Tailor-Made Sorghums

THE FIRST grain sorghums that reached the United States from Africa more than two generations ago could not be harvested and threshed without a lot of hand labor. They grew 4 to 6 feet tall; some had bent heads, and they were not suited to the combine. Engineers and plant breeders joined forces to solve the difficulty, They improved the combined harvester-thresher. It was made lighter and mounted on rubber tires; it could be transported easily, so that operators from the Wheat Belt could move westward into the grain-sorghum region for the autumn harvest. The breeders produced tailor-made new varieties that could be combined. Together the improvemcnts saved seven-eighths of the man-hours needed to harvest the grain by hand and thresh it later. Consequently, during the War, when labor was scarce, many farmers were able to grow eight times more sorghum than if they would have had to depend on hand labor. The extra grain contributed materially to the supply of feed and industrial alcohol. Besides, harvesting with combines saved about two dollars an acre in harvesting costs—a total saving of some 12 million dollars a year.

Even more impressive is the story of six varieties, distributed since 1940, that were grown on 7 million acres by 1944—Martin, Plainsman, Westland, Midland, Caprock, and Bonita. They comprise 80 percent of the sorghum harvested for grain in the United States. They have erect heads and usually grow to only 2 to 3 feet, so that harvesting is easy. Altogether, these developments of a generation have given the Great Plains a crop that is as important to that area as corn is to the more humid Corn Belt.

Combines were not used for harvesting any crop in the Southern Great Plains until about 1918. In 1920, J. B. Sieglinger selected some dwarf, erect-headed plants from the progenies of a cross between milo and kafir that grew at the United States Southern Great Plains Field Station at Woodward, Okla. Nobody had bothered much about such plants before. They were nondescript, unprepossessing hybrids no taller than wheat plants, although both parents stood 4 to 6 feet, and the milo parent had crooknecked heads. But from his selections Sieglinger bred Beaver and Wheatland, which were distributed to growers in 1928 and 1931. The value of Wheatland for Kansas was quickly recognized after small fields of several new varieties were harvested with a combine.

Two quick-maturing combine-type varieties, Colby and Day, originated at Woodward, were distributed later in Kansas and Nebraska after tests of numerous similar strains. The new varieties, especially Wheatland, soon were grown extensively, but they had some serious faults. All were susceptible to milo disease, or pythium root rot, which was first observed in 1925. Also, like their milo parent, they were subject to chinch bug injury. There was a need also for kinds that matured earlier than Wheatland and Beaver, but later than Colby and Day.

The Agricultural Experiment Stations of Kansas, Texas, Oklahoma, Nebraska, Colorado, and New Mexico, cooperating with the Department, set out to breed better kinds. Pythium-resistant offspring of Wheatland were tested extensively. One, named Westland, was distributed in Kansas in 1942 and grown on a million acres by 1944.

A Texas farmer, W. P. Martin, found a promising plant in his field of Wheatland in 1936. When tested in a nursery, it was found to resist pythium root rot. It was increased, given the name of Martin, and distributed in 1941. By 1943 it was grown on 3 million acres, and has been the leader since then. Like Westland, it matures earlier than Wheatland.  Martin has reddish-yellow grains somewhat smaller and harder than those of milo. The heads are upstanding and open enough to dry quickly, so that combine operators can even start harvesting it soon after it has been dampened by dew or rain. Martin’s early maturity permits it to be grown as far north as South Dakota, yet it is the leading grain sorghum in southern Texas (where the crop is harvested in early summer), other parts of Texas, and Oklahoma.

The breeding work at the Texas Agricultural Experiment Station, at Lubbock and Chillicothe, produced three varieties that were released between 1941 and 1943. Plainsman and Caprock were devolped from milo kafir crosses by R. E. Karper and D. L. Jones. The third, Bonita, was selected from a Chiltex-hegari cross by J. R. Quinby. Plainsman and Caprock mature later and yield better than Martin and Westland when everything is favorable, but are not so well suited to dry conditions or short seasons. Bonita has found an important place in north-central Texas, where chinch bugs may work havoc with other improved kinds.

Meanwhile, a new disease, charcoal rot, appeared. It can cut the yield of all the new kinds and cause their stalks to fall down after they ripen but before the grain is dry enough for combining. Martin is particularly susceptible. A condition called weakneck also causes ripe stalks to fall over and be lost at harvest.

