History of Seed Cotton

 INTRODUCTION:

Hybrid Seed Cotton

In cotton hybrid seed production is done either by conventional hand emasculation and pollination or by non-conventional (Male Sterility Based).The main aim of hybrid cotton seed production is to produce seed of high vigour and viability

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History:-
Cotton is a major fiber crop of global significance. It is grown in tropical and sub-tropical regions of more than 80 countries.

The major cotton producing countries are China, India, USA, Pakistan, Uzbekistan, Turkey, Brazil, Greece, Argentina, Australia and Egypt contributing about 85% of global production. 

 

India has the largest area under cotton cultivation in the world (9.1 million ha.) and grows all four cultivated species namely, G. hirsutum, G. barbadense, G. herbaceum and G. arboreum on commercial scale.

The major cotton growing states are Punjab, Haryana, Rajasthan, Madhya Pradesh, Maharashtra, Gujarat, A.P., Tamil Nadu and Karnataka.

India is the pioneer country for commercial cultivation of cotton hybrids which covers more than 50% of the cotton area. Cotton hybrids have 50% higher productivity than varieties.

Moreover, hybrids have wider adaptability, high degree of resistance to biotic and abiotic stresses and better fibre quality. Hybrids can be developed with comparatively lesser time frame than straight varieties. The hybrids are highly productive and have uniform fibre quality.

Developments:
The first intra-hirsutum hybrid cotton Hybrid - 4(H-4) was released in 1970 from Main cotton Research Station, Surat of G.A.U. by Dr. C.T. Patel.

This was followed by the development of world first inter-specific hybrid Varalaxmi in 1972 from U.A.S., Dharwad by Dr. B.H. Katarki.

Thereafter, development of hybrids got momentum and numerous location specific superior hybrids were released in the country. The successful hybrids earlier developed were of inter or intraspecific new world cotton which are susceptible to pests and diseases compared to Asiatic cotton.

METHODS OF PRODUCTION OF HYBRID SEEDS:
There are two methods:

1) Conventional Hybrids:
Majority of the hybrids released so far are conventional ones. Development of such hybrids involve three steps viz. (i) Identification and growing of male and female parents, (ii) emasculation of female parent and (iii)
pollination of female parent with identified male parent.

Cotton is an often cross pollinated crop. The average outcrossing is 6%. The pollen is heavy and sticky and hence cross pollination occurs only by insects i.e. honey bees and bumble bees. In diploid cottons conventional method is highly uneconomical since boll setting is low due to small flower size and brittle pedicel.

2) Male-sterility based hybrids:
The development of hybrids using male sterility eliminates the process of emasculation since the anthers are sterile in female parent without pollen. Thus the cost of hybrid seed production can be reduced.

However, pollination has to be done manually. In cotton, mainly two types of male sterility such as genetic male sterility and cytoplasmic genetic male sterility are used for seed production.

ADVANTAGES AND DISADVANTAGES:-
ADVANTAGE:-

• Superior fibre properties,
• Superior yield performances,
• Wider adaptability,
• Good price for the produce.

Disadvantages:-

• High cost of seed,
• High cost of cultivaton,
• Difficulty in seed production,
• Neps and motes especially in inter-specific by birds.

SEED STANDARDS FOR CERTITIED HYBRID COTTON SEED:-

Hybrid seeds produced after meeting the above field requirements should meet the following seed standards as per Indian minimum seed certification standars:-