Regrowth characteristics of an S. 23 perennial ryegrass sward defoliated at early stages of reproductive development

1973 ◽  
Vol 80 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ieuan Davies
Keyword(s):  
Perennial Ryegrass ◽  
Reproductive Development ◽  
Late Spring ◽  
Growth Stages ◽  
Stem Extension ◽  
Early Stages ◽  
Herbage Quality ◽  
Stem Development ◽  
Cutting Height

SummaryPatterns of stem development in late spring/summer regrowths after initial cuts at three growth stages are described. The stages at which the initial cuts were taken were: (a) before stem apices were raised to defoliation level (5 cm), (b) two weeks later when the apices of about 90% of the stem tillers were raised above this height, and (c) four weeks after (a), when the apices of all stem tillers were raised well above cutting height.Following an initial cut at stage (a) stem development was quickly resumed, the most advanced tillers being devoid of leaf blades. After initial cuts at the later stages there was virtually no stem development until after the fourth week of regrowth.The greater proportion of stem tillers in the earlier regrowth was not reflected in reduced digestibility during the first six weeks from cutting.Reproductive (apical) development was generally weak in tillers in which stems developed in midsummer (after cutting at stages b and c); at least two-thirds of these tillers were indeterminate.The significance of the distinct batch of stem tillers developing in spring is discussed, and the data are also considered in relation to (i) avoiding stemmy regrowths in spring, (ii) stem development and herbage quality, and (iii) summer stem extension and the perennation of the sward.

The pattern of reproductive development and the leafiness of spring and early summer regrowths in two contrasting varieties of ryegrass

1972 ◽  
Vol 78 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Ieuan Davies
Keyword(s):  
Perennial Ryegrass ◽  
Reproductive Development ◽  
Early Summer ◽  
Stem Length ◽  
Floral Initiation ◽  
Selection Methods ◽  
Stem Apex ◽  
Early Stages

SUMMARYEarly stages in the development of reproductive tillers of S. 24 and S. 23 perennial ryegrass are described. The pattern of development of the stem apex and of the unemerged leaves present at the time of floral initiation is traced up to the time when internode extension results in the elevation of the stem apices above the level of defoliation. If tillers with stems about 10 cm long, or more, escape damage to the stem apex during defoliation, the regrowth may be expected to deteriorate rapidly in leafiness, since at this stage there are few or no unemerged leaves. Tillers with 3–4 cm stems generally bear 1–2 unemerged leaves, and hence the regrowth is more leafy.For a given stem length apical development was slightly more advanced in S. 24 than in S. 23. Consideration is given to selection methods to be used in breeding for leafy regrowths in springtime.

scholarly journals Improving summer and autumn feed quality in New Zealand hill country

2014 ◽  
Vol 76 ◽  
pp. 145-148
Author(s):  
G.M. Rennie ◽  
W.Mcg King ◽  
T.L. Knight ◽  
B. Devantier ◽  
C.J. Hoogendoorn
Keyword(s):  
Early Summer ◽  
Late Spring ◽  
Hill Country ◽  
Pasture Quality ◽  
Herbage Quality ◽  
Dead Material ◽  
Hill Farming ◽  
Cutting Height ◽  
Clover Content

Abstract Management of late spring surpluses to restrict reproductive growth can increase the quality of hillcountry pastures during summer and autumn. This occurs through a reduction in accumulated stem and dead material and an increase in clover content. However, there is little information on the magnitude and longevity of these effects. This trial investigated the effects of four late spring defoliation intensities on herbage quality, measured at the end of spring and during summer. Treatments were applied through regular cutting of hill pastures in areas of medium fertility and slope on two aspects in each of four geo-climatically different hill-farming regions over two years. Pasture herbage quality at the end of spring followed expected trends: defoliation to low residual pasture height led to higher quality herbage. The maximum difference in quality between the lowest cutting height and nil cutting at this time was nearly 2 MJME/kg DM. With a change to uniform cutting height across all plots in early summer, these pasture quality differences reduced and disappeared. Keywords: Pasture quality, hill country, grazing management

scholarly journals Quality of herbage at different latitudes.

