Psidium guajava L.
Psidium guajava L. is an evergreen fruit tree of the Myrtaceae family, which is native to Central and South America. It is commonly known as guava, bayabas, kuawa, or guayabo, among other names, and is widely cultivated throughout the tropical and subtropical regions of the world.
Appearance
The guava tree can reach up to 10 meters in height and has a shallow root system. Its leaves are oval-shaped, leathery, and glossy, measuring up to 15 cm in length. The tree has a smooth, mottled bark that ranges in color from green to reddish-brown.
Its flowers are white or pink, and its fruit is a round or oval berry that can range in size from small to large, depending on the cultivar. Its skin is thin, and the pulp can be white, pink, or yellow, with numerous small, hard seeds.
Uses
The guava fruit has a sweet and tangy taste and is used in various culinary preparations, such as desserts, jams, jellies, and beverages. Its leaves and bark have medicinal properties and are used to treat various ailments, such as diarrhea, dysentery, and respiratory infections.
The guava tree is also used for its wood, which is durable and resistant to decay, and as an ornamental plant in gardens and parks.
In addition, guava is rich in vitamins A and C, dietary fiber, and antioxidants, making it a nutritious fruit that promotes overall health.
Light requirements
Psidium guajava L. prefers full sun or partial shade. It grows well in areas with bright and direct sunlight. The plant can tolerate shade, but it may not flower and fruit as abundantly as those growing in full sun.
Temperature requirements
Psidium guajava L. is a tropical plant that grows best in warm and humid conditions. The optimal temperature range for growth is between 20 and 32°C. Temperatures below 10°C can cause damage to the plant, and frost can cause it to die.
Soil requirements
The plant prefers well-draining soils that are rich in organic matter. The ideal soil pH range for Psidium guajava L. is between 5.5 and 7. The plant can also tolerate slightly acidic or alkaline soils. The soil should be moist but not waterlogged, as it can cause root rot.
Cultivation Methods
Psidium guajava, commonly known as guava, grows well in tropical and subtropical regions. The plant prefers well-draining soils of average fertility and full sun exposure. It can adapt to different soil types, ranging from sandy soils to heavy loams, but it thrives well in loamy soils with a pH range of 4.5 to 7.0.
Propagation is through seeds or vegetative means such as cuttings, air-layering, or grafting. Seeds germinate within three weeks and are transplanted into individual containers after they develop two to four true leaves. Alternatively, use cuttings from healthy, mature stems and remove all but the top 3-4 leaves. Cleanly cut the stem and dip the end in rooting hormone. Plant in damp soil and cover with a plastic bag to maintain humidity.
Spacing for guava plants depends on the variety and environmental conditions. In ideal conditions, spacing of 3-8 meters between plants and 4-13 meters between rows is recommended.
Watering Needs
Guava plants require regular and consistent moisture to produce high-quality fruits. In areas with consistent rainfall, irrigation may be unnecessary, but supplementary watering may be necessary in drier areas, particularly during fruiting.
Apply water to wet the soil to a depth of 30 cm. Frequency of irrigation depends on soil type, temperature, and plant growth stage. Inadequate water may cause poor fruit quality, while excessive water may lead to root rot and reduced yield.
Fertilization
While guava grows well in a range of soils, regular fertilization is essential as it removes nutrients from the soil. A soil test will indicate nutrient deficiencies and acidity. Guavas require a balanced fertilizer with an N:P:K ratio of 6:6:36. Apply fertilizer at the rate of 200-250 g/plant/year in split doses during the growing period.
Guava plants also require micronutrients such as zinc, iron, and manganese. Foliar application of micronutrients may help prevent deficiencies and enhance crop yield and quality.
Pruning
Pruning guava plants is essential for the removal of dead or diseased branches, promote air circulation and sunlight penetration for improved fruit quality. Pruning is best done after harvesting fruit.
Remove suckers from the base of the plant regularly. Suckers may produce lower quality fruit or may serve as hosts of pests and diseases. In mature guava plants, remove branches that are more than four years old, weak, or crossing each other.
Prune the tree to a central leader system, which involves maintaining one upright central stem and removing competing leaders.
Propagation of Psidium guajava L.
Psidium guajava L. can be propagated through several methods including:
Seed propagation
Seeds are the most common method of plant propagation. The seeds should be collected from ripe fruits and washed in running water. These seeds can be sown directly in potting soil or in sand beds, germinating within 2-3 weeks. However, seed-grown plants may not have the same characteristics and qualities as their parent plants.
Cuttings
Cuttings are another method for propagating Psidium guajava L. They should be taken from 4-6 month-old semi-hardened wood that is free of diseases and pests. Cuttings measuring about 15-20 centimeters in length should be taken with 2-3 nodes. These cuttings should then be treated with plant growth hormones before planting in potting soil.
Air layering
Air layering is another method for propagating Psidium guajava L. It involves creating a slit in the stem and inserting a mixture of peat moss and sand. After the roots have developed, the plant can be cut from the mother plant and potted in potting soil.
Grafting
Grafting is a more complex method of propagation where a scion from the desired plant is grafted onto a rootstock from a different plant. This method is usually reserved for specific cultivars that possess desirable traits and characteristics.
Disease and Pest Management for Psidium guajava L. Plants
Psidium guajava L., also known as guava, is a fruit-producing plant that can be affected by various diseases and pests. Here are some of the most common ones:
Diseases
Anthracnose: This fungal disease affects the leaves, twigs, flowers, and fruits of guava plants. Symptoms include black spots with yellow halos that eventually turn brown and grow in size, leading to fruit rot. Anthracnose can be managed by removing infected plant parts and using fungicides such as copper-based solutions or chlorothalonil.
Fusarium Wilt: This soil-borne disease is caused by a fungus that affects the roots of guava plants. Symptoms include yellowing and wilting leaves, slower growth, and eventually plant death. Fusarium wilt can be prevented by avoiding contaminated soil and disinfecting tools and equipment. Infected plants should be removed to prevent further spread of the disease.
Powdery Mildew: This fungal disease affects the leaves of guava plants, causing a powdery white coating on the surface. It can be managed by improving air circulation, reducing humidity, and using fungicides such as neem oil or potassium bicarbonate.
Pests
Fruit Flies: These insects lay eggs on the surface of the fruit, which hatch into larvae that feed on the flesh. To manage fruit flies, harvest ripe fruit as soon as possible, apply sticky traps near the plants, and use insecticides approved for use on fruits.
Scale Insects: These pests attach themselves to the stems and leaves of guava plants, sucking sap and weakening the plant. They can be managed by removing them with a soft brush or cloth and using insecticides such as horticultural oil.
Aphids: These small insects feed on the sap of guava plants, causing leaves to curl and distort. They can be managed by using insecticidal soap or neem oil, and by introducing natural predators such as ladybugs or lacewings.
By following these management techniques, guava plants can be protected from diseases and pests, leading to a healthy and fruitful harvest.
