188 YEARBOOK OF AGRICULTURE 1961 ver, 36 percent of Alta fescue, and 60 percent of subterranean clover. Early harvest docs not work on all seed crops, however. In the same test, the take of pure live seed of birdsfoot Producing Seeds of Cotton trefoil was reduced substantially by early harvest. The first seed set was be- ginning to shatter before the germina- and Other Fiber Crops tion of harvested seed was high enough to meet the requirements of State and BILLY M. WADDLE AND REX F. COLWICK interstate seed laws. Enough nutrients were left in the windrowed straw of crimson clover for the seed to finish maturing. The result FOUR LARGE companies produce the was the largest amount of seed, the cotton seed that is used on 90 percent highest germination, and the lowest of the planted acreage in the Southern percentage of damaged and shriveled and Southeastern States. seeds. The rest of the acreage in that part Records were kept of the appearance of the Cotton Belt is planted with seed of the stems, the leaves, the floret, the produced by public agencies and by seed, and the moisture content of the several companies that primarily serve seed. Color pictures were used as their own immediate districts. guides to pinpoint the time to harvest In some parts of the Cotton Belt, a crop for maximum yields. Only the particularly in Texas and Oklahoma, seed moisture at the time of cutting a large percentage of the planting seed was a true indication of the time to is produced by companies that supply windrow the crop each year. seed for local needs. Results of research studies indicate Most of the planting seed in the Far that a seed is at its peak in quality at Western States is produced by selected maturity and that it should be har- growers under the supervision of the vested immediately in order to get the grower-owned cooperative organiza- highest percentage of quality seed. tions, which control conditions rigidly Seeds start deteriorating immediately under the supervision of seed-certifying upon reaching maturity, and all man agencies. They make the planting seed can do is to retard the change by regu- available to the producers at prices lating the time and method of harvest slightly above costs. and treatment after harvest. Public agencies conduct the breed- ing programs in the Western States. JESSE E. HARMOND is Head of the When the new varieties are developed Small Seed Harvesting and Processing Sec- and proved, small amounts of early-in- tion^ Agricultural Engineering Division^ crease seed lots are made available to Agricultural Research Service, He began re- the organizations of cotton seed grow- search in agricultural engineering in the ers. They increase the seed through the Department in 1939* He established the steps of foundation, registered, and Seed Cleaning Research Laboratory on the certified categories and distribute the campus oj Oregon State College in 1953. seed to the growers. In each State, ex- JAMES E. SMITH, JR., is field plant ma- cept California, the controls that guar- terials technician for the Soil Conservation antee purity are under the direction Service in Texas, stationed at Temple, Tex. of the State's official seed-certifying JOSEPH K. PARK íV an agricultural en- agency. gineer in charge of research in the harvesting The seed-distributing agency in of small seed, conducted by the Department California is grower owned and works of Agriculture and Clemson Agricultural closely with the breeders at the U.S. Experiment Station, Clemson, S,C, Cotton Field Station at Shafter in the PRODUCING SEEDS OF COTTON AND OTHER FIBER CROPS 189 development and distribution of pure mixing of seed when it is harvested, seed to the growers of the San Joaquin ginned, and bagged. Valley. The organization is its own The increase phase from the founda- certifying agency. Small amounts of tion seed is generally known as regis- selfed seed are furnished the distribu- tered seed and goes through essen- tors by the ñelá station. The subse- tially the same procedures as for the quent increases and sales are con- production of the foundation seed, ex- trolled by the distributors. Technical cept that the requirements for isolation supervision in the maintenance of pure and amount of contamination are not seed is furnished by station officials. quite so rigid as in the earlier phase. The result is the production and main- The final stage is known as certified tenance of adequate supplies of high- seed and may be produced for i or 2 yielding, pure seed of highest quality years, depending on the practices of at a relatively low cost. the seed-certifying agency in a given Different