Defoliation effects on perennial grasses — continuing confusion

Barnes, D. L.

doi:10.1080/00725560.1972.9648683

Cited by 8 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Grazing was used in this study since estimates of the seasonal pattern of grass production, using intermittent cutting at regular intervals, differ substantially from those generated by studying the pasture under grazing (Barnes 1972, Coughenour et al 1984, Blackburn and Kothmann 1989).…”

Section: Introductionmentioning

confidence: 99%

Irrigation Impact on Harvest Efficiency in Grazed Old World Bluestem

Teague¹,

Dowhower²

2002

Journal of Range Management

View full text Add to dashboard Cite

In 1992 and 1993, pastures of WW-Spar Old World bluestem (Bothriochloa ischaemum L.) were maintained at 2 levels of soil water, rainfall and rainfall plus 25 mm/week of supplementary irrigation. At both moisture levels the grass was maintained at 2 levels of standing crop, averaging 1,548 and 2,154 kg ha'1, using continuous variable stocking. Measurements were made to determine how different levels of soil moisture interacted with grazing intensity to change leaf area index, leaf-stem and live-dead ratios, tiller density, and the proportion of gross leaf production that was grazed (harvest efficiency). The proportions of live to dead, and leaf and stem biomass, remained constant under the different levels of soil water content. Soil water content alone had no effect on leaf area index, tiller density and the proportion of live or dead, leaf and stem. Winter tiller survival was significantly higher in the pastures with higher soil water content. Increasing soil water content and increasing grazing intensity interacted to reduce the proportion of dead leaf, increase production of new tillers, and increase the proportion of leaf grazed by decreasing leaf that died and was not grazed. This study indicates that if continuously grazed Old World bluestem was maintained at a standing crop of 1,500 kg ha'1, harvest efficiency would be higher in wet years or under irrigation than if standing crop was higher.

show abstract

Section: Introductionmentioning

confidence: 99%

Irrigation Impact on Harvest Efficiency in Grazed Old World Bluestem

Teague¹,

Dowhower²

2002

Journal of Range Management

View full text Add to dashboard Cite

show abstract

“…Large integrative grazing trials dominate the literature whereas detailed analytical experiments on individual plants are com-paratively rare. However, comprehensive information on the growth and development of individual species, and particularly their reactions to defoliation are essential prerequisites for satisfactory pasture management (Barnes 1972;Taylor & Whalley 1976;Lorenz 1978).…”

Section: Introductionmentioning

confidence: 99%

The effect of severe defoliation on the subsequent growth and development of five rangeland pasture grasses of south‐western Queensland

Brown

1985

Australian Journal of Ecology

View full text Add to dashboard Cite

Young plants of five arid zone grasses. Cenchrus ciliaris, Astrebla lappacea, Artstida armata, Thyridolepis mitchelliana, and Digitaria ammophila, were heavily defoliated and their subsequent regrowth and development monitored and compared with that of intact plants. Defoliation impaired the development of both roots and plant tops in all species. Regrowth was inconsistent with theories of assimilated reserves stored in roots to support regrowth. The species differed in their apportionment of assimilate between competing plant parts. The differences were similar in both intact and defoliated plants. Both C. ciliaris and A, lappacea maintained a large root mass but produced few inflorescences whereas A. armata and D. ammophila did the opposite. T. mitchelliana had an intermediate pattern of allocation. Both D. ammophila and A. armata resumed flowering soon after defoliation. The different reactions to defoliation are discussed in relation to historical deterioration in pasture condition which may be linked with the prolific seeding capacity of A. armata.

show abstract

“…Several authors have previously noted that while the importance of understanding growth patterns is emphasized, often no mention is made of investigating patterns of defoliation (Barnes 1972, Gammon and Roberts 1978c, Spedding 1965. Thus, there is often no method for making meaningful comparisons of plant responses to defoliation among various grazing systems; nor, are there any criteria for determining realistic defoliation patterns when conducting simulated grazing studies.…”

mentioning

confidence: 98%