Get To Know The Cashew Apple
The cashew apple is the fleshy part attached to the cashew nut.Cashews are native to Brazil and were introduced to Tanzania and Mozambique by Portuguese explorers in the 16th century. Cashew apples are oval-shaped, yellow to red in color, juicy and very astringent. They contain five times the vitamin C of oranges, potassium, fiber, and other minerals.
Cashew apples can be eaten raw and used to make juices, chutneys, jams, and alcoholic drinks. Though the nut is more well-known, cashew apples have significant nutritional value and culinary utility.They are highly perishable, lasting only 1-2 days after harvesting, so they are often preserved as chutneys or candies. Cashew apples must be fully ripe when picked or the acrid taste can cause irritation.
The cashew tree is evergreen and can live for over 100 years. The tree is large, growing to 14 meters (46 ft) in height, with a dense rounded canopy.The cashew tree is generally grown in tropical lowlands between the latitudes of 25°N and 25°S, at elevations up to 1,500 meters (4,900 ft) above sea level. Soil requirements are light, sandy, well-drained soil with a slightly acid pH between 5 and 6.5.
Choosing The Best Location and Soil
The cashew tree thrives in tropical climates with hot weather and does not tolerate freezing temperatures. It requires a minimum average temperature of 65-95°F (18-35°C).The ideal climate for cashew cultivation is coastal tropical savanna with a dry season of 3-5 months. Cashew trees can tolerate drought but cannot withstand waterlogging.
Cashew trees grow best in well-drained, sandy loam or sandy clay loam soil with a slightly acidic pH between 5 and 6.5.The soil should be deep and contain organic matter. Cashews can also be grown in lateritic soils.The site should receive plenty of sunlight, at least 6 to 8 hours of direct sun exposure per day.
Cashew trees require:
• Rainfall: 1000-2500 mm per year. The rainy season should last 3-5 months.
• Altitude: Up to 1500 m above sea level.
• Relative Humidity: 65-90%.
• Solar Radiation: 200-250 cal/cm2/day.
• Wind Speed: No more than 12 km/hour to prevent flower and leaf drop.
• Soil drainage: Well-drained, deep, sandy loam or sandy clay loam soil with a slightly acidic pH between 5 and 6.5.
• Organic matter: 2-3%
• N, P, K: 0.25, 0.1 and 0.5% respectively.
Proper site selection and soil conditions are critical to successfully growing a cashew tree. Lack of necessary climate and soil requirements will result in slow growth, poor nut set and yield. It is best to have the soil analyzed to determine any deficiencies before planting. Correcting problems before planting will get your cashew orchard off to the best start.
Planting and Caring for Your Cashew Apple
Cashew trees can be propagated from seeds, cuttings, or grafting. Seeds have a low germination rate so vegetative propagation is preferred. For cuttings, select healthy, mature wood of the current season’s growth, 10-15 cm long with multiple buds. Treat cuttings with rooting hormone and plant in well-draining rooting medium. Keep soil moist and maintain high humidity.
For grafting, the most common method is epicotyl grafting where scions (shoot tips) are grafted onto rootstocks once the rootstock develops its first true leaves. The graft union should be 10-15 cm above the soil.
Planting spacing depends on soil fertility and training system. A spacing of 8 x 8 meters up to 10 x 10 meters is common. This translates to 125 to 100 trees per hectare. Dig holes at least 60 cm deep and wide. Partially fill the hole with topsoil and compost or manure. Plant the seedling and fill the hole with the remaining soil. Water thoroughly after planting.
Pruning cashew trees to maintain tree health and shape. Remove dead or crossing branches. For the first 3 years, prune the tree to a single stem. After establishment, minimum pruning is required.
Irrigation is required only in very dry regions, especially in the first 3 years. Water deeply but do not overwater as this may cause root rot. Provide about 25-50 mm of water per week. Once established, cashew trees can tolerate some drought.
Fertilization should be based on soil analysis. A general recommendation is 50 g each of nitrogen, phosphorus and potassium (NPK) per tree in the first year, increasing to 500-1000 g NPK per mature tree. Apply fertilizer at the start of the rainy season.