1981 ◽  
Vol 29 (2) ◽  
pp. 141-150 ◽  
Author(s):  
B. Deinum ◽  
J. de Beyer ◽  
P.H. Nordfeldt ◽  
A. Kornher ◽  
O. Ostgard ◽  
...  
Keyword(s):  
Cell Walls ◽  
Reproductive Development ◽  
Rapid Rate ◽  
Long Day ◽  
Herbage Quality ◽  
Stem Development

In a cooperative experiment, yield and herbage quality of timothy was measured during the uninterrupted growth of the 1st cut at 6 lat. (51-69 deg N). Rate of production was greatest at Tromso (69 deg N), apparently because of the long day and rapid reproductive development. Digestibility of OM declined faster at higher lat. because stem development proceeded faster and less leaf DM was produced. At the same morphological stage, digestibility of the whole crop was better at higher lat. because of the better digestibility of the cell walls from the stems. It was concluded that rate of lignification could not keep pace with the rapid rate of stem development. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Developmental characteristics of grass varieties in relation to their herbage production: 2. Spring defoliation of Dactylis glomerata: the fate of reproductive tillers which are cut, but whose stem apex is retained

1976 ◽  
Vol 87 (1) ◽  
pp. 33-38 ◽  
Author(s):  
I. Davies
Keyword(s):  
Dactylis Glomerata ◽  
Extension Growth ◽  
Critical Stage ◽  
Stem Apex ◽  
Stem Extension ◽  
Early Stages ◽  
Leaf Retention ◽  
Developmental Characteristics ◽  
Cutting Height

SummaryEarly stages in the development of reproductive tillers of cocksfoot were studied in uncut swards, and in regrowth after cuts taken at a critical stage.In uncut swards, initial stages of stem extension (up to 10 cm) occurred over 3 weeks. During this period the last three or four leaves initiated on the tiller became visible externally. Tillers with stems of less than 2 cm generally had one or two partially emerged blades. Those with stems 2–6 cm long carried two, three or, occasionally, four partially emerged blades; the sheaths of two, and sometimes three of these leaves extended beyond the stem apex. Hence, for tillers with 2–6 cm stems, even lenient defoliation involving the removal of only one expanded blade would result in the severance of a further two, three or four developing leaves; at an earlier stage only one or two developing leaves would be severed.In the regrowth studies it was found that defoliation of reproductive tillers whose apices were below cutting height and which, at the time of cutting, had stems of up to 8 cm, led to contrasting effects: some made only negligible regrowth, whilst others made rapid extension growth. Some of the most rapidly extending tillers retained no leaf blades, and therefore the alternative effects of defoliation cannot be completely explained in terms of leaf retention. Other possible mechanisms contributing to these effects are discussed.

A Leaf Bud Development Scale for Rabbiteye Blueberry

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 455f-456 ◽  
Author(s):  
D. Scott NeSmith ◽  
Gerard Krewer ◽  
Jeffrey G. Williamson
Keyword(s):  
Reproductive Development ◽  
Developmental Differences ◽  
Research Management ◽  
Growth Stages ◽  
Vaccinium Ashei ◽  
Bud Development ◽  
Dormant Bud ◽  
Mouse Ear ◽  
Highbush Blueberries ◽  
Winter Chilling

Crop vegetative and reproductive development are frequently divided into stages to describe progression of development. Such a description is useful in denoting developmental differences between cultivars, for making crop management decisions based on growth stages, and for clear communication among individuals concerned with research, management, and production of the crop. We have developed such a scale for leaf bud development in rabbiteye blueberry (Vaccinium ashei Reade). Our scale has six stages briefly described as follows: 1) dormant bud; 2) early green tip; 3) late green tip; 4) unfolding stage; 5) mouse-ear stage; 6) fully opened bud. Categorizing buds in this manner has proven useful in comparing rates of leaf development between cultivars and in response to winter chilling. The stages appear to be relevant to highbush blueberries (V. corymbosum) as well.

scholarly journals The dynamics of sprouts generation and colonization by macrofungi of black cherry Prunus serotina Ehrh. eliminated mechanically in the Kampinos National Park

2018 ◽  
Vol 60 (1) ◽  
pp. 34-51 ◽  
Author(s):  
Katarzyna Marciszewska ◽  
Andrzej Szczepkowski ◽  
Anna Otręba ◽  
Lidia Oktaba ◽  
Marek Kondras ◽  
...  
Keyword(s):  
National Park ◽  
Qualitative Data ◽  
Late Spring ◽  
Black Cherry ◽  
Mycological Research ◽  
Response Dynamics ◽  
Vegetation Season ◽  
Cut Stump ◽  
Cutting Height ◽  
The Relationship

