Citrus is a group of flowering plants that include trees and shrubs. People grow them mainly for their delicious fruits, which can be eaten fresh, squeezed for juice, or used in marmalades and pickles.
These plants are not too big, usually around 5 to 15 meters tall. They have thorny branches and their green leaves stay on all year long, arranged in a pattern where each leaf comes after the other.
The flowers of citrus plants are usually found alone or in small groups. They have a lovely scent and are about 2 to 4 centimeters in diameter. The petals are white, and there are many thin stalks called stamens.
The fruits of citrus plants are famous for their wonderful smell. This fragrance comes from certain natural substances like flavonoids and limonoids, which are found in the skin of the fruit. Most citrus fruits are juicy and filled with a liquid called juice. This juice is very sour because it contains a lot of citric acid, which gives citrus fruits their distinct tangy taste.
Citrus fruits are not just tasty, they are also healthy. They are a great source of vitamin C and flavonoids. However, the amount of vitamin C in each fruit can vary depending on the type of citrus and how it was grown.
Unlike other fruit trees, citrus trees are special because they never stop growing, and their fruits don’t get better or tastier once they are picked. In fact, the longer the fruits stay on the tree, the sweeter they become.
Citrus fruits are grown all over the world.
TYPES OF CITRUS CROPS
- Sour and Sweet Oranges
The growth and production of citrus plants depend on different things about the soil they are planted in, like how well water can move through it, how much water it can hold, and how deep it is. These things can be different depending on the type of soil.
Citrus plants can grow in many different types of soil. However, for the best results, they should be planted in soil that drains well, is rich in nutrients, has good air circulation, and has a pH level between 6 and 6.5.
Citrus trees need lots of sunlight and protection from strong winds. They also cannot survive in places where the temperature drops below freezing for long periods of time.
They can handle hot temperatures as long as they have enough water in the soil.
PLANTING AND CULTURAL PRACTICES
Citrus trees can be grown by grafting or budding. The most commonly used method is grafting.
Grafting involves joining the top part of one tree, called the scion, with the roots of another tree, called the rootstock. To start this process, new citrus trees are propagated by planting seeds for the rootstocks.
Here is a step-by-step procedure for planting citrus trees:
1. Prepare the land by using a non-selective herbicide called CLAMPDOWN 480SL 200ml/20l. This herbicide helps to kill all types of weeds and makes land preparation easier and more effective.
2. Dig planting holes that are about 0.5 x 0.5 x 0.5 meters in size.
3. Fill the holes with a mixture of topsoil, manure, and DAP (a type of fertilizer). To enhance nutrient absorption and stimulate growth, it is recommended to add HUMIPOWER to the mixture. Use 1 ton of manure, 50 kilograms of fertilizer, and 1 kilogram of Humipower per hole.
4. Water the holes unless the soil is already moist enough.
5. Plant the grafts in the holes at the same depth they were in the nursery. The bud union, which is the joint between the scion and rootstock, should be about 300 millimeters above the ground.
6. Determine the spacing between the trees based on their size. Standard-sized citrus trees should be spaced 12-25 feet apart, while dwarf citrus trees should be set 6-10 feet apart. The exact distance may vary depending on the variety, with larger fruits requiring more space.
7. Citrus trees need regular irrigation as rainfall is often uneven and insufficient. Supplemental watering is necessary to prevent moisture stress from affecting growth and production. Newly planted grafts should be watered daily until they establish.
8. Regular pruning is important to remove dead wood and prevent overcrowding of trees. Pruning becomes necessary when the trees grow too big and start intertwining with each other.
9. Remove branches that touch the ground, as they can hinder fruit removal, irrigation, and attract ants to the trees.
10. Keep the area under the tree canopy free from weeds. Weeds compete with the citrus trees for nutrients and water and can harbor harmful pathogens.
Remember, CLAMPDOWN 480SL 200ml/20l is a non-selective herbicide that effectively controls all types of weeds in the garden.
PESTS AND DISEASE CONTROL
The false coddling moth is a type of caterpillar that burrows into the fruit’s skin, leaving a discolored mark where it enters. Inside the fruit, it feeds on the pulp, causing the fruit to ripen prematurely and fall from the tree. Young larvae stay on the outer part of the fruit, while older ones move deeper inside. They prefer the navel end of citrus but can burrow anywhere, leaving excrement around the entry points.
To control false coddling moth, you can spray either KINGCODE ELITE 50EC (10ml per 20 liters of water), LEGACY 50EC (15ml per 20 liters of water), or SINOPHATE 750SP (20g per 20 liters of water).
Aphids are small insects that reproduce quickly and can cause significant damage to citrus trees during the growing season. They attack the tree by sucking the sap from the leaves. Signs of aphid infestation include puckered marks, yellowing, and twisted leaves, giving them a deformed appearance. As the infestation worsens, leaf drop and dieback of twigs and branches can occur. Aphids excrete honeydew, which attracts ants and promotes the growth of sooty molds.