procedures are used by the State. Certified seed usually composes seed companies and public agencies in the bulk of planting seed stock for the their improvement programs. producers. One is the pedigree method, which In all stages of the work to multiply uses inbred lines for composite mix- the seed of a variety, close supervision tures, in which inbred lines and the is maintained by the Crop or Seed Im- composites are tested for yield and provement Association to assure vari- fiber quality. etal purity and the best possible seed Another is the selection of numerous for cotton producers. open-pollinated plants in pure seed The responsibility of the seed-certify- fields and subsequent elimination of ing agencies in most of the States where undesirable types by yield and fiber cotton seed is produced for planting in tests. The best strains are kept for final the Cotton Belt is to assure purity and increase. germinating ability of the seed. The A third procedure is the selection of Crop Improvement Association ap- limited numbers of individual plants proves applications from growers to from chosen fields of registered or produce seed in the certification pro- foundation plantings. Such selections gram and inspects the fields for proper are also screened vigorously by strain isolation and possible contamination and fiber tests to give the best stocks. by weeds and offtype cotton plants. After the extensive selection and test- Sometimes an association may super- ing phases of the programs have pro- vise the ginning of the cotton and the duced the variety or varieties judged to bagging of the seed. be superior in one or more attributes, All seed companies and associations the seed-increase program is inaugu- engaged in producing and selling pure rated, and the variety is released. seed utilize the services of official seed- testing laboratories. MOST OF THE SEED companies utilize The laboratories determine the ger- a number of similar features in their mination percentage (which must not variety-increase programs. Three steps be below a specified minimum), the are usual. percentage of impurities in the form of Foundation seed is produced from seeds of other crops and weeds; inert breeder seed or parent seed. Care is matter; and the total percentage of taken to maintain the proper isolation pure seed. from other varieties and types of cot- The farmer who buys approved vari- ton—cotton is easily cross-pollinated eties of seed that have been tested by by bees and other insects—and to an approved laboratory and carry the assure that no contamination results label of the Crop Improvement Asso- from volunteer plants in the field. ciation therefore is assured of the best Great care is exercised to prevent the possible seed. I go YEARBOOK OF AGRICULTURE 1961 In the South and Southeast, the seed seed is common throughout the belt, companies commonly make contracts but it is less popular in the Western with dependable farmers for seed for States than the acid-delinted seeds. use by the industry. The contract Flame delinting has gained some growers agree to produce the seed popularity. It removes some of the seed under the restrictions and controls of the fuzz. Some large producers in the official certifying agency to guarantee South use it to remove any patches of varietal purity. fuzz on machine-delinted seed. The production of pure seed by the The use of delinted cotton seeds al- small companies of Texas and Okla- lows a more precise seeding rate, which homa for their own localities usually is aids in planting to a stand and more confined to the company landholdings, rapid germination. Another advantage and contractual arrangements are not is the ease with which the delinted seed common. is graded by gravity grading machines. In the grower-owned seed organiza- The light, immature seed can be re- tions of California, New Mexico, and moved; the quality is improved there- Arizona, contracts are made with the by. Fuzzy seeds also are gravity graded, farmers to produce the pure seed under but the process is not so effective as stipulated conditions of land cleanli- with delinted seeds. ness, isolation, and approved produc- Fungicides are applied to the seeds tion practices. The seed organizations before planting to destroy or remove supervise the contracts. seedborne disease organisms. The The production of pure seed in all treatment is recommended for all regions of the Cotton Belt is processed planting seed in the Cotton Belt. In by one-variety gins or by gins that are the slurry method, the seeds are treated thoroughly cleaned before the ginning with a water-fungicide mixture. of pure