags to reduce PHL and to improve food security in Malawi and elsewhere in sub-Saharan Africa. Our results also contribute to the broader literature on agricultural technology adoption in low-resource settings and offer practical insights for policymakers and stakeholders who are promoting sustainable agricultural practices.

2. Materials and Methods

We used two data sets. The first was collected from smallholder farmers in November 2022 in three districts of Southern Malawi, Chikwawa, Mulanje, and Zomba, and the second in October 2023 in three districts of Central Malawi, Mchinji, Kasungu, and Ntchisi. These districts were selected due to their high maize production, which is the primary grain crop in Malawi [11], and for their logistical accessibility.

2.1. Data Collection Methods

2.1.1. Smallholder Farmer Interviews

In 2022, individual interviews were conducted with 363 smallholder households from the Southern Malawi districts of Chikwawa, Mulanje, and Zomba. These households were divided into two groups, participants and non-participants, in a nutrition improvement project promoted by the International Potato Centre (CIP). Thus, survey respondents were obtained from households that had participated in the CIP project and those that had not. We used a multi-stage simple random sampling technique to select 164 nutrition project participants and 195 non-participants for the current study. First, three districts were selected that had participated in the CIP project. Second, within a district, two extension planning areas (EPAs) where the CIP project had been implemented were selected. Third, we segregated individuals and households into two groups based on whether they had participated in the CIP project. Finally, we selected survey participants from a list of project participants that was provided by the CIP. The number of households participating was proportional to the number participating in the CIP project in each district—153 in Zomba, 150 in Mulanje, and 60 in Chikwawa. The number of participants from each EPA in the district was the same.

In October 2023, an additional 627 smallholder farmers were interviewed in the Central Malawi districts of Mchinji, Kasungu, and Ntchisi. These interviews focused on awareness, adoption, and barriers to adoption of hermetic bags. Participants in both the 2022 and 2023 surveys were at least 18 years old, actively engaged in grain production as a smallholder farmer, and involved in local postharvest storage of the crops they had grown.

2.1.2. Focus Group Discussions (FGDs)

In addition to the smallholder farmer interviews, 12 focus group discussions (FGDs) were held in central Malawi, with four FGDs conducted in each district. Each FGD consisted of 10 participants, either all men or all women, to enable equitable participation. The inclusion criteria for FGD participation were the same as those for the smallholder farmer interviews.

2.1.3. Data Analysis

Probit and logistic regression models and a Chi-squared (χ²) test were used to elucidate associations among parameters of interest. The Probit equation was used as follows to estimate the determinants of adoption of PICS bags:

$$y_{ij}={\alpha }_1+{\delta }_1{x}_i+{\gamma }_1{d}_j+{\epsilon }_{ij}$$

(1)

where $y_{ij}\ge 0$ is the adoption of PICS bags of household $i$ in district $j$ (i.e., $PICS$ is equal to one if household $i$ used PICS bags and equal to zero otherwise), $x_i$ is a vector of the determinants of adoption, $d_j$ is a vector of district dummies, while ${\epsilon }_{ij}$ is a random error term. We chose the Probit model to generate estimates for Equation (1), because the dependent variable, adoption of PICS bags, had a binary response—yes or no. Binary choices commonly are modeled by using non-linear models such as Probit and Logit [12]. A detailed model specification of the Probit is provided by Wooldridge [12]. Probit is the preferred non-linear choice model, even though it assumes a normal distribution for all unobserved components [13]. The key variables included participation in a nutrition project, nutrition knowledge, off-farm income, the household head’s gender, age, education, household size, mobile phone access, and distance to farmer group meetings. Farmers participating in nutrition projects were assumed to better understand the impact of postharvest losses on nutrition security, making them more likely to adopt technologies like PICS bags. The Probit model was used to estimate the likelihood of adoption based on these factors.

Logistic regression coefficients were estimated by using maximum likelihood and are presented with odds ratios (ORs) and Wald χ² statistics. The logistic model used in this study is represented as the following:

$$\mathrm{P}\left[Y_i=1|X\right]={\displaystyle \frac{1}{1+e^{-({\beta }_0+{\sum }_{i=1}^n{\beta }_i{X}_i)}}}$$

(2)

where the dependent variable, Y, is the usage of hermetic bags (1 = used; 0 = not used). Independent variables, X_i, are the gender of the farmer (i = 1), education level of the farmer (i = 2), source of hermetic bags (i = 3), and pesticide use during storage (i = 4), while β₀ and β_i (i = 1, 2, 3, and 4) are coefficients to be estimated.

