A comparison of the root growth, root morphology and root response to defoliation of Aristida ramosa R.Br. and Danthonia linkii Kunth

1981 ◽  
Vol 32 (4) ◽  
pp. 565 ◽  
Author(s):  
AR Harradine ◽  
RDB Whalley

Establishing plants of Aristida ramosa R.Br. and Danthonia linkii Kunth grown in root observation tubes differed markedly in their root growth and root morphology. Radicle extension of A. ramosa proceeded far more rapidly than that of D. linkii, and root branching occurred earlier and to a much greater extent in D. linkii. From 2 months after germination onwards, the maximum rooting depth of A. vamosa was greater than that of D. linkii, although total root dry weights for the two species were not significantly different. At 25 weeks from germination, 48 % of the root dry weight of D. linkii was present in the 0-10 cm level of the soil profile, while the corresponding figure for A. ramosa was 33 %. Root weight and rooting depth of both species were severely reduced by foliage clipping at weekly or monthly intervals, with roots being more sensitive to clipping than shoots. Clipping led to a concentration of root mass in the 0-10 cm level. The rapidly establishing seedling root system of A. vamosa would give it a competitive advantage over D. linkii in the environment of the north-western slopes of New South Wales. The results of the clipping trial suggest that grazing management may be manipulated to alter the relative abundance of A. ramosa and D. linkii in native pastures.

2016 ◽  
Vol 1 (1) ◽  
pp. 013
Author(s):  
Aprilia Ike Nurmalasari ◽  
Eka Tarwaca Susila Putra ◽  
Prapto Yudono

The research aims to study the change of morphology root characters of eight hybrid oil palms under iron toxicity (Fe). Field experiment done in arranged in a Randomized Complete Block Design (RCBD) two factors and three blocks as replications. The first factor was Fe concentration. It consists of two levels which are concentration 0µ.g-1 and concentration 600 µg.g-1 Fe. The second factor is the hybrid of oil palms which consists of eight hybrid oil palms as Yangambi, Avros, Langkat, PPKS 239, Simalungun, PPKS 718, PPKS 540 and Dumpy. Fe was applied by pouring FeSO4 solvent for 600 µg.g-1 500 ml.-1plant.-1day-1 on two months of plants after transplanting in the main nursery. Data were collected on root morphology and plant dry weight The data were analysis of variance (ANOVA) at 5% significanly, followed by Duncan's multiple range test (DMRT). The relationships by among variables were determined by correlation analysis. The results showed that Fe concentration 600 µg.g-1 inhibits relatively root growth rate, narrows surface area, reduces the diameter, and shrinks root volume of all hybrid oil palms tested. The slowing relatively root growth rate, narrowing of root surface area and root diameter also root volume shrinkage due to Fe stress. It was also shown that the dry weight of plants was inhibit by existing of Fe toxicity.


1981 ◽  
Vol 29 (2) ◽  
pp. 121 ◽  
Author(s):  
GM Lodge

Emergence and survival of the seedlings of warm-season native perennial grasses Aristida ramosa R.Br., Bothriochloa macra (Steud.) S . T. Blake, Dichanthium sericeum (R.Br.) Camus, Sporobolus elongatus R.Br., Eragvostis leptostachya Steud. and Chloris truncata R.Br. and the cool-season species Stipa variabilis Hughes and Danthonia linkii Kunth were studied in both native pastures and sown monospecific plots on the north- west slopes of New South Wales. The most favourable period for the successful emergence and establishment of warm-season grasses was from mid summer to early autumn. Cool-season native perennial grasses established best from seedlings that appeared from mid autumn to late winter. Few seedlings were observed to germinate in spring, probably as a result of large variations in temperature, low minimum temperatures or intra and interspecific competition. Seedlings growing in native pasture spent long periods in the vegetative phase compared to the early flowering of seedlings in the sown plots. In the pasture studied only two seedlings flowered over 700 days after emergence, and many others after persisting for up to 2 years died without producing seed. These findings indicate that the seedlings in these native pastures were under considerable stress and that the adult populations of the species examined were relatively stable and little recruitment occurred.


