Sauer - 1993 - Historical geography of crop plants, a select rost

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Monocots 213 palustris), is an annual with a wide native range; it is currently an incipient domesticate as a grain crop. The native range of Z. aquatica, sensu lato, extends from Idaho and Manitoba to the maritime provinces of Canada and New England and southward to Texas and Florida. Its main habitats are shallow lakes and slow-moving streams with silty or muddy bottoms. It is commonly associated with cattails and water lilies. Along the seaboard, it sometimes grows in brackish marshes by river mouths. Suitable habitats are highly disjunct, and wildrice, like most aquatic plants, is dependent on bird dispersal for its wide range. Wildrice is a regular food of waterfowl and various other birds. It is also attractive to moose and muskrat. As in all cereal grains, the wildrice in natural stands has shattering inflorescences. Seed is not buoyant, but sinks to the bottom and remains dormant over winter or over several winters. Upon germination, ribbon-like leaves float to the surface in spring, followed in summer by the emergent stalks, which usually reach about 1 m, sometimes as much as 3 m in height. Indian peoples began harvesting Zizania prehistorically, especially in the northern glaciated terrain where it is most abundant. Traditionally, two people harvested the ripening grain from a canoe, one propelling the canoe while the other used sticks to bend the inflorescence over and gently dislodge the ripe grain. Most of the grain escaped harvest, even if a stand was reworked several times, and Indian exploitation probably had no more bad effects than waterfowl feeding; neither did if result in domestication. By 1900, wildrice bought from Indian gatherers had entered commerce as an expensive delicacy. Ingenious harvesting machines were invented, mounted on boats or pontoons. In both Canada and the U.S., exploitation was generally limited by government regulation, and much of it remained in Indian hands. There have, of course, been many attempts to expand the stands. During the 1930s, for example, the Indian branch of the U.S. Civilian Conservation Corps carried out extensive seeding attempts. As a rule, attempts to manage and expand natural stands had little effect, one way or the other. The species already occupied all suitable habitat, and artificial planting was a waste of seed. In the 1950s in northeastern Minnesota, a different approach was begun, namely, planting of wildrice in artificial paddies separate from the natural stands. The planting stock was still of the wild, shattering type, and the stands regenerated annually from the seed that escaped harvest. Zizania grain at maturity has a remarkably high water content, usually over 40% by weight, and remains viable for only a few days if exposed to air drying. Grain harvested for consumption is usually promptly killed in the early stages of processirig by drying and parching. Saving grain for artificial planting requires storage in cold water. This peculiar adaptation, the need for Zizania grain to be kept constantly in cold water to remain viable, has been a real obstacle to domestication, which has not yet been overcome. Even when the crop is grown in an artificial paddy, farmers have commonly continued to rely on natural reproduction from shattered seed stored over winter in the mud. A crucial process in the domestication of other grain crops was therefore blocked:
214 Historical Geography of Crop Plants: A Select Roster automatic selection of mutations for nonshattering was not begun by planting harvested grain. Finally during the 1960s, deliberate selection of mutations that reduced shattering was begun in Minnesota, first by private entrepreneurs and then by a University of Minnesota breeding program. These cultivars were rapidly adopted for planting artificial wildrice paddies in northeastern Minnesota. They allowed machines to harvest in one operation three times the grain obtained by repeated harvests of the shattering forms. However, the farmers usually continued to rely on reproduction by the grain that escaped harvest. In the 1980s, Zizania cultivation on a much larger scale was begun far outside the native range in California’s Sacramento Valley. This is a region where paddy cultivation of Oriental rice has long been important. Some new shatter-resistant cultivars were selected locally. More importantly, the California farmers generally practiced cold storage and sowing of harvested grain. The paddies, in a region of expensive irrigation water and high evaporation, were not maintained as permanent artificial marshes, but were drained and allowed to dry between wildrice crops. Sometimes the land was rotated to Oriental rice or other crops. As a result, intense automatic selection for ¡ess shattering and less dormancy began. It should be interesting to see how rapidly this may produce a truly domesticated cultivar, dependent on harvesting and sowing. By the mid-1980s, California growers had more than 6000 ha of wildrice, with average harvests ten times the maximum obtained from native stands and accounting for about half of the world crop. This was too much wildrice for the existing market demand, and large stocks remained in storage with reduced planting as a result. The crop is costly to grow, largely because viable seed is expensive and much of it remains dormant after sowing. Also, much of the wildrice crop is harvested by flocks of redwing blackbirds. Whether Zizania will ever join Oryza as a staple rather than a luxury remains to be seen. H ORD EUM — BARLEY (Bar-Yosef and Kislev 1989; Bender 1975; Harlán* 1975, 1976; Murray 1970; Wiehe 1968; Zohary and Hopf 1988) Hordeum includes about 25 species native to the north temperate regions, mainly in open, dry habitats. Some are tolerant of salinity and alkalinity. Most are weedy and have spread in artificially disturbed sites. A single wild species H. spontaneum is the progenitor of all the cultivated barleys. H. spontaneum {=H. vulgare subsp. spontaneum) today ranges widely through the Levant and southwestern Asia as an agricultural weed. However, truly wild populations occupying natural habitats are concentrated in a coherent arc, the so-called Fertile Crescent, extending from the Jordan Valley northward to the Anatolia-Syria border region and then curving eastward along the Iran-Iraq border region. Wild barley and wheats are important members of the winter annual grassland and oak parkland of this Mediterranean climatic region. As the long summer drought sets in, they quickly mature a large crop of grain.
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Sauer - 1993 - Historical geography of crop plants, a select rost

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