leaf appearance
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Author(s):  
A. A. Brovdi ◽  
◽  
V. V. Polishchuk

The results of morphometric analysis of the leaves in floribunda roses varieties, such as Pomponella, Lovely Green, Carmagnola, Arthur Bell, Lilli Marleen, Westpoint, Minerva, Novalis, Goldelse, Rotkappchen, Friesia, Lavaglut, Iceberg, Santa Monika, Mathias, Bella Rosa, Cream Abundance, Hans Gonewein, Let's Celebrate and Gebruder Grimm, which have different origins and differ significantly in morphological and decorative characteristics are presented. The studies were conducted during 2018–2021 on the experimental plots of the Department of Landscape Gardening of Uman National University of Horticulture according to the generally accepted method. The description of the morphological traits of the varieties was carried out by the method of visual assessment using measurements and calculations. As a result of the research, it was found that the studied genotypes significantly differ in the biometric parameters of the compound leaf, features of the surface of leaf blades, their shape and size. The highest leaf blades areas were noted in the varieties Novalis 15.1 сm2, Rotkappchen 12.0 cm2 and Pomponella 11.8 cm2. The lowest biometric traits of the leaf were recorded in the varieties Santa Monika, whose compound leaf length is 9.2 cm, Mathias 9.1 cm, Bella Rosa 10.8 cm and Cream Abundance 9.8 cm. The size of the leaf, its shape, color and gloss, are important for the overall impression of the planting object and determine the decorative value of the respective variety. Of all the varieties, Westpoint, Rotkappchen, Hans Gonewein, and Gebruder Grimm have the glossiest leaves. The bright shine together with dark green color of the leaves of these varieties make their bushes more expressive and bright and, therefore, more attractive for use in ornamental gardening. The results of the study are of practical importance, since they make it possible to select varieties that are valuable for ornamental gardening, not only in decorativeness of the flower, but also in the characteristics of their leaf appearance.


2021 ◽  
Vol 73 (6) ◽  
pp. 1413-1421
Author(s):  
M.E.R. Santos ◽  
I.C. Ferreira ◽  
B.H.R. Carvalho ◽  
G.O. Rocha ◽  
G.S. Borges ◽  
...  

ABSTRACT The objective this study was to identify differences in the morphogenic patterns of four Urochloa brizantha cultivars (marandu, piatã, xaraés and paiaguás grasses) during the stockpiling period. A completely randomized design was used, with three replications, in experimental plots of 9m². The evaluations took place over 2 years. The grasses were stockpiled for 92 (Year 1) and 95 (Year 2) days. The leaf appearance rate of paiaguás grass was higher, compared to other grasses. In Year 1, the stem elongation rate of xaraés grass was higher than other grasses. At the end of stockpiling period of Year 1, the tiller population density (TPD) was higher in the paiaguás grass, intermediate in the xaraés and marandu grasses and lower in the piatã grass. At the end of the stockpiling period in Year 2, TPD was higher in the paiaguás grass canopy, intermediate in the marandu and piatã grasses canopies, and lower in the xaraés grass canopy. Paiaguás grass has greater leaf growth during the stockpiling period and is therefore suitable for use under stockpiled grazing. Xaraés grass has high stem elongation during the stockpiling period, which is why its use under stockpiled grazing must be accompanied by adjustments in pasture management.


2021 ◽  
Vol 9 (3) ◽  
pp. 256-267
Author(s):  
Nauara Moura Lage Filho ◽  
Aline Da Rosa Lopes ◽  
Aníbal Coutinho Do Rêgo ◽  
Felipe Nogueira Domingues ◽  
Cristian Faturi ◽  
...  

