Responses of individual plants to harvesting

Jameson, Donald A.

doi:10.1007/bf02860815

Cited by 267 publications

(159 citation statements)

References 278 publications

Supporting

Mentioning

147

Contrasting

Unclassified

Order By: Relevance

“…5) and also herbage accumulation rates (Fig. 1) for the cutting systems are similar to those of most other cutting experiments in that they show an increase of herbage DM availability with less frequent defoliation (Jameson 1963;Alcock 1964;Harris 1978), and often the increase is large. However, responses of grazing animals to changes of grazing frequency are generally much smaller.…”

Section: Comparison Of Cutting and Grazingsupporting

confidence: 81%

Simulation by cutting of stocking rate and rotational and continuous management

Harris¹

1983

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

Ryegrass (Lolium perenne)-white clover (Trifolium repens)-dominant pasture was harvested weekly by cutting to meet annual herbage dry matter (DM) requirements of 15 (8400 kg DM), 20 (11 200 kg DM), and 25 (14 000 kg DM) ewe equivalents (ee) per ha according to a budget simulating seasonal changes of the feed requirements of a 55 kg breeding ewe. Herbage was removed in patterns corresponding to continuous and rotational management and a comparison was made with continuous and rotational systems grazed with wether hoggets. Rotational management by cutting met feed requirements of all stocking rates except for 25 ee during summer drought. Continuous management by cutting met feed requirements at 15 ee but large feed deficits developed for the 20 and 25 ee stocking rates. After 8 months the 25 ee continuous system was changed to rotational management and later provided the herbage requirements for 25 ee. In systems where conservation was possible, feed deficits did not develop at other times of the year to utilise conserved herbage. Standing herbage mass was increased and sheep liveweight tended to be higher with rotational compared to continuous grazing but the relative response was much less than that obtained with cutting. Relationships between the levels of standing herbage mass and herbage accumulation rates of the systems were examined. Large increases of herbage production were obtained by accumulating standing herbage mass in spring, but negative herbage accumulation rates occurred for systems with high levels of standing herbage mass in summer. Stability of the systems was defined using the Noy-Meir (1975) rationing herbage to stock by 'feed budgeting' could substitute for less readily measured physiological parameters used in models to predict pasture production.

show abstract

Section: Comparison Of Cutting and Grazingsupporting

confidence: 81%

Simulation by cutting of stocking rate and rotational and continuous management

Harris¹

1983

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

show abstract

“…Plants with a basal meristem such as Thalassia testudinurn are tolerant of certain levels of harvesting as long as the meristem is not damaged by the grazing activity (Jameson, 1963). Some of the new leaf material produced after grazing may be replaced using energy reserves stored as carbohydrates in the rhizomes.…”

Section: Discussionmentioning

confidence: 99%

Herbivory effects on Thalassia testudinum leaf growth and nitrogen content

Zieman¹,

Iverson²,

Ogden³

1984

Mar. Ecol. Prog. Ser.

109

View full text Add to dashboard Cite

The pattern of turtle grazing on Thalassia testudinum in St. Croix seagrass beds begins with the establishment of a grazing plot by initial removal of leaf blades, followed by repeated grazing of several centimeter-long leaf blades within a maintained grazing area. Plants within the grazed area exhibit increased specific growth rate as a consequence of increased light flux to unepiphytized leaf bases. Leaf width is reduced in the grazed area as a consequence of grazing stress. The leaf bases contain a higher proportion of nitrogen and a lower lignin content than the leaf tips, in addition to lacking epiphytes. Our data suggest that the grazing areas are abandoned when the sediment ammonium concentration IS reduced, leading to reduced growth rates of T. testudinum. Effects of sea urchin grazing on T testudinum were similiar to effects of turtle grazing but were reduced in magnitude as a consequence of lower urchin grazing pressure.

show abstract

“…This breeding criterion facilitates the selection of high-yield lines, with a broad-sense heritability of 45.0% (calculated according to Caradus & Woodfield 1990). In grass breeding, there is usually little or no relationship between isolated plant vigor and grassland yield, preventing the selection of superior lines (Jameson 1963). However, the strong association between the performance of isolated brachiariagrass plants and grassland enables successful breeding selection based on isolated plant vigor.…”

Section: Brachiariagrass (1) Recent Breeding Effortsmentioning

confidence: 99%

The Present Status of C<sub>4</sub> Tropical Grasses Breeding and Molecular Approaches

Tsuruta

Shimoda

Kouki³

et al. 2015

JARQ

View full text Add to dashboard Cite

Tropical grasses have been widely utilized as warm-season grasses in the warm temperate zone since the early 20th century because of their high yields as well as for perennial forages in their native tropical areas. The high yield of tropical grasses is mainly due to C4 photosynthesis. However, the soaring demands for animal production sparked by economic development in tropical countries mean genetic improvement of such grasses is urgently needed. Considerable breeding efforts have been made to create and develop new tropical grass cultivars, although direct selection from natural populations remains the main method used for breeding. Cross-breeding has not proliferated due to a lack of genetic information concerning the polyploidy, high sterility, outcrossing, and apomixis of these grasses, although several of these difficulties are starting to be resolved by advanced research using molecular biology tools. These tools are an effective means of achieving genetically improving of tropical grasses, and further development is anticipated. In this review, achievements in the improved guineagrass, brachiariagrass, sorghum, and zoysiagrass are introduced and discussed.

show abstract

Responses of individual plants to harvesting

Cited by 267 publications

References 278 publications

Simulation by cutting of stocking rate and rotational and continuous management

Simulation by cutting of stocking rate and rotational and continuous management

Herbivory effects on Thalassia testudinum leaf growth and nitrogen content

The Present Status of C<sub>4</sub> Tropical Grasses Breeding and Molecular Approaches

Contact Info

Product

Resources

About