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Secale cereale L.


Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Toxicity
  5. Description
  6. Germplasm
  7. Distribution
  8. Ecology
  9. Cultivation
  10. Harvesting
  11. Yields and Economics
  12. Energy
  13. Biotic Factors
  14. References


Cultivated for the grain, used to make flour, the importance of which is second only to wheat. Canadian and United States whiskies are made mainly from rye. Roasted grains substitute for coffee. Grains mixed with others are used for livestock feed. As pasturage, crop grazed fall or spring and then allowed to head-out and mature. Crop also used as green manure and cover crop, hay, silage with crimson clover. Straw used as packing material for nursery stock, bricks and tiles, for bedding, paper manufacture, archery targets, and mushroom compost.

Folk Medicine

According to Hartwell (1967–1971), the grains are used in folk remedies for cancers and tumors. Reported to be laxative (Duke and Wain, 1981).


Per 100 g, the grain is reported to contain on a zero-moisture basis (ZMB): 375–382 calories, 11.8–14.6 g protein, 1.9–3.0 g fat, 80.5–84.4 g total carbohydrate, 2.2 g fiber, 1.8–2.0 g ash, 43–45 mg Ca, 377–422 mg P, 3.4–4.6 mg Fe, 1.1–6.9 mg Na, 524 mg K, 0 mg b-carotene equivalent, 0.28–0.54 mg thiamine, 0.23–0.25 mg riboflavin, 1.8–1.9 mg niacin, and 0 mg ascorbic acid. Rye is generally considered a little less nutritious than wheat.


Ergot Poisoning may be a problem.


Tall, hardy, tufted annual grass, 1–1.5 m tall, with blue-green cast, culms slender, erect, overtopping the foliage, glabrous except pubescent near the spike, glaucous; leaves many, soft, 1.2 cm or less broad, smooth or slightly scabrous, long-pointed; leaf-sheaths long and loose; ligule short and jagged; spike terminal, 7.5–15 cm long, curved, much-awned, slender, compact; spikelets with 2 fertile florets; lemmas long and narrow, tapering into awns, Prominently keeled; kernel oblong, 0.8 cm long, light brown, narrowly grooved on face, short-pointed, glabrous (Reed, 1976).


Reported from the Central Asian, Near East, and China-Japan Centers of Diversity, rye, or cvs thereof, is reported to tolerate aluminum, anthracnose, bacteria, disease, drought, fruit, fungi, high pH, hydrogen flouride, insects, low pH, nematodes, poor soil, salt, sand, rust, virus, waterlogging, and weeds (Duke, 1978). Many farmers put rye on their worst soils, since rye tends to do better than other cereals under such conditions. Few cvs have been developed. Intergeneric hybrid with wheat known as Triticale. Some varieties include: Petkuser, Schlaustedt, Rosen, St. John, Abrussi, South Georgia, Dean, Mammoth, White, Rimpau, and Virginia Winter. Sometimes divided into S. fragile Blob., an annual from southwest Asia and S. cereale L., a wild perennial form from southern Europe and central Asia, derived from S. montanum Gus., grown in America. 2n = 14 (Reed, 1976).


Probably native to southwestern Asia, but now widely cultivated in the temperate regions of the world. Grown in every state in the United States, often where conditions are unfavorable for wheat (Reed, 1976).


Ranging from Boreal Moist to Rain through Subtropical Dry to Moist Forest Life Zones, rye is reported to tolerate annual precipitation of 2.2 to 17.6 dm (mean of 103 cases = 7.9), annual temperature of 4.3 to 21.3°C (mean of 103 cases = 11.1), and pH of 4.5 to 8.2 (mean of 88 cases = 6.4) (Duke, 1978, 1979). An extremely hardy plant, often grown where other grains will not grow. Thrives on infertile, submarginal areas; renouned for its ability to grow on sandy soils.


Rye grows rapidly and vigorously from seed, giving a rapid cover crop useful for erosion control or early pasture. Selected varieties are hardier to cold areas than other cereal grains. Seed broadcast or drilled at seed rate of 40–68 kg/ha. Sown in fall, winter, or spring, covered shallow enough to reach soil moisture. Intercropped with wheat in some countries. Responds to fertilization, but will grow on soils of limited fertility. Nitrogen and phosphorus required on sandy soils. Usually given less favorable places in rotations (Reed, 1976).


Harvested in early summer until fall, depending when it was planted. Directly harvested with combine or from windrows when dry. Milling of rye is essentially the same as that for wheat (Reed, 1976).

Yields and Economics

Grain yields in United States vary from 675–2025 kg/ha, depending on variety and cultivation methods (Reed, 1976). In 1979, the world low production yield was 300 kg/ha in South Africa, the international production yield was 1,602 kg/ha, and the world high production yield was 6,923 kg/ha in Norway. The residue coefficient, defined as the ratio of the weight of dry matter of residue to recorded harvested weight, ranges from 1.20 to 1.95, the upper limit determined by USDA experts. The residues are figured as straw and include an additional factor of 0.25 for chaff (NAS, 1977a). South Dakota, with 26% of US production, North Dakota (16%), Nebraska (10%), and Minnesota (9%), account for most US production, averaging ca 18.2 q/ha. World production averages 34.2 million MT annually. The major producers, in order, are: USSR, West Germany, Czechoslovakia, United States (mostly produced in North Central States), France, Hungary, Spain, Netherlands, Argentina, and Turkey. In US, prices for rye are lower than for wheat, competing as feed, not food (Reed, 1976).


