Grapefruit belongs to the category of citrus. Grapefruit comes in variety of color ranging from yellow to pink and red and taste ranging from acidic to bitter and sweet to sugar. The grapefruits are the rich source of Vitamin A and C. It has also health benefits such it helps to control blood sugar level and insulin levels.

Saharanpur Special: Released by Saharanpur Botanical Garden. The fruits are round in shape, oblate, yellow in color and has smooth surface. It has medium thick rind. The fruits contain numerous seeds and the fruits ripen in November to February month.

Marsh Seedless: Released in 1968. The variety has medium to large fruits which are oblate to round in shape. The skin of fruit is light yellowish in color, fruit contains 0-6 seeds. The variety matures in December to January month which gives an average yield of 92.8kg fruit per tree.

Poorman Orange: The fruit is hardy, large, thin skinned, juicy and delicious and has sweet fruit. The skin is golden in color having orange color flesh which contains few seeds. It is used best for making marmalade and drinks.

Thompson: It is also known as pink marsh. It is an early maturing variety and grows well in Indian climate.

Foster: Released in 1968. The variety contains medium to large size fruits which are oblate in shape. The skin is pale yellow in color and flesh is pink in color. The variety ripens in November to December month and gives an average yield of 51.4kg fruit per tree.

Other state varieties:

Duncan: Fruit are medium to large in size, flat, light, yellow in color having length of 9-10cm and width of 10-11cm. The fruit has an average weight of 400-500gm having peel thickness of 0.8-0.9cm. It contains 30% juice content, 9-11% soluble content and 45-50mg Vitamin C in per 100ml juice. It gives an average yield of 24-28qtl/acre. The fruit matures in November to December month.

Ruby Red: Fruit is medium to large in size, peel is yellowish pink in color when matures. The average weight of fruit is 500-550gm per fruit. The length of fruit is 9-10cm and width is 10-11cm, the peel thickness is 0.8-0.85cm. The fruit contains 30% juicy content which contains 10-11% total soluble content and 1.2-1.4% acidic content. In 100ml juice there is 50-55mg Vitamin C content. It gives an average yield of 32-36qtl/acre which gets ready in November month.

Star Ruby: Released in 2009. They have medium sized trees, small to medium size fruits which are oblate to roundish in shape. Fruit contains soft peel which is glossy yellow in color and contains red color flesh. Fruits are mainly seedless (1-2 seeds) which are juicy and rich Vitamin C content. It is an early maturing variety which matures in end-November and gives an average yield of 53kg/tree.

Red Blush: Released in 1995. It has small to medium size fruits and are oblate in shape. The fruits are mildly acidic and high in TSS content. Mainly 0-8 seeds are found per fruit. The fruit matures in end-November and it gives an average yield of 76.5kg fruit per tree.
 

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

Spacing:
For grapefruit, use spacing of 5mx5m is recommended. Dig pit of 1mx1mx1m, kept open in sun for some days. Add 15-20kg of well decomposed cow dung, SSP@500gm per Pit.

Sowing depth:
Pits of size 60×60×60cm should be dug for planting seedlings.

Propagation:
Grapefruit can be propagated either by Seed or By Budding.

Seed Propagation:
Fruits from healthy plants with high density are selected for extracting seeds. Seeds should be mixed with ash and are left in the shade to dry. To prevent seed viability, they should be sown immediately at a distance of 3-4cm. Germination may take 3-4 weeks. Unhealthy seedlings should be removed from the field. Proper care must be taken to protect the seedlings from various diseases and insect-pests.

Budding:
Sow citrus seeds in nursery on bed of 2mx1m size and with 15cm distance between the rows. 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.

Pruning of young trees is very essential. Pruning provides them proper shape and size. Training is done to provide single stem with 6-7 branches. Lowermost branches should not be allowed to grow below the height of 50-60cm from the ground surface. Main objective of pruning is to get higher yields with good quality of fruits. Pruning also includes removal of diseased, dead and weak branches.
 

Seed rate:   
Minimum plant density of 81plants/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.

For good growth and high yield, irrigation is necessary. When new leaves start developing i.e. in February to march month, at the time of fruit development i.e. in April to July month and then in mid-September to end-October irrigation should be done. In winters, irrigation is given at the interval of 20 days and in summers, irrigation is given at the interval of 10 days.

• Pest and their control:
  

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.

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 Phosphomidon @1ml or Monocrotophos @1.5ml per 3-4 times fortnightly. Pheromone traps are also available for detecting leaf minor moths.

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, 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. Spraying of Bordeux 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 helps 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. 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.