Sayed Reza Hashemi ^1*; Zaigham Kazimi ²

1, Department of Agricultural Economics and Extension, Faculty of Agriculture, Bamyan University, Bamyan, Afghanistan

 

Manuscript link
http://dx.doi.org/10.30493/DAS.2024.466164

Abstract

Potato is a highly consumed staple food in Afghanistan, ranking third in dietary preferences among households, following wheat and rice. Bamyan province is responsible for around 70 percent of the potato production in the country. Although the province possesses a distinct comparative advantage in potato production within the country, potato producers face significant levels of waste during various stages of production. Hence, this study was carried out to examine the fundamental causes of potato waste and determine the techniques for reducing it. The study was conducted in four districts of the province, utilizing the multistage sampling approach. A total of 390 potato growers were interviewed using semi-structured questionnaires. Descriptive and inferential methods were employed for data analysis. Based on exploratory factor analysis, the key factors that significantly impact postharvest waste management, as perceived by farmers, are ‘appropriate storage management’, ‘proper harvesting and post-harvesting practices’, ‘pests and diseases control’, ‘suitable cultivation activities’, and ‘irrigation management’. Specialized training programs are necessary for farmers to enhance their formal education and embrace new methods. Furthermore, Introducing improvements to storage facilities and employing simple postharvest techniques such as curing, sorting, and washing can effectively minimize waste in the studied area.

Keywords: Potato, Waste reduction, Bamyan, Afghanistan

Introduction

Potato is a prevalent staple in Afghan families and is therefore grown extensively as a primary crop, particularly in the central highlands of the nation. Due to its significant strategic value, it is necessary to make efforts to enhance production by optimizing efficiency and reducing waste at all stages of the production process. In Afghanistan, the crop is grown on an area of over 32 thousand hectares and produces an estimated yearly output of more than 513 thousand metric tons (MT) [1]. Bamyan province, due to its advantageous climatic conditions, is the largest potato producer in the country, contributing to around 70 percent of the total potato production inside the nation.

Although Bamyan province has a unique and unparalleled advantage in terms of its product, a significant amount of it is wasted each year at different phases of production, particularly postharvest. According to a study, potatoes in Afghanistan experience an annual loss of 35%, making them one of the most susceptible goods in the country [2]. Furthermore, underdeveloped countries experience a far higher incidence of horticulture product waste, such as potatoes, with a range of 25-30%, primarily due to inadequate storage practices. In contrast, affluent countries have a lower waste rate of 5-6% [3].

Potato waste is the portion of the crop that becomes unusable owing to physical, physiological, or biological damage, such as tubers greening, sprouting, or decaying, caused by improper preharvest, harvesting, and storage conditions. Consequently, waste reduction strategies have become a prominent benchmark for measuring efficiency in both businesses and the agriculture sector. Regarding the previously mentioned production and waste of potatoes in Afghanistan, approximately 179 thousand metric tons of the crop are squandered each year, resulting in a loss of nearly US$ 35.9 million in the country’s GDP. Furthermore, research suggests that a 15 percent decrease in waste can result in an annual savings of nearly US$ 5.38 million [1][4].

While it is unavoidable to have potato waste during mechanical harvesting, farmers can optimize their procedures to reduce mechanical loss [5]. The peak volume of potato waste occurs during the periods of planting and post-harvest. The key variables that significantly contribute to waste reduction in potato production include selecting the appropriate planting date, implementing a regular irrigation schedule, allowing the potatoes to fully ripen, storing them in standard facilities, and segregating any damaged potatoes [6]. According to a previous study, the primary causes of potato waste, resulting in losses of 10-15 percent throughout production, include inadequate seeds, inferior varieties, pest and disease infestations, and incorrect irrigation practices [7]. The same study contended that typical storages losses of approximately 30-50% typically occur due to factors such as improper temperature, high humidity, inadequate ventilation, pests, and diseases. However, these losses can be reduced to only 5-6% in contemporary and well-equipped storages [7]. Another study showed that the overall percentage of potato losses, encompassing both pre-harvest and post-harvest stages, amounts to 33 percent. Among these losses, 90 percent occur specifically due to improper actions during the post-harvest period [8]. To prevent the occurrence of fungal and bacterial diseases, it is important to appropriately regulate the temperature, humidity, and ventilation in potato storage. In order to impede the sprouting of potatoes, it is important to store them in complete darkness. Additionally, to avoid the buildup of carbohydrates in stored potatoes, the temperature should be regulated according to the quantity of potatoes being stored, the level of ventilation, and the humidity of the storage area [9].

