Rye

Description

Rye, Secale cereale, is an herbaceous annual or biennial in the family Poaceae that is grown primarily for its grain. Rye has an erect slender stem topped with a curved spike which is 7–15 cm (3–6 in) length. The head is made up of individual spikelets each with two florets which produce 1–2 kernels. The spikelets and arranged alternately along the length of the head.The leaves of the plant grow from nodes on the stem and are lance-like blades, blue-green in color. Rye can reach 1–3 m (3.3–10 ft) in height and is either grown as an annual (spring rye) or biennial (winter rye). Modern rye does not occur naturally but is likely derived from wild ancestors found in Afghanistan, Iran and the Middle East.


Uses

Rye grain can be used to make alcoholic drinks such as whiskey, gin and beer or used as a livestock feed. Rye flour can be used to make bread. Rye is extensively grown as a winter cover crop to prevent soil erosion and the mature stems are commonly used as animal bedding.


Propagation


Basic requirements
Rye is a cool season annual grass which can be grown in a wide range of soils and climates. Rye grows best when planted in well draining sandy or light loams but can also be grown in clay soils. The optimum pH for rye growth is between 5.6 and 6.5. Rye will germinate when soil temperatures are between 4 and 5°C (39–41°F). Daily temperatures should not exceed an average of 20°C in order for the plant to grow adequately. Winter rye should be planted in fall to mid-winter depending on the variety and be overwintered for a summer harvest, while spring rye is planted in the spring for summer harvest.

Propagation
Rye is propagated directly from seed and can be sown by broadcasting or by drilling. Seeds should be sown to a depth of 2.5–5.0 cm (1–2 in) allowing 15–18 cm (6–7 in) between rows where seeds are drilled. Seeding If seeds are broadcast, they must be covered to ensure adequate germination. Seeding rates are generally between 100 to 150 kg of seed per hectare for winter rye and 150 to 200 kg per hectare for spring rye to produce a plant stand of 200-300 plants per square meter.

General care and maintenance
Rye fields should be kept free from weeds through the use of herbicides or by harrowing. Herbicides may be applied while the plants are at the tillering stage of growth. Rye will benefit from the addition of nitrogen which is often the biggest yield limiting factor in rye cultivation. Fertilizer should be applied when the crop begins to grow and the application may be split over two applications.

Harvesting
Rye is ready to harvest when the leaves are dead and the stems have turned yellow-brown in color. Rye is commonly harvested by combine but can also be harvested by hand.


References

CABI Crop Protection Compendium. (2010). Secale cereale (rye) datasheet. Available at: http://www.cabi.org/cpc/datasheet/49471. [Accessed 07 April 15]. Paid subscription required.

USDA NRCS. Cereal Rye. US Department of Agriculture, Elsberry Plant Materials Center, Missouri. Available at: https://plants.usda.gov/plantguide/pd.... [Accessed 07 April 15]. Free to access.

Van Veldhuizen, B. (2010). Growing small grains in your garden. University of Alaska Fairbanks. Available at: http://www.uaf.edu/files/snras/C135.pdf. [Accessed 07 April 15]. Free to access.


Common Pests and Diseases

Bacterial blight (Bacterial leaf blight, Black chaff)
Xanthomonas translucens

Symptoms
Water soaked spots on foliage; shriveling dead leaves; glossy yellow or brown streaks; plant appears stunted, slow plant growth
Cause
Bacteria
Comments
Disease spread through infected seed and splashing water
Management
Use only certified, disease-free seed; treat seeds with a fungicide prior to planting to prevent diseases which allow bacteria to enter easily; practice crop rotation to reduce disease build-up in soil

Rust
Puccinia reconita

Symptoms
Chlorotic flecks or brown necrotic spots on leaves or stems; yellow streaks or patches on foliage; brown necrotic streaks on foliage; raised orange pustules may be present on lesions
Cause
Fungus
Comments
Disease emergence favors moist weather and moderate temperatures
Management
The most effective method of controlling rusts is to plant resistant varieties of wheat; other methods of control include: destroying alternate hosts; applications of appropriate protective fungicides; growing wheat varieties that mature early