Narratives obtained from smallholder farmer interviews and FGDs were analyzed by using Thematic Analysis (TA) to identify common barriers to the adoption of hermetic bags by smallholder farmers. All statistical analyses were conducted using XLSTAT (ver 2023; Addinsoft, New York, NY, USA) and STATA version 14.

2.2. Study Limitations

A potential limitation of this study is the reliance on self-reported data from survey respondents and focus group participants. While such data provide valuable insights, they are subject to biases such as recall bias and social desirability bias, which may influence the accuracy of reported practices and perceptions regarding hermetic bag adoption. This limitation does not undermine this study’s overall contributions but highlights the need for complementary observational or experimental approaches in future research to validate self-reported findings.

3. Results

3.1. Summary Statistics

In the southern region survey, only 11% of the sampled households used hermetic bags (

Table 1. Descriptive results.

Variable 1	Value
Hermetic bags used (1 yes/0 no)	11%
Nutrition project participation (1 yes/0 no)	46%
Nutritional knowledge (No. of practices known)	9.5 ± 1.7
Production diversity (No. of food groups)	4.3 ± 1.3
Off-farm income/year (Malawi Kwacha)	154,000 ± 228,000
Gender of household head (1 male/0 female)	74%
Age of HH head (years)	36.6 ± 10.2
Household size	5.4 ± 1.8
Primary education (1 yes/0 no)	69%
Secondary education (1 yes/0 no)	26%
Tertiary education (1 yes/0 no)	0.6%
Access to phone (1 yes/0 no)	69%
Access to bicycle (1 yes/0 no)	57%
Distance to farmer’s group meeting point (km)	1.40 ± 1.44
Distance to village market (km)	2.62 ± 2.63

¹ “Hermetic bags used” and “Distance to farmer’s group meeting point” are based on 363 responses; all other values are based on 362 responses.

). Interviews with 627 smallholder farmers in the central region found that although 83% of the respondents were aware of hermetic bags as a means for grain storage, only 20% had ever used them. About half of those who had used the bags had received them as a donation, usually from an NGO (Figure 1). Only 7.2% of the farmers purchased bags beyond those that they had used the first time. Among the farmers who had used hermetic bags, more than half of them used the bags only for storing grain intended for human consumption, and less than half utilized the bags for seed storage. Thus, the effective usage of hermetic bags was very low in both central and southern Malawi.

Forty-six percent of the sampled households in the southern survey were participants in the nutrition project that was implemented by CIP (Table 1). We expected that nutrition project participation would influence usage of hermetic bags due to increased awareness of the importance of improved postharvest management to nutrition security. Another key factor was off-farm income. The average annual off-farm income of households in this survey was MK 154,000 (approximately USD 193.00), and we expected households (Table 1) with an income higher than the average to be more likely to use hermetic bags as they could more easily afford a technology that was deemed expensive by less well-off households. We also observed that the average distance to farmer groups’ meeting points was 1.4 km, while the average distance to the village market was 2.6 km. Distance to farmer groups’ meeting points was used as a proxy for farmer participation in farmer groups, and our expectation was that the shorter the distance, the more likely that the farmer would be able to access and use hermetic bags due to increased awareness.

3.2. Determinants of the Adoption of Hermetic Bags

In the southern regional survey, we found a strong positive correlation between the use of hermetic bags and participation in the CIP project and the distance to the farmer’s group meeting point. CIP project participants were 41% more likely to use hermetic bags than were non-participants. Other influential socioeconomic factors included the age of the household head and household size. Variables that were not significantly associated with the adoption of hermetic bags included the following: distance to village market, off-farm income, education level of household head (primary, secondary or tertiary), gender of household head, and access to a phone or to a bicycle.

In a follow-up study in the central region (

Table 2. Logistic regression estimates for variables influencing hermetic bag adoption by smallholder farmers in Malawi (n = 627).

Predictor	Odds Ratio	Confidence Interval	χ2	p
Gender
Male vs. Female	1.3	1.0–1.7	3	0.08
Education level
Post-primary school vs. Primary school and below	1.4	1.0–1.8	4.5	0.03
Source of hermetic bags
Donations vs. Buying	6.1	3.6–10.3	4.5	<0.0001
Pesticide used during storage
No vs. Yes	1.2	0.9–1.6	0.99	0.32

), we found no significant differences in hermetic bag usage between male and female farmers, or between those who did or did not use pesticides during storage. Farmers with an education beyond primary school were 40% more likely to have used hermetic bags than less-educated farmers. Additionally, those who had used the bags were six times more likely to have received them as donations rather than to have purchased them. There was no link between receiving bags as a donation and their continued use and purchase of additional bags (χ² = 0.013, p = 0.910).

