Defoliation frequency and genotype effects on stolon and root reserves in white clover

1998 ◽  
Vol 49 (6) ◽  
pp. 983 ◽  
Author(s):  
A. R. Lawson ◽  
P. W. G. Sale ◽  
K. B. Kelly
Keyword(s):  
White Clover ◽  
Large Fraction ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Starch Concentration ◽  
Nitrogen Concentrations ◽  
Defoliation Frequency ◽  
Water Soluble Carbohydrate ◽  
Nitrogen Contents ◽  
Principal Method

The effect of defoliation frequency (1 or 3 defoliations over a 42-day period) on the starch, water soluble carbohydrate (WSC), and nitrogen contents of 3 white clover cultivars (Haifa, Irrigation, and S184) was examined. The clover plants consisted of single stolons growing in a sand/scoria mix in an unheated glasshouse and fertilised weekly with a nitrogen-free solution. Starch concentrations ranged from 1·3% in frequently defoliated Haifa to 15·3% in infrequently defoliated S184 plants. However, there was no interaction between cultivar and defoliation frequency, with the starch concentration in S184 (11·2%) being twice that in Irrigation (6·0%) and 3 times that in Haifa (3·8%). The starch concentration was also less with frequent (3·7%) than with infrequent (10·3%) defoliation. The starch was localised in the old stolon material (12·2%), with lower levels of starch in both the young stolon (6·0%) and roots (4·0%). Furthermore, the cultivar and defoliation frequency effects on the starch concentrations were most pronounced in the old stolon. More frequent defoliation also resulted in a small reduction in the WSC and nitrogen concentrations in both the young and old stolons of Haifa, but not of Irrigation. It was concluded that although starch reserves were the principal method of reserve storage in white clover, WSC and nitrogen reserves will form a relatively large fraction of the reserve pool when starch reserves are depleted under conditions such as frequent defoliation.

Defoliation frequency and cultivar effects on the storage and utilisation of stolon and root reserves in white clover

2000 ◽  
Vol 51 (8) ◽  
pp. 1039 ◽  
Author(s):  
A. R. Lawson ◽  
K. B. Kelly ◽  
P. W. G. Sale
Keyword(s):  
White Clover ◽  
Plant Size ◽  
Water Soluble ◽  
Cultivar Differences ◽  
Soluble Carbohydrate ◽  
Leaf Production ◽  
Plant Weight ◽  
Stolon Length ◽  
Defoliation Frequency ◽  
Leaf Appearance

The effects of defoliation frequency (2 or 6 defoliations over a 91-day period) on the reserve status and growth rate of 2 white clover cultivars, cvv. Irrigation (medium-leafed) and Haifa (large-leafed), were examined over the final 42 days of the defoliation treatments. The clover plants consisted of single stolons growing in a sand/scoria mix in an unheated glasshouse, and were fertilised weekly with a solution containing essential nutrients excluding nitrogen. More frequent defoliation reduced the leaf appearance rate, stolon elongation rate, and plant size, and increased stolon death, with all of these effects being less pronounced in Irrigation than in Haifa (18% v. 30%, 60% v. 80%, and 23% v 34%, respectively, for leaf appearance rates, stolon elongation rates, and the proportion of stolon length that died). With infrequent defoliation, the combined utilisation of starch and water-soluble carbohydrate (WSC) reserves in the first 14 days after defoliation was equivalent to 15% of the plant weight at defoliation, and to 95% of the new leaf produced during that period. Frequent defoliation reduced the reserve content and remobilisation less in Irrigation than in Haifa, with the combined mass of remobilised starch and WSC over the first 14 days after defoliation being 2.9% and 2.0% of the plant weight at defoliation, and 29% and 19% of leaf production over that period, for Irrigation and Haifa, respectively. The greater reserve mobilisation in Irrigation than in Haifa plants under frequent defoliation probably contributed to their higher growth rates and reduced stolon death. These cultivar differences with frequent defoliation suggest that Irrigation is more suited to frequent defoliation than Haifa.