Loose smut
Ustilago tritici

Symptoms
Early emergence of heads; dark green or black masses in place of kernels
Cause
Fungus
Comments
Spores rupture out from protective membrane on heads; fungus can survive in infected seed
Management
Use only certified smut-free seed; treat seeds with hot water prior to planting to kill fungi; treat seeds with systemic fungicide (fungi inside seed) fungicide; grow resistant varieties

Powdery mildew
Erysiphe graminis

Symptoms
Patches of cottony, white-gray growth on upper surface of leaves which turn gray-brown; chlorotic patches develop on leaves opposite fungal growth; fungal fruiting bodies usually become visible as black dots on the mildew
Cause
Fungus
Comments
Disease emergence favors heavy nitrogen fertilization; high humidity and cool temperatures
Management
Planting resistant varieties is one of the best ways to protect plants from powdery mildew; other control strategies include: application of appropriate foliar fungicides, if available; removal of crop debris from field after harvest to reduce the level of overwintering fungus; removal of volunteer wheat plants which can act as a reservoir for the disease

Net blotch
Drechslera teres

Symptoms
Dark green water soaked spots; narrow brown blotches with netted appearance, surrounding tissue yellow; stripes running the length of leaf
Cause
Fungus
Comments
High humidity promotes spread of the disease
Management
Rotate rye with resistant crops; grow resistant varieties; remove and crop residue from soil surface; destroy volunteer rye plants

Armyworms (Armyworm, Western striped armyworm)
Mythimna unipunctata
Spodoptera praefica

Symptoms
Entire leaves consumed; notches eaten in leaves; egg clusters of 50-150 eggs may be present on the leaves; egg clusters are covered in a whitish scale which gives the cluster a cottony or fuzzy appearance; young larvae are pale green to yellow in color while older larvae are generally darker green with a dark and light line running along the side of their body and a pink or yellow underside
Cause
Insect
Comments
Insect can go through 3–5 generations a year
Management
Organic methods of controlling armyworms include biological control by natural enemies which parasitize the larvae and the application of Bacillus thuringiensis; there are chemicals available for commercial control but many that are available for the home garden do not provide adequate control of the larvae

Wireworms
Aeolus spp.
Anchastus spp.
Melanotus spp.
Limonius spp

Symptoms
Death of seedlings; reduced stand; girdled stems and white heads; wireworm larvae can be found in soil when dug round the stem; larvae are yellow-brown, thin worms with shiny skin
Cause
Insect
Comments
Larval stage can last between 1 and 5 years depending on species
Management
Chemical control impossible in a standing crop, must be applied at preplanting or as a seed treatment; if wireworms are known to be present in soil fallow field during summer and till frequently to reduce numbers; rotate to non-host crop where possible; avoid planting susceptible crops after a wireworm infestation on cereals without either fallowing of applying appropriate pesticide

Aphids (Bird cherry-oat aphid, Russian wheat aphid, Corn leaf aphid, etc.)
Rhopalosuphum padi
Diuraphis noxia
Sitobion avenae

Symptoms
Yellow or white streaked leaves; flag leaves may be curled up; plants may be stunted and tillers may lie parallel to the ground; plants may turn a purple color in cold weather; insects are small and soft-bodied and may be yellow, green, black or pink in color depending on species; insects secrete a sugary substance called "honeydew" which promotes the growth of sooty mold on the plants
Cause
Insect
Comments
Fields should be checked for aphid populations periodically after emergence
Management
Sturdy plants can be sprayed with a strong jet of water to knock aphids from leaves; insecticides are generally only required to treat aphids if the infestation is very high - plants generally tolerate low and medium level infestation; insecticidal soaps or oils such as neem or canola oil are usually the best method of control; always check the labels of the products for specific usage guidelines prior to use; in commercial plantations aphid numbers are usually kept in check by predators and natural enemies; beneficial insect populations should be assessed before chemical control is considered; if no beneficial insect populations are present and aphids are damaging then apply appropriate insecticides

Barley yellow dwarf
Barley yellow dwarf virus (BYDV)

Symptoms
Stunted growth of plants; yellow green blotches at leaf tip, leaf margin or leaf blade; leaves turning bright yellow, red or purple
Cause
Virus
Comments
Transmitted by a few species of aphid; spread of disease is completely dependent on the movement of aphid vectors
Management
Control of aphid population can provide some control of disease but is dependent on knowing which aphids are active in the field; planting to avoid periods of peak aphid activity can provide a measure of control