Morphogenetic and structural characteristics of field-grown timothy cultivars differing in maturity

1996 ◽  
Vol 76 (2) ◽  
pp. 277-282 ◽  
Author(s):  
G. Bélanger
Keyword(s):  
Structural Characteristics ◽  
Leaf Size ◽  
Phleum Pratense ◽  
Extension Rate ◽  
Primary Growth ◽  
Early Maturing ◽  
Tiller Density ◽  
Leaf Appearance ◽  
Leaf Extension ◽  
Phleum Pratense L

The leaf area development of grasses and, subsequently, radiation interception depends on morphogenetic processes such as leaf extension and appearance. No detailed studies of leaf extension and appearance of field-grown timothy (Phleum pratense L.) cultivars differing in maturity have been reported in the literature. Leaf extension and appearance of field-grown timothy cultivars differing in maturity and their impact on sward structural characteristics such as leaf size per tiller and tiller density were studied during primary growth in the spring of 1991 and 1992. The leaf extension rate of early-maturing cultivars was greater than that of late-maturing cultivars during primary growth of timothy. There were no differences in leaf appearance rates among cultivars Hence, individual tillers of early-maturing cultivars developed a larger leaf size than late-maturing cultivars. In 1992, late-maturing cultivars had a greater tiller density than early-maturing cultivars which compensated for the smaller leaf size. Different tiller density-tiller size characteristics of early and late-maturing timothy cultivars resulted in a similar outcome in terms of LAI. Key words:Phleum pratense L., timothy, leaf extension, leaf appearance, tillering

Morphogenetic characteristics of timothy grown with varying N nutrition

1998 ◽  
Vol 78 (1) ◽  
pp. 103-108 ◽  
Author(s):  
G. Bélanger
Keyword(s):  
Leaf Area ◽  
Structural Characteristics ◽  
Nitrogen Deficiency ◽  
Phleum Pratense ◽  
Radiation Interception ◽  
N Nutrition ◽  
N Deficiency ◽  
Leaf Appearance ◽  
Leaf Extension ◽  
Phleum Pratense L

The leaf area development of grasses and subsequently radiation interception depends on morphogenetic processes such as leaf extension and appearance. Leaf extension and appearance of timothy (Phleum pratense L.) grown with varying rates of N nutrition and their impact on sward structural characteristics were studied during primary growth in spring and during a summer regrowth. With no N applied in spring and summer, the leaf extension rate (LER) and the leaf appearance rate (LAR) of timothy were approximately 40% and 65% of that obtained under non-limiting N conditions (140 kg N ha−1 in spring and 120 kg N ha−1 in summer). Nitrogen deficiency reduced tiller density in spring but increased it in summer. The differential effect of the N deficiency on LER and LAR modified the sward structural characteristics. Nitrogen deficiency decreased the length of mature leaves, their width and the total leaf length per tiller. The reduced LER associated with N deficiency explained for the most part the N effect on leaf area expansion and radiation interception. Key words: Phleum pratense L., timothy, leaf extension, leaf appearance, tillering, nitrogen

scholarly journals Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu
Keyword(s):  
Genotypic Variation ◽  
Leaf Size ◽  
High Rate ◽  
Time Interval ◽  
Extension Rate ◽  
Leaf Production ◽  
Maize Cultivars ◽  
Plant Environment ◽  
The Difference ◽  
Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

A DEMOGRAPHIC ANALYSIS OF GROWTH DIFFERENCES BETWEEN NUI AND RUANUI RYEGRASS AT HIGH AND LOW NITROGEN INPUTS

1982 ◽  
pp. 125-132
Author(s):  
W.F. Hunt ◽  
B.J. Mortimer
Keyword(s):  
Nitrogen Nutrition ◽  
Leaf Size ◽  
Demographic Analysis ◽  
High Nitrogen ◽  
Phenotypic Differences ◽  
Nitrogen Inputs ◽  
Growth Differences ◽  
Tiller Density ◽  
Leaf Appearance ◽  
Low Nitrogen

Because of phenotypic differences, monocultures of Nui have tillers that are on average 43% larger but 20% less dense than monocultures of Ruanui. Nui tillers had larger leaves for most of the year and also more leaves per tiller during spring when Nui leaf appearance rates tended to be higher. Nui growth rates were higher in spring when temperature and nutritional limitations were removed. Nui yielded 54% more than Ruanui annually under high nitrogen nutrition. High nitrogen nutrition increased tiller density and death, tiller and leaf appearance rates, and leaf size and growth rate during the warmer months. Intermittent applications of nitrogen increased temporarily tiller and leaf appearance rates in apparent compensation for preceding lower rates. High nutrition tillers were more severely defoliated and had fewer leaves at the beginning of regrowths.