Relations between fibre and water soluble carbohydrate contents of pasture species and their digestibility and voluntary intake by sheep

1973 ◽  
Vol 13 (61) ◽  
pp. 165 ◽  
Author(s):  
PJ Michell
Keyword(s):  
Chemical Composition ◽  
Lolium Perenne ◽  
White Clover ◽  
Dry Matter ◽  
Dactylis Glomerata ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Dry Matter Digestibility ◽  
Voluntary Intake ◽  
Water Soluble Carbohydrate

Neutral detergent fibre (NDF), acid detergent fibre (ADF) and water soluble carbohydrate (WSC) levels were determined on 80 samples of known apparent dry matter digestibility (DMD) and voluntary intake of dry matter (DMI). The pastures consisted of regrowths of six species: Trifolium repens (white clover cv. Grasslands Huia), Lolium perenne x L. multiflorum (short rotation ryegrass c.v Grasslands Manawa), Lolium perenne (long rotation ryegrass cv. Grasslands Ariki), Lolium perenne (perennial ryegrass cv. Tasmania No. I), Dactylis glomerata (cocksfoot cv. Currie) and Dactylis glomerata (cocksfoot cv. Grasslands Apanui), cut eight times between May 1969 and August 1970. Overall, white clover had a lower NDF and a lower WSC content than the ryegrasses but both groups had similar ADF contents. Cocksfoots had higher NDF and ADF, and lower WSC contents than the ryegrasses. NDF and ADF could be used to predict the DMD of all species in all seasons with residual standard deviations (RSD) of 3.0 and 3.2 DMD units (per cent) respectively. No significant relations (P < 0.05) were present between DMD and WSC content. Seasonal differences were present in the relations between DMI and chemical composition. The RSD of the overall regressions of intake with NDF, ADF, and WSC contents were 9.3, 9.4, and 8.9 DMI units (g/day/kg0.75) respectively. Within seasons, DMI was best predicted by regressions with detergent fibre content and here the RSD had a range of 3.4 to 5.2 DMI units. Within species over all seasons, DMI was predicted best by regressions with WSC content and the RSD had a range of 5.7 to 7.9 DMI units. The usefulness of the chemical composition measurements in explaining the reason for the low intakes, previously found with winter pasture, is discussed.

Quantitative digestion of fresh herbage by sheep:V. The digestion of four herbages and prediction of sites of digestion

1979 ◽  
Vol 92 (3) ◽  
pp. 605-616 ◽  
Author(s):  
M. J. Ulyatt ◽  
A. R. Egan
Keyword(s):  
Organic Matter ◽  
Small Intestine ◽  
Organic Acids ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Water Soluble Carbohydrate ◽  
Dietary Origin

SUMMARYThe extents and sites of digestion of organic matter (OM), and its constituent watersoluble carbohydrates, organic acids, pectin, cellulose, hemicellulose and crude protein have been studied in sheep prepared with re-entrant duodenal cannulas and fed four fresh herbage diets, Ruanui perennial ryegrass, Tama Westerwolds ryegrass, Pitau white clover and Fakir sainfoin, at each of two levels of intake.The water-soluble carbohydrate, organic acids and pectin of all diets were almost completely digested within the rumen. Some 10% of water soluble carbohydrate reached the duodenum on each diet, though this may not have been of dietary origin. Only on legume diets, where pectin concentration was higher, did measurable amounts of pectin reach the intestine, accounting for some 5% of the pectin.Hemicellulose and cellulose digestibilities differed between diets, being lowest for sainfoin, and next lowest for clover. Between 79 and 94% of digestible hemicellulose was digested in the stomach, but diet and intake had no significant effect on this partition. Of the digestible cellulose, 87–97% was digested in the stomach.Digestibility of N was lowest for sainfoin and highest for Tama ryegrass. There were no significant differences between herbage species or intake in the percentage of digested N digested in the stomach or intestines. The tannin contained in sainfoin had no effect on nitrogen digestion.Data from this and other studies reported in the literature were examined as a basis for establishing prediction equations whereby the partition of digestion of the major carbohydrate and nitrogenous constituents in stomach and intestines might be estimated from data obtainable from standard digestibility trials. Regressions were developed for predicting the amounts of OM, cellulose, and hemicellulose digested in the stomach. There are not yet enough suitable data available to predict the amount of nitrogen entering the small intestine.

