Phosphorus-utilisation efficiency and leaf-morphology traits of Rytidosperma species (wallaby grasses) that differ in their growth response to phosphorus fertilisation

2016 ◽  
Vol 64 (1) ◽  
pp. 65 ◽  
Author(s):  
Heidi A. Waddell ◽  
Richard J. Simpson ◽  
Hans Lambers ◽  
Brent Henderson ◽  
Megan H. Ryan ◽  
...  

Rytidosperma species are perennial grasses found in cool temperate grasslands of Australia. The species differ in their intrinsic growth rates, response to phosphorus (P) fertiliser application and critical external P requirements (P required for 90% maximum growth). The present study examined whether internal P-utilisation efficiency (PUE) by Rytidosperma species influenced these differences. The PUE of nine Rytidosperma species and two grasses of Mediterranean origin, Bromus hordeaceus L. and Lolium perenne L., was assessed using alternative measures of shoot P concentration or its reciprocal. No measure of PUE was correlated with the critical external P requirements of the species. One measure of PUE, shoot dry matter per unit P, when assessed at a common shoot P content was correlated with potential growth rate (P < 0.001; r = 0.93; 4 mg shoot P). However, other measures of PUE were not correlated with potential growth rates. All of the fast-growing species (B. hordeaceus, L. perenne, Rytidosperma duttonianum (Cashmore) Connor & Edgar and Rytidosperma richardsonii (Cashmore) Connor & Edgar) exhibited high PUE, whereas PUE varied substantially among the slower-growing species. The fast-growing Rytidosperma species differed in the contribution that area-based P concentration of leaves and specific leaf area (SLA) made to the achievement of high PUE, and they retained shoot-morphology traits normally associated with slow-growing species such as smaller leaf area, smaller SLA and higher leaf dry matter content.

2016 ◽  
pp. 99-103
Author(s):  
Árpád Szalacsi ◽  
Gergely Király ◽  
Szilvia Veres

Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.


1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.


1975 ◽  
Vol 26 (1) ◽  
pp. 31 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson

Growth analysis was applied to grain sorghum (cv. RS610) grown at low, medium and high population densities, i.e. 14,352, 143,520 and 645,836 plants ha-1 respectively. The medium densities had two arrangements of plants, square (S) and rectangular (R). Crop growth rates, inflorescence growth rates, leaf area indices, net assimilation rates and leaf growth rates were calculated from growth functions of plant dry matter and leaf area over time. Differences in crop growth rate between populations in the early stages were attributed to leaf area development—specifically to the initial leaf area (dependent on seedling number) and not to differences in leaf growth rates. Peak crop growth rates were 15.0, 27.5, 26.0 and 45.8 g m-2 day-1 for the low, medium (S), medium (R) and high populations respectively.The large difference between the growth rates of the medium (S) and the high populations was not explained by differences in the amount of radiation intercepted. Although leaf area indices were 4.6 and 10.2 respectively for the two populations, both canopies intercepted almost all of the noon radiation. Light extinction coefficients were 0.45 and 0.29 respectively. The relationship between net assimilation rate and leaf area index was such that for comparable leaf area indices above 2, plants at higher densities showed greater improvement in yield per unit increment in leaf area index. A maximum grain yield of 14,250 kg ha-1 was obtained at the high population density as a result of higher dry matter production, but a similar harvest index to that of the crops grown at the other densities. Inflorescence growth rate (g m-2 day-l) slightly exceeded crop growth rate in the latter part of grain filling, which indicated that there was some retranslocation to the grain of previously assimilated material. The maximum grain yield represents an efficiency of utilization of short-wave solar radiation during crop life of 2.5 x 10-6g cal-1. *Part IV, Aust. J. Agric. Res., 26: 25 (1975).


