Chapters 5.26
5.26 -Planting Fig Trees to Combat Drought
Sarah Douglas, University of Guelph, Canada
Suggested citation for this chapter.
Douglas,S. (2022) Planting Fig Trees to Combat Drought, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Background
Ficus, or fig, trees originated in Asia Minor and have spread around the world (Lansky, 2011). The fig appears to be one of the earliest crops cultivated by humans for food and medicinal use (Lansky, 2011), and was domesticated around 6500 years ago (Kislev, 2006). There are approximately 850 species of fig globally (Lansky, 2011). They are very resilient to drought, can be grown in a variety of soils and regions, and are easy to propagate and grow (Balehegn, 2014). Figs are already grown in parts of Africa such as Ethiopia but are underutilized in other African countries due to a lack of knowledge about the plant and technical knowledge about its use (Balehegn, 2015). Ficus agroforestry can be an economically stable, environmentally friendly self-sustainable agricultural system for farmers in drought-prone areas. There have low external input requirements, are resilient to water scarcity, diseases and pests, contribute to food security and household income, and have environmental benefits (Dhanya, 2016).
Growing Fig Trees: Step by Step Instructions
Climate Factors
Figs are produced in over fifty countries worldwide (World Mapper, 2016), but the main fig producing countries include Turkey, Egypt, Algeria, Iran, Morocco, the Syrian Arab Republic, USA, and Spain (Jafari, 2017). They are also widely grown in Africa, South America, and Asia (World Mapper, 2016). Fig trees are able to thrive in arid and semi-arid climates because of their high tolerance to water stress due to a characteristic succulence that helps it to retain large amounts of water in almost all parts of the tree (Balehegn, 2015). Figs can be grown in a wide variety of soils ranging from clay to course sand (Abdolahipour, 2019). The ideal soil situation would be light, deep, loamy and well-draining soil that is rich in humus (Balehegn, 2015) with a pH ranging from 6.0 to 6.8 (Andrade, 2014). A soil depth of 1-1.5 metres is adequate (CABI Invasive Species Compendium, 2019). Fig trees can grow are grown at altitudes between zero and 3000 metres (CABI Invasive Species Compendium, 2019). They require plenty of light, growing best with eight hours or more of sunlight (Alfrey, 2016). Annual rainfall of 750 mm is sufficient to produce decent crop yields (Alfrey, 2016), but figs can tolerate less than 430 mm of annual precipitation (CABI Invasive Species Compendium, 2019). Figs can grow in temperatures down to 15 degrees Fahrenheit and can survive at zero degrees with heavy mulch (Barth, 2013).
Type
Figs are divided into four types based on pollination and cropping characteristics. The ‘Common’ type is recommended for farmers looking for lower costs and labour intensity because it requires insect pollination to produce a commercial crop (Mars, 2017). Ficus thonningii is an example of a wild common fig that is native to thirty-three sub-Saharan countries (Balehegn, 2015). Only the female trees produce consumable fruits so that is another important consideration (Lansky, 2011).
Propagation
Fig trees take between two to five years to reach maturity and harvest is possible, both of cuttings and fodder leaves (Balehegn, 2015). Farmers can grow one to four meter cuttings into mature trees within two to five years (Balehegn, 2015).
Table 1: Indigenous protocols and requirements for successful propagation/establishment of Ficus thonningii (takend from Balehegn, 2015).
Planting
Fig tree roots tend to be quite invasive and can choke out other plants. If farmers desire to constrain tree roots, fig trees can be contained in pots or build retaining walls underground to keep roots structured. If growing in pots, soil should be replaced every three years (Alfrey, 2016). Applying mulch has positive impacts on the number and width of leaves, growth rate, length and diameter of shoots, and fruit quality (Jafari, 2017), as well as suppresses weed growth, improves infiltration, increases water retention, protects from erosion and nutrient leaching (Jafari, 2012), and regulates soil temperatures throughout the year (Jafari, 2012).
Pruning
Fig trees produce well with or without pruning (California Rare Fruit Growers, 1996). However, pruning does have some advantages, such as training them to produce low-hanging fruit in the crown for picking, improved air circulation, and increased quality of fruit (though decreased quantity). Trees should only be pruned in the initial years, as pruning after these years causes a loss in crop (California Rare Fruit Growers, 1996). Irrigation
Although fig trees are resistant to drought, their growth can be negatively impacted by severe drought conditions. In excessively dry conditions, plants develop few leaves and produce either minimal or no fruits (Andrade, 2014). However, there are ways to mitigate these stresses that can occur in rain-fed orchards (Jafari, 2017). Farmers have used mulching, micro-catchments, supplemental irrigation and potassium nutrition to help alleviate soil moisture stress (Abdolahipour, 2019). Farmers should be warned that when planted in poorly drained soils, fig tree roots may rot (Andrade, 2014). Because the fig evolved in dry, hot climates, they do not have high fertilizer, compost or irrigation needs, and too much of these inputs can hamper their growth (Barth, 2013).
As already noted, on rainfed farms, 750 mm of annual rainfall should be sufficient to produce a decent crop (Alfrey, 2016). If farmers are practicing irrigation, young trees should be watered regularly until they have established themselves. For mature trees, deep watering weekly or biweekly is sufficient (California Rare Fruit Growers, Inc, 1996). Do not irrigate heavily during fruit development and ripening because it can cause the fruit splitting (Alfrey, 2016). Yellow, falling leaves are a sign of water stress (California Rare Fruit Growers, Inc, 1996).