Effects of upland pastures sown with two contrasting Lolium perenne varieties on the performance of beef steers when compared to steers grazing permanent pastures

2005 ◽  
Vol 2005 ◽  
pp. 194-194
Author(s):  
C. L. Marley ◽  
D. A. Davies ◽  
J. E. Vale ◽  
J. G. Evans ◽  
N. D. Scollan ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Lolium Perenne ◽  
White Clover ◽  
High Water ◽  
Water Soluble ◽  
Production Performance ◽  
Soluble Carbohydrate ◽  
Beef Steers ◽  
Water Soluble Carbohydrate

Grazing experiments have shown that using a ryegrass (Lolium perenne L.) variety bred by conventional techniques for high water-soluble carbohydrate (WSC) concentrations can improve liveweight gain in pre-weaned lambs (Lee et al., 2001) and increase milk yields and reduce N excretion in dairy cows (Miller et al., 2001) compared to conventional ryegrass. The aim of this study was to determine the effects of using reseeded upland pastures, sown with either a ryegrass variety bred for elevated levels of WSC or a control ryegrass on the production performance of grazing steers when compared to steers grazing permanent ryegrass/white clover pastures.

scholarly journals Diurnal changes in the nutritive composition of four forage species at high and low N fertiliser

2017 ◽  
Vol 79 ◽  
pp. 111-118
Author(s):  
L.A. Box ◽  
G.R. Edwards ◽  
R.H. Bryant
Keyword(s):  
Chemical Composition ◽  
White Clover ◽  
Crude Protein ◽  
Nutritive Value ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Diurnal Changes ◽  
Nitrogen Inputs ◽  
Nutritive Composition ◽  
Water Soluble Carbohydrate

Chicory and plantain have been suggested as alternative grazed forages to perennial ryegrass for New Zealand dairy systems. While diurnal changes in plant chemical composition have been described for ryegrass there is currently little information for herbs. This experiment aimed to compare the effect of nitrogen inputs (low and high) and harvesting time (am versus pm) on the chemical composition of four forages (ryegrass, plantain, chicory and white clover). The effect of harvest time was greater than N fertiliser inputs on chemical composition for all forages. Ryegrass showed the greatest increase in water soluble carbohydrate diurnally, at the expense of neutral detergent fibre and to a lesser extent crude protein. This suggests afternoon allocation of ryegrass may be beneficial to improve the nutritive value of pasture on offer; allocation timing is less important for white clover, chicory and plantain. Keywords: chicory, clover, crude protein, plantain, ryegrass, water soluble carbohydrate

scholarly journals Decreasing Defoliation Frequency Enhances Bromus valdivianus Phil. Growth under Low Soil Water Levels and Interspecific Competition

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1333
Author(s):  
Javier García-Favre ◽  
Yongmei Zhang ◽  
Ignacio F. López ◽  
Daniel J. Donaghy ◽  
Lydia M. Cranston ◽  
...  
Keyword(s):  
Soil Water ◽  
Block Design ◽  
Field Capacity ◽  
Water Levels ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Defoliation Frequency ◽  
Four Blocks ◽  
Water Soluble Carbohydrate ◽  
Reduced Water

