Orange is one of the common fruits in Kenya with popularity in all parts of the country ranking the forth most eaten fruit after banana, pineapple and mangoes. The fruit market is very much ready in open markets country wide. Oranges does well in tropics and sub-tropics, this article focuses to give the fruit production guide stepwise for beginners.
Agro ecological conditions
- Temperature – minimum 150 C to 300C and 240C to 300C optimum.
- Rainfall- does well in arid and semi-arid with moderate rainfall, 750mm to 100mm
- Soil factors- loamy, sandy loam, red, black soils free drain with pH ranging from 5.5-6.0
- Sunshine- The crop does well where its exposed for at least 6-8hrs to sun light
- Altitude –up to 2100m above sea level
Varieties
Washington naval, minneola and valencia
Land preparation
Plough the land deeply removing all weed and stumps if any. Site the orange farm near accessible road for easy fruit transportation. The field require wind breakers hence its advisable to plant trees on the side since strong winds make the flowers and budding fruits drop, this compromise quantity of production. Trees planted may include eucalyptus; mulberry-sericulture may come along this line to enhance multipurpose farming.
Planting
Transplant in the field at onset of rains. Clear the field and dig planting holes 60 x 60 x 60 cm well before the onset of rains, add well decomposed organic manure in the holes and mix with soil. Spacing varies widely, depending on elevation, rootstock and variety. Generally, trees need a wider spacing at sea level than those transplanted at higher altitudes. Usually the plant density varies from 150 to 500 trees per ha, spacing of 5m x 6 m. It is very important to ensure that seedlings are not transplanted too deep. After transplanting, the seedlings ought to be at the same height or preferably, somewhat higher than in the nursery. Under no circumstances must the graft union ever be in contact with the soil or with mulching material if used.
Watering
When watering the crop avoid water logging, actually drip irrigation is much better in order to save on water as the crop will require 1,400mm per tree yearly, it’s a hardy plant and that’s why it does well in arid and semi arid areas.
Plant nutrition
Basically, an orange plant needs Nitrogen, Potassium, Phosphate along with some Micro-nutrient such as Magnesium, Zinc, Iron, etc for good development of vegetative plant growth. Keeping orange tree full of organic manure is helpful to the orange plant in bearing healthy and delicious oranges. The table below shows yearly nutrient required in maximizing fruit production, micro-nutrients should also be integrated whenever deficiencies are spotted, this calls for prompt scouting.
| year | nitrogen | phosphorus | potassium |
| 1st year | 150 | 50 | 25 |
| 2nd year | 300 | 100 | 50 |
| 3rd year | 450 | 150 | 75 |
| 4th year | 600 | 200 | 100 |
NB: Timely application of suitable manure and fertilizer play an important role in enhancing Orange fruit production. You can make use of any best fertilizer for orange trees in your farm.
Pest management
Snails, Citrus Red Mites, Citrus Bud Mite, Brown Soft Scale, Citrus leafminer, Citrus Thrips, Orange dog Caterpillars, Mealybugs, Citrus psylla, Citrus Whitefly, Fruit fly, Blackfly, Bark eating caterpillar, Aphids etc.. are some common insect and pest, that are observed on an orange tree. The pests can be controlled using appropriate pesticide.
Disease management
Orange diseases include twig blight, collar and root rot, damping off etc observe the following to avoid diseases in orange fields:
- Use of disease-free planting material to avoid disease problems
- Choosing root stocks and cultivars that are tolerant or resistant to prevalent diseases
- Application of fungicides such as copper based fungicides as they can control several disease problems. However, it must not be forgotten that high Copper accumulations in the soil is toxic for soil microbial life and reduce the cation exchange capacity
General tree management
- Keep the trees free of weeds.
- Maintain a single stem up to a height of 80-100 cm.
- Remove all side branches / rootstock suckers.
- Pinch or break the top branch at a height of 100 cm to encourage side branching.
- Allow 3-4 scaffold branches to form the framework of the tree.
- Remove side branches including those growing inwards.
- Ensure all diseased and dead branches are removed regularly.
- Careful use of hand tools is necessary in order to avoid injuring tree trunks and roots. Such injuries may become entry points for diseases.
Harvesting
Generally, an orange plant becomes mature at the age of one year. After which they start flowering and budding, less number of fruit are obtained in the first harvesting. Usually, Depending on the types of orange cultivated, from the 4th year onward, you will be able to harvesting oranges. And an orange tree used to give fruit for about 25 yrs in an economic life. Collect those tasty and delicious oranges at three different intervals, during a year.
Post harvest physiology and handling
Fruits meant for processing should be harvested when they turn yellow entirely on their skin, those for direct market should be harvested when half green and half yellow.
Harvested fruits should be cooled to remove field heat, and then packed in fruit trays ready for marketing or processing.