3.3. Barriers to the Adoption of Hermetic Bags: Results from Focus Group Discussions

We found four main barriers to the adoption of hermetic bags by smallholder farmers, with unavailability and high investment costs being the most significant (

Table 3. Barriers to hermetic bag adoption by smallholder farmers.

Barrier	Frequency (n = 627)
Unavailability in local community markets	28%
High initial cost	27%
Lack of knowledge and misconceptions	8%
Low harvest (small quantities of grain that do not warrant the use of expensive bags)	1%
No barrier reported	36%

). Of the 627 farmers interviewed, 28% cited the lack of local availability, and 27% mentioned high purchase costs as obstacles.

3.3.1. Unavailability of Hermetic Bags in Community Markets

Members of all 12 FGDs cited the unavailability of hermetic bags in local markets as a reason for not using or discontinuing the use of hermetic bags. One participant remarked the following: “Our main problem is unavailability. These bags must be accessible in our area. If they are sold far from us, only the wealthy can travel to acquire them”.

3.3.2. High Initial Investment Cost

Members of 11/12 of the FGDs viewed the high investment cost of hermetic bags as a major barrier to adoption, as the price of the hermetic bags was significantly higher than that of conventional bags. One participant said, “…these bags are expensive. At present, one bag is around MK3000 (equivalent to USD 1.8, at the time of interviews), while the conventional bags are around MK350 (USD 0.2)”.

3.3.3. Lack of Knowledge and Misconceptions

Some participants were uninformed about hermetic bag technology and its benefits. They did not know that hermetic bags could be used for grain storage, responding that the only bags with liners they had seen were those used for fertilizer packaging. A participant reported the following: “Here we only know fertilizer bags that have plastic papers inside. These hermetic bags have not yet reached us”.

Participants in 7/12 FGDs thought that hermetic bags would lead to the loss of seed viability, e.g., “I feel like the maize inside can be damaged due to excessive heat and may not germinate when planted”.

Response to farmer’s concern: Storage of seeds in any bag exposed to excessive heat will have reduced germinability. Dried seed stored in hermetic bags germinates at a 26% higher rate than similar seed stored in conventional plastic bags [3].

Still, other participants did not know how to properly identify or use hermetic bags for grain storage, as reflected in their storage experiences with other products, e.g., “I once used fertilizer bags to keep grain and it rotted, so I am convinced that bags with plastic lining are not good for grain storage”.

Response to farmer’s concern: The plastic used to make fertilizer bags may look the same as that used to make hermetic bags, but these plastics are very different. Fertilizer bags are similar to conventional plastic bags and cannot be used for hermetic storage. When used properly, grain stored in hermetic bags is of better quality than grain stored in other types of plastic bags [3].

3.3.4. Low Harvest

The quantity of grain produced was identified by 4/12 FGDs as an obstacle to the adoption of hermetic bags. Smallholder farmers with low yields cited the small amount of grain to be stored as a reason for not investing in the bags, as they saw no need to make such an investment given their limited harvests: “I do not harvest enough to justify purchasing hermetic bags”.

Response to farmer’s concern: Storage in hermetic bags avoids the need for chemical pesticides on food grain. There is a need to store at least 40 kg (in a 50 kg capacity bag) until the next planting season to be economically worthwhile for seed storage.

4. Discussion

Despite the well-documented effectiveness of hermetic bags in preserving grain quality during storage [3,5], their adoption among smallholder farmers in Malawi remains low. The poor penetration of this technology in a country like Malawi is a significant concern as many smallholder farmers produce and store their own food, especially maize. The current study explores the barriers hindering the adoption of hermetic bags by farmers. Storage in these bags, when used properly, result in little to no damage to the stored grain as long as the bag remains intact.

Hermetic bags were donated to smallholder farmers so they could experience the benefits of improved grain storage. However, there was no clear link between the receipt of donated bags and their continued use, and adoption rates remained low. Factors other than the farmer’s willingness to use the bags, e.g., high price, limited availability, and inadequate knowledge, were important barriers to adoption. For example, some farmers reported grain damage from improper use, e.g., storing grain with a high moisture content, which underscores the need for better training. Thus, simply providing a technology without addressing systemic barriers to its utilization can effectively block the adoption of even quite beneficial technology.