Abstract The experiment conducted in the Kampinos National Park since 2015 is aimed at investigating the relationship between the dynamics of black cherry sprouting response and the type and term of implementation of the mechanical elimination procedure. It also identifies macrofungi colonizing trees undergoing eradication. Three treatments, basal cut-stump, cutting (height: ca. 1 m) and girdling, were performed on 4 terms: early and late spring, summer and winter. Each variant was conducted within two plots, and applied to 25 trees, to 600 trees in total. For two consecutive vegetation seasons, sprouts were removed approximately every 8 weeks with the exception of winter-treated trees. Qualitative data were analysed, that is, the number of trees with and without sprouts at subsequent controls, and at the end of the second season, except winter-treated trees. Initially, almost 100% of the trees cut at the base and cut high responded by sprouting. The share of trees without sprouts gradually increased during the following vegetation season, from 3rd to 5th repetition of the sprouts removal, depending on the variant of experiment. Girdling contributed to a delay in sprouting. The effectiveness of procedures, expressed as share of trees without sprouts at the end of the second vegetation season, ranged widely (12%–84%), and depended statistically significantly on the date of the treatment. The effectiveness was higher for treatments done in early (average 68%) and late spring (average 74%), as compared to those done in summer (average 35%). Mycological research concerned 600 trees, including those treated in winter, without sprouts removal. Occurrence of 26 taxa of macrofungi was confirmed on 25% of trees; most of them having wood-decaying properties. Chondrostereum purpureum was most frequent, colonizing 9% of trees. Impact of plots varying soil moisture on succession and rate of fungi colonization, and on sprouting response dynamics requires further research.

Results from experiments with winter wheat, spring barley and grass, comparing a liquid N-fertilizer either alone or with added herbicide, and top-dressings of ‘Nitro-Chalk’ without or with herbicide sprayed alone

1974 ◽  
Vol 83 (3) ◽  
pp. 511-529 ◽  
Author(s):  
A. Penny ◽  
S. C. R. Freeman
Keyword(s):  
Winter Wheat ◽  
Weed Control ◽  
Perennial Ryegrass ◽  
Spring Barley ◽  
Barley Grain ◽  
N Fertilizer ◽  
Growth Stages ◽  
Liquid Fertilizer ◽  
Grass Weed ◽  
Better Than

SummaryDuring 1970–3 three experiments with winter wheat, three with spring barley, two with permanent grass and one with perennial ryegrass measured the effects of a liquid N-fertilizer (26% N) sprayed over the leaves either alone or with a herbicide added to it. ‘Nitro-Chalk’ (21% N) was used as the standard for comparison. The liquid N-fertilizer was made from urea and ammonium nitrate; the herbicide was a mixture of dichlorprop and MCPA. Each experiment tested all combinations of the two N fertilizers applied to give 38, 75 or 113 kg N/ha without the herbicide and with either 2·8, 5·6 (recommended dose) or 8·4 1/ha of herbicide. The 24 treatments were applied to winter wheat at growth stages 4–5 of the Feekes scale, to barley at growth stage 5 and to grass in late spring and again to regrowth after cutting.Herbicide alone sometimes scorched the leaves but seldom badly. Liquid N-fertilizer nearly always scorched the leaves and the amount of scorch was increased by adding herbicide; scorch also was increased by increasing the amount of either and so was most severe when most liquid fertilizer and most herbicide were sprayed together; this damage did not decrease yields appreciably except when only 38 kg N/ha was given.Spraying the herbicide with the liquid fertilizer always gave slightly better weed control than herbicide alone in the wheat, but not always in the barley; in the grass, weed control was no better than from herbicide alone.‘Nitro-Chalk’ gave larger yields of wheat grain than the liquid N-fertilizer did in seven of nine comparisons without herbicide and in 20 of 27 with it, of barley grain in five of nine comparisons without herbicide and in 15 of 27 with it, of permanent grass in 25 of 27 comparisons without herbicide and in 70 of 81 with it, and of perennial ryegrass in nine of nine comparisons without herbicide and in 25 of 27 with it. Thus herbicide did not alter the advantage that ‘Nitro-Chalk’ had.Percentages of N in the crops were larger with ‘Nitro-Chalk’ than with the liquid N-fertilizer but were changed little by herbicide.

Candidate gene-based association genetics analysis of herbage quality traits in perennial ryegrass (Lolium perenne L.)