According to the phytomass files (Duke, 1981b), annual productivity ranges from 0 to 45 MT/ha. A hectare of rye, yielding 1,258 kg, equivalent to 4,201,720 kcal, required the following inputs, machinery equivalent to 234,000, gasoline equivalent to 30,327, diesel to 428,025, seed to 262,856, transportation to 33,667, herbicides to 17,576, N to 493,920, P to 30,000 for a total input equivalent ca 1,500,000 kcal/ha. The output:input energy ratio was 2.75. Note that even in this low-fertilizer requirement plant, N was the biggest energetic input, at ca 1/3 the total energy input. Another calculation there, on rye grown on summer fallow gave a rye yield of 2509 kg/ha for an output:input ratio of 10.2:1, the highest US ratio cited in Pimentel (1980). (See Table 11) Research reiterated by Palz and Chartier (1980) indicated that straw from winter wheat, summer wheat, winter barley, summer barley, winter rye, and oats all gave calorific values based on moisture-free dry matter of 17.0 (±5%) MJ/kg, or based on air dry matter 15.06 (± 3.5%) MJ/kg. High N fertilization raised calorific values by ca 425 KJ/kg. Increasing moisture content from 14 to 20% reduced calorific value by 9%. Since straw available as feedstock is normally air-dry, a calorific value of 15 MJ/kg is assumed by Palz and Chartier (1980) for all cereal varieties and species. The assumed grain straw ratio for wheat is 1.23 barley is 1.45 oats is 1.16 rye is 0.07 other cereals is 1.10. Elsewhere, Palz and Chartier assume 17.5 MJ/kg as the typical energy value for the dry matter of herbaceous materials.

Biotic Factors

Rye is cross-fertilized, hence pollination is not a problem. The most serious disease of rye is ergot (Claviceps purpurea). Other fungi known to attack rye plants include: Alternaria tenuis, Anguina tritici, Ascochyta graminicola, Calonectria graminicola, C. nivalis, Cercosporella herpotrichoides, Cerebella andropogonis, Cladochytrium graminis, Cladosporium herbarum, Cochliobolus sativus, Colletotrichum graminicola, Corticium solani, Curvularia inaequalis, Dilophospora alopecuri, Dinemasporium graminum, Erysiphe graminis, Fusarium acuminatum, F. avenaceum, F. culmorum, F. equiseti, F. graminearum, F. heterosporium, F. nivale, F. orthoceras, F. oxysporum, F. poae, F. roseum, F. scirpi, F. sporotrichiodes, Gibberella saubinetii, G. zeae, Griphosphaeria nivalis, Helminthosporium inocuspicuum, H. sativum, H. teres, H. tritici-repentis, H. tuberosum, Heterosporium secalis, Lagena radicicola, Leptosphaeria herpotrichoides, L. herpotrichoides f. riticea, L. secalis, Lophodermium arundinaceum, Macrophoma secalina, Marasmius ritici, Marasemia graminicola, Naucoria cerealis, Nectria secalina, Ophiobolus r inis, Olpidiaster radicis, Phialea temulenta, Pleospora trichestoma, P. vulgaris, Puccinia ceronata, P. disperse, P. elymi, P. glumarum, P. graminis, P. recondita, P. rubigo-vera, P. secalina, P. straminis, P. striiformis, Pyrenophora relicina, P. trichestoma, Pythium aphanidermatum, P. aristosperum, P. arrhenomanes, P. debaryanum, P. graminicola, P. volutum, Rhizoctonia solani, Rhynchosporium e lis, Sclerospora secalina, Sclerotinia graminearum, Scolecotrichum graminis, Selenophoma donacis, Septoria nodorum, S. secalis, S. tritici, Spermedia clavus, Stemphylium botryosum, Tilletia caries, T. contraversa, T. foetida, T. secalis, T. tritici f. secalis, Tuburcinia occulta, Typhula graminum, T. itoana, Urocystis occulta, Ustilago hordei, U. nuda, U. spegazzinii, U. tritici, U. vavilovii, Vetnovicia graminis, Wojnowicia graminis. Bacteria isolated from rye include: Pseudomonas coronafaciens and Xanthomonas translucens var. secalis. Plants parasitising rye include: Cuscuta epithymum var. vulgaris, C. pentagona, and Striga lutea. Virus diseases include: Agropyrum streak mosaic, Barley false stripe, Barley yellow dwarf, Maize streak, Red-leaf, Rice stripe, and Strait mosaic. Nematodes isolated from rye include: Anguillulina pratensis, A. devastatrix, A. secalis, A. dipsaci, Anguina tritici, Belonolaimus gracilis, B. longicaudatus, Ditylenchus dipsaci, D. radicicola, Helicotylenchus dihystera, H. pseudorobustus, Heterodera avenae, H. hordecalis, H. latipons, Meloidogyne arenaria, M. incognita, M. incognita acrita, M. javanica, Merlinius brevidens, Paraphelenchus pseudoparietinus, Pucephalobus leunatus, Pratylenchus neglectus, P. penetrans, P. pratensia, P. tunidiceps, Radopholis similes, Rotylenchus buxophilus, Subanguina radicola, Tylenchorhynchus claytoni, T. sylvatica, Tylenchus hordei, T. polybyphnus, T. secalis. Some of the more important insect pests of rye include: Barley thrips (Limothrips denticornis), Aster leafhopper (Macrostoles fascifrons), Armyworm (Pseudaletia unipuncta), and Apamea sordens (Ag. Handbook No. 165, 1960; Reed, 1976).


Complete list of references for Duke, Handbook of Energy Crops
Last update Friday, January 9, 1998 by aw