Producing Seeds of Cotton and Other Fiber Crops

BILLY M. WADDLE AND REX F. COLWICK.

FOUR LARGE companies produce the cotton seed that is used on 90 percent of the planted acreage in the Southern and Southeastern States.

The rest of the acreage in that part of the Cotton Belt is planted with seed produced by public agencies and by several companies that primarily serve their own immediate districts.

In some parts of the Cotton Belt, particularly in Texas and Oklahoma, a large percentage of the planting seed is produced by companies that supply seed for local needs.

Most of the planting seed in the Far Western States is produced by selected growers under the supervision of the grower-owned cooperative organizations, which control conditions rigidly under the supervision of seed-certifying agencies. They make the planting seed available to the producers at prices slightly above costs.

Public agencies conduct the breeding programs in the Western States. When the new varieties are developed and proved, small amounts of early-increase seed lots are made available to the organizations of cotton seed growers. They increase the seed through the steps of foundation, registered, and certified categories and distribute the seed to the growers. In each State, except California, the controls that guarantee purity are under the direction of the State's official seed-certifying agency.

The seed-distributing agency in California is grower owned and works closely with the breeders at the U.S. Cotton Field Station at Shafter in the development and distribution of pure seed to the growers of the San Joaquin Valley. The organization is its own certifying agency. Small amounts of selfed seed are furnished the distributors by the field station. The subsequent increases and sales are controlled by the distributors. Technical supervision in the maintenance of pure seed is furnished by station officials. The result is the production and maintenance of adequate supplies of high-yielding, pure seed of highest quality at a relatively low cost.

Different procedures are used by the seed companies and public agencies in their improvement programs.

One is the pedigree method, which uses inbred lines for composite mixtures, in which inbred lines and the composites are tested for yield and fiber quality.

Another is the selection of numerous open-pollinated plants in pure seed fields and subsequent elimination of undesirable types by yield and fiber tests. The best strains are kept for final increase.

A third procedure is the selection of limited numbers of individual plants from chosen fields of registered or foundation plantings. Such selections are also screened vigorously by strain and fiber tests to give the best stocks.

After the extensive selection and testing phases of the programs have produced the variety or varieties judged to be superior in one or more attributes, the seed-increase program is inaugurated, and the variety is released.

MOST OF THE SEED companies utilize a number of similar features in their variety-increase programs. Three steps are usual.

Foundation seed is produced from breeder seed or parent seed. Care is taken to maintain the proper isolation from other varieties and types of cotton cotton is easily cross-pollinated by bees and other insects and to assure that no contamination results from volunteer plants in the field. Great care is exercised to prevent the mixing of seed when it is harvested, ginned, and bagged.

The increase phase from the foundation seed is generally known as registered seed and goes through essentially the same procedures as for the production of the foundation seed, except that the requirements for isolation and amount of contamination are not quite so rigid as in the earlier phase.

The final stage is known as certified seed and may be produced for 1 or 2 years, depending on the practices of the seed-certifying agency in a given State. Certified seed usually composes the bulk of planting seed stock for the producers.

In all stages of the work to multiply the seed of a variety, close supervision is maintained by the Crop or Seed Improvement Association to assure varietal purity and the best possible seed for cotton producers.

The responsibility of the seed-certifying agencies in most of the States where cotton seed is produced for planting in the Cotton Belt is to assure purity and germinating ability of the seed. The Crop Improvement Association approves applications from growers to produce seed in the certification program and inspects the fields for proper isolation and possible contamination by weeds and offtype cotton plants. Sometimes an association may supervise the ginning of the cotton and the bagging of the seed.

All seed companies and associations engaged in producing and selling pure seed utilize the services of official seed-testing laboratories.

The laboratories determine the germination percentage (which must not be below a specified minimum), the percentage of impurities in the form of seeds of other crops and weeds; inert matter; and the total percentage of pure seed.

The farmer who buys approved varieties of seed that have been tested by an approved laboratory and carry the label of the Crop Improvement Association therefore is assured of the best possible seed.

In the South and Southeast, the seed companies commonly make contracts with dependable farmers for seed for use by the industry. The contract growers agree to produce the seed under the restrictions and controls of the official certifying agency to guarantee varietal purity.

The production of pure seed by the small companies of Texas and Oklahoma for their own localities usually is confined to the company landholdings, and contractual arrangements are not common.

In the grower-owned seed organizations of California, New Mexico, and Arizona, contracts are made with the farmers to produce the pure seed under stipulated conditions of land cleanliness, isolation, and approved production practices. The seed organizations supervise the contracts.

The production of pure seed in all regions of the Cotton Belt is processed by one-variety gins or by gins that are thoroughly cleaned before the ginning of pure seed. This practice further assures a minimum of risk of seed mixtures and is considered one of the prime requisites in the production of pure seed.

In ginning, the cotton is subjected to a minimum amount of machining. A loose seed roll is used to avoid mechanical damage.

Delinting the removal of seedcoat hairs and short fibers that remain after ginning is common throughout the Cotton Belt. Chemical delinting, mechanical delinting, and flame delinting are used.

Chemical delinting uses concentrated sulfuric acid (with later washing in water) or hydrochloric acid gas (later neutralized by soda ash). Chemically delinted seed is used mainly in the western irrigated part of the belt. Commercial acid-delinting plants are in all the Western States.

Mechanical delinting is performed by the same type of machinery that is used by the cotton oil mills to remove seed fuzz before the crushing of the seed. The use of mechanically delinted seed is common throughout the belt, but it is less popular in the Western States than the acid-delinted seeds.

Flame delinting has gained some popularity. It removes some of the seed fuzz. Some large producers in the South use it to remove any patches of fuzz on machine-delinted seed.

The use of delinted cotton seeds allows a more precise seeding rate, which aids in planting to a stand and more rapid germination. Another advantage is the ease with which the delinted seed is graded by gravity grading machines. The light, immature seed can be removed; the quality is improved thereby. Fuzzy seeds also are gravity graded, but the process is not so effective as with delinted seeds.