Sustainability Of Indigenous Post Harvest Technology Among Maize Crop Farming
1.1 Background of the study
Maize remains one of the major food staples in developing countries worldwide, and in Africa in particular. In Africa, maize is produced mainly through the use of IK (Hart & Vorster, 2006:1). In Africa, as in many other developing countries, the assumption is that agricultural development cannot succeed if does not follow the kind of development model which assumes that a country‟s social and economic development must be externally induced (Hart & Vorster, 2006:1). This assumption ultimately ignores the roles of those who hold indigenous knowledge and the impact they can have in the process of agricultural development (Hart & Vorster, 2006:2)
Storage is an integral part of any food maize processing chain. Storage of raw and processed maize, including legumes has been used by humans since the beginning of history as a pre-requisite for ensuring food security due to off time availability and for withholding seed maize for long periods. Maize storage and handling is a major concern for pulse growers and processors worldwide. Pulses can remain in an edible condition for several years if properly stored. However, during ambient storage conditions, maize are subjected to various physical, chemical and biological changes. The basic advantage of good storage is to create environmental conditions, which protect the product from the extremes of outside temperature and relative humidity fluctuations, both diurnal and seasonal, and maintain its quality (Cox and Collins, 2002). Both pulse maize quality and quantity are affected by intrinsic and extrinsic factors and, among these, temperature and moisture content are the most important influences of shelf-life. Maize viability and reproduction of biological agents in maize are dependent to a great extent on the temperature and moisture levels (White, 1995). Improper storage conditions influence the post-harvest storability of pulses. Various pests and microorganisms attack the pulses and their products after harvest, in storage and during transportation to the market. The application of pesticides results in chemical residues in the food that are extremely hazardous to health. Establishment of efficient and effective post-production storage systems is warranted in order to minimize qualitative and quantitative losses (Mohan, et al., 2011). Storage plays a vital role in the food supply chain, and several studies reported that maximum losses happen during this operation (Bala, et al., 2010; Majumder, et al., 2016).
In most of the places, crops are grown seasonally and after harvesting, maize are stored for short or long periods as food reserves and as seeds for next season. Studies report that in developing countries such as India, about 50–60% of the maize are stored in the traditional structures (e.g., Kanaja, Kothi, Sanduka, Gummi Kacheri) and earthen pots at the household and farm level for self-consumption and seed (Grover and Singh, 2013). The indigenous storage structures are made of locally available materials (grass, wood, mud) without any scientific design and cannot guarantee to protect crops against pests for a long time. Estimated losses as high as 59.48% in maize after storage for 90 days in the traditional storage structures (granary/aerated bags) have been reported (Costa, 2014).
Hermetic storage is a type of modified atmosphere (MA) that can be applied for the protection of maize. It is also called ‘‘sealed storage’’ or‘‘air-tight storage’’ or ‘‘sacrificial sealed storage’’ or ‘‘biogenerated MA’’. This method takes advantage of sufficiently sealed structures that enable insects and other aerobic organisms in the commodity or the commodity itself to generate the MA by reducing the O2 and increasing the CO2 concentrations through respiratory metabolism to prevent insect development (Navarro, 2012).
In other words, hermetic storage (HS), also known called as “sealed storage” or “airtight storage”, is gaining popularity as a storage method for cereal, pulses, coffee, and cocoa maize in developing countries, due to its effectiveness and avoidance of the use of chemicals and pesticides. The method creates an automatic modified atmosphere of high carbon dioxide concentration using sealed waterproof bags or structures. As the structures are airtight, the biotic portion of the maize (insects and aerobic microorganisms) creates a self-inhibitory atmosphere over time by increasing carbon dioxide concentration (oxygen decreases) due to its respiration metabolism. Some studies have reported that the aflatoxin production ability of Aspergillus flavus is also reduced at high concentrations of CO2 (Tefera et al., 2011; Adler et al., 2000).
Hermetic storage has been observed to be very effective in avoiding the losses (storage losses less than 1%) during long distance (international) shipments (Villers et al., 2010). Ease of installation, elimination of pesticide use, favourable costs and modest infrastructure requirements are some of the additional advantages that make the hermetic storage options attractive (GHI, 2014).
The CO2 concentration inside the bags is usually used as an indicator of the biological activity of maize. (Cardoso et al., 2008; Bartosik et al., 2008). Permeability of the bag and the gas partial pressure effect the movement of gases (O2 and CO2) in and out, whereas the concentration of these gases inside the bag depends on the balance between these exchanges and the respiration of the biotic portion of maize. Higher initial moisture content tends to increase the CO2 concentration because of the increased respiration, however, the change was not found to be significant (Cardoso et al., 2008).
Another factor affecting the respiration rate is maize temperature. It has been observed in experimental studies that the temperature inside the bags follows the ambient temperature trend, and for every 10-degree increase in temperature, the CO2 concentration increases by about 1.5% (Cardoso et al., 2008). World Food Programme (WFP) in their Action Research Trial in Uganda and Burkina Faso found out that if properly sealed, the hermetic storage units were themselves very efficient in killing the pests and insects without any use of phosphine fumigation (Costa, 2014). Various hermetic storage options, such as metallic jute bags, Purdue Improved Cowpea Storage (PICS) bags, Super Maize bags, etc., have been developed and widely promoted in the last few years. These bags are being considered practical and cost-sustainable post-harvest technology, and are becoming very popular in several countries (Zeigler and Truitt, 2014).
The metal silo technology is an effective method of reducing maize post-harvest losses for indigenous farmers. This technology provides maize protection for both short and longtime storage against pathogen damage, animal and insect pest. In some locations, the siloes are made of painted aluminium sheeting which helps prevent corrosion and improves their appearance (Yusuf and He, 2013). It is considered to be one of the key technologies which will be helpful in reducing postharvest losses and improving food security of smallholder farmers.