The objective of this study was to evaluate regrowth period (RP), morphogenetic, structural and productive characteristics of the guinea grass cultivar Tanzania [Megathyrsus maximus (syn. Panicum maximum)] under different stubble heights (SH) during dry (DS) and rainy (RS) seasons in the eastern Amazon region. The treatments were: 5, 15, 25, 35, 45 and 55 cm SH, distributed in a randomized complete block design with 6 replicates. In the 2 seasons, RP decreased linearly with increase in SH, and was considerably shorter in the RS (47 d). Leaf appearance rate decreased linearly from 0.071 to 0.051 leaves/tiller/d with increasing SH, and it was higher during the RS. Increase in SH increased leaf elongation rate, stem elongation rate and leaf area index. In the RS, climatic conditions favored the morphogenesis, resulting in higher herbage accumulation (8,693 kg DM/ha) than in the DS (2,597 kg DM/ha). In associating seasons with SH, we recommend that Tanzania grass be managed at SH between 35 and 45 cm in the DS, resulting in RP from 61 to 64 days, and at SH of 35 cm in the RS, resulting in RP of 41 days. Studies to test this management strategy seem warranted.


Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1846
Author(s):  
Fernando Ongaratto ◽  
Marcia Helena Machado da Rocha Fernandes ◽  
Erick Escobar Dallantonia ◽  
Lais de Oliveira Lima ◽  
Guilherme Alves do Val ◽  
...  

Pasture intensification through higher stocking rates, nitrogen fertilization and intensified grazing management in beef cattle production optimizes pasture use by increasing the forage harvested. We aimed to assess its effects on the morphogenesis and canopy structure of Urochloa brizantha ‘Marandu’ (marandu palisadegrass) pastures. The treatments consisted of marandu palisadegrass pastures managed under continuous stocking and a canopy height of 25 cm, with different levels of intensification: extensive, semi-intensive, and intensive systems N-fertilized with 0 kg, 75 kg, and 150 kg N ha−1 year−1, respectively, as ammonium nitrate (32% of N), with four replicates (paddocks) in a completely randomized design. Phyllochron (9.8 days) and leaf lifespan (34.7 days) were shorter in intensified pastures, whereas herbage mass was similar among treatments. Extensive pastures had a higher proportion of senescent material; thus, more intensive systems showed higher proportions of leaves and stems, although the leaves-to-stem ratio remained similar across production systems. The defoliation interval was lower in intensive (14.4 days) and higher in extensive (18.7 days) treatments. Thus, pasture intensification accelerates leaf appearance, decreases leaf lifespan, shortens the tiller defoliation interval and increased herbage accumulation rate but does not change herbage mass. The extensive system produces excessive forage losses due to dead material.


2021 ◽  
Vol 10 (9) ◽  
pp. e56310918536
Author(s):  
Newton de Lucena Costa ◽  
Antônio Neri Azevedo Rodrigues

The natural regrowth of Axonopus aureus in native pasture of Roraima´s savannas was evaluate, during early rainy period. The experimental design was a completely randomized, with four replications. The treatments consisted of four pasture rest periods (14, 28, 42 and 56 days after beginning of the rainy period). Evaluations were carry out during the period of June to August of 2016. The parameters measured were dry matter (DM) yields and grass morphogenetic and structural characteristics. The green and total DM, number of tillers plant-1, number of axillary tillers plant-1, number of live tillers plant-1, number of live leaves tiller-1 and leaf area index were directly proportional to rest periods. The leaf appearance and elongation rate were negatively affect by rest periods, while the dead DM was not affect by rest periods. Considering the low green DM availability of A. aureus, its recommends the utilization of some management practice, preferentially grazing or mowing, to remove the dead DM with low nutrition value and permit a grass vigorous regrowth in the beginning of the rainy period.