To control aphids, you can spray either KINGCODE ELITE 50EC (10ml per 20 liters of water), LEXUS 247SC (8ml per 20 liters of water), or PRESENTO 200SP (5g per 20 liters of water).
The orange dog caterpillar is a large brown caterpillar that feeds on citrus tree leaves and can quickly defoliate an entire tree within a few days.
To control the orange dog caterpillar, you can spray either KINGCODE ELITE 50EC (10ml per 20 liters of water), BACIGUARD 16WDG (15g per 20 liters of water), or SINOPHATE 750SP (20g per 20 liters of water).
Citrus whiteflies are tiny white-winged insects that often feed on the underside of citrus tree leaves. When disturbed, they flutter around the tree. They suck the sap from the leaves, causing them to curl and become deformed. Whiteflies excrete honeydew, which attracts ants and encourages the growth of sooty mold.
To control citrus whiteflies, you can spray either TAURUS 500SP (10g per 20 liters of water), LEXUS 247SC (8ml per 20 liters of water), or PRESENTO 200SP (5g per 20 liters of water).
Fruit flies deposit their eggs under the skin of mature and ripening fruit. The hatched maggots feed on the fruit’s flesh, causing it to rot and potentially fall from the tree.
To control fruit flies, you can spray either PENTAGON 50EC (10ml per 20 liters of water) or LEXUS 247SC (8ml per 20 liters of water).
Citrus leafminer larvae feed on young foliage within the leaves, creating distinctive silvery tunnels or mines. Heavy infestations can lead to defoliation.
To control citrus leafminer, you can spray either ALONZE 50EC (5ml per 20 liters of water), SINOPHATE 750SP (20g per 20 liters of water), or AMAZING TOP 100WDG (5g per 20 liters of water).
Brown soft scale insects attach themselves to the wood, foliage, and sometimes the fruit of citrus trees. They suck sap from the tree, causing leaves to yellow and drop. The presence of brown soft scale insects is often mistaken for natural tree growth.
To control brown soft scale, you can spray either LOYALTY 700WDG (5g per 20 liters of water), EMERALD 200SL (10ml per 20 liters of water), or LEXUS 247SC (8ml per 20 liters of water).
Citrus thrips are tiny orange or pale yellow insects that mainly attack young leaves and juvenile fruit. They feed on the tree’s sap, resulting in shriveled leaf buds, curled and distorted leaves, and scabbed or streaked fruit.
To control citrus thrips, you can spray either ALONZE 50EC (5ml per 20 liters of water), PROFILE 440EC (30ml per 20 liters of water), or DEFENDER 25EC (40ml per 20 liters of water).
Citrus bud mites are very small mites that hide in flower and axillary buds. They cause abnormal growth in leaves, flowers, and fruit, leading to reduced tree growth and yield.
To control citrus bud mites, you can spray either ALONZE 50EC (5ml per 20 liters of water) or BAZOOKA 18EC (10ml per 20 liters of water).
Citrus canker is a highly contagious bacterial infection that affects citrus trees. It causes yellow halo-like lesions or scabs on the fruit, leaves, and twigs of the trees. Severe infections can lead to leaf loss, blemished fruit, fruit drop, and die back.
The canker bacterium spreads easily through air currents, insects, birds, and even humans via clothing and infected tools.
To combat citrus canker, you can use Copper-based fungicides such as GREENCOP 500WP, TRINITY GOLD 425WP, or COLONIZER 440WP. These fungicides help suppress and prevent bacterial infections.
Sooty mold is a fungus that blackens the leaves and fruits of citrus trees. It occurs due to honeydew secretions from insects like whiteflies, aphids, and mealybugs. The best way to prevent this disease is by controlling the insects.
If you want to cleanse the sooty mold, you can spray JAMBO CLEAN on the affected areas.
Greasy spot is a fungal disease that affects citruses. It shows yellowish-brown blister spots on the leaves, usually on the underside. As the disease progresses, the spots turn oily and can cause significant leaf loss. Grapefruit rinds are particularly vulnerable to infestation.
To treat greasy spot, you can spray ABSOLUTE 375SC, RANSOM 600WP, or EXEMPO CURVE 250SC.
Anthracnose is an infection that causes twig dieback, premature leaf drop, and dark staining on the fruit. It spreads through dark fungal spores. The infected parts develop brown to black sunken lesions.
To combat anthracnose, you can use RANSOM 600WP, DUCASSE 250EC, or EXEMPO CURVE 250SC.
Bacterial blast starts as black lesions in the leaf petiole and progresses into leaf axils. It causes leaf blades to curl, dry, and drop prematurely. When the twig lesion girdles the stem, twig and branch dieback can occur.
