SWEET ORANGE (MALTA)

Malta is citrus fruit grown in India. It is commonly called as sangtra. It occupies nearly 30% of total area under citrus cultivation. Mandarin, Sweet Orange is commercially grown citrus species in India. Production of Mandarin orange is increasing every year in central and western parts of country. India ranks third in the production of orange after banana and mango fruits. In India, Orange is being grown in Rajasthan, Himachal Pradesh, Punjab and Uttar Pradesh.

It can be grown on wide variety of soils. Medium-Light Loam soils with pH of 6.0-8.0 are suitable for its best growth.

Jaffa: Tree has a similar shape to pineapple tree. Bigger sized fruits, round in shape with yellowish orange skin color. 9-12 seeds are present in single fruit. Fruit ripens in the month of December. The average fruit yield is 54 kg per plant.

Blood Red: Trees are larger in size than Jaffa. Fruits are medium-sized. Deep orange color Fruits at Maturity. Red color Flesh with 1-2% acidity.9-12 seeds is present per fruit. Juice color is Reddish. The average fruit yield is 43 kg per plant.

Valencia Late: Vigorous, Heavy Bearer Trees with Medium size fruits. Fruits are oval shaped. At ripening the color of skin turns to golden yellow. Fruit ripens late up to the month of February. 2-7 Seeds are present per fruit. The average fruit yield is 40 kg per plant.

Hamlin: Medium to long size fruits, slightly egg shaped, smooth clear skin, top is round, flesh is deep orange color, juicy, best in taste, fruit contains 1-5 seeds, ripens in mid-November.

Other state varieties:

Mousambi: Trees are medium in size. Fruits are medium in size. Juice is totally acid less with 10% TSS. Fruit ripens in the month of November. 20-25 Fruits are present per fruit. The average fruit yield is 40 kg per plant.

Pineapple: Trees are medium in size having spreading habit. Medium-size and Juicy Fruits. 10-20 Seeds are present per fruit. Fruit Ripens in the months of December-January. The average fruit yield is 38 kg per plant.
 

Land need to be prepare properly for growing seedlings. Land should be ploughed, Cross ploughed and leveled. Terrace planting is done on hills. High density planting is possible in hilly areas.

Time of Sowing
Sowing is done in June-July month and February to March month.

Spacing
For sweet oranges use spacing of 8m x 8m is recommended.

Sowing Depth
Depth of 1feet is used for planting.  

Method Of Sowing

Propagation
Root stock raising: Sow citrus seeds in nursery on bed of 2mx1m size and with 15cm distance between the row. When seedlings are of 10-12cm height, transplanting is to be done. Select healthy and uniform size seedling for transplantation purpose. Remove dwarf and weak seedlings. If needed, pruned roots slightly before planting. In nursery, Budding is done when plant are of pencil thickness. Shield budding or T shape budding is done for that, T shaped slot is made in bark of tree at distance of 15-20cm from ground. Horizontal cut of about 1.5-2cm long is given, and vertical cut of 2.5cm long is made from middle of horizontal cut. Remove bud from bud stick and insert it into T shape slots, afterward wrapped it with plastic paper.  

T budding is done during February-March and also in August- September. Propagation in sweet orange, kinnow, grape fruit is done by T budding while for lime and Lemon, it is propagated by Air layering method.
 

For proper growth of trunk of plant, Shoots in 50-60cm near ground level should be removed. Centre of plant should remain open. Water suckers should be removed at early stages of growth.

Seed Rate
Minimum plant density of 208 plant/acre should be maintained.
 

Fertilizer Requirement (gm/tree)

Application of Urea@50gm/tree, SSP@50gm/tree and MOP@50gm/tree should be given per year. Along with these, use of zinc sulphate should be done in April, June and September month. Half dose of nitrogen and potash is given in February-March month and rest of the dose is given in the June-July month. Complete dose of phosphorus is given in spring season before 20 days of plant growth.

Sangtra require irrigation at regular intervals. Lifesaving irrigation should be given in winters and summers. Irrigation is necessary for Flowering, Fruiting and proper plant growth. Over irrigation may also lead to diseases like Root rot and collar rot. High frequency irrigation is beneficial. Salty water is injurious for crop plants. Partial drying out of soil in spring may not affect plants.

• Pest and their control:
  

Leaf miner: Larvae inside the upper or lower surface of young and newly emerged leaves are curled and look distorted. Young trees show a reduction in growth due to leaf miner. Best management for leaf miner is to leave it alone and let the natural enemies to feed upon them and parasitize their larvae. It can also be controlled by spraying Phosphamidon  @1ml or Monocrotophos @1.5ml per 3-4 times fortnightly. Pheromone traps are also available for detecting leaf minor moths.