Bromus valdivianus Phil. (Bv) is a water stress-tolerant species, but its competitiveness in a diverse pasture may depend on defoliation management and soil moisture levels. This glasshouse study examined the effect of three defoliation frequencies, based on accumulated growing degree days (AGDD) (250, 500, and 1000 AGDD), and two soil water levels (80–85% of field capacity (FC) and 20–25% FC) on Bv growth as monoculture and as a mixture with Lolium perenne L. (Lp). The treatments were applied in a completely randomised block design with four blocks. The above-ground biomass of Bv was lower in the mixture than in the monoculture (p ≤ 0.001). The Bv plants in the mixture defoliated more infrequently (1000 AGDD) showed an increase in root biomass under 20–25% FC compared to 80–85% FC, with no differences measured between soil water levels in the monoculture. Total root length was highest in the mixture with the combination of infrequent defoliation and 20–25% FC. Conversely, frequent defoliation treatments resulted in reduced water-soluble carbohydrate reserves in the tiller bases of plants (p ≤ 0.001), as they allocated assimilates mainly to foliage growth. These results provide evidence that B. valdivianus can increase its competitiveness relative to Lp through the enhancement of the root growth and the energy reserve in the tiller base under drought conditions and infrequent defoliation in a mixture.

Variation in the response of Lolium genotypes to defoliation

1994 ◽  
Vol 45 (6) ◽  
pp. 1309 ◽  
Author(s):  
WJ Fulkerson ◽  
K Slack ◽  
KF Lowe
Keyword(s):  
Root Growth ◽  
Lolium Multiflorum ◽  
Selection Criterion ◽  
Evaluation Process ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Plant Water ◽  
Leaf Stage ◽  
Defoliation Frequency ◽  
Water Soluble Carbohydrate

A glasshouse study was undertaken to determine the effect of defoliation frequency (three times at one leaf stage or once at three leaf stage of the regrowth cycle) and height (20, 50 or 120 mm) on regrowth, plant water soluble carbohydrate (WSC) reserves and root growth of seven Lolium perenne and two Lolium multiflorum cultivars. The sensitivity to defoliation was in decreasing order: biennial, PI perennials (cv. Ellett, AN2327, LP30, LP31), P2 perennials (cv. Kangaroo Valley, Yatsyn, Pacific). The effect of frequent, compared to infrequent, defoliation was to suppress regrowth by l00%, 95% and 80%; stubble WSC (mg/plant) by 97, 89 and 81%; root DM (g/plant) by 76, 60 and 6%, for biennial, P1 and P2, respectively. The effect of defoliation height accentuated this response, with biennials defoliated frequently at 20 mm stubble height all dying. Under defoliation conditions producing optimal yield, the yield was positively related to sensitivity to defoliation, giving regrowths of 2.90, 2.68, 1.53 g DM per plant for biennial, P1 and P2 plants, respectively. In view of the marked defoliation by cultivar interaction, response to defoliation should be considered as a possible selection criterion in any evaluation process.

Forage yield and quality interactions between white clover and contrasting ryegrass varieties in grazed swards

1996 ◽  
Vol 126 (3) ◽  
pp. 295-299 ◽  
Author(s):  
D. R. Evans ◽  
M. O. Humphreys ◽  
T. A. Williams
Keyword(s):  
White Clover ◽  
Nutritive Value ◽  
Late Summer ◽  
Water Soluble ◽  
Forage Yield ◽  
Soluble Carbohydrate ◽  
Yield And Quality ◽  
Water Soluble Carbohydrate ◽  
The Impact ◽  
Grazed Swards

SUMMARYThe impact of white clover on seasonal yield and nutritive value traits in perennial ryegrass was investigated using six ryegrass varieties which expressed contrasting levels of water soluble carbohydrate (WSC). These were sown in an upland environment at Syfydrin, near Aberystwyth, in mixtures with white clover and in monocultures. Plots were grazed by sheep and sampled during 1991–93. Grass yields in mixtures and monocultures were similar except during mid to late summer when clover contents were high. White clover had a considerably lower WSC content but a much higher crude protein (CP) content than the ryegrasses. The WSC content of grasses in mixed swards was consistently lower than in monocultures and markedly so during mid to late summer. Use of ryegrass varieties with a relatively high WSC content can compensate for this depletion. Consequently high WSC grasses may reduce the amounts of nitrogen excreted by ruminants grazing mixed swards by increasing the efficiency of protein use from clover.

