Template:Chapters 2.10
2.10 - Mesh Shade Greenhouse for Small Scale Farmers
Harisha Kaur , University of Guelph,Canada
Suggested citation for this chapter.
Kaur,H. (2022)Mesh Shade Greenhouse for Small Scale Farmers . In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Background for Mesh Shade Greenhouse
Many African and Asian smallholder farmers aim to grow plants for more food security, generating an income and preserving crop biodiversity. However, regions that have extreme climate conditions may not benefit from the traditional outdoor farming methods which rely solely on sunlight, soil fertility and rainwater. Without a proper shelter for the plants, they can go through temperature and water stress with extreme dehydration leading to leaf curling and reduced growth. If it is too humid, there can be a risk of a pest disease outbreaks leading to infestations that can be costly to fix. Additionally, if a certain area is susceptible to extreme weather events such as hurricanes, the wind can destroy the seedlings and stems, resulting in a reduced crop area (Kumar, et al., 2022).
A greenhouse is an effective solution for plants to be in a controlled environment with protection from extreme weather to aid with growth. One of the most common ways to build a greenhouse is with materials such as plastic made of polycarbonate, polyethylene, or glass panes (Figure 1) (Sebulke, 2024). These are all great options but may not work in very hot climates, as glass tends to retain heat faster, causing overheating. Additionally, traditional solid greenhouses may restrict the airflow ventilation and can also result in uneven light distribution (Akrami, et al., 2020). Therefore, a mesh shade greenhouse (Figure 2) is a great way for African and Asian farmers to tackle these problems by allowing the perfect amount of sunlight, temperature regulation and improved airflow (Ahemd, et al., 2016). It is crucial for small scale farmers to take into count these challenges when aiming to grow plants and consider if building a mesh shaded greenhouse will be the most effective option.
Benefits of Constructing a Mesh Shade Greenhouse
Many farmers that focus on planting in regions such as Africa and South Asia face extreme weather conditions such as very hot days. Since mesh nets are made with materials that have a certain degree of opacity, it allows only some sunlight to pass through while reducing intense sunlight. Therefore, instead of direct sunlight hitting the plants, it is more spread out throughout the area. This will aid in protecting crops from the stress of heat, allowing for better temperature regulation and overall healthier crops. Additionally, since mesh allows for reduced sunlight
exposure, it will lessen the soil evaporation which in turn helps cool the greenhouse environment and conserve water in areas that might be limited in available freshwater (Ahemd et alt., 2016). According to the World Health Organization, water scarcity affects one in three people in the Africa Region, while 95 percent of farmers are reliant on rainfall (WHO, 2023). Mesh shade greenhouses are not closed off completely like a typical glass greenhouse, so there is a better air ventilation flow for the plants to grow (Akrami, et al.,2020). As hot air arises inside the greenhouse, it can easily escape through the openings of the mesh while cooler air from the outside can enter in. In turn, this lowers humidity levels and prevents pests and fungal diseases (Akrami, et al,. 2020). Therefore, mesh shade greenhouse can improve crop cultivation and yield through the controlled temperatures. Shade nets allow the growth of many types of plants from flowers to nursery seedlings. In Africa and Asia, several types of mesh shade greenhouses are used to grow a variety of vegetables, berries, citrus, root crops and even decorative plants (Ojiewo, 2013). By small scale farmers being able to diversify their crops, it allows for new markets with potentially bigger income growth.
Another major benefit for building a mesh shade greenhouse is that it is more cost effective than a regular glass greenhouse. A glass greenhouse built in Asia or Africa will range from several thousand to tens of thousands of dollars due to the glass panels and structural framework required such as aluminum and glass panels. The overall cost of a mesh greenhouse is much less, depending on the size of the greenhouse. In populated hot climate areas such as India, the average green net price is 140 Rupees per kg ($1.70 USD per kg). Although the labour costs are much cheaper since mesh greenhouses are typically lightweight, farmers in Asia and Africa can use local bamboo sticks for the poles (Shiri, 2023). Notably, since mesh shade greenhouses are simpler to build, the labour cost decreases significantly and takes much less time than glass greenhouses.
How to Construct a Mesh Shade Greenhouse?
For smallholder farmers to create a mesh greenhouse, it can be simple with the correct materials and proper care. The first task is ensuring that the greenhouse is in an area of land that is flat and has lots of sunlight with easy access for maintenance and watering. It is also recommended for workers to draw a simple design including measurements and dimensions for the placement of materials. Mesh shade greenhouses can vary in sizes, depending on crop requirements, available materials, and climate conditions. A widely used mesh shade greenhouse for African and Asian farmers is called the tunnel greenhouse (Figure 3) (OrgaKart, 2016). It has a semi-circular shape which is easy to assemble. They can hold a variety of crops, making it the perfect affordable option for small scale farmers. Another popular choice is the flat-top greenhouse (Figure 4), which has a rectangular shape with a flat roof (Murali, 2013). The reason why they are commonly used in African and Asian regions is due to their uniform light distribution and airflow, allowing healthy growing yields such as leafy greens and herbs (Mendoza-Fernandez et alt., 2021). They are also more suitable for permanent crop production, making them great for long term money income.
