Production, persistence, and water-soluble carbohydrate accumulation in 21 contrasting populations of Dactylis glomerata L. subjected to severe drought in the south of France

1997 ◽  
Vol 48 (7) ◽  
pp. 933 ◽  
Author(s):  
F. Volaire ◽  
F. Lelièvre

In rainfed Mediterranean areas, summer drought is the main factor affecting the persistence of perennial grasses. Most available cultivars of Dactylis glomerata (cocksfoot) exhibit low persistence in this environment; therefore, research is needed on the relationships between plant physiology and recovery after severe drought. In the field, we subjected a large range of populations and cultivars of cocksfoot to 3 months of drought followed by 3 weeks of rewatering. Principal component and cluster analysis discriminated 3 groups of genotypes: (1) late heading populations and cultivars of temperate origin (ssp. glomerata) that exhibited high tiller mortality in summer; (2) early heading populations of Mediterranean origin (ssp. hispanica) that survived well but had a low growth potential; (3) very early heading Mediterranean cultivars (ssp. glomerata × hispanica) that survived and recovered actively. The study of bases of youngest enclosed leaves (surviving organs) showed that osmotic potential in living bases was not significantly different between groups of populations; dry matter content was higher in bases of hispanica populations at the onset of drought; total water-soluble carbohydrate and fructan contents increased as drought progressed and reached 35-40% of dry matter in bases at the end of the drought. Drought survival was best correlated with both the ratio between low and high weight fructans in July (summer) and the heading date (R2 = 0·75, P < 0·001). Recovery yield after autumn rewatering was highly correlated with both of these variables and the dry matter content in leaf bases in June (R2 = 0·75, P< 0·001), which may be associated with levels of summer dormancy. These results emphasise the role of ontogeny in drought resistance and can be used to predict plant survival in a large range of populations of cocksfoot.

2004 ◽  
Vol 55 (11) ◽  
pp. 1183 ◽  
Author(s):  
Y. Sanada ◽  
T. Takai ◽  
T. Yamada

The water-soluble carbohydrate (WSC) content of Dactylis glomerata L. (cocksfoot) during vegetative growth is lower than that of other temperate grasses. Variation in the WSC content of vegetative growth among cultivars was measured in order to assess the potential to improve forage quality. There were significant differences among cultivars for WSC content (P < 0.01) in all maturity groups. Average WSC content of the late (L) maturity group was higher than that of the early (E) and medium (M) maturity groups. Variation in the WSC content was largest among group L cultivars and smallest in group M. The WSC content of cultivars in groups M and L was consistent across 2 years (interactions between cultivars and years were not significant). Brown stripe infection was shown to reduce WSC content in susceptible cultivars. As a result of multiple regression analysis with WSC content as the dependent variable, dry matter content, heading date, thickness of stems, and resistance to brown stripe were selected as independent variables that were correlated with WSC. Therefore, variation for these traits must also be monitored in any program to increase WSC content in orchardgrass.


1973 ◽  
Vol 13 (61) ◽  
pp. 165 ◽  
Author(s):  
PJ Michell

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.


2000 ◽  
Vol 51 (6) ◽  
pp. 749 ◽  
Author(s):  
T. A. Ciavarella ◽  
R. J. Simpson ◽  
H. Dove ◽  
B. J. Leury ◽  
I. M. Sims

The concentrations of water-soluble carbohydrate (WSC) and its components, starch, total nitrogen, and dry matter of phalaris (Phalaris aquatica L. cv. Australian) pasture were varied by shading for periods ranging from 38.5 to 46.5 h. In unshaded pasture, WSC concentrations were lowest at sunrise [103 mg/g dry matter (DM)] and increased until early afternoon (to 160 mg/g DM). Sucrose and starch increased in concentration during daylight, whilst the concentrations of glucose, fructose, fructan, and a component of WSC considered to be mainly the carbohydrate moiety of glycoside(s) were relatively constant. The concentrations of starch, and all components of WSC except sucrose, were reduced by shading, but increased to the concentrations observed in the unshaded pasture within 2–4 h after removal of the cover. The fructans present in phalaris were determined to be oligosaccharides of degree of polymerisation (DP) 3 and DP 4 and high molecular mass fructans with DP >10. Nitrogen concentration of shaded pasture was initially higher (4.7% DM) than in unshaded pasture (3.9% DM), but decreased after removal of the shade cover. Dry matter content was reduced in shaded pasture, partly due to increased retention of water on the exterior of plants. The experiment was a precursor for a grazing trial in which the WSC content of pasture was to be altered by shading. It indicated that shading would potentially alter WSC and N concentrations, and DM content, but would have only a relatively small impact on the digestibility of the pasture.