Similar outcomes have been observed in other contexts. For example, in Paraguay, small-scale farmers used donations of equipment, fertilizer, and seeds to promote conservation agriculture only as long as subsidies and technical assistance were available [14]. In another case in Tunisia, drip irrigation technology was not frequently adopted due to barriers such as capital constraints, lack of information, and insecure land tenure [15]. As a result, even when farmers recognize a technology’s benefits, there may be other barriers that hinder adoption. These two previous cases and the current study all provide examples of well-intentioned donations that must be integrated into comprehensive strategies in order to succeed. These strategies must include sufficient and continuing technical support and education, while addressing the socioeconomic outcomes of successful adoption.

Other barriers to adoption, such as farmers’ limited awareness, cautious attitude, access to finance, and absence of sustainable distribution networks, still need to be addressed [16,17]. Overcoming these challenges requires targeted advertising, effective rural distribution, and securing financial support for both consumers and distributors [18]. For example, although only 17% of farmers reported never having heard of hermetic bags, this gap in awareness still indicates limited information diffusion. More importantly, the information that was available was insufficient or unavailable at the right level to keep misconceptions, such as the belief that hermetic bags were too expensive or compromised seed viability, from developing, persisting, and impeding adoption. These problems suggest that current strategies for introducing hermetic bag technology are insufficient and that donors providing free bags had neither effectively prepared nor sufficiently evaluated the recipient communities for the new technology. Overcoming barriers such as those documented in this study requires specifically designed promotional strategies and continuing support. Elsewhere, socioeconomic barriers, logistical barriers, and inadequate training and information at the correct level have all been problematic, such as in Ethiopia [19] and Tanzania [20]. Local unavailability of bags is a major barrier in West and Central Africa, where PICS outreach programs enhance adoption [21]. Training combined material support that emphasizes access and affordability is critical to all of these adoption programs. Thus, targeted subsidies, localized production, comprehensive training, and sustained market-building initiatives are required to drive adoption and maximize the benefits of hermetic storage technologies.

Successful adoption strategies should also directly tackle perceived risks and emphasize relevant benefits [22]. Misconceptions should be addressed in a pre-adoption phase before the technology is introduced and then be continually corrected after the technology’s introduction to help it take root and succeed [23]. In the case of hermetic bags, promotional messaging for hermetic bags should have addressed cost and seed viability concerns upfront by providing farmers with accurate information and emphasizing the clear advantages of hermetic bags over conventional storage. This messaging could have emphasized that there is a 3.6-fold greater loss in seed viability in polypropylene bags than in hermetic bags [3]. Another important point could have been that despite the higher initial cost of a hermetic bag (USD 2.00–4.00) than a conventional bag (USD 0.40), farmers would benefit over the course of the storage season, as conventional storage leads to around 20% more grain weight loss, i.e., 10 kg in a 50 kg bag, than is observed in a hermetic bag.

The relative unavailability and perceived high cost of hermetic bags in Malawi can be at least partially attributed to the lack of local manufacturing, as all available brands are imported, which means that import duties and shipping costs are added to the final price. If hermetic bags were manufactured in-country, then these extraneous expenses would be reduced or eliminated. Local production could also increase the availability of bags in local markets, create non-farm jobs in the private sector, and open another communication channel to dispel misconceptions and provide information on benefits [22].

5. Conclusions

The low adoption of hermetic bags in Malawi, despite their proven benefits in reducing postharvest losses, exposes the inadequacy of current promotional strategies and the persistence of key barriers unrelated to the performance of the bags. Our findings do not support the hypothesis that current promotional strategies are sufficient to result in high adoption rates. Instead, our findings indicate that barriers such as perceived high costs, limited availability, and persistent misconceptions need to be better addressed. Additional barriers of lesser importance include a lack of financing, no clear distribution network, and the absence of local production. Over time, the availability of related projects and participation of farmers in farmer groups have potential to increase adoption. Future projects could include the following: (i) evaluating microfinancing, subsidies, or credit schemes to make the initial bag purchase more affordable; (ii) evaluating the potentially local private-sector manufacture of bags to reduce costs and improve supply chains; (iii) evaluating the environmental impact of their widespread adoption, particularly with regard to plastic waste generated by hermetic bags; and (iv) developing targeted educational campaigns to dispel misconceptions and introduce complementary postharvest technologies to increase the adoption of hermetic bags and improve food safety and security nationwide.