Avena(redirected from Avenar)
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(oat), a genus of herbaceous plants of the family Gramineae. It comprises approximately 70 species. The genus is divided into two sections: Euavena, which includes annual species (cultivated species and wild oat), and Avenastrum, which includes perennial species (meadow and steppe grasses). The plants have a fibrous root system, linear leaves, and a paniculate inflorescence with one-to-three-flowered or multiflorous spike-lets. The grain is a caryopsis covered with hairs. In tunicate forms, the fruit is tightly enclosed in a lemma; in awned forms, the external lemma has an awn. The most commonly cultivated species in temperate countries of the northern and, partly, the southern hemispheres is the oat plant (Avena sativa), which is divided into three groups of varieties: grex. var. diffusae has a diffuse panicle and tunicate grain, grex. var. orientalis has a tight panicle and tunicate grain, and grex. var. nudae has a naked grain. The species A. byzantina is cultivated in the Mediterranean region, the southern United States, Argentina, Australia, and the USSR (small areas in Azerbaijan and Uzbekistan). Animated oats (A. strigosa) are sown in Spain, France, and Belgium.
The oat plant is a spring or winter species. The root extends into the soil to depths to 120 cm. The stem has a tunicate ligule at its junction with the leaf blade. The spikelets have one to three (rarely four) flowers in tunicate forms and two to seven flowers in nude forms. One thousand grains weigh 20–40 g; their membranes make up 25–40 percent of their weight.
The vegetative period of the oat plant is 80–110 days. The plant requires a good amount of moisture and cool weather. Seeds begin to sprout at 1°–2°C; shoots can tolerate short frosts up to 7°–8°C. The plant is self-pollinating; cross-pollination is very rare. It grows best in peat-podzols, gray forest soils, and chernozems.
Oats are a basic grain feed. The grain contains 9–19.5 percent protein, 21–55 percent starch, 7–24 percent cellulose, 2.9–5.7 percent ash, and 2–11 percent fat. It also contains vitamins. Oats are made into groats, meal, and other similar products. Animals are fattened with the straw and green mass of oat plants, especially in mixtures with legume plants (vetch and peas), hay, and silage.
The oat plant was first cultivated in the second millennium B.C. Its cultivation was probably introduced into Russia in the seventh century A.D. The oat plant is a younger crop than wheat and barley, among which it grew as a weed. When the plant appeared further north, it was hardier and grew in pure plantings. Between 1960 and 1972, the worldwide plantings of oat averaged 30–32 million hectares (ha) annually; the annual gross harvest of grain was about 60 million tons. As of 1972, the world’s largest planted areas and gross harvests were recorded in the USSR (11.4 million ha; 14.1 million tons), the United States (5.5. million ha; 10.1 million tons), Canada (2.5 million ha; 8.8 million tons), Poland (1.3 million ha; 3.1 million tons), and the Federal Republic of Germany (0.8 million ha; 2.9 million tons). The yield in quintals per ha was 12.3 in the USSR (8.9 in 1913, 10.1 in 1965, 15.3 in 1970); 18.3 in the United States, 18.7 in Canada, 24 in Poland, and 35.7 in Federal Republic of Germany.
The principal regions of oat cultivation in the USSR are Byelorussia, the Baltic region, northern Kazakhstan, Siberia, the nonchernozem and central chernozem zones of the RSFSR, and the forest steppe and the lowland forest of the Ukraine. The best varieties are L’govskii 1026, Orel, and Nadezhnyi. In 1974, 48 varieties were regionalized. The oat plant is a field crop. It is usually placed in the last field of a crop rotation, following legumes, row crops, and fertilized winter crops. The average amount of mineral fertilizer used is 30–45 kg/ha N, 45–60 kg/ha P2O5, and 45–60 kg/ha K2O. The seeds are sown in rows spaced 15 cm or 7.5 cm apart; the rate of sowing is 5–6 million viable seeds per ha (1.8–2.5 quintals per ha). The seeds are placed at depths of 3 to 6 cm. Oats are harvested by a sectional method when the grain of the upper spikelets is completely ripe or directly by a combine. The principal pests are the wireworm and the frit fly; plant diseases include rust and smut.
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K. S. MITROFANOVA