2021 ◽  
Vol 53 (1) ◽  
pp. 89-97
Author(s):  
Adalberto Di Benedetto ◽  
Danilo Carnelos ◽  
Jorge Lozano Miglioli ◽  
Pablo Fujinuma ◽  
Ernesto Giardina

Although vegetable nursery growers decide on plug sizes based on the types, production time and schedule of the crops to grow, they usually choose individual small cell sizes because these allow short plant-raising periods and reduced costs. However, larger plugs produce a finished plant after transplant in a shorter period of time than smaller plugs. Nursery growers end the propagation period when roots take up the plug cell and plantlets can be removed from the plug tray without damage. Thus, this study aimed to investigate the effect of three plug-cell sizes and a single BAP application (100 mg L-1) on the shoot and root growth and time to transplant of different lettuce genotypes. Nursery decreased as plug cell volume increased and with the single BAP spray. A novelty result was that the transplant dates were assigned when the marginal root dry weight accumulation decreased, i.e., based on objective rather than on subjective observations. The significant leaf area and dry weight accumulation found could be explained by growth parameters such as the rate of leaf appearance, the relative rate of leaf area expansion, the relative growth rate, the net assimilation rate and the partition coefficient from root: shoot allometries. Highlights Root restriction due to small plugs in transplant trays delay lettuce transplant. Exogenous cytokinin (BAP) overcame root restriction and decreased time to transplant. Time to transplant can be addressed on an objective basis: it were assigned when the marginal root dry weight accumulation decreased.


2021 ◽  
Author(s):  
Benoit Clerget ◽  
Estela Pasuquin ◽  
Rene Carandang ◽  
Abigail J. Domingo ◽  
Heathel L. Layaoen ◽  
...  

AbstractIn Asia, direct sowing and water savings are major trends in previously transplanted and flooded irrigated rice systems because of the higher cost of wages and increasing water shortage. Previous experiments showed that the leaf appearance rate varies between aerobic and flooded cropping systems. This study aimed to further understand how the planting method affects the development rate, flowering time, and yield of lowland irrigated rice crops. A two-year experiment was undertaken at the International Rice Research Institute, Philippines, using three contrasting rice varieties and three planting methods (transplanted, wet direct-seeded, and dry direct-seeded; at a density of 25 plants m-2) in a field submerged in 3–5 cm water from two weeks after the transplanting date. The effect of the planting method was similar in the three varieties, mostly without interaction between the two factors. In 2013, the leaf number of seedlings grown in seedling trays was two leaves behind that of direct-seeded plants at the time of transplanting. However, the young transplanted plants recovered quickly; produced new leaves at a faster rate (with a shorter phyllochron); reached panicle initiation, flag-leaf emergence and flowering time 1 week later; and developed more leaves compared to the direct-seeded plants. In 2014, growing in the nursery induced no delay in leaf appearance due to temperatures lower than those in 2013; therefore, the planting method did not affect the leaf appearance rate. Thus, plant development was primarily delayed by the density stress in the seedling trays under warm temperatures; however, the transplanted rice plants had lower plastochron duration than the direct-seeded plants, which made up for the initial delay in leaf appearance. In both years and at similar plant density, the transplanted plants produced more tillers bearing larger upper leaves that led to a higher leaf area index; however, grain yields were similar for the transplanted and direct-seeded crops.Highlights- In seedling trays, leaf appearance stopped at the appearance of the fourth leaf.- After transplanting, leaf appearance resumed at a faster rate than in direct-seeded plants.- Transplanted plants had delayed panicle initiation and flowering time, more tillers, and more and larger leaves per tiller, but similar grain yield compared to direct-seeded plants at similar planting density.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 443
Author(s):  
Boubacar Gano ◽  
Joseph Sékou B. Dembele ◽  
Thierry Klanvi Tovignan ◽  
Bassirou Sine ◽  
Vincent Vadez ◽  
...  

