Cotton

Botanical Name :- Gossypium spp.

Family :- Malvaceae

Origin :- India

2n :- 26, 52

Importance :-

• It is white gold.
• Backbone of textile industry.
• 45 % world's fiber need is met from cotton.
• 10 % of world's edible oil.

Classification based on origin :-

1. Southern Ethiopia

                                G. herbaceum :- 2n = 26 (Diploid)

2. India

                                G. arboreum :- 2n = 26 (Diploid)

                                G. herbaceum and G. arboreum both present genome A and known as Desi cotton / Old world cotton / Asiatic cotton.

3. South America

                                G. barbadense :- 2n = 52 (Tetraploid)

                                Known as egyptian cotton, Present genome D.

4. Central America

                                G. hirsutm :- 2n = 52 (Tetraploid)

                                Upland cotton known as American cotton.

Cotton classified based on area :-

1. Northern India

                                G. herbaceum

                                G. arboreum

2. Central / Southern India

                                G. herbaceum

                                G. arboreum

                                G. hirsutm

Crop description :-

• Tap root system deep > 1.6 m in soil.
• Cotton seed contain 14 - 26 % oil and 35% proteins.
• Germination takes place in 4 - 7 day after sowing.
• 20 - 35 days after first square formation flowering take place (60 - 80 days).
• Boll attains 90% size within 15 - 18 days.
• Mature size is attained within 25 days.
• Fiber elongation is complete by 21 - 24 days.

Branches :-

                           1. Sympodial :- Reproductive branch

                           2. Monopodial :- Vegetable branch

Temperature :-

• A temperature between 27 to 32 °C is optimum for boll development (Fruiting) and maturation but above 38 °C yield are reduced.
• Optimum temperature for vegetative growth is 21 °C.

pH :-

• 5.5 - 8 with 7 - 8 optimum.

Salinity tolerance level :-

• The crop is high tolerant to soil salinity.

Water requirement :-

• Cotton need 700 mm to 1300 mm.
• Irrigation provide when 75 % depletion of ASM (Available Soil Moisture) in clay 50% ASM at sandy loam soil.

Seed rate :-

• Bt Cotton :- 1 - 1.5 kg/ha
• Hybrid :- 2 - 3 kg/ha
• American Cotton :- 15 - 25 kg/ha
• Desi Cotton :- 12 - 18 kg/ha

Plant population :-

• Bt Cotton :- 10000 plant / ha
• Hybrid :- 67000 plant / ha

Dibbling :-

• 3 cm depth in dibbling.
• Per hole seed hybrid 2 seed.

Soil :-

• Soil depth should be more than 60 cm.
• Maximum seed cotton yield has been recorded in deep (> 90 cm) soils.

Planting :-

North Zone	Central Zone	Southern Zone
1st week of May for the new varieties and 3rd week to 1st week of June.	3 week of June to 1 week of July and irrigated land May start.	1.      June :- Karnataka 2.      June / July :- Red soil of Andhra Pradesh 3.      August :- Tamil Nadu

Interculture Operation :-

• Gap should be filled at 10th day.
• Thinning should be done at 15th day.
• Nipping after 80 - 90 days.

Yield :-

                With improve packages of practices, it is possible to get about 15 - 20 quintals of seed cotton / ha. Much higher yields (25 - 30 q/ha) may be obtained from hybrids.

Varieties :-

1. Hirsutum Varieties :-

                                        MCU - 5 (Extra long), 7, 9, 10, 11, 12

                                        LRA - 5166

2. Arboreum :-

                          Lohit, K - 9, 10, 11

3. Barbedense :-

                           Suvin (Anjali), Surabi, Sujata

4. G. herbaceum :-

                               Digivijaya

5. Hybrids :-

                    Jayalakshmi, TCHB - 213, HB - 224

 Plant Growth Regulators

            Plant growth regulators are organic chemicals that are produced internally in plants, or artificial substances that are used in plants from outside, which change the growth and modification of plants. Growth substances start those live chemical reactions that make it possible to grow roots, stems and flowers. “The plant growth regulator play essential role in increasing the quality and production of the crop.”

Five major plant growth regulators and their uses :-

Uses	Plant Growth Regulators
Rooting	Auxins, Cytokinins, Gibberellins, Ethylene
Growth	Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene
Flower initiation	Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene
Fruit set	Auxins, Cytokinins, Gibberellins, Ethylene
Fruit growth	Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene
Fruit ripening	Auxins, Cytokinins, Gibberellins, Ethylene
Abscission	Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene
Senescence	Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene

Plant Growth Regulators and their Uses

Name	Chemical Name	Trade Name	Uses
ABA	Abscisic acid	Abscisin / Rooting	Defoliant
Acifluorfen	5-[2-Chloro-4-(Trifluoromethyl)Phenoxy]-2-Nitrobenzoic acid	Blazer	Reduce growth
Chloroquat	2-Chloroethyl-Trimethyl ammonium chloride	Cycocel	Lodging preventor
4-CPA	2-(3-Chlorophenoxy)-Propionic acid	Fruitone	Fruit thinner (Reducing the number of fruits)
Diaminozide	Succinic acid-2, 2dimethyl hydrazine	Alar	Growth retardant
2, 4-D	(2, 4-Dichlorophyenoxy) Acetic acid	Plantagard	Herbicide
Ethephone	2-Chloroethyl phosphonic acid	Cepha	Sugarcane ripener
Glyphosate	N-Phosphonomethyl glycine	Round-up	Sugarcane ripener
GA-3	Gibberellic acid	Berelex / Pro-gibb	Grape enlarger, Seedless grape production
Kinetin	6-Furfuryl aminopurine		Dormancy breaker
IAA	Indol-3-acetic acid	Rhizopon-A	Plant cell enlarger
IBA	Indole-3-butyric acid	Seradix	Plant cell enlarger
Maleic hydrazide	1-2-dihydro-3, 6-pyidazinedione	Sprout stop	Growth retardant
Mapiquat chloride	N, N-Dimethyl piperidinium chloride	DPC	Growth retardant
NAA	NAA (1-Naphthyl acetic acid)	Fruit thinner	Fruitone-N (Fruit reducer)
TIBA	3, 3, 5-tri-iodobenzoic acid	Regim-8	Growth retardant

• Maikel :- It is used to shorten wheat plants.
• Ethylene :- It is used to ripening of fruits.