Regrowth of smooth bromegrass ( Bromus inermis Leyss.) following defoliation

100

Otfinowski, R., Kenkel, N. C. and Catling, P. M. 2007. The biology of Canadian weeds. 134. Bromus inermis Leyss. Can. J. Plant Sci. 87: [183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198]. Smooth brome (Bromus inermis Leyss.), a native of central Eurasia, was introduced to Canada as a forage and hay crop around 1888. Early reports of plants escaped from cultivation appear in 1903, and based on the number of collections prior to 1920, smooth brome spread most rapidly in western Canada. It is common along roadsides, forest margins, clearings, shorelines and disturbed areas, but its most detrimental impact is on the diversity of prairies and native grasslands. For example, in Riding Mountain National Park, MB, plant diversity of fescue prairies recently invaded by smooth brome decreased by 70%. Vegetative proliferation through underground rhizomes is key to the invasiveness of smooth brome, but long-range dispersal of seeds is facilitated by animals, wind and the transport of hay. Smooth brome is effectively controlled using selective applications of glyphosate and well-timed clipping. However, restoration of infested areas depends on the composition of native seed banks. Smooth brome remains valuable as a forage and cover crop in every province and territory in Canada. [183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198]. Le brome inerme (Bromus inermis Leyss.), plante indigène du centre de l'Eurasie, a été introduit au Canada pour la production fourragère vers 1888. Les premiers rapports mentionnant des plants retournés à l'état sauvage datent de 1903. D'après le nombre de prélèvements effectués avant 1920, on constate cependant que l'espèce s'est répan-due plus rapidement dans l'ouest du pays. Le brome inerme colonise souvent le bas-côté des routes, la lisière des bois, les clairières, les rivages et les terres perturbées, mais l'espèce nuit le plus à la diversité de la flore des prairies et des pâturages naturels. Dans le parc national Riding Mountain, au Manitoba, on a noté une diminution de la diversité des plantes de 70 % dans les prairies à fétuques récemment envahies par le brome inerme. L'efficacité du brome inerme vient essentiellement de sa reproduction végé-tative par rhizomes, mais les animaux, le vent et le transport du foin favorisent la dispersion des graines sur de grandes distances. L'application sélective de glyphosate et une coupe opportune permettent une lutte efficace contre cette adventice. Toutefois, la restauration des lieux infestés dépend de la composition des réserves de semences indigènes. Le brome inerme garde son utilité comme culture fourragère et culture abri dans toutes les provinces et tous les territoires du Canada. Mots clés: Bromus inermis Description and Account of Variation(a) Description. Rhizomatous perennial, 2-15 dm tall, the culms topped with open panicles 5-20 cm long with ascending or spreading branches. Rhizomes up to 1.5 m long without branching or producing stems, 2-5 mm wide, with pale scales. Culms smooth...

Section: Response To Other Human Manipulationsmentioning

confidence: 99%

The biology of Canadian weeds. 134. Bromus inermis Leyss

Otfinowski

Kenkel²,

Catling³

2007

100

“…Repeated defoliation beginning in the spring reduces vigor of plants (see Buwai and Trlica 1977;Lauenroth et al 1985;McLean and Wikeem 1985;Horton 1991;Willms 1991;Willms and Fraser 1992;Zhang and Romo 1994); other studies Harrison and Romo 1994;Romo et al 1995;Romo and Harrison 1999) have shown no adverse effects of a single defoliation on plant growth. In a similar light, greater reductions in plant growth occur when plants are defoliated later in the growing season or when dormant as compared to defoliation early in plant growth Harrison and Romo 1994;Romo et al 1995;Romo and Harrison 1999). In the present study, plants defoliated early in the growing season (May and June) either recovered their production potential sooner or at the same time as plants defoliated later in the growing season (July and August) or when dormant (September, October, November, and April).…”

Section: Discussionmentioning

confidence: 99%

“…Some plants in the Shortgrass Prairie of Colorado recover from defoliation in 14 to 26 mo, while other species require much longer rest periods . In the Northern Mixed Prairie of Saskatchewan, some plant species regain their production potential the year following defoliation (Harrison and Romo 1994;Romo et al 1995;Romo and Harrison 1999), yet growth of other plants is reduced for 1 to 2 yr (Romo et al 1995;Kowalenko and Romo 1998).…”

mentioning

confidence: 99%

Plant production after defoliation of native, Northern Mixed Prairie on hummocky terrain in Saskatchewan