To prevent bacterial blast, you can spray Copper-based fungicides like GREENCOP 500WP, COLONIZER 440WP, or TRINITY GOLD 425WP.
Root Rot/Brown Rot/Collar rot is a tree disease caused by a soil-inhabiting fungus. It shows dark brownish patches of hardened bark on the trunk, often with seepage. The bark eventually dries, cracks, and dies, leaving a dark sunken canker. It can also cause browning and decay on the fruit, as well as yellowing and die-back on the foliage due to splashing by rain or irrigation.
To treat Root Rot/Brown Rot/Collar rot, you can drench the soil with GEARLOCK TURBO 250WP, PYRAMID 700WP, or CHANCETYL ELITE 800WDG.
Citrus greening is caused by a bacterium spread by aphid-like psyllids. It results in yellowing in one section of a tree, stunted growth, leaf and fruit drop, twig dieback, and small, bitter-tasting fruits.
To combat citrus greening, you can use Copper-based fungicides like GREENCOP 500WP, COLONIZER 440WP, or TRINITY GOLD 425WP.
Powdery mildew is characterized by white powdery spores on the upper leaf surface, causing the leaves to turn pale whitish to grey-green. Severe infection leads to defoliation, withering of young shoots, diebacks, and premature fruit fall.
To treat powdery mildew, you can spray RANSOM 600WP, DOMAIN 250EC, or DUCASSE 250EC.
Citrus gummosis occurs when fungal spores splash onto the trunk and infect the bark. It leads to the death of bark tissue and can cause tree decline. Infected trees produce amber-colored gum as a defense mechanism. Prevention is key to controlling this disease, and systemic fungicides like GEARLOCK TURBO 250WP, CHANCETYL ELITE 800WDG, TRINITY GOLD 425WP, or COLONIZER 440WP can be used.
Please note that it’s important to follow the recommended instructions and dosages when using any fungicides or treatments for citrus diseases.
NUTRITION & NUTRITIONAL DEFICIENCIES
To ensure the plants remain healthy and produce well, it’s important to provide them with an adequate supply of nutrients, both macro and micronutrients.
Macronutrients are nutrients that plants need in relatively large amounts.
To supply nutrients effectively, it is recommended to apply both basal and foliar fertilizers.
Basal fertilizers, like DAP, CAN, NPK, and UREA, are absorbed by the plants through the roots. Mixing them with HUMIPOWER at a ratio of 50:1 improves nutrient uptake and stimulates growth.
Foliar fertilizers, such as OPTIMIZER, DIMIPHITE, ZINC GOLD, LAVENDER, GOLDCHANCE RANGE, LEGENDARY, PORTEGE GOLD, and VITABOR GOLD, are absorbed through the foliage. They provide both macro and micronutrients and help prevent nutrient deficiencies.
Nutrient deficiencies can cause various issues in plants, such as twig die-back, yellowing, reduced growth, and abnormal fruit characteristics.
Nitrogen deficiency results in light green to yellow foliage throughout the tree. Phosphorus deficiency leads to yellowing of older leaves and can affect fruit quality. Potassium deficiency causes pale yellow leaf margins and smaller fruits. Zinc deficiency shows as yellow blotches between green veins on leaves.
Copper deficiency causes dark green leaves on angular shoots and twig die-back. Iron deficiency results in yellowing of interveinal areas and eventual canopy dieback. Boron deficiency affects the growing points of the tree and can cause misshapen fruit with dark spots.
To correct these deficiencies, you can use specific products like GOLDCHANCE SUPER GROWTH, LAVENDER, LEGENDARY, DIMIPHITE, GREENPHITE, ZINC GOLD, BIO DISTINCTION, COLISEUM, PORTEGE GOLD FE 6%, EURO GOLD PLUS, MICRO GOLD 11% DTPA, or VITABOR GOLD.
When applying foliar sprays, it’s advisable to mix the product with INTEGRA at a rate of 3ml/20l. This improves the efficacy of the product.
To prevent resistance build-up, it’s recommended to alternate the use of different chemicals, especially for fungicides and insecticides, throughout the crop’s season.
Timely application of fertilizers, insecticides, fungicides, and herbicides is crucial.
When harvesting citrus fruits, it’s important to wait until they are mature. Ripening occurs after the fruit is mature, and it involves starches converting to sugars, a decrease in acids, and changes in color and texture.
Harvest the fruits by cutting them off with pruning shears or by pulling the fruit stalk from the tree. Fruits do not increase in sweetness or continue to ripen once they are separated from the tree.
The color of the fruit is not always an accurate indicator of ripeness. Taste is the best indicator of ripeness.
Harvested fruits can be stored for several weeks at cool temperatures.
Remember to follow the recommended instructions and guidelines for each product and practice proper crop management for optimal results.