Oats

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Oats
Avena byzantium C. Koch.
Family- Poaceae



Oats is one of the oldest cereal cultivated by man. Avena strigosa sap. strigosa was found in the remains of lake dwellings of Bronze Age 3500-1000 B.C. A. fatua ssp. fatua was associated with Iron Age (from 1000 B.C.) and sub-species sativa was recorded at several ancient Slav sites (900-500 B.C.). Wild oats were cultivated by cave dwellers in Switzerland before 1000 B.C. and in Britain carbonised grains of both cultivated and wild forms mixed with wheat and barley were found. They belong to the Iron Age about 400-250 B.C. (Mallow 1930 cf. Brian F. Bland, 1971).
Origin: It was assumed that presently cultivated types of Avena sativa originated in Europe, until Vavilov (1926) came across them as a weed in Emmer wheat in Persia. Now it is believed to be native to Asia.

Wild species of Oats

Avena is a large genus of annual or perennial grasses, comprising about 70 species, found chiefly in temperate and subtropical regions.
    1. A. abyssinica Spier.
    2. A. brevis Spier.
    3. A. fatua Philip.
    4. A. ludoviciana Huskins
    5. A. chinensis (nuda) Huskin
    6. A. sativa L.
    7. A. sterilis Spier.
    8. A. strigosa Nishiyama

Cytology


Three broad groupings based on the number of chromosomes are recognised. They are-
    1. Diploid 2n=14
    2. Tetraploid 4n=28
    3. Hexaploid 6n=42

The cultivated species of oats are mostly hexaploids while the wild species, which could contribute valuable genes are mostly diploids and tetraploids.  But the existence of sterility barriers between the diploid, tetraploid and hexaploid species often complicated the process of gene manipulation and transfer. However, Sadanaga and Cimone (1960) successfully transferred crown rust resistance from A. strigosa (2x) to A. sativa (6x). Brown (1964) used the embryo culture technique to overcome the fertility barriers between A. strigosa and A. sativa.

Botany of the Indian oat



An erect, tufted annual grass 0.6-1.5 m tall with terminal panicles 15-30 cm long, bearing large (2-2.5 cm) drooping awned spikelets. The leaves are abundant, and bluish green in colour. The awned spikelets enclose usually 2, rarely3, yellowish grains. The grain is narrow (2cm long, 3mm broad and 2mm thick) hairy and grooved lengthwise.


Ecology

The common oat grows best in a cool, moist climate. Cool weather is particularly important for high yield and good quality. The red oat is best adapted to warm climates. Oats are grown successfully under a wide range of soils but grows best on friable loam, or soils suitable for wheat and barley.


Oat grain

Most of the grain is filled with aleurone and starchy endosperm. Embryo is situated to the lower side of the grain containing coleoptile, coleorhiza etc.

Uses


Products from oat grain such as oatmeal, oatcakes and cookies are used as food. Oat is also used as feed for livestock. Oats are superior to the other cereals as food for horses and are excellent for breeding animals and young stock.


Oat husks

They are used as raw material for nylon manufacture as a selective solvent in the purification of butadiene (starting point for manufacture of synthetic rubber) in refining lubricating old and resin, in the manufacture of fungicides, herbicides, disinfectants and preservatives. Oat husks ground and added to other feeding stuffs to produce oat feed meal. It is used as filter-aid in breweries, as a filler in linoleum manufacture, source of fibre for paper and board, as a source of hemp-cellulose.

Diseases and pests

Fungal diseases-
    1. Stem rust caused by Puccinia graminis.
    2. Crown rust caused by Puccinia coronata
    3. Covered smut caused by Ustilago kolleri
    4. Speckled leaf blotch caused by Septoria sp.
    5. Leaf blotch caused by Helminthosporium avenae
    6. Powdery mildew caused by Erysiphe graminis
Viral diseases
    1. Eye spot mosaic (Marmor terrestre var. oculatum Mc Kinney). It is a soil borne disease.
    2. Apical mosaic (Marmor terrestre var. typicum Mc Kinney). It is a soil borne disease.
Pests
    • Stem borer (Sesame infernos Wlk.)
    • Aphid (Rhopalosiphum maidis Fitch.)
    • Surface grasshopper (Chrotogonus trachypterus Blanch.)
    • Termites (Odontotermes obsess Ramb. Microtermes obesi Holm)

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