2013 ◽  
Vol 64 (3) ◽  
pp. 244 ◽  
Author(s):  
L. W. Pembleton ◽  
J. Wang ◽  
N. O. I. Cogan ◽  
J. E. Pryce ◽  
G. Ye ◽  
...  
Keyword(s):  
Association Mapping ◽  
Candidate Gene ◽  
Perennial Ryegrass ◽  
Association Studies ◽  
Phenotypic Variance ◽  
Genome Wide Association Studies ◽  
Quality Traits ◽  
Near Infrared Reflectance ◽  
Genome Wide ◽  
Herbage Quality

Due to the complex genetic architecture of perennial ryegrass, based on an obligate outbreeding reproductive habit, association-mapping approaches to genetic dissection offer the potential for effective identification of genetic marker–trait linkages. Associations with genes for agronomic characters, such as components of herbage nutritive quality, may then be utilised for accelerated cultivar improvement using advanced molecular breeding practices. The objective of the present study was to evaluate the presence of such associations for a broad range of candidate genes involved in pathways of cell wall biosynthesis and carbohydrate metabolism. An association-mapping panel composed from a broad range of non-domesticated and varietal sources was assembled and assessed for genome-wide sequence polymorphism. Removal of significant population structure obtained a diverse meta-population (220 genotypes) suitable for association studies. The meta-population was established with replication as a spaced-plant field trial. All plants were genotyped with a cohort of candidate gene-derived single nucleotide polymorphism (SNP) markers. Herbage samples were harvested at both vegetative and reproductive stages and were measured for a range of herbage quality traits using near infrared reflectance spectroscopy. Significant associations were identified for ~50% of the genes, accounting for small but significant components of phenotypic variance. The identities of genes with associated SNPs were largely consistent with detailed knowledge of ryegrass biology, and they are interpreted in terms of known biochemical and physiological processes. Magnitudes of effect of observed marker–trait gene association were small, indicating that future activities should focus on genome-wide association studies in order to identify the majority of causal mutations for complex traits such as forage quality.

Effect of surface applied glycine betaine on herbage production and quality of perennial ryegrass - white clover pastures

2008 ◽  
Vol 48 (5) ◽  
pp. 687 ◽  
Author(s):  
J. M. Lee ◽  
K. Elborough ◽  
W. D. Catto ◽  
D. J. Donaghy ◽  
J. R. Roche
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Glycine Betaine ◽  
Moisture Stress ◽  
Quality Parameters ◽  
Plant Tolerance ◽  
Cold Temperatures ◽  
Herbage Quality ◽  
Effect Of Surface

Osmoprotectants have been reported to reduce the detrimental effects of various environmental stresses in many different plant species. However, there is little research available concerning pasture species. Two experiments were undertaken with the aim of quantifying the effect of surface applications of exogenous glycine betaine (GB) on herbage production and quality of perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repens L.) pastures during periods of moisture stress and cold temperatures over 2 years. Pastures fertilised with GB were compared with unfertilised pastures and pastures fertilised with nitrogen (N). Rates of 0.5, 1.0 and 1.5 kg GB/ha.defoliation were applied in experiment 1 and 5 kg GB/ha.defoliation was applied in experiment 2. Surface applications of GB did not significantly affect herbage production relative to unfertilised pastures; herbage yields averaged 12 248 and 12 693 kg DM/ha over 11 months in experiment 1, and 7253 and 7177 kg DM/ha over 6 months during summer and autumn in experiment 2, for the unfertilised control and GB, respectively. During both experiments, herbage quality parameters were not affected by GB application, although the proportion of white clover in the sward between summer and winter during experiment 1 was greater (P < 0.01) in plots treated with GB than in untreated plots. Application of N fertiliser increased (P < 0.001) herbage production, but did not consistently affect herbage quality. The failure of surface applications of exogenous GB to improve the herbage production or quality of perennial ryegrass–white clover pastures suggests that it is not an appropriate method to enhance plant tolerance to environmental stress at the concentrations applied in these studies.

The effect of the height of defoliation on two clones of perennial ryegrass

1972 ◽  
Vol 79 (3) ◽  
pp. 509-514 ◽  
Author(s):  
R. G. Simons ◽  
Alison Davies ◽  
Arthur Troughton
Keyword(s):  
Perennial Ryegrass ◽  
Significant Interaction ◽  
Leaf Tissue ◽  
Ground Level ◽  
Above Ground Level ◽  
The Difference ◽  
Cutting Height ◽  
Leaf Appearance

SUMMARYA significant interaction between genotype and cutting height was found in an experiment conducted to investigate regrowth from cutting heights of 2 cm and 5 cm above ground level in two contrasting genotypes with fast and slow rates of leaf appearance. There was, however, no evidence that production of herbage above the initial cutting height was increased by raising the height of cutting. This observation, and the difference between the genotypes, can be explained not only in terms of differences in the proportion of total above-ground parts harvested, but also in the scale of losses of leaf tissue by death.

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