seed. This practice further as- Fuzzy (nondelinted) seed may be sures a minimum of risk of seed mix- treated by dust applications of the ap- tures and is considered one of the propriate fungicide, but slurry treat- prime requisites in the production of ments are also used. Delinted seeds are pure seed. treated easily by the slurry method. In ginning, the cotton is subjected In localities where the pink boll- to a minimum amount of machining. worm is a problem, quarantine regula- A loose seed roll is used to avoid me- tions have been established to help pre- chanical damage. vent its spread. Seeds sent from an area Delinting—the removal of seedcoat of pink bollworm infestation to another hairs and short fibers that remain after area must receive appropriate treat- ginning—is common throughout the ment to assure bollworm-free seeds in Cotton Belt. Chemical delinting, me- the shipment. Steam sterilization treat- chanical delinting, and flame delinting ment of all cotton seeds is practiced in are used. Arizona. Extreme care is necessary to Chemical delinting uses concen- prevent damage by overexposure to trated sulfuric acid (with later washing heat and steam. Methyl bromide gas in water) or hydrochloric acid gas or other approved treatments may be (later neutralized by soda ash). Chem- used in other States. ically delinted seed is used mainly in Cotton seeds and the attached fiber the western irrigated part of the belt. (seed cotton) are harvested by hand or Commercial acid-delinting plants are machine. About 50 percent of our cot- in all the Western States. ton crop is harvested by hand. The Mechanical delinting is performed worker grasps the seed cotton and picks by the same type of machinery that is it from the bur or snaps the bur con- used by the cotton oil mills to remove taining the fiber and seed from the seed fuzz before the crushing of the stem. The seed cotton is placed in a seed. The use of mechanically delinted bag or basket and carried to a wagon PRODUCING SEEDS OF COTTON AND OTHER FIBER CROPS IQI or trailer. When the trailer is fully the plant are called desiccants. Defolia- loaded, it is taken to a cotton gin, tion is practiced primarily to aid me- where the seeds are separated from the chanical picking. Desiccation is used lint by ginning. chiefly to facilitate stripping before The procedure in machine harvest- frost. ing is like hand harvesting, except that Cotton should not be harvested while the machine replaces human hands in it is wet from dew or rain. If seed cot- the removal of the seed cotton from the ton is stored in the trailer or elsewhere plant. The two machine-harvesting at a moisture content of 12 percent or methods are picking and stripping. more, heating will occur and damage Mechanical picking by spindle ma- the seed and fiber. Damp cotton re- chine removes only the lint and seed quires more processing in the gin and from the plant. The burs, unopened exposes the seeds to more mechanical bolls, and plant are left intact. Me- damage. chanical stripping removes the burs, The time of harvest of the cotton bolls, and some leaves and stems from crop may aflfect the quality of seed. In the plant. Stripping is necessarily a parts of the irrigated West where it is once-over operation and must be con- more efficient to harvest only one time ducted after frost or defoliation. by mechanical harvester, it is necessary Mechanical picking by spindle ma- to defoliate before the first killing frost chine can be done several times as the or to w^ait until after frost for the single crop matures. It is often possiljle there- harvest. fore to obtain more uniformly mature For the production of the best seed, it seed from mechanical picking than is necessary to harvest the first part of from once-over stripping. The Far the crop before first frost to assure that Western States harvest up to 90 per- all seed saved for planting will be fully cent of the crop by this method. matured. Therefore the practice of Hand snapping and machine strip- hand harvesting the early-season crop ping are practiced chiefly in the west- for planting seed is common in some ern parts of Texas and Oklahoma, places. The agencies handling cotton where about 30 percent of the United seed will not accept seed harvested States crop is grown. Picking by hand after frost except in an emergency. or spindle machine is practiced in the In the rain-grown areas of the Cot- rest of the Cotton Belt. ton Belt, adverse weather may lower The precautions to be observed in the quality of the seed. Excess rain in harvesting to maintain high quality the early or midpart of the harvest are generally like those