Pantel¹,

Romo²,

Bai³

2010

Resting plants after grazing is central to sustaining potential plant production. Growth of graminoids and forbs was determined for 3 yr after a single defoliation to 7.5 cm in May, June, July, August, September, October, November, or April on five different landform elements in the Northern Mixed Prairie. Green standing crop and cumulative green standing crop of forbs, graminoids, and their total varied with months of defoliation, landform elements, and years after defoliation. Green standing crop and cumulative green standing crop of forbs, graminoids, and their total was less than the control (P ≤ 0.05) on at least one of five landform elements until the second year after defoliation. This pattern of growth suggests the need to defer grazing for at least 1 yr after use to allow plants to regain their production potential. Plants defoliated early in the growing season recovered their production sooner or at the same time as those defoliated later in the growing season or when dormant. Generalizations that spring or early summer defoliation of native range reduces production and late summer or dormant season grazing has no effect on production warrants reconsideration where adequate rest is provided following a short period of grazing.Key words: Landform, landscape, primary production, rangeland, regrowth, standing crop

“…In Utah, desert wheatgrass tillers emerge in late summer to autumn, they overwinter and resume growth the following spring (Mueller and Richards 1986;Olson and Richards 1988a). Northern wheatgrass produces tillers continuously through the growing season (Zhang and Romo 1994) whereas smooth bromegrass tillers in autumn and/or spring, depending on time of defoliation (Harrison and Romo 1994). In Saskatchewan, a cohort of crested wheatgrass tillers can emerge in autumn if temperatures are cool and if abundant precipitation is received (Romo pers.…”

Section: Discussionmentioning

confidence: 99%

“…Smooth bromegrass (Bromus inermis Leyss.) requires 1030-1180 GDD to reach maximum regrowth following defoliation (Harrison and Romo 1994). By comparison, northern wheatgrass (Agropyron dasystachyum [Hook.…”

mentioning

confidence: 99%

Regrowth of crested wheatgrass (Agropyron cristatum [L.] Gaertn.) following defoliation

Romo¹,

Harrison²

1999

Self Cite

] Gaertn.) on the amount of time required to reach peak regrowth, the lag period for regrowth to begin, regrowth biomass, tiller survival and replacement, and carryover effects of defoliation the following year were investigated. Regrowth of crested wheatgrass was determined during the summers of 1990, 1991 and 1992 in central Saskatchewan following a single defoliation to a 5-cm stubble height at eight stages of growth. Crested wheatgrass regrew 54-130 g m -2 of biomass when defoliated tillers had ≤3.6 leaves. Regrowth began accumulating within 3-53 growing degree-days (GDD) and peaked in 705-875 GDD. Rates of leaf development after defoliation (218-252 GDD phyllochron -1 ) equaled or were faster than control (218-330 GDD phyllochron -1 ). Regrowth biomass accounted for 35-76% of total annual production. Total annual production was greatest when plants were defoliated during vegetative growth or at peak growth. In 1991 and 1992, etiolated growth in the spring following defoliation was reduced by defoliation in the previous year. Tiller replacement was not affected by defoliation and averaged 1.2 tillers tiller -1 (SE = 0.1) in 1991 and 1.5 tillers tiller -1 (SE = 0.1) in 1992. Two periods of grazing can be expected from crested wheatgrass if it is grazed when tillers have ≤3.6 leaves; however, the impacts of a second grazing must be determined. If crested wheatgrass is grazed late in the growing season, only one period of grazing can be expected, and production will likely be less the following growing season, necessitating a rest period for plants to regain their production potential. ] Gaertn) sur la durée de repos avant la reprise de la croissance, sur le temps nécessaire pour atteindre la repousse maximale, sur la biomasse de la repousse, sur la survie et sur le renouvellement des talles, ainsi que les arrière-effets sur la croissance l'année suivante. La repousse de la graminée était mesurée au cours des étés 1990, 1991 et 1992 dans le centre de la Saskatchewan à la suite d'une seule fauche à la hauteur de 5 cm, effectuée à 8 stades de croissance. La repousse atteignait 54 à 130 g de biomasse au mètre carré (m 2 ) quand les talles étaient coupées lorsqu'elles ne portaient pas plus de 3,6 feuilles chacune. Elle commençait à s'accroître au bout de 3 à 53 degré-jours de croissance (DJC), pour atteindre son maximum aux alentours de 705-875 DJC. Le taux de croissance foliaire après défoliation, soit 218 à 252 DJC par feuille, était égal ou plus rapide que celui observé dans les parcelles témoins (218-330 DJC). La biomasse de la repousse représentait de 35 à 76 % de la production annuelle totale. Cette dernière était à son maximum lorsque la fauche avait été exécutée durant la phase végétative ou au niveau de croissance maximum. En 1991 et en 1992, la croissance étiolée au printemps suivant l'année de défoliation était diminuée. Le renouvellement des talles n'était pas touché par le régime de fauche et se maintenait aux alentours de 1,2 talles par talle morte (ET = 0,1) en 1991 et à 1,5 en 1992. On peut donc obt...