Due to the aforementioned economic importance of potato crop in Bamyan province, and taking into consideration the primary methods and practices that can be conducted to reduce potato waste postharvest, this study aimed to ascertain the primary elements that contribute to the reduction of potato waste, taking into account the specific agro-climatic conditions of Bamyan region in Afghanistan.

Methodology

Study area 

Bamyan is a province characterized by its steep terrain, located in the central highlands of Afghanistan. The province is located 190 Km northwest of Kabul, the capital city of the country, with a central altitude of 2,800 meters above sea level. The region experiences an extended period of winter lasting for six months, during which the temperature can reach as low as -20 °C in midwinter. In addition to the city center, the province is divided into seven districts: Waras, Panjab, Yakawlang1, Yakawlang2, Kahmard, Sayghan, and Shibar. Potato, wheat, barley, and beans are the primary crops in this region. Potato, in particular, contributes to around 70 percent of the country’s domestic output of this crop [10].

Research population and sample size

Due to the broad and unidentified research population, the sample size was determined using the Cochran formula:

Where, (n₀) represents the sample size, (Z) represents the confidence level at 95% (1.96), (p) represents the estimated proportion of the population with the characteristic being studied (farmers), (q) represents the estimated proportion without the characteristic, and (e) represents the sampling error at a 5% level. Due to the unspecified quantity for (p), a maximum rate of variability of 0.5 is utilized in this calculation. Therefore, value of the variable (q) is also 0.5, as it is consistently derived from the expression ‘1 – p’. Therefore, a representative sample size of 390 farmers was set for this study

Data collection 

The study employed a multi-stage sampling strategy to collect data from four districts in Bamyan province: Yakawlang1, Bamyan Center, Shiber, and Saighan. A total of 390 farmers were selected at random from each district to receive the questionnaires. Face-to-face interviews were done specifically with potato producers. Every farmer was notified about the objectives and purposes of the study and gave their consent to take part.

The questionnaire comprised two components. The initial segment comprised of inquiries of a general nature regarding the age, educational background, agricultural expertise, and the specific method employed by the participants for potato storage. In the second phase, participants were provided with a list of 26 proposed strategies intended to mitigate potato postharvest losses across the whole production cycle. The participants were instructed to assess the efficacy of each mechanism using a 5-point Likert scale, which ranged from ‘Not at all’ to ‘Perfect’. The choice of these 26 mechanisms was based on a combination of current literature [6-9], expert viewpoints, and practical factors.

In order to guarantee the dependability of the questionnaires, a preliminary survey was carried out with a sample of 30 participants. The Cronbach’s Alpha (α) value calculated was 0.97, indicating a good level of reliability for the questionnaires. In order to improve the content validity, the questionnaires were examined by 5 specialists from the agriculture faculty, who made any necessary modifications.

Data analysis 

The variables were analyzed using SPSS 24 for both descriptive and analytical purposes. In order to conduct inferential analysis, Exploratory Factor Analysis (EFA) was utilized to identify the primary factors contributing to potato waste and to propose effective strategies for reducing waste in the specified province.

Results

Descriptive data analysis

Participants demographics

The survey found that the mean age of potato growers was 41 years, which fell within the age range of 25 to 65. The majority of the participants, accounting for almost 70 percent, were within the age range of 25 to 45 years, and possessed an average of 9 years of professional experience. Considering the characteristics of this population, the introduction and adoption of novel measures to reduce potato waste can be easily implemented within this community. Nevertheless, it is crucial to acknowledge that over 55 percent of the farmers did not possess formal or primary schooling. To solve this situation effectively, extensionists should be empowered by extensive training on potato waste management. The study findings indicate that 65 percent of farmers employ semi-modern storage techniques, whilst 35 percent depend on older storage approaches. Semi-modern storages are well-built facilities that are fitted with modern tools such as thermometers, moisture meters, and ventilation equipment and operated manually.

Prioritizing the influence of the surveyed mechanisms on the reduction of potato waste

The primary options identified by participating farmers for reducing potato waste were optimum irrigation frequencies, suitable irrigation methods, and suitable cultivation methods. Notably, the suitable use of pesticides and weeding were among the less emphasized solutions (Table 1).

