Cotton is originated in India.
It is popularly known as WHITE GOLD.
It is Backbone of textile industry.
About 45% of the world fibre and 10-25% of the edible oil is met by cotton.
BT cotton is effective against Bollworm pest complex of cotton.
THERE ARE 2 TYPES OF COTTON BASED ON BRANCHING
These are popularly known as Vegetative branches( Auxiliary buds).
These are known as Reproductive branches.
CLASSIFICATION OF COTTON
There are 4 cultivated species of Cotton out of 20 species. They are as follows.
1. Gossypium arborium
2n= 26, and is Diploid in nature.
About 16% of the area in India is covered by this variety.
Varieties: Lohit, Virnar, K9, K10, K11.
2. Gossypium herbaceum
2n=26, and is also diploid in nature.
Both of these species are called as Desi cotton/ Asiatic cotton.
About 8% of the area is covered by this variety.
Varieties: Digvijaya, Sanjay.
3. Gossypium hirsutum
2n=52, and is tetraploid in nature.
It is generally called as American cotton.
About 36% of the area is covered by this variety.
Varieties: MCU 5(Extra long), Ganganagaragety, Bikanerinerma, Mahalaxmi.
4. Gossypium barbadense
2n=52, and is also tetraploid in nature.
It is having higher fibre length of 3.6- 5 cm
Both of these species are known as Egyptian / Sea island cotton.
About 40% of the area is covered by this variety.
Varieties: Suvin (Anjali), Surabi and Sujatha.
1.H- 4: First hybrid variety of cotton (G-67*Amaricannectorless) developed by C. T Patel, Surat in 1970.
2. Varalaxmi: (G.hirsutum* G. Barbadence).
3. Maruvikas/Raj: 1st Hybrid of Hirsutum in Rajasthan.
4. Savita: Hybrid of G. Hirsutum.
5. Surya: Hybrid of G. Hirsutum.
It is having Taproot system.
It contains 35% of protein.
Germination takes place in 4-7 days after sowing.
Crop is highly tolerant to soil salinity.
For proper bud formation and flowering daytime temp should be higher than 20 degree, lower than 40 degree
Night temp should be more than 12 degree but less than 27 degree.
A temperature between 27 and 32 degree is optimum for boll development (fruiting) and maturation but above 38 degree yields are reduced.
Optimum temperature for vegetative growth is 21 degree.
5.5 to 8
Deep Black Cotton soils can be used for sowing
Seed depth should be more than 60 cm.
Coarse textured soil is preferred for high rainfall areas.
Clay soil is preferred during moisture problem.
Desi Cotton: 10-18 kg and Spacing of 67.5*30cm
American Cotton: 15-25 kg and Spacing of 67.5* 30cm
Hybrid Cotton: 2-3kg and spacing of 100*60cm
Plant population: 50,000- 80,000 (Average of 65,000)
For BT Cotton: 1-1.5kg/ha
Plant Population: 10,000
In North India: 1st Fortnight of may (From 15thof may).
In Central India: Last week of June to First week of July.
In Tamil Nadu: Sep- Oct.
Depth should be 3cm
Gap should be filled at 10th day after sowing.
Thinning( Removal of leaves and shoots) should be done at 15th day after sowing.
Nipping (Pinching of shoots/ leaves) 80-90 days after sowing.
Topping is followed in cotton which involves removal of growing point once from each plant at a height of 1-1.2 m to protect further terminal growth.
SQUARE IN COTTON
The formation of flower bud in cotton is known as square and Fruit is called as Boll/Capsule.
Seperation of fibre from cotton is called Ginning.
It generally ranges between 30- 35%.
Important weeds are Trianthima, Echinoclova, Diseria. To control weeds Diuron @ 0.5kg a.i./ha is sprayed. Cotton is highly sensitive to 2,4- D and Glyphosate, injured by a spray drift.
2,4-D resistant cotton is gene tfd-A.
FERTILIZER RECOMMENDATION : It should be manured with FYM or Compost atleast once in 3 years at the rate of 12-15 tons/ha. The fertilizer dose of 100:50:50 (NPK) kg/ha- Irrigated cotton
80:40:40 (NPK) kg/ha- Rainfed cotton hybrids
50:25:25 (NPK) kg/ha- For both Desi and Egyptian varieties.
Yield varies from 15-20 quintals per acre fetches about 2.5 lakh rupees.