Leaf and stem nutritive value of timothy cultivars differing in maturity

1997 ◽  
Vol 77 (2) ◽  
pp. 237-249 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Nutritive Value ◽  
Weight Ratio ◽  
Phleum Pratense ◽  
Cultivar Differences ◽  
Early Maturing ◽  
True Digestibility ◽  
Phleum Pratense L

The nutritive value of herbage is a function of the nutritive value of its component leaves and stems and their proportion in the herbage. A previous study indicated that the proportion of leaves in the herbage did not explain entirely the differences in in vitro true digestibility and NDF concentrations between early and late-maturing timothy (Phleum pratense L.) cultivars. It was therefore hypothesized that the leaves and stems of early and late-maturing cultivars differ in nutritive value. The evolution of leaf and stem nutritive value of field-grown timothy cultivars differing in maturity, and the relationships between parameters of leaf and stem nutritive value, and the leaf to weight ratio (LWR) were studied during primary growth in two experiments. On a given date, stems of early-maturing cultivars had in vitro true digestibilities of dry matter and cell wall up to 61 g kg−1 DM and 71 g kg−1 DM lower that those of late-maturing cultivars, respectively. The NDF concentration of stems of early-maturing cultivars was up to 32 g kg−1 DM greater than that of late-maturing cultivars. There were no cultivar differences in leaf in vitro true digestibilities of dry matter and cell wall, and NDF concentration on a given date. At a given LWR, however, the leaves and stems of early-maturing cultivars had greater in vitro true digestibilities of dry matter and cell wall, and a lower NDF concentration than those of late-maturing cultivars. Our results indicate that differences in herbage nutritive value at a given stage of maturity between early- and late-maturing timothy cultivars is explained by a greater nutritive value of leaves and stems of the early-maturing cultivars. Key words: Phleum pratense L., timothy, cultivar, digestibility, cell wall, leaf, stem

Short Communication: Yield trend analysis of an ageing timothy sward using a modelling approach

2012 ◽  
Vol 92 (7) ◽  
pp. 1263-1266 ◽  
Author(s):  
Qi Jing ◽  
Gilles Bélanger
Keyword(s):  
Solar Radiation ◽  
Trend Analysis ◽  
Air Temperature ◽  
Dry Matter ◽  
Short Communication ◽  
Phleum Pratense ◽  
Climatic Variations ◽  
Primary Growth ◽  
Phleum Pratense L ◽  
Modelling Approach

Jing, Q. and Bélanger, G. 2012. Short Communication:Yield trend analysis of an ageing timothy sward using a modelling approach. Can. J. Plant Sci. 92: 1263–1266. Observed and simulated potential dry matter (DM) yields of the timothy (Phleum pratense L.) primary growth were compared to disentangle the yield trend from the effect of year-to-year climatic variations in an ageing sward (1 to 7 yr). Observed DM yields were close to simulated potential DM yields in the first 4 yr, but they were around 60% of simulated potential DM yields in the last 3 yr. This confirms that variations in air temperature and/or solar radiation could not explain the lower DM yield observed in the last three production years.

Digestibility and cell wall concentration of early- and late-maturing timothy (Phleum pratense L.) cultivars

1996 ◽  
Vol 76 (1) ◽  
pp. 107-112 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Field Experiments ◽  
Weight Ratio ◽  
Phleum Pratense ◽  
Early Maturing ◽  
Mathematical Relationships ◽  
The Relationship ◽  
Phleum Pratense L

Ear emergence or heading of early- and late-maturing cultivars of timothy (Phleum pratense L.) in the spring varies by as much as 3 wk. Two field experiments were conducted to describe the evolution of digestibility and cell-wall concentration of early- and late-maturing timothy cultivars during primary growth and to analyze the relationship between parameters of nutritive value and the leaf blade to biomass weight ratio (LWR). Compared with late-maturing cultivars of timothy on a given date, early-maturing cultivars had lower in vitro true digestibilities of DM and cell wall and a greater NDF concentration. Differences in in vitro true DM digestibility and NDF concentration between early- and late-maturing cultivars were not only related to the proportion of leaf blades in the biomass. Different parameters are, therefore, required to describe the mathematical relationships between digestibility and NDF concentration and LWR of early- and late-maturing cultivars. Key words:Phleum pratense, timothy, cultivars, digestibility, cell wall

scholarly journals Seasonal patterns of root, tiller and leaf production in a Grasslands Ruanui ryegrass sward

1996 ◽  
pp. 73-76
Author(s):  
C. Matthew
Keyword(s):  
Principal Component Analysis ◽  
Root Formation ◽  
Principal Component ◽  
Component Analysis ◽  
Seasonal Patterns ◽  
Extension Rate ◽  
Leaf Production ◽  
Leaf Formation ◽  
Leaf Appearance ◽  
Leaf Extension

In a Grasslands Ruanui perennial ryegrass (Lofium perenne L.) sward at Palmerston North, root mass, root appearance, tiller population density, tiller appearance and death rates, and leaf extension and leaf appearance rates were measured at 2-monthly intervals over a 12-month period, commencing November 1988. Tiller appearance was lowest in November, but was also low in May, increasing to a peak in August. Root appearance showed a pronounced peak in August. Leaf extension and leaf appearance rates were low during the period of high root and tiller formation in August, but high in November when tiller and root formation were low, suggesting co-ordination of these processes, with sequential activation of tillering, root formation and leaf formation activity winter. Principal component analysis to gain an objective overview of these data indicated a primary peak of activity in August (spring), and a secondary peak in March (autumn). The seasonal patterns observed for Grasslands Ruanui ryegrass appear to be different from those reported in the literature for Ellett and Grasslands Nui cultivars. ---.----._- - - - Keywords: leaf extension rate, Lolium perenne, principal component analysis, root growth, tiller appearance

NITROGENASE ACTIVITY OF ALFALFA GROWN ALONE AND IN MIXTURE WITH GRASS UNDER GREENHOUSE CONDITIONS

1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS
Keyword(s):  
Medicago Sativa ◽  
Nitrogenase Activity ◽  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Bromus Inermis ◽  
Smooth Bromegrass ◽  
Medicago Sativa L ◽  
Dactylis Glomerata L ◽  
Phleum Pratense L ◽  
Nodule Tissue

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference

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