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Briza media

Perennial quaking grass, quaking grass

Briza media (Hegi, 1997)

BOTANY

Perennial, 20-50 cm high, cespitose with low-density, short rhizomes, young shoots extravaginal.

Culms are 20-50 cm high, slender, erect, smooth and glabrous; two to three noded, nodes glabrous.

Leaf sheaths of the young shoots at the beginning are closed up to the apex, later but slightly torn open, glabrous, smooth or sparsely scabrous.

Ligule is a fringe 1-2 mm long, collarshaped and membranous.

Leaf blades are 5-15 cm long, 2-4 mm wide, flat, smooth and glabrous, scabrous only at the margins.

Inflorescence a panicle, 5-16 cm long, 4-12 cm wide, open, spreading, pyramidshaped. The lowest lateral branches come off in pairs from the main axis, erectly sticking out, sparsely ramified, lengths of rachises are highly unequal, thin, scabrous and 5-20 mm long.

Spikelets with 3-14 florets, 4-7 mm long, broadly ovate or cordate, pendulous.

SUITABILITY FOR RESTORATION

In the Alps this European species occurs in hilly, montane and subalpine zones. At lower locations mainly in thin populations, at higher altitudes in densely grown turfs also. In nutrient-deficient meadows and pastures, along road embankments, on rocky slopes, and in low-density stands. On clay soil, loam and sandy loam that is moderately dry or moist up to wet, alkaline, often nutrient-deficient, moderately acid soil, rich in humus or peat, with a pH of 3.8-7.2. Indicating nutrient-deficiency and light (heliophyte), shallow-root plant on humus. Good but low-productive forage. In meadows and pastures without fertilization the plant is stimulated by maintenance, but disappears with intensified fertilization and grazing.

All-purpose grass for restoration in montane to alpine regions, less qualified for highly acid and moist soils; cespitose, preferably for poor habitats, intermediate forage quality.

SEEDS

Glumes similar, three to five-veined, 2.5-3.8 mm long, broadly ovate to orbiculate as seen from dorsal view, upper margin rounded, vaulted, membranous, margins hyaline, glabrous, midvein sparsely scabrous.

Seeds

Lemma seven to nine-veined, 3.6-4.2 mm long, similar shape to glumes, densely arranged, membranous, green, often coated purple, margins hyaline and whitish. Palea two-veined, 3.5-4 mm long, flat, ovate, apex slightly nicked, keels prominent and narrow-winged.

Anther 2-2.5 mm long.

Fruit about 2 mm long, broadly elliptic in contour, light brown.

Thousand seed weight: 0.3-0.5 g.

REQUIREMENTS
(soil and climate)

Warm, moist to moderately dry soils with a pH of 5.0-7.5 are suitable for seed gain cultivation. Compacted waterlogged soils should be avoided.

CULTIVATION

Like most grasses, perennial quaking grass needs a carefully prepared, fine, crumbly seedbed. Seeds have sufficient seed flow; however, they can be easily blown away by the wind.

This species is relatively fast-growing compared to most of the species described. It can be sown underneath spring corn, blank seed is also possible. Attention should be paid to low-density cover crop populations. Open sowing should be carried out by the end of June at the latest, in order to allow sufficient tillering in autumn. In this case, it is recommended that the crop is irrigated during summer droughts.

Crop yields: Under average conditions, optimal maintenance allows for yields between 120 and 300 kg/ha.

Seed rate: 10-12 kg/ha is common.

Generally speaking, a decrease in the seed rate can help to produce welldeveloped and well-tillered single plants. However, this is only recommended where there is expert knowledge and best population tending.

Row spacing: 15-20 cm, depending on the construction of the seeder. Broadcast sowing is also possible in combination with a curry comb.

FERTILIZATION

Phosphorus and potassium: although quaking grass requires few nutrients, moderate fertilization (40-60 kg/ha P2O5 and 80-100 kg/ha K2O) works well. Fertilization with liquid or solid manure (in late summer and early autumn) stimulates the growth the single plants until their rest period. Application of liquid manure in spring should be avoided because of nitrogen mobilization during an unfavourable vegetation stage.

Nitrogen: this should be applied in early spring, only with mineral fertilizer, in amounts of 50-70 kg/ha depending on soil and climate.

MAINTENANCE AND WEED CONTROL

The straw of the cover crop should be removed immediately and then cut.

As for most grasses the following rules apply. Before sowing, only contact herbicides should be used, preferably up to three days before the beginning of sowing. Hormone-type and broadspectrum herbicides should generally not be used until the species has reached the three leaf stage. It should be noted that the herbicides mentioned in Table 3 are not registered for use in seed cultivation in some countries.

Having tended the species well after the cover crop harvest, densely grown populations can develop until autumn.

Where heavy growth of weed grasses is evident, the specific application of Ethofumesate can control Poa annua in particular. However, an expert should be responsible for evaluation as well as composition. National guidelines on the use of herbicides should always be followed.

Rust diseases: perennial quaking grass is extremely sensitive. Especially after the first seed harvest in summer, the population may be infected within a couple of days and collapse as a result. Continuous monitoring and - weather permitting - prophylactic spraying with a suitable fungicide are advisable.

If the crop is already infected by rust, it should be cut and removed immediately, and combined with spraying about one week after the cutting in order to save the remaining population. Crop yield losses need to be reckoned with the following year.

HARVEST AND YIELDS

Resistance to lodging: intermediate.

Shattering tendency: intermediate.

Ripeness: culms and flower spikes change colour from reddish light brown to tawny or light brown. Until complete ripeness is reached, there is a low shattering tendency, which then becomes high. As for most grasses appropriate to the habitat, it is very important to keep an eye the ripening in order to optimize crop yield and quality.

Flowering propagation stand

Ripening period: between the end of June and the beginning of July, depending on climate and ecotype.

Harvesting technique: direct threshing is possible and easy. Because of a high accumulation of biomass, the straw from the harvest should at least be chaffed or carried away. More than for other species, seed producers should set the threshing drum at a low rotational speed, with a comparatively wide gap between drum and threshing concave. Large sieves are needed. In order to avoid high losses at threshing, the air supply should be reduced, if necessary to zero.

Seeds should be cleaned with great care. Cleaning with air and adequate sieve systems is normally sufficient.

Crop yields: Under average conditions, optimal maintenance ensures yields between 120 and 300 kg/ha.


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