2016 ◽  
Vol 50 (6) ◽  
Author(s):  
Parvaze A. Sofi ◽  
Iram Saba

The present study was undertaken to assess the response of common bean under drought in respect of root traits and biomass partitioning in fifteen common bean genotypes. The basal root whorl number and the number of basal roots was highest in case of WB-185 and lowest in case of SR-1, whereas, the basal root growth angle was highest in case of WB-258 and lowest in case of WB-249. Rooting depth measured as the length of longest root harvested was highest in case of WB-6 (66.2) while as lowest value was recorded for WB-112 (20.4). Dry root weight was highest in case of WB-216 (0.45) and lowest value was recorded for WB-341 (0.22). Similarly leaf biomass was highest in case of WB-6 (0.58) followed by WB-216 (0.58) and the lowest value recorded for WB-1186 (0.12). Shoot dry weight was highest for WB-6 (0.55) followed by WB-216 (0.44) and the lowest value recorded for WB-1186 (0.118). Pod dry weight was highest for WB-489 (2.28) followed by WB-216 (2.19) and the lowest value recorded for WB-83 (0.68).489. Root biomass proportion was highest for WB-195 (18.34) and lowest for WB-489 (10.00). Similarly leaf biomass to total biomass was highest in case of WB-83 (23.19) whereas lowest value was recorded for WB-1186 (7.60). Highest stem biomass proportion was recorded for Arka Anoop (19.19) and the lowest value was recorded for WB-1186 (7.591). Biomass allocation to pods was highest in case of WB-489 (69.92) followed by WB-1186 (68.69) whereas lowest value was recorded for WB-83 (45.40).


1996 ◽  
Vol 14 (3) ◽  
pp. 105-110 ◽  
Author(s):  
Edward F. Gilman ◽  
Thomas H. Yeager ◽  
Diane Weigle

Abstract Dwarf burford holly (Ilex cornuta ‘Burfordii Nana’) fertilized with 22.1 g N/container/yr of nitrogen during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving 14.8 g N/container/yr. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight and new shoot:regenerated root dry weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after transplanting. When plants were without irrigation for 4 or 6 days in the first week after transplanting, those planted without the nursery container on the root ball were more stressed (more negative xylem potential) than those planted with the container still on the root ball. However, two weeks later, plants without the nursery container were less stressed due to root growth into landscape soil.


HortScience ◽  
2010 ◽  
Vol 45 (12) ◽  
pp. 1882-1884 ◽  
Author(s):  
Kenneth B. Marcum ◽  
Mohammad Pessarakli

Relative salinity tolerance of 32 perennial (Lolium perenne L.) and three intermediate (Lolium ×hybridum Hausskn.) ryegrass turf cultivars was determined by measuring turf leaf clipping dry weight, root weight, rooting depth, and percent green leaf canopy area relative to control (non-salinized) plants. After gradual acclimation, grasses were exposed to moderate salinity stress (6 dS·m−1) for 6 weeks through solution culture in a controlled environment greenhouse. Shoot parameters were highly correlated, being mutually effective predictors of salinity tolerance. After 6 weeks of salinity stress, percent green leaf canopy area (GL) was correlated with relative (to control) final week leaf clipping weight (LWREL) (r = 0.90) and with linear slope of decline of weekly leaf clipping weight over the 6-week exposure to salinity (LWSLOPE) (r = 0.66). Rooting parameters root dry weight (RW) and rooting depth (RD), although significantly correlated with all shoot parameters, were only moderately effective in predicting relative salinity tolerance. ‘Paragon’ was the most salt-tolerant as indicated by all parameters. Other salt-tolerant cultivars included Divine and Williamsburg. Intermediate ryegrass cultivars (Froghair, Midway, and Transist) were invariably found within the most salt-sensitive category for all parameters.


HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 517-520 ◽  
Author(s):  
Giorgio Bargioni ◽  
Giorgio Baroni ◽  
Pietro Tonutti ◽  
Andrea Pitacco ◽  
Angelo Ramina

Effects of scion inclination on root growth and distribution were studied on INRA GF 677 (Prunus persica × Prunus amygdalus) and apple/M.9 trees. At planting, central leaders were positioned vertically (0°) or inclined 45° or 60° to the north and south. Three years after planting, root total dry weight of inclined trees was lower than that of the control (0°, vertical central leader). Five years after planting, the isotropic distribution of the normal root systems was distorted by inclination in both species. Roots were more numerous and more elongated in the direction of inclination. Statistical analysis of root density data, using a polar coordinate system, confirmed that the trunk inclination reduced root development and redirected root distribution. The major effect was induced on GF 677 by 60° inclinations. Tree orientation did not seem to influence root distribution.