Inferential data analysis

Sampling adequacy test

To determine the sampling adequacy, Kaiser–Meyer–Olkin (KMO) and Bartlett’s tests were applied (Table 2). The KMO coefficient was equal to 0.806 which is higher than the threshold of 0.7 signifying that the sampling adequacy was met [11].

Exploratory factor analysis (EFA) results

To identify the mechanisms of potato waste reduction, EFA was applied using Principal Component Analysis and the Varimax Rotation Method. A total of 5 factors with eigenvalues greater than one were identified after factor analysis (Table 3). Out of the eighteen variables included in the model, there are five primary underlying factors suggested to explain for 62.95% of the variance among all the variables. In order to identify each of the proposed factors, the Varimax Rotation Method was utilized to group the interconnected variables based on their highest factor loadings with each factor. Consequently, it is necessary to investigate each group of interconnected variables and assign the appropriate label to the underlying factor.

Factor 1 encompasses five factors, Factor 2 encompasses four variables, and Factors 3, 4, and 5 each encompass three variables. The first factor with the highest rotated eigenvalue of 3.358 and the highest relative variance explanation power (18.66% of the total variance) is considered the most important. Conversely, the factor with the lowest rotated eigenvalue of 1.638 and the lowest relative variance explanation power is deemed the least important according to the participants. When considering the interrelationship of the grouped variables, factor 1 represents “Appropriate Storage Management”, factor 2 represents “Proper Harvesting and Post-harvest Practices”, factor 3 represents “Pests and Diseases Control”, factor 4 relates to “Suitable Cultivation Activities”, and finally, factor 5 signifies “Irrigation Management”.

Discussion

The farmers in the examined area have a limited formal education, which could make it difficult to implement technically advanced practices. Therefore, specific training programs are needed to effectively transmit information. Nevertheless, the targeted farmers are in the age range of 25 to 45 years is relatively youthful, indicating a possible willingness to embrace novel methods aimed at minimizing postharvest waste. This observation is exceptionally effective when combined with the upgrade in storage facilities, since a significant portion of farmers (35%) still rely on traditional storage methods. The effectiveness of such improvements in reducing waste could be a key area for targeted interventions.

Farmers give higher importance to irrigation-related aspects, such as determining the most effective irrigation frequencies and selecting appropriate irrigation technologies, compared to storage and post-harvest management procedures. This observation suggests that the user believes that effective management of the field has a greater impact on reducing waste than measures that occur after the harvest. While irrigation method [12] and other preharvest practices contribute to improved postharvest performance of stored products, lower-ranked factors such as ventilation and relative humidity control remain crucial for efficient storage. This suggests a potential lack of awareness or experience among farmers regarding the benefits of advanced storage management.

The questionnaire in this study did not include other postharvest methods such as curing, sorting, and washing because they are not commonly used in the studied area. Implementing these methods can significantly decrease postharvest losses in potato crops during the storage period [13] and subsequent commercialization. Hence, it is imperative for agricultural extensionists to focus on the simplification and education of these techniques for the farmers.

According to EFA, five key aspects had a significant impact on reducing potato waste: storage management, harvesting and post-harvest techniques, pest and disease control, growing activities, and irrigation management. The storage management had the greatest variance, highlighting its overall perceived significance by farmers. Nevertheless, the wide array of elements underscores the complex and diverse nature of waste reduction, indicating that a holistic approach that encompasses all these areas may be crucial for substantial enhancements.

Conclusion

Potato is a crucial crop in Afghanistan, especially in Bamyan province accounting for nearly 70% of the country’s domestic production. Despite favorable conditions, significant waste occurs, particularly during storage, leading to a significant economic loss.  Targeted training programs are essential to address the limited formal education among farmers, especially given their willingness to adopt new methods due to their relatively young age. Upgrading storage facilities, when conventional methods are still used, is critical to decreasing postharvest waste. While farmers focus on irrigation methods and other preharvest procedures, there is a need to improve awareness about the benefits of advanced storage management techniques such as ventilation and humidity control. Additionally, implementing postharvest practices such as curing, sorting, and washing could help to reduce losses. According to the study, efficient waste reduction requires a comprehensive approach that includes storage management, harvesting, post-harvest procedures, pest and disease control, and irrigation.

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Cite this article:

Hashemi, S. R., Kazimi, Z. Potato waste reduction mechanisms: Evidence from Bamyan province, Afghanistan. DYSONA – Applied Science, 2025;6(1): 1-7. doi: 10.30493/das.2024.466164