Fertilizer
Limited research has been done on fig’s fertilizer needs (Irget, 2008). However, studies have shown that basic NPK fertilization along with between 280 and 420 g of Ca per tree does reduces the impacts of drought stress and increases fig yields and quality through increased weight and reduced sunscald and crack incidence (Irget, 2008). The benefits carry on into the years following application (Irget, 2008). In the section on ‘Soil Health’ below, it is explained how fig trees also produce organic fertilizer through litter decomposition.
Harvesting
Fig fruits must be harvested only when fully ripe because they will not mature once picked. Gently harvest fruit when it is soft and starting to bend at its neck (Alfrey, 2016). Yellow colouring is most desirable on the market (Jafari, 2017). Because fresh figs only last several days if stored in cool temperatures, drying figs is a way of maintaining freshness. Drying figs in the sun takes four to five days and will keep for six to eight months (Alfrey, 2016). Lay figs down in one layer on wooden/plastic trays and place in the sun (Manolopoulou, 2017). Because sun drying means figs are exposed to rain, extreme heat, dew, dust, microorganisms, and rodents, constructing plastic open-air tunnels overtop of the figs can protect them (Oksar, 2017). These are cheap, easy structures to construct that decrease drying time by 24 hours (Oksar, 2017).
Fig Tree Uses
Fodder
Fig trees are superior biomass producers and can produce up to 50.4 kilograms of dry matter per tree every year, depending on their age. Leaves are used as fodder for livestock such as goats, and can improve animal productivity (Balehegn, 2015). Fodder can be used as fuel. Fig tree leaves are a safe, non-polluting, bio-renewable energy source thanks to the rich content of natural latex (Lansky, 2011).
Shade Trees
Fig trees serve as shade trees in cultivated plots. They are often left standing when forests are cut down to remain as shade trees to protect other crops (Beentje, 2007).
Soil Health
The fig tree can naturally improve soil quality around the base of its trunk. This aids the development of the tree and helps plants growing underneath (Balehegn, 2015). When it rains, the arrangement of leaves and branches allow the tree to catch and channel raindrops down the stem into the soil, increases moisture content (Balehegn, 2015). The leaves of the tree are highly compostable, so when they fall and decompose, organic matter content is increased (Balehegn, 2015) and essential nutrients are reintegrated into the soil (Dhanya, 2013). This litterfall, which includes leaves, twigs, flowers, fruits, and buds (Dhanya, 2013), can be used as mulch for dryland soil as it fulfills up to 76.60% of nitrogen, 20.24% of phosphorus and 67.76% of potassium requirements for dryland crops per hectare. This allows farmers to reduce fertilizer application and labour, because litter can be ploughed into the land during land preparation. It is estimated that ficus trees can decrease expenditures on inorganic fertilizers by 49%, not including savings on transportation and labour costs for application (Dhanya, 2013).
Food and Income Sources
Fig fruits can be eaten as part of a regular diet or in food insecure months, or sold for extra income. Nutritionally, figs contain high levels of magnesium, calcium, iron, potassium, and fiber, amino acids, flavonoids, antioxidants, and polyphenols, and smaller levels of vitamins B6, K, E, B1, and A (High Atlas Agriculture and Artisanal, n.d.). When grown in combination with staple food crops like millet and sorghum, figs help fulfill some nutritional requirements of subsistence farming families (Dhanya, 2016). Figs are made into jams or candied with heavy syrup and sold as confectionaries (Aksoy, 2017). In markets, they are usually sold dried, whole, sliced, cubed or ground into a paste. Concentrated fig juice can be extracted from pressed figs or figs boiled with water, and then be drank as juice, used as pastry glaze, or distilled to make wine, vinegar, or other alcoholic drinks (Aksoy, 2017).
To sell figs fresh, they must be sold the day of or after they are picked. This means that when fig trees in an area that ripen at the same time may cause market prices to drop (Upale, 2011). Because they quickly spoil, farmers could dry figs to sell instead.
Nutrition Facts
Daily values based on 2000 calorie diet and 155 pounds body weight (Nutritionvalue.org):
Figure 4: Proteins and Aminoacids, 100 g raw fig (Nutritionalvalue.org).
Figure 5: Minerals, 100 g raw fig (Nutritionalvalue.org).
Pests and Diseases
Fig trees are prone to nematode attacks. Leaf rust that causes early leaf fall and reduced crop yields can be caused by Cerotelium fici. Fig trees are vulnerable to pests such as Carpophilus hemipterus (which can infest fig fruit and transmit parasitic fungi), Hypoborus ficus (causes drying out and death of the tree), and Homotoma ficus that feeds on fig leaves and causes them to yellow and fall off (CABI Invasive Species Compendium, 2019).
Dangers
Dried figs can develop mold infestations that can produce noxious compounds called aflatoxins (Lansky, 2011), which may cause cancer, liver dysfunction, congenital anomaly, bleeding, etc. in humans and animals (Sahin, 2017). Stress during drought years can increase the chance of these fungi appearing and therefore increase the levels of aflatoxins in figs (Lansky, 2011). Fig trees produce white sap that can cause bleeding under the nails and blistering, so farmers are recommended to wear gloves, wristbands, and/or scarves for protection (Ferreira, 2016).
Purchasing Seed and Related Materials
Alibaba: https://www.alibaba.com Seeds of Africa: https://www.seedsforafrica.co.za/search?q=fig Rare Exotic Seeds: https://www.rarexoticseeds.com/en/ficus-carica-seeds-common-fig-seeds.html
Online Resources:
Video on Propagation from Cuttings: https://www.youtube.com/watch?v=bQ0ASRum3ik
Video on Growing a Tree from Seed: https://www.youtube.com/watch?v=PVQ7oQpfcOg
Video on How to Dry Figs: https://www.youtube.com/watch?v=yVuD2G0pU2Y
How and Why to Prune Fig Trees: https://www.youtube.com/watch?v=tADEOd64Gmk
References
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