Sorghum is the fifth most important cereal crop world-wide and feeds millions of people in the Sahel. However, it often faces early-stage water deficit due to false onsets of rainy seasons resulting in production decrease. Therefore, developing early drought tolerant material becomes a necessity but requires a good knowledge of adaptation mechanisms, which remains to be elucidated. The present study aimed at assessing the effects of early drought stress on ten elite sorghum varieties tested over two years (2018–2019) at the National Agronomic Research Centre (CNRA) of Bambey (Senegal, West Africa). Two different water regimes (well-watered and drought stress) were applied during the dry season. Water stress was applied by withholding irrigation 25 days after sowing for one month, followed by optimal irrigation until maturity. Soil moisture measurements were performed and allowed to follow the level of stress (down to a fraction of transpirable soil water (FTSW) of 0.30 at the end of stress). An agro-physio-morphological monitoring was carried out during the experiment. Results showed highly significant effects of early drought stress in sorghum plants growth by decreasing leaf appearance, biomass, height but also yield set up. The combined analysis of variance revealed highly significant differences (p ≤ 0.01) between varieties in the different environments for most characters. Under water deficit, the variability was less strong on leaf appearance and plant height at the end of stress. The adaptation responses were related to the capacity of varieties to grow up fast and complete their cycle rather, increase the dead leaves weight, reduce photosynthesis rate, stomatal conductance, leaf transpiration and increase the roots length density. However, varieties V1, V2, V8 and V9 showed promising behavior under stress and could be suitable for further application in West Africa for sorghum breeding and farming.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka A. Basavaraddi ◽  
Roxana Savin ◽  
Luzie U. Wingen ◽  
Stefano Bencivenga ◽  
Alexandra M. Przewieslik-Allen ◽  
...  

AbstractEarliness per se (Eps) genes are reported to be important in fine-tuning flowering time in wheat independently of photoperiod (Ppd) and vernalisation (Vrn). Unlike Ppd and Vrn genes, Eps have relatively small effects and their physiological effect along with chromosomal position are not well defined. We evaluated eight lines derived from crossing two vernalisation insensitive lines, Paragon and Baj (late and early flowering respectively), to study the detailed effects of two newly identified QTLs, Eps-7D and Eps-2B and their interactions under field conditions. The effect of both QTLs was minor and was affected by the allelic status of the other. While the magnitude of effect of these QTLs on anthesis was similar, they are associated with very different profiles of pre-anthesis development which also depends on their interaction. Eps-7D affected both duration before and after terminal spikelet while not affecting final leaf number (FLN) so Eps-7D-early had a faster rate of leaf appearance. Eps-2B acted more specifically in the early reproductive phase and slightly altered FLN without affecting the leaf appearance rate. Both QTLs affected the spike fertility by altering the rate of floret development and mortality. The effect of Eps-2B was very small but consistent in that -late allele tended to produce more fertile florets.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 100
Author(s):  
Sayaka Takahashi ◽  
Erina Takahashi

To discuss the diversity of morphological traits and life strategies of trees, the functional relationship between leaf expansion and vessel formation must be clarified. We compared the temporal relationship among tree species with different leaf habits and vessel arrangements. Twigs, leaves, and trunk core samples were periodically acquired from 35 sample trees of nine species in a temperate forest in Japan. We quantitatively estimated leaf expansion using a nonlinear regression model and observed thin sections of twigs and trunks with a light microscope. Almost all of the first-formed vessels in twigs, which formed adjacent to the annual ring border, were lignified with a leaf area between 0% and 70% of the maximum in all species. The first-formed vessels in trunks lignified between 0% and 95% of the maximum leaf area in ring-porous deciduous Quercus serrata and ring-(radial-)porous evergreen Castanopsis cuspidate. Their lignification occurred earlier than in diffuse-porous deciduous Liquidambar styraciflua, diffuse-porous evergreen Cinnamomum camphora and Symplocos prunifolia, and radial-porous evergreen Quercus glauca and Quercus myrsinifolia. The timing varied in semi-ring-porous deciduous Acanthopanax sciadophylloides and diffuse-porous evergreen Ilex pedunculosa. The observed differences in the timing of vessel formation after leaf appearance were reflected in their differing vessel porosities and were connected to the different life strategies among tree species.


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