Technology interventions and improved storage structures can significantly reduce store losses. However, it is important to understand that training of smallholders is equally as necessary as the technology dissemination (Kitinoja, 2013). Along with making these technologies available at a reduced price, the government agencies and organizations have to ensure the development of facilities to provide information and training about the use and maintenance of these technologies in the local language, for successful adaptation and effective use of these technologies.
Post-harvest development contributes to food security in several ways. Improved storage technologies such as biological pest control or controlled atmosphere storage reduce post- harvest losses, thereby increasing the amount of food available for consumption. For example, control of the larger maize borer greatly reduced maize lost in on-farm storage among smallholders in a number of African countries, heightening their food security (Goletti and Wolff, 1998). Further, post-harvest can provide income-generating opportunities for farmers in rural areas. Studies of the commercialization of smallholder producers in a number of developing countries show that producers’ nutritional status is typically not compromised; income gains generally lead to higher spending on food in absolute terms (Von-Braun and Kennedy, 1994).
1.2 Problem Statement
Maize is cultivated in many regions in Nigeria. Apart from their nutritional benefit they fix nitrogen in soil, improves soil nitrate content and saves fertilizer costs and increase yield of subsequent crops (Joshi, 1998). Being cultivated in large quantity in different regions has shown a negative relationship on their wellbeing and nutritional status (most of the families are food insecure) (SDC, 2017). Smallholder farmers in Sub-Saharan Africa face numerous challenges after their maize leaves the field. Farmers who store maize may experience significant quantity losses due to damage from rodents, insect pests, and mould, and subsequent price discounts for damaged maize (Kaminski and Christiaensen, 2014; Kadjo et al., 2015; Kadjo et al., 2016). Deterioration of maize maize quality due to insect damage leads to rejection in the market and loss of income (Abate and Ampofo, 1996). Part of the reason quantity loss occurs is that many farmers lack access to effective and safe storage technology, such as airtight (hermetic) storage bags or jute bags. These technologies have the potential to positively impact household welfare but are currently not available in many rural settings (Gitonga et al., 2015).
Despite storage technology being pointed out by many researchers in reduction of postharvest losses and improving household food security, there is a scarcity of information on maize loss. Hence this study will go deeper to assess the effectiveness of three storage technologies (metal silo, hermetic bag (PICS) and aerated bag, on reducing post-harvest losses and improving food security and come up with practical strategies on how to reduce post-harvest losses during storage of maize. Storage point was selected because it is the only stage where the maize spends a longer time after harvest waiting for the market or being used as household food, also on this stage the contact time between rodent, microorganisms, bruchids and maize is longer, therefore during storage almost all types of losses occurs (quality loss, economical loss and weight loss).
The results obtained from this study will help to come up with sustainable post-harvest technology in terms of cost effectiveness and performance, which will help to reduce losses that occur during storage and hence improve food security and wellbeing (increase household income) of indigenous farmers.
1.3 Objectives of study
Assessment of effectiveness of aerated bags, jute bags and hermetic bags in reduction of post-harvest losses of maize at household level.
- To identify the sustainability of aerated bags, jute bags and hermetic bags for maize storage
- To examine major types and causes of maize losses occurring in aerated bags, jute bags and hermetic bags
- To evaluate the level of understanding/knowledge on post-harvest management of maize
- To evaluate the quality of maize stored in aerated bags, jute bags and hermetic bags
- Research Questions
- What is the sustainability of aerated bags, jute bags and hermetic bags for maize storage?
- What are the major types and causes of maize losses occurring in aerated bags, jute bags and hermetic bags?
- What is the level of understanding/knowledge on post-harvest management of maize?
- What is the quality of maize stored in aerated bags, jute bags and hermetic bags?
The study is of importance to the following stakeholders:
The government and policy makers will benefit in the sense that the study will inform policy and development relating to food security in the country including the choice of appropriate technologies on postharvest maize management practices.
Farmers will be equipped with the information on how to improve their management practices in order to reduce grain losses at household level.
Development partners will learn about progress toward meeting Millennium Development Goals especially on hunger and poverty reduction through the adoption of improved post-harvest maize management technologies.
1.6 Limitations of the Study
The study had no control of other variables that may also have effect on post-harvest practices such as; chemicals and preservatives.
Also the researcher was short on time as he was engaged in other academic works in school.
Finances too was a great challenge in carrying out this work, mainly on transportation to the selected schools.
1.7 Scope of the Study
The study was limited to indigenous farmers in Boluwaduro L.G.A. in Osun state. The respondents for the study include farmers and state agricultural development officers. The study focused on the sustainability of post-harvest technology in Boluwaduro. The study used questionnaires, interview schedule and observation checklist to collect data from the respondents The findings of the study cannot be generalized to other parts of the country unless a similar study is done in areas with similar characteristics.
Post-harvest treatments deal with fruit protection and enhance fruit quality, the development of post-harvest treatments has permitted the creation of the current global fruit and vegetable trade.
Food security – Having physical and economic access to access sufficient, safe and nutritious food.
Harvest – Deliberate action to separate the food stuff from its growing medium.
Winnowing – Separation of the grain from the chaff.
Pest – An insect or small animal which is harmful or which damages crops.
Preservation – To keep something in order to prevent it from being damaged.
Physiological maturity – This is when maize kernel has a maximum content of dry matter.
Food security – World bank summit report (1996) refined food security as existing when all people at all times have access to sufficient, safe & nutritious food that meet their dietary needs and preferences for an active and healthy life.[email protected][email protected]