A. F. Swanson selected a stiff-stalked plant from his plots of kalo at the Fort Hays' Branch Experiment Station in Kansas. This variety, named Midland, was distributed to Kansas farmers in 1944. In 1945, Midland was planted on 300,000 acres from known supplies of pure seed; probably 200,000 acres more were planted from commercial grain supplies. Midland matures early enough for growing in most parts of Nebraska and western Kansas. Its stiff stalks and resistance to stalk diseases make it good for combining.

Midland produces bronze-yellow grains smaller than typical milo kernels. The stalks are taller and the heads shorter than those of the other combine types. It is as early as Martin, maybe a little earlier. Midland ranks next to Westland in Kansas, and is the leading variety in Nebraska.

Plainsman and Caprock are somewhat alike, except that Caprock ripens later and has larger heads. Both produce large reddish-yellow grains in rather compact, kafir-like heads. Their short, thick stalks resist lodging, but the thick heads, standing barely out of the boot, dry out rather slowly after a rain. Plainsman and Caprock are adapted to places having favorable moisture conditions and a fairly long growing season.  Under such conditions, they produce larger yields than do the quicker-maturing sorts.

Westland has large yellow grains. The somewhat open heads extend well above the boot and leaves. Thus, Westland resembles Martin, except in being a little later in maturing. The grains are larger and softer than those of Martin. Westland leads in Kansas.

Bonita is rather unusual because of its numerous tiller stalks and small heads. Each row appears as a wide band of Keads. The production of late branch heads often interferes with combining, because the green material adds moisture to the grain. The grains are small, soft, and chalky-white, rather like those of its hegan parent. Bonita is grown most]y in Texas.

Much of the grain sorghum grown under irrigation in California and Arizona since 1938 consists of a variety called Double Dwarf milo 38, a productive, pythium-resistant variety developed by the California Agricultural Experiment Station. It is combined readily when planted thickly on rich irrigated land. In the thinner planting necessary for the Great Plains, it produces recurved heads that make harvesting harder.

A variety called combine kafir is grown on 100,000-odd acres in western Texas and other localities. It was developed at Woodward and resembles the familiar Blackhull kafir, but it has shorter heads and stalks.

Other new kinds, although somewhat taller than the special combine types, also are stocky enough for successful combining. Among these is waxy-seeded Cody, grown for its starch, which makes a tapioca-like dessert. It usually grows 3 to 4 feet tall. It was developed in cooperation with the Kansas Agricultural Experiment Station. Coes, a quick-maturing, white-seeded kind grown in the higher altitudes of the western Great Plains, also is usually combined. Coes grows as high as 4 feet. It was developed in cooperation with the Colorado Agricultural Experiment Station.

All the new disease-resistant types have given the farmer a new crop that he can grow by mechanized methods, an economical and more stable supply of feed grain, and an alternative cash crop for the cotton and wheat regions. Grain sorghum stubble and the crop residue left after combining afford fair protection against soil blowing. The combine varieties stand long enough after maturity for the grain to be gathered by livestock. Sorghum thus can supplement wheat pasture for the range livestock that are fed in the Great Plains region before going East to the packing plants. The “sheeping off” of combine grain sorghums opens a new opportunity in livestock feeding. Breeders and farmers are well satisfied with the improved sorghums, but even better types are on the way.

THE AUTHOR
John H. Martin is an agronomist in the Bureau of Plant Industry, Soils, and Agricultural Engineering. His work includes research on the culture, utilization, adaptation, genetics, economics, and the improvement of sorghum throughout the United States.

FOR FURTHER READING
Leukel, R. W.: Chemical Seed Treatments for the Control of Certain Diseases of Sorghum, U. S. D. A. Technical Bulletin 849, 1943.
Leukel, R. W., Martin, John H., and Lefebvre, C. L.: Sorghum Diseases and Their Control, U. 8. D. A. Farmers’ Bulletin 1959, 1944.
Martin, J. H.: Sorghum Improvement, U. S. D. A. Yearbook, pages 523-560, 1936.
Martin, J. H.: Breeding Sorghum for Social Objectives, Journal of Heredity, volume 36, No. 4, pages 99-106, 1945.
Martin, J. H., and Stephens, J. C.: The Culture and Use of Sorghums for Forage, U. S. D. A. Farmers’ Bulletin 1844, 1940.

ALSO, IN THIS BOOK
Genetics and Farming, by E. R. Sears, page 245.
G-Men of Plant Diseases, by Paul R. Miller, page 443.