scholarly journals The effect of forage species and stage of harvest on the processes of digestion occurring in the rumen of cattle

1986 ◽  
Vol 56 (2) ◽  
pp. 439-454 ◽  
Author(s):  
D. E. Beever ◽  
M. S. Dhanoa ◽  
H. R. Losada ◽  
R. T. Evans ◽  
S. B. Cammell ◽  
...  
Keyword(s):  
Small Intestine ◽  
White Clover ◽  
Live Weight ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Late Season ◽  
Forage Species ◽  
Water Soluble Carbohydrate ◽  
Microbial N

1. Pure swards of perennial ryegrass (Lolium perenne L. cv. Melle) or white clover (Trifolium repens L. cv. Blanca) were harvested daily as either primary growth (May-June) or mid- (July) and late- (August-September) season 4-week regrowths and offered to Friesian steers at two levels of feed allowance (18 and 24 g dry matter (DM)/kg live weight), to examine the effect of forage species and stage of harvest on nutrient digestion and supply.2. The early- and mid-season grasses had low nitrogen (23 g/kg DM) and high water-soluble carbohydrate (169 g/kg) contents whilst the late-season grass had a higher N content (28 g/kg). All clover diets had high N (average 45 g/kg) and low water-soluble carbohydrate (89 g/kg) contents, and DM digestibility on all diets ranged from 0.77 to 0.83 (mean of two feeding levels).3. Mean total rumen volatile fatty acid concentrations were significantly (P < 0.001) higher on the clover diets, whilst on the grass diets molar proportions of propionate showed a slight but not significant decline with advancing season and tended to be higher than those on the clover diets. Mean rumen ammonia concentrations were significantly (P < 0.001) lower on the early- and mid-season grasses (59 mg NH3-N/1) than the late-season grass (242 mg/l) and early-season clover (283 mg/l) which were all significantly (P < 0.01) lower than the mid-and late-season clovers (372 and 590 mg/l) respectively.4. Rates of organic matter (OM) and N digestion in the rumen were estimated using established nylon-bag techniques and found to be high on all diets, but significant effects due to forage species (clover > grass; P < 0.001) were detected, whilst overall potential degradability in the rumen exceeded 0.89 for both OM and N on all diets.5. Significantly (P < 0.001) more OM entered the small intestine of calves fed on white clover (10.2 g/kg live weight) than those fed on ryegrass (8.33 g/kg) and similar effects due to level of feeding (g/kg; low 7.9, high 10.6; P < 0.05) and stage of harvest (g/kg; early 8.3 v. mid 10.0, late 9.50; P < 0.05) were also detected. Non-NH3-N (NAN) flow (g/kg) to the small intestine was increased by forage species (grass 0.56, clover 0.69; P < 0.05) and stage of harvest (early 0.59 v. mid 0.65, late 0.64; P > 0.05) whilst NAN flow/N intake ranged from 0.96 to 1.65 g/g (mean 1.25) on the grass diets and from 0.64 to 0.84 g/g (mean 0.75) on the clovers (P < 0001).6. Microbial N flow to the small intestine averaged 0.72 of duodenal NAN (grass 0.76, clover 0.69). Efficiency of microbial N synthesis was high on all diets, (g/kg OM truly digested in the rumen; grass 33.5, clover 36.3), as was the estimated extent of in vivo feed N degradation (g/g N intake; grass 0.75, clover 0.79).7. A model is described to simulate the progress curves of the ratio, degraded N:degraded OM in the rumen for the six diets, using indices obtained in the present study. The results are ratified with the in vivo observations of N utilization in the rumen for the grass and clover diets.8. It is concluded that both forage species and stage of harvest can significantly influence the processes of rumen digestion and nutrient supply, but with the fresh forages examined in the present study, it would appear that the processes of digestion in the rumen greatly outweighed the passage of potentially digestible nutrients from the rumen.

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