Once the farmers have decided which mesh shade greenhouse they want to build, they can begin collecting bamboo or other sticks and cut them to their desired length for the poles. Then, the farmers install the poles into the frame of the ground while securing the poles together at the corners with nails and/or screws. It is important to assure that the poles are spaced out evenly, so the support is strong. Then, farmers must decide on what type of mesh shade netting they want to use for their greenhouse. Lighter colours such as white will reflect more sunlight within the greenhouse, while darker mesh shade will absorb more heat. Overall, hot climates like in South Asia and Africa should strive for a more lighter colour net, as it will prevent heat buildup. Farmers must roll out the mesh shade net and put it over the framework, ensuring that it is cut perfectly and covers the entire greenhouse. It is recommended to use staples, or clips so that the net does not fall, or wrinkle. Farmers can then make any necessary adjustments for extra security such as anchoring the greenhouse with either concrete blocks or stakes. After completed, it is the decision of the farmers to continue maintaining their mesh shade greenhouse by regularly checking for any damage and keeping it free from debris to avoid any pest infestations (Serfilis, 2022).
Constraints to Mesh Shade Greenhouses
Even though mesh shade greenhouses are affordable to small scale farmers, they do have weaker structural integrity than a regular glass greenhouse. Since the structure is being held together with bamboo or local sticks, it is more vulnerable to damage from extreme weather conditions such as strong winds or heavy rainfall. There are certain situations where mesh shade greenhouses could be inappropriate as well. Some regions such as the Western Pacific and Indian Ocean are more prone to experience extreme weather events such as typhoons, and storms (Kuleshov et alt., 2014). This in turn will severely damage the mesh shade greenhouses, wasting all the work and money invested. Additionally, the tiny holes from the net can allow small insects to enter the growing area, causing possible damage to plant tissues, stunted growth, and transmission of diseases. Some of the most common insects that damage plants around Asia and Africa are whiteflies, thrips, and aphids (Abate, 1996). Then, certain crops do require a stricter climate control such as tropical fruits like mangoes, and high value vegetables such as tomatoes (Oijewo, 2013). Therefore, mesh shade greenhouses may be too simple, and these crops may require a more advanced greenhouse system with controlled humidity and cooling systems. Lastly, as mentioned, mesh shade greenhouses require a regular maintenance check which can involve fixing holes, replacing damaged nets, cleaning debris, and repairing structured poles.
Overall, mesh shade greenhouses can work effectively across different regions throughout Asia and Africa for small scale farmers. They work the best in very hot climates where excessive sunlight and ultraviolet (UV) radiation may be harmful towards the crops. The mesh net can filter out the UV rays and is mostly used in areas such as the Sahel region in Africa and the semi-arid regions in South Asia (Ahemd et alt., 2016). Mesh shade greenhouses are mainly suitable for smallholder farming communities due to their lower cost, easy construction, and income opportunities of many endless types of crops. They allow farming communities to feel empowered to improve crop biodiversity by also tackling the challenges of water scarcity and pest pressure.
Practical Links to Get Started
Link to Mesh Shade Greenhouse Tutorials: https://youtu.be/iqheuTD79_M?si=TL-pFB5FGv4OB9yi https://youtu.be/T_9LPP0k7JI?si=2IFDMU-A7-4Ar6Gf
Link to Purchase Materials for Mesh Shade Greenhouse: https://www.shademesh.org/technology/shade-mesh-greenhouse-agricultural.html https://www.bettermicn.com/products-category/sun-shade-net.html https://www.bcgreenhouses.com/product/shade-cloth/
Additional Readings: https://blog.bcgreenhouses.com/cool-down-a-greenhouse-creating-a-healthy-greenhouse-environment https://eyouagro.com/blog/greenhouse-shade-cloth-guide/
References
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3. Akrami, M., Salah, A. H., Javadi, A. A., Fath, H. E. S., Hassanein, M. J., Farmani, R. (2020). Towards a sustainable greenhouse: Review of trends and emerging practices in analysing greenhouse ventilation requirements to sustain maximum agricultural yield. Sustainability 12(7), 2794. https://www.mdpi.com/2071-1050/12/7/2794
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5. Kuleshov, Y., Mcgree, S., & Jones, D. (2014). Extreme weather and climate events and their impacts on island countries in the western pacific: cyclones, floods and droughts. Atmospheric and Climate Sciences 4(05):803-818
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7. Mendoza-Fernández, A. J., Peña-Fernández, A., & Sanchez, L. (2021b). The role of technology in Greenhouse Agriculture: Towards a sustainable intensification in Campo de Dalías (Almería, Spain). Agronomy 11(1), 101. https://www.mdpi.com/2073-4395/11/1/101
8. Murali, P. (2013). My green house. My Green House. https://muralisterracegarden.blogspot.com/2013/10/my-green-house.html
9. Oijewo, C. (2013). Good Agricultural Practices for African Nightshade Production in Sub-Saharan Africa. Conference: Proceedings of a Technical Consultation Workshop At: Held in Arusha, Tanzania.
https://www.researchgate.net/publication/253341994_Good_Agricultural_Practices_for_African_Nightshade_Production_in_Sub-Saharan_Africa10. Parbst, K. (2010, April). Using shading for greenhouse temperature control. Greenhousemag.com. https://www.greenhousemag.com/article/gmpro-0410-shading-greenhouse-temperature-control/
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12. Shriji, G. (2023). What is a shade net house and its prices. Shri Ji Irrigation. Retrieved July 4,2 2023. https://www.shrijigreen.com/blog/what-is-a-shade-net-house-and-its-price/
13. WHO. (2023). Water. World Health Organization. https://www.afro.who.int/health-topics/water
14. Orgakart. (2021). A guide to shade netting and its uses. https://orgakart.com/uncategorized/a-guide-to-shade-netting-and-its-uses/