Author(s):  
S. A. Adeosun ◽  
A. O. Togun

Aims: To assess the field establishment of two tea cultivars under Cocoa Pod Husk (CPH) and Poultry Manure (PM). Study Design: Randomized complete block design arranged in Split-plots (cultivars as main plots and organic amendments as sub-plots) with four replications. Place and Duration of Study: Cocoa Research Institute of Nigeria stations in Ibadan and Owena, Southwest Nigeria between May 2016 and November 2017 (Rainy and dry seasons of 2016; Rainy season of 2017).  Methodology: Milled CPH and cured PM were applied each at the rates of 150 and 300 kg Nha-1 to established C143 and C318 tea cultivars on the field; unfertilized tea cultivars served as control. Data on number of leaves, number of branches, leaf area, plant height and stem diameter were collected on monthly basis; while dry matter was assessed at 15 months after transplanting. The data were analyzed with ANOVA and correlation at α.05. Results: The C143 performed better than C318 and 150 kg Nha-1 of CPH and PM enhanced the vegetative growth and dry matter of tea better than 300 kg Nha-1 in Ibadan and Owena. Cultivar 143 was significantly (P=0.05) better than cultivar 318 in number of leaves, number of branches and stem diameter in Ibadan; and in number of leaves and leaf area in Owena. CPH at 150 kg Nha-1 increased number of leaves, number of branches, leaf area, plant height and total dry matter by 135.11, 88.19, 346.12, 65.33 and 428.11% at Ibadan; and by 349.09, 245.41, 376.89, 80.89 and 231.49% at Owena, compared to control. On the interaction, tea cultivar 143 that received 150 kg Nha-1 CPH produced significantly (P=0.05) higher number of leaves, leaf area and total dry matter at Ibadan and Owena. Leaf area was positively correlated with number of leaves (r=0.87) in Ibadan and stem diameter (r=0.80) in Owena. Conclusion: CPH at 150 kg Nha-1 enhanced the growth and dry matter content of C143 tea established on the field in Ibadan and Owena, and is therefore recommended for tea cultivation in Southwest of Nigeria.


Author(s):  
Aleš Jezdinský ◽  
Kristína Petříková ◽  
Katalin Slezák ◽  
Robert Pokluda

During the experiments it was examined two irrigation levels: 1. optimal water supply – the irrigation activation by available water capacity (AWC) < 65 %; 2. drought stress – irrigation activation by AWC < 45 %) and inoculation of plants by the vesicular-arbuscular mycorrhizal fungusGlomusin leek culture. The effect of treatments on the photosynthetic rate (A), transpiration rate (E), water use efficiency (WUE), biomass production (weight, dry matter content of different plant part), size of pseudostem, leaf area and specific leaf area (SLA) was observed. The drought stress had effect on all observed parameters: it decreased the photosynthetic and transpiration rate (A: from 5.04–5.37 to 3.33–3.43 µmol CO2.m−2. s−1, E: from 1.78–1.91 to 0.99–1.03 mmol H2O. m−2. s−1in the average of 5 measuring date), the weight total fresh weight of plants: from 355–453 g to 152–255 g), and the leaf area, the length and diameter of pseudostem, too. The WUE, the dry matter content and the thickness of leaves increased under stress. In the most parameters, the water supply had stronger effect than the inoculation. The inoculation had positive effect mainly under drought stress: it improved the WUE at 3 measuring time (from 3.45 to 3.50 μmol CO2.mmol H2O−1, in the average of 5 measuring date), increased the weight (total fresh weight of plants: from 152 g to 255 g) and the leaf area (from 0.16 to 0.12 m2).


Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Damjana Levačić ◽  
Sven D. Jelaska

Alongside the direct destruction of natural habitats and changes in land use, invasive species are considered one of the greatest threats to global biodiversity. Daisy fleabane Erigeron annuus (L.) Pers. is among the most widespread invasive plants in Croatia. Invasions of E. annuus may be aided by morphological variability, which this study investigates. The variability of life traits (stem height, fresh and dry leaf mass, length, width and leaf area, specific leaf area, and leaf dry matter content) was examined among 18 locations throughout Zagreb and Medvednica Mt. Overall, 87 plant specimens and 435 leaves were measured and analysed using univariate and multivariate statistics. Viable populations were recorded in diverse habitat types, mostly with marked human impact. We determined Grime’s CR plant life strategies for all, except for two localities with C/CR plant strategies. Two populations with a more pronounced competitive strategy had high leaf dry matter content, with smaller leaves and medium height stems. Significant differences between the localities were found, with the specific leaf area (SLA) and plant height being the most diverse. Despite its high morphological variability, daisy fleabane had a consistent CSR strategy, which likely enables its widespread invasions across variable habitats.


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