Weed control, especially in the first 3 years, is important for healthy tree growth. Circle weeding around the base of the tree should be done regularly. Integrated pest management using biological control and organic pesticides can help control pests and diseases in cashew orchards.
Managing Pests and Diseases
Common pests of cashew trees include mealybugs, scale, mites, and nut borer. Mealybugs suck sap from plant tissues while scales secrete honeydew which promotes sooty mold growth. Mites feed on leaves and developing nuts. Nut borer larvae bore into nuts rotting the kernel. Control measures include:
• Conserve natural enemies such as lady beetles, parasitic wasps and lacewings.
• Prune tree canopy to increase air circulation.
• Apply lime sulfur or neem oil spray.
• Use pheromone traps for nut borer.
• Practice good orchard sanitation like removing fallen nuts to eliminate overwintering sites.
Important diseases of cashew include dieback, anthracnose, and leaf spot. Dieback causes wilting and death of new shoots and flowers due to fungal infection (Lasiodiplodia). Prune infected branches and spray copper fungicides.
Anthracnose appears as necrosis on leaves, flowers and developing nuts. It is caused by Colletotrichum gloeosporioides and managed by fungicide sprays (copper or mancozeb) and sanitation. Leaf spot results in defoliation and reduced yields. The fungus Septoria anacardii is responsible and can be managed similarly as anthracnose.
Other issues include:
• Root pathogens (Phytophthora) causing root rot. Improve soil drainage and apply phosphonate fungicides.
• Deficiency of nutrients like zinc or boron. Have soil analyzed and based on results, apply recommended fertilizers.
• Nematodes damaging roots. Nematicide application or soil solarization can help.
• Rodents feeding on nuts. Use mechanical traps, baits or netting around nut clusters.
An integrated approach combining scouting, sanitation, natural control methods and judicious use of chemicals in case of serious outbreaks will help keep damage from pests and diseases to a minimum in cashew orchards.
Harvesting and Storing Your Cashew Apples
Cashew apples mature 90-120 days after flowering. They are ready to harvest when fully ripe, red to orange in color, and with a slight softness. The apples detach easily from the tree when ripe. Pick cashew apples by gently twisting until the stem separates from the branch. Handle fruits carefully to avoid damage.
The ideal time to harvest is in the morning when it is cool. Harvested apples should be sorted to remove any damaged or diseased fruits before packing. Fresh cashew apples deteriorate quickly due to high moisture content and are very perishable. Freshly harvested apples last only 1-2 days.
Proper post-harvest handling and storage help maintain quality and extend shelf life. The key factors include:
• Temperature: Keep cashew apples in a cool shaded area after harvesting. Refrigeration at 4-8°C (39-46°F) will prolong shelf life up to 1 week.
• High humidity: >90% relative humidity. Cashew apples lose moisture quickly in low humidity causing shriveling. Use perforated plastic bags or moist cloth covering.
• Gentle handling: Avoid compression and dropping during harvest and packaging. handle gently to prevent bruising.
• Packaging: Use shallow, well-ventilated containers lined with moist cloth or sawdust. Do not stack heavy objects on top.
• Ripening treatment: For longer storage, use ripening agents like calcium carbide (0.75-1 g per kg of fruit) or ethylene (100-200 ppm) before refrigeration. This can extend life up to 2-3 weeks.
• Preservation: When fresh storage is not possible, cashew apples can be processed into products like:
› Juice: Boil and strain apples, preserve by pasteurization or canning. Lasts 6-12 months.
› Jam/chutney: High sugar or salt content preserves apples for at least 1 year.
›Dried/candied: Remove moisture to extend shelf life to 6-12 months.
› Wine/liquor: Fermentation converts apples into alcoholic drinks with a shelf life of 1-5 years.
Proper harvest and post-harvest management of cashew apples allow farmers to fully utilize this deliciously nutritious fruit. With care and processing, cashew apples need not be wasted and can be enjoyed year-round.