Citrus Psylla: These are Juice sucking pests. Damage is mainly caused by Nymphs. It injects a plant toxin liquid which burns foliage and skin of fruit. Leaves curl and fall off prematurely. It can be controlled by pruning of diseased plants, burning them. Spraying of Monocrotophos-0.025% or carbaryl- 0.1% can also be helpful.

Scale Insects: Citrus scale insects are small insects that suck sap from the citrus trees and fruits. Honeydew is produced which is feasted upon by ants. They do not have much mouth parts. Male citrus scale has a short life span. There are mainly two types of scale on citrus plants armored scale and soft scales.  Armored scale insects insert their mouth parts in the plant and never move again, eating and reproducing in the same spot. Soft scale bugs on citrus form a protective coating, which in turns cover citrus leaves and prevents photosynthesis. Once dead and soft scale will fall from tree instead of remaining stuck, they can be controlled with the introduction of indigenous parasitic wasps. Neem oil is also effective against them. Spraying of Parathion (0.03%) emulsion, dimethoate 150ml or malathion @0.1% are effective against scale control.

Aphids & Mealy Bugs: They are small sap sucking pests. Bugs are present on the underside of leaves. Synthetic pyrethroids or pest oil can be used to control aphids and bugs.

• Disease and their control:
  

Citrus Canker: Plants have lesions on stems, leaves and fruits with brown, water-soaked margins. Citrus canker bacteria can enter through plant’s stomata into the leaves. Younger leaves are highly susceptible. Lesions oozes bacterial cells which can be dispersed by blowing wind to healthy plants in area.

Contaminated equipment tends to spread disease to healthy plants. Bacteria can stay viable in old lesions for several months. It can be detected by appearance of lesions. It can be controlled by cutting of effected branches, twigs by spraying of Bordeaux mixture @1%. Aqueous solution of 550ppm, Streptomycin Sulphate is also helpful in controlling citrus canker.

Gummosis: Exudation of gum from bark of tree is the characteristic symptom of gummosis disease. Affected plant leaves turns to pale yellow in color. Hardness masses of gum are common on stem and leaf surfaces. In severe cases, bark may be destroyed by rotting and tree may dies. Plant dies before the fruit matures. This disease is also called foot rot. This disease can be managed through proper selection of site with proper drainage, use of resistant varieties etc. Plant injuries should be avoided. Drench the soil with 0.2% metalaxyl MZ-72 + 0.5% trichoderma viride, which help to control this disease. Bordeaux mixture should be applied to plant upto 50-75 cm height from ground level at least once in a year.

 

Powdery mildew: White cottony powdery growth is noticed on all aerial plant parts. Leaves tend to become pale yellow and crinkle. Distorted margins are also seen. Upper surface of leaves are more affected. Young fruits drop off prematurely. Yield is reduced significantly.  To control powdery mildew, affected plant parts should be removed and destroyed completely. Carbendazim, three times at 20-22 days of interval helps to control this disease.

Black Spot: Black spot is a fungal disease. Circular, dark spots on fruits are seen. Copper spray in early spring should be sprayed on foliage helps to cure plants from black spots. It should be repeated in 6 weeks again.

Zinc Deficiency: It is very common in citrus trees. It is notified as yellow areas between main lateral veins and midrib of the leaves. Twigs may die back, dense shoots having stunted bushy appearance is commonly seen. Fruits tend to become pale, elongated and small in size. Proper fertilizer application should be given to the citrus tree to prevent zinc deficiency. Zinc sulphate should be provided by dissolving 2 table spoons in 10 liters of water. This should be sprayed thoroughly on all the tree branches and foliage. It can also be cured by providing cow or sheep manure.

Iron deficiency: Color of new leaves changes to yellowish green. Iron chelates should be provided to the plants. Cow or Sheep manure is also helpful to cure plants from iron deficiency. This deficiency mostly occurs in case of alkaline soils.

On attaining proper size, shape along with attractive color having TSS to Acid ratio of 12:1, kinnow fruits is ready for harvest. Depending upon variety fruits are generally ready for harvesting in Mid- January to Mid- February. Do harvesting at proper time as too early or too late harvesting will give poor quality.

After harvesting, wash fruits with clean water then dip fruits in Chlorinated water@2.5ml per Liter water and then partially dried them. To improve appearance along with to maintain good quality, do Citrashine wax coating along with foam. Then these fruits are dried under shade and then packing is done. Fruits are packed in boxes.