A-Z on Sweet Orange Farming
The orange (specifically, the sweet orange) is the fruit of the citrus species Citrus sinensis in the family Rutaceae. The fruit of the Citrus sinensis is considered a sweet orange, whereas the fruit of the Citrus × aurantium is considered a bitter orange. The sweet orange reproduces asexually (apomixis through nucellar embryony); varieties of sweet orange arise through mutations.
The fruit of the orange tree can be eaten fresh, or processed for its juice or fragrant peel. As of 2012, sweet oranges accounted for approximately 70% of citrus production. In 2013, 71.4 million metric tons of oranges were grown worldwide, production being highest in Brazil and the U.S. states of Florida and California.
Introduction to Sweet Orange Plantations in Kenya
The Orange is one of the top citrus fruits being grown in most of the countries after banana and passion.
This fruit is rich in vitamins like C, A, B and phosphorus. Oranges can be consumed fresh or in the form of juice, squash, syrup and jam. Oranges are main source of peel oil, citric acid and cosmetics. These orange products have an excellent value in the international and local market.
The most common sweet orange variety is called the “Valencia” orange.
Commercial cultivation of sweet oranges is very much successful and profitable when proper cultivation practices are followed. Pest and disease management is very important in orange cultivation as these plants are more prone to different pests and diseases.
Health Benefits of Orange:- The following are some of the health benefits of oranges.
- Oranges are good source of vitamin ‘C’.
- Oranges reduce the risk of liver cancer.
- Oranges help in relieving constipation.
- Oranges promote healthy body tissues.
- Oranges are good for bone and teeth health.
- Oranges boost immune health.
- Oranges are good for digestion.
- Oranges help in fighting against infections.
- Oranges are good for kidney health.
Climate Requirements for Sweet Orange Farming
Oranges can be grown both in tropical and sub-tropical climatic conditions up to 1,500 meter(above m.s.l.). However, dry climate with a soil temperature around 25 °C would be optimum for plant root growth. When it comes to best crop growth, dry and arid conditions coupled with well defined low rainfall ranging from 75 cm to 250 cm are most favourable conditions. Sweet Orange crop is very sensitive to frost conditions and high humid conditions caused to spread many diseases. The other risk involved in the sweet orange cultivation is, during hot months, hot winds causes the crop to shed the flowers and young fruits. For achieving good yield of the crop, it is necessary to maintain good temperatures throughout its growth period.
Soil Requirements on Sweet Orange Farming
Sweet Oranges can be grown in wide variety of soils such as alluvial, sandy loam to loam, red sand soils to black clayey soils.. However, soil properties like soil reaction, soil fertility, drainage, free lime and salt concentrations are some important factors of soil to be used for sweet orange cultivation. Deep and well-drained light loamy soils are the best for sweet orange plantation. Soil pH of 6.0 to 7.5 is the best for orange cultivation. If the crop is planned on large scale or commercial line, one should consider going for soil testing to find out the suitability and fertility of the soil.
Selection of Site and Land Preparation
Site selection and land preparation is very important in sweet orange cultivation. When this crop is grown commercially, make sure the site is closer to markets and has transport facility. As the flower and fruit drops are common during hot months due to hot winds, it is advised to provide windbreaks on the sides from which heavy winds are possible. One can go for growing eucalyptus and Mulberry trees for windbreaks.
When it comes to land preparation, using tractor, land should be cross ploughed and levelled by crushing any clods. Make sure all the weeds from previous crops are removed.
Propagation, Planting and Spacing on Sweet Orange Farming
Sweet Orange trees are propagated by seeds and vegetatively propagated by T-budding. However, Budded plants are the best planting materials for quick growth and high yielding. When it comes to planting Pits size of 75 cm x 75 cm x 75 cm at 7 meter x 7 meter spacing should be dug and filled the pits with top soil and 10 kg of well decomposed farmyard manure (FYM). Budded plants should be placed in the center of the pits and staked.
For high density planting, spacing would be less. Usually for closed spacing accommodating 150 plants per 1 acre has been considered. Irrigation should be carried out immediately after transplanting the material in the field.
Irrigation is critical step in sweet orange cultivation as usually citrus trees require more water when compared to other fruit crops due to recurrent growth and development. Irrigation depends on factors like soil type, climatic conditions and age of plants.