needed to season may be harmful. In years of bad maintain the quality of the cotton weather, such as 1957, substandard fiber. Timing the harvest when the seed may be accepted from necessity. cotton is fully and uniformly mature is Most of the larger companies operate first. Clean harvesting with a mini- at enough different locations to coun- mum amount of such material as terbalance this problem in most years, grass, leaves, and plant bark permits unless unusual weather occurs gen- minimum handling and cleaning in erally over large areas. the gin. It reduces the possibility of If the seed is suspected of having mechanical damage from excessive poor quality following excessive rain- machining of the fiber. fall, some checks are available to the To reduce leaf trash in the harvested seedsmen. A preliminary free-fatty cotton, the leaves often are removed acid test of the seed may be used to from the plant or killed by the appli- pinpoint germination potential. Ex- cation of a chemiical in spray or dust cessive free-fatty acid is an indication form. The chemicals that remove the of low quality, and this advance infor- leaves from the plant are called de- mation can be of value to the seeds- foliants. Those that kill the leaves on man in saving his planting seeds. 192 YEARBOOK OF AGRICULTURE 1961 The storage of seed with excess mois- ture because of rainfall just before harvest may result in the lowering of seed quality or the destruction of the seed. Most distributing organizations Producing and Harvesting have proper storage bins, including facilities for drying moist seed with forced air. Seeds of Oilseed Crops All of the varietal maintenance and production programs we have dis- J. O. CULBERTSON, H. W. JOHNSON, AND cussed are efficient and successful. If U G. SCHOENLEBER the farmer plants genetically pure seed of the variety or varieties recom- mended for his soil and climatic con- ditions, he is sure he has the best THE LEADING oilseed crops grown in possible seeds. the United States are soybeans, pea- nuts, flaxseed, safHower, castorbeans, THE PRODUCTION of planting seed of and sesame. A large amount of oil is leaf and stem fiber crops is on an ex- obtained from cottonseed, but cotton perimental basis in the United States. is a fiber crop, and we do not consider There is no large commercial produc- it here. tion of fiber crops other than cotton in The seeds and oil from them have the Nation. Flax and hemp are no many uses. longer produced for fiber in this coun- Soybean oil is used in margarine, try, but seed stocks of the best varieties shortening, paints, varnishes, and that have been developed by research other industrial products. Although agencies are maintained. soybeans are generally classified as an Kenaf has shown some promise of oilseed, the monetary value of the pro»- being a good substitute for jute in the tein, or meal, equals or exceeds that of event of emergency needs. Consider- the oil. able research on this crop has led to Peanut oil is used for edible purposes. varieties that are high yielding and Nearly all linseed oil from flaxseed resistant to some of the major diseases goes into the manufacture of paints, that attack the crop. The seed can be varnishes, and linoleum. harvested with machines, but the acre- Safflower oil is used primarily as a age is so small that only limited drying oil, but an increasing amount amounts of seed are maintained. is being consumed in edible products. Other fiber crops—sansevieria, ra- The major uses of castor oil are as a mie, phormium, and jute—are propa- drying oil and for hydraulic fluids. gated vegetatively. Research in mech- Nearly all the sesame grown in this anizing the propagation, growing, and country is consumed as whole seed. harvesting of some of them is carried The harvested acreages of soybeans, on by public agencies. peanuts, and flax in the United States in i960 were about 23.6, 1.5, and 3.3 BILLY M. WADDLE became Assistant million acres, respectively. Branch Chief of the Cotton and Cordage Safflower acreage has been rising Fibers Research Branch, Crops Research steadily, and about 300 thousand acres Division, Agricultural Research Service, at were grown in i960. Castor bean acre- Beltsville, Md., in igßS. age in i960 was about 30 thousand, REX F. COLWIGK became Head of Cot- and that for sesame, 10 thousand. ton Harvesting Investigations of Harvesting The same general cultural practices and Farm Processing Branch, Agricultural that produce the best yields of high- Engineering Research Division, at State quality seed for industrial uses also College, Miss., in igjg. produce the best seed for planting.