2003 ◽  
Vol 43 (1) ◽  
pp. 47 ◽  
Author(s):  
H. Lloyd Davies ◽  
D. Petrie ◽  
R. Paliskis

A series of experiments were conducted to measure the response by cattle grazing 'native pastures' on the North Coast of New South Wales to supplements of energy, protein and the administration of mineral supplements.In all experiments there were liveweight responses to both energy and protein supplements. The magnitude of the response to the grain supplements was affected by treatment of the grain with extruded grain tending to give a superior liveweight response. The response to nitrogen supplements differed between non-protein-nitrogen (urea) and protein — always in favour of the protein supplement. There were no liveweight responses to copper cobalt or selenium. Supplemental copper administered in a variety of ways increased liver copper concentration, plasma copper and ceruloplasmin and coat colour changed from yellow to red. The low copper storage levels were not associated with high molybdenum values in the feed on offer. Administration of selenium did not increase the unsatisfactory pregnancy rate but did raise the level of circulating glutathione peroxidase.


1979 ◽  
Vol 1 (3) ◽  
pp. 244 ◽  
Author(s):  
AR Harradine ◽  
RDB Whalley

On the north-western slopes of New South Wales, native pastures are subjected to frequent and often severe moisture stress during the summer growing season (Daniel and Watt 1967) so the relative drought tolerances of the component species may be important in determining pasture composition. Survival of three common native species from this area, Aristida ramosa R.Br., Danthonia linkii Kunth and Dichanthium sericeum (R.Br.) A. Camus, when subjected to water stress was compared in a glasshouse pot trial. The use of cycles rather than a single water stress in drought resistance studies, to simulate field conditions more closely, has been emphasised by Gates (1974). This experiment was designed to determine the relative tolerance of the above three species to repeated, increasing periods of water stress in a limited volume of soil. Pots of different sizes were used to determine the effect of differences in the rate of development of water stress on plant survival.


HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1732-1735 ◽  
Author(s):  
Hassan Salehi ◽  
Morteza Khosh-Khui

Turfgrass seeds can be sown individually, in mixes, or overseeded to provide green color and uniform surfaces in all the seasons. This investigation was conducted to compare different turfgrass species and their seed mixtures. In this research, the turfgrasses—perennial ryegrass (Lolium perenne L. `Barball'), kentucky bluegrass (Poa pratensis L. `Merion'), common bermudagrass (Cynodon dactylon [L.] Pers.), and strong creeping red fescue (Festuca rubra L. var. rubra `Shadow')—in monoculture or in mixtures of 1:1 (by weight) and a 1:1:1:1 (by weight) and two sport turfgrasses—BAR 11 (Barenbrug Co.) and MM (Mommersteeg Co.)—were used. The seeds were sown in March and October (spring and fall sowing) in 1998 and 1999. The experiments were conducted in a split-split block design with year as main plot, sowing season as subplot, and turfgrass types as subsubplot. The turfgrasses were compared by measuring visual quality, chlorophyll index after winter and summer, rooting depth, verdure and/or root fresh and dry weight, tiller density, and clippings fresh and dry weight. Fall sowing was superior to spring sowing and resulted in greater root growth, clipping yield, and chlorophyll content. Poa+Cynodon seed mixture was the best treatment and had high tiller density, root growth, and chlorophyll content. Lolium and Festuca monocultures, and Poa+Festuca and Cynodon+Festuca seed mixtures were not suitable with regard to low tiller density, sensitivity to high temperatures, low root growth, and low tiller density, respectively. The cool-warm-season seed mixture (Poa+Cynodon) can be used alternatively in overseeding programs in the areas with soil and environmental conditions similar to this research site.


1974 ◽  
Vol 22 (3) ◽  
pp. 133-142
Author(s):  
J.J. Schuurman ◽  
J.J.H. de Boer

The effect of a loose topsoil of 23-63 cm depth overlying a dense subsoil of 35-75 cm depth on root and shoot development was compared with the effect of a homogeneous column of loose soil of 98 cm depth. Shoot weights and, to a large extent root weights, were similar during early growth, but, at later stages, they were higher in the heterogeneous soil columns. Throughout growth, root weights were greater in loose topsoil of the heterogeneous soil columns than in the corresponding layer of the homogeneous columns. Total root weights were higher in the homogeneous columns up to May 23rd, but, at later dates they were higher in the heterogeneous columns. Decreases in root weight at the boundary zone between the layers were mainly due to decreased root branching and, secondarily, to decreased root number. Rooting depth in the dense subsoil increased with increasing thickness of the topsoil, and probably with increasing depth of the water table. Shoot/root ratios at later growth stages were highest for the heterogeneous columns with thin top-soil layers, indicating the presence of favourable growing conditions despite restricted root development. This was confirmed by water consumption data. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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