Sweet Orange plants are sensitive to water stagnation; hence water logging the tree trunk should be avoided. Irrigate the sweet orange orchard after transplanting. A grown-up sweet orange tree requires about 20-25 irrigations in a year, amounting about 1,400 mm of water. It is recommended to go for drip irrigation as it has many advantages. The advantages of drip irrigation system are as given below.
- Irrigation or amount of water is controlled and can be supplied as per requirement.
- Drip irrigation makes the water to be applied at the plant root system.
- As systematic watering, this improves plant growth and quality and yield of the crop.
- Water wastage is reduced about 60% when compared to flood irrigation.
- As water is supplied at root system, fertilizers applied at roots are used very efficiently.
- This reduces the soil erosion and nutrients when compared to flood irrigation.
- Land levelling work is minimized so the labour requirement.
- Drip irrigation helps in reducing weeds, pests and diseases.
- Crops can be grown any time with drip irrigation.
Manures and Fertilizers
Sweet Orange trees respond very well to manures and fertilizers, applying these nutrients at right stages will result in high yields.
Carrying regular intercultural operations play important role in higher crop yield. As part of this, weed growth should be controlled by mulching. Regular ploughing between tree rows for removing grass weeds. Spading of tree basins should be carried for proper soil aeration and fertilizers absorption. Chemical weedicides are also effective in controlling weeds.
Mulching is another important task for soil moisture conservation and erosion control. Apart from this, mulching also helps in controlling weed growth and turning into organic matter. This also reduces the number of irrigation by preventing water evaporation. Mulch material like dry leaves with thickness of 7 to 8 inch can be used in tree basins.
Orange growers can earn some extra income by opting for intercropping. Legumes and any vegetable crops can be grown as inter crops during pre-bearing stage (During Initial 3 year period). However, make sure the inter crops don’t compete with nutrients provided for orange trees. When growing inter crops, it may need extra care, manures, irrigation along with orange orchard maintenance.
Training and Pruning
Training and pruning task is very important and this directly impacts the fruit quality and crop yield. The trees are trained to a single system and any shoot emerging from the portion below the bud union should be nipped off regularly. In order to allow the growth of a strong trunk, all shoots in the first 50- 60 cm from ground level developed in the early stage should be removed. The centre of the plant should remain open. Branches should be well distributed to all sides. Cross twigs and water suckers are to be removed early. The bearing trees require little or no pruning. All diseased, injured and drooping branches and dead wood are to be removed periodically for initiating citrus greening. Training of plants should be completed in first three years so that plants attain a mechanically strong canopy.
Pests and Diseases of Sweet Orange
Controlling pests and diseases in orange orchard is very important throughout its growth period.
Pests Found in Orange Cultivation: The main pests found in orange cultivation are black fly, citrus psylla, citrus leaf miner, bark eating caterpillar, mealy bugs, citrus aphids, citrus thrips, fruit fly and mites. These pests cause to produce poor quality fruits and results in low crop yield. Spraying with insecticides like monocrotophos, phosalone, dimethoate, phosphamidon, and quinalphos depending upon the type of pest infestation has been found to be effective in most cases of these pests.
Diseases Found in Orange Cultivation: The main diseases found in orange cultivation are twig blight, gummosis, damping off, root and collar rot. The affected plants should be sprayed with Ridomil MZ 72, Bavistin, Benomyl etc. depending on the type of infection.
Note: Contact your local agronomist for pests and disease symptoms and their control. They are the best source for pest control solutions in sweet orange production.
Harvesting Sweet Orange
Sweet Orange crop yield starts from 4th or 5th year the grafted variety tends to mature around 2-3years. Fruits should be harvested when they are fully ripe and attain proper size, attractive colour and acceptable sugar: acid ratio. Mature fruits can be picked in 2 to 3 cycles.
Sweet Orange Crop Yields
Yield of sweet orange crop depends on many factors like soil type, climatic conditions and orchard management practices. On an average 25 to 30 tonnes/ha can be obtained. When it comes to yield by individual tree, from fourth or fifth year, 50 to 80 fruits per tree can be expected and the crop stabilizes in the 8th year. Average yield for each tree is about 450 to 500 fruits after stabilization.
Marketing of Sweet Oranges
Sweet Orange fruits keep well for a long time under ambient conditions and hence can be transported to long distances for marketing. Sweet Oranges can be transported to local markets or fruit suppliers can also buy in bulk at the farm. For commercial marketing, contact any fruit processing units or export agents. Market value of sweet oranges depends on the season, quality of fruit. The price of sweet oranges varies from season to season.