Cuzco Corn

1.2. Another sample of modern maize specimens. The first cob on the right is Cuzco Gigante: the two in the centre belong to the Cuzco Gigante subrace known as Saccsa (see Grobman et al., 1961: 299-300); and the one on the left is of Cuzco Gigante Amarillo, a hybrid race derived from Cuzco Gigante and Cuzco Cristalino Amarillo (see Grobman et al., 1961: 300-301). Photograph by Carlos Ochoa.
Maize: Origin, Domestication, and Its Role in the Development of Culture (2013) by Duccio Bonavia

Letters on the United provinces of South America addressed to the Hon. Henry Clay by Don Vicente Pazos (1819)
Maize (Indian corn.) A native production of America, like the potatoe. It is produced in amazing abundance in Cuzco, and yields from 1 to 200 fold. Several varieties are cultivated, one whose kernel is an inch long. The stalks usually attain the height of from 8 to 10 feet, and they contain almost as much sugar as the sugar-cane; a syrup, resembling molasses, is frequently extracted from them.

Floricultural Cabinet 21: 93 (April, 1853)
A collection of varieties of Indian Corn was exhibited by G. T. Davy, Esq., of Sussex-square, Hyde-park. They were from Cusco, and consisted of very fine large kinds little known in this country, but unfortunately too tender for our climate. It was hinted, however, that they might be found worth a trial in some of the Colonies, whose summers are longer and warmer than our own. It was stated that this Cusco corn was quite different from the Indian corn of North America.

Squier: Peruvian Maize (1866)

Cuzco Corn for Sugar (1880)
The stalk of Cuzco corn, though having a somewhat higher purity-coefficient than the Imphee and Dark Amber, would also serve for syrup only; and considering its low percentage in the juice, and smaller production on the same area, there can be no reason to prefer it to the Amber Cane.

Southern Cultivator (1880)
I also tried the Cusco or Peruvian corn; planted fifty hills. It grew to be twelve to fourteen feet high, but did not have an ear on it.

Kentucky Dept. of Agriculture, Labor and Statistics (1881)
CUZCO CORN. The following report would indicate that this variety of corn is unsuited to our climate. While the test is not entirely satisfactory, yet it is sufficiently so to carry conviction with it of its unfitness, until further experiments demonstrate the contrary:

Ohio State University (1881)
Last spring we received, through the kindness of Claude V. Burke, Esq., of Yolo, California, a few kernels of the "Cuzco" corn, a variety grown by the Cuzco Indians, in the Andes mountains, and forming a large portion of their food. The kernels are as large as Lima beans, and are surrounded by such a thin bran that they are prepared for the table by simply boiling them. Part of the seed was started in sods in the hot-bed, and all was planted in the open air in May. The corn grew luxuriantly, but never formed a kernel.

Tracy: Cuzco Corn x Black Mexican (1888)
In 1881, Cuzco corn, a soft variety, from Brazil, was fertilized with pollen from Black Mexican. As a result there were "obtained two quite good ears, many of the grains being black and wrinkled like sweet corn, others being white but wrinkled, still others being white and smooth like the variety. In 1882 the white wrinkled grains were planted where there was little chance of mixture. The tassels were carefully removed as they appeared, and in due season the silk was fertilized with Early Minnesota pollen. The result was quite a lot of ears, some showing all sweet grains, some nearly all of the Cuzco type; but I think none of them black, although some of them showed considerable red. The best ear was selected and the sweet grains planted in 1883 and the silk again fertilized with Early Minnesota. This season there was considerable black corn, there being much more color than in 1882. The best two ears were selected and planted and left to fertilize themselves. There was much less color shown this season than any year previous. In 1885 the best were planted, and no color appeared. In 1887 the best ears were planted, and no color showed. In 1888 the best two were planted, and this season a good many grains were as black as the Mexican, and some ears are as much marked with red or black as is the ordinary red blazed. I could not find that there was any red or black within a mile."

American Farming and Stock Raising, 3: 1907 (1892)
In California Cuzco corn is cited, in the local agricultural press, at over 19 feet high. ... "the variety of Cuzco corn having only 330 grains per pound ..."

Webber: Cuzco Corn hybrids (1900)
Only very few of the numerous important problems here presented to the plant breeder have as yet been taken up. In the hope of securing better-yielding races the exceedingly large-kernelled Cuzco, or Peruvian Corn recently imported into the United States by the Department of Agriculture, was used in hybridising with certain of our best races. The Hickory King, a very large-kernelled white dent, and Leaming, a well-known yellow dent, were used as the seed-bearing parents. The Cuzco, from which the pollen for the hybrids was obtained, was grown from kernels of a graphite colour, this colour being distinct from that of any race of Corn in the United States with which I am familiar.

Webber: Xenia. USDA Bulletin 22 (1900)
Hickory King x Black Cuzco - "On the four kernels which showed xenia the change consisted simply in irregular spots of the characteristic dark plumbeous color of the Cuzco."

[CybeRose note: It is very odd that the slate-colored form of Cuzco corn behaves much like the Black Mexican sweet corn in crosses. I.e., the cross-breed seeds may be black, white or dotted. Both are 8-rowed, though one is Peruvian while the other is from New England (despite the "exotic" name).]

Cook: Staircase Farms of the Ancients. National Geographic (1916)
The usual behavior of the Cuzco corn in the United States is to produce plants of enormous size that mature very little seed, often none at all. It has been taken for granted that the size of the plants should be in proportion to the enormous kernels, and that our seasons were not long enough to permit this type of corn to mature.
    But in Peru one does not see these gigantic, infertile plants, nor any indication that the corn crop requires a large amount of heat to bring it to maturity. The impression one gets from the Peruvian corn-fields is that the plants are not taller than with us and rather more slender, the most striking peculiarity being the prevailing red color of the foliage. The best development and largest ears of the Cuzco corn are found in some of the higher valleys, at elevations between 9,000 and 11,000 feet, in districts where the summer climate is cooler than in any of the corn-growing regions of the United States.
    Thus it becomes apparent that the possibility of utilizing the Cuzco type of corn in the United States is still practically untried, because of our lack of information regarding the normal behavior of the plant and the natural conditions to which it is adapted. As might have been expected, if these facts had been known, the best results thus far obtained from the Cuzco corn in the United States have been in California, in the cool climate of the coast districts, where there is too little heat for our eastern varieties to thrive.

Collins: Tropical Varieties of Maize. J Hered 9: 147-154 ( 1918)

Jones The Origin of Flint and Dent Corns (1924)
Cuzco seeds show a slight tendency to indent due perhaps to their very large size, since smaller seeded floury varieties are perfectly smooth. Many of the seeds on the hybrid ear are well indented. All of the seeds have varying amounts of soft and hard starch and seeds of dent type and flint type can be found on all of the ears. There seems to be no doubt but that fairly good flint and dent types could be separated from this cross.