1968 ◽  
Vol 71 (3) ◽  
pp. 393-403 ◽  
Author(s):  
A. J. Thomson ◽  
H. H. Rogers

SUMMARYResults from three trials are presented. The main variables were date of harvest, plant density and variety. Measurements were made of whole-crop yields and yields from plant fractions (leaf, stem, cob). Quality components—digestibility, acid-pepsin solubility, water-soluble carbohydrates, nitrogen and ash—were estimated for whole crop and fractions. There were successive samplings for quality components.Whole-crop yield from fractions and yield of quality components increased with density. Whole-crop yield differed significantly with harvesting date as did all fractions except cob, although the proportion of cob increased with time. The earlier harvesting date gave greater yields of quality components.There was no effect of density on the dry-matter content but later harvesting resulted in higher dry matter.The only quality component affected by density was nitrogen content but there were large effects of harvesting date on digestibility and the acid-pepsin components.Regressions were computed for quality components on dry-matter proportion of cob and the dry-matter content of the whole crop. Regressions were significant for the acid-pepsin soluble components and the water-soluble carbohydrate component on the proportion of cob. Regressions of digestibility and pepsin-soluble components (total and organic) on dry-matter content were significant.The implications of these findings to the breeding of maize varieties are discussed.


1978 ◽  
Vol 58 (4) ◽  
pp. 559-569 ◽  
Author(s):  
J. W. G. NICHOLSON ◽  
D. A. YOUNG ◽  
R. E. McQUEEN ◽  
H. DE JONG ◽  
F. A. WOOD

The potential use of green potato (Solanum tuberosum L.) vines as a livestock feed was investigated. Fresh vines contained less than 12% dry matter (DM) and did not produce a stable silage in plastic bag, laboratory silos. Satisfactory silages were produced by wilting or by the addition of barley, malt, barley + malt, molasses, chopped hay, chopped hay + barley + malt, formaldehyde and/or formic acid. Only the silages from wilted vines or those containing hay had a suitable consistency for storage and handling in conventional silage systems. Sheep readily ate a silage made from potato vines with the addition of 5% barley, 0.5% malted barley and 20% chopped hay or straw. The dry matter content of the vines from two cultivars changed only slightly over a 5-wk sampling period but the acid detergent fiber (ADF) content increased and the N content dropped. Except for the cultivar Wischip, there was little variation among nine cultivars sampled on the same day for pH (5.15–5.95), DM (10.3–12.9%) and ADF (26.5–32.4%). The N content ranged from 1.6 to 2.4% of the DM and the water soluble carbohydrate content from 7.5 to 3.3% of the DM. The levels of glycoalkaloids found should be safe for ruminant animals. It was concluded that potato vines harvested prior to senescence contain a useful level of nutrients for ruminants. Pesticide residues and mechanical systems for harvesting the vines are major concerns to be resolved before on-farm application can be recommended.


1998 ◽  
Vol 1998 ◽  
pp. 150-150
Author(s):  
J. K. Margerison ◽  
D. V. Illingworth ◽  
D. W Jackson

Increasing importance of home grown proteins has resulted in a renewed interest in grass-clover mixed swards. The objective of this experiment was to asses the effect of wilting on effluent production levels, polluting potential of the silage effluent, and silage quality in grass and grass-clover mixed swards.Perennial rye grass (G) and a grass clover mixed sward (0.75 perennial ryegrass, 0.25 white clover, GC) was cut in mid may. The G and GC was then precision chopped and ensiled in experimental silos at 0, 24 and 48 hours following cutting, with 5 replicate silos of each silage being made at each time period. The silage effluent was collected, the quantity produced was recorded and the biochemical oxygen demand and the chemical oxygen demand was measured. The silage was allowed to ferment followed by which the silage was sub-samples and composite samples 3 of each silage were analyzed for dry matter content, crude protein levels, neutral detergent fibre, water soluble carbohydrate, pH, lactic acid, acetic acid, proprionc acid, butyric acid, total volatile acid levels. The data were analyzed using the general linear model ANOVA in Minitab.


2006 ◽  
Vol 57 (2) ◽  
pp. 243 ◽  
Author(s):  
L. R. Turner ◽  
D. J. Donaghy ◽  
P. A. Lane ◽  
R. P. Rawnsley

This study investigated the influence of leaf stage-based defoliation interval on water-soluble carbohydrate and nitrogen energy reserve status, regrowth of leaves and roots, and tiller number of cocksfoot (Dactylis glomerata L.) cv. Kara plants up to 24 days (3.5-leaf stage) following defoliation. Treatments were based on defoliation intervals of 1-, 2-, and 4-leaf stages of regrowth, with treatments terminated when the 1-leaf defoliation interval had been completed 4 times, the 2-leaf interval 2 times, and the 4-leaf interval once. Selected plants were destructively harvested prior to commencement of treatments (H0), immediately following cessation of treatments (H1), and at 5 days (H2), 10 days (H3), and 24 days (H4) following H1. Leaf, root, and tiller dry matter yield were determined at each harvest event, as well as tiller number/plant. Levels of water-soluble carbohydrate and nitrogen reserves in plant stubble and roots were determined at each destructive harvest. Initiation and death of daughter tillers were monitored from H0 to the completion of the study. More frequent defoliation of cocksfoot plants resulted in reduced water-soluble carbohydrate assimilation and therefore leaf, root, and tiller dry matter accumulation during the subsequent recovery period. Defoliation at the 1-leaf stage severely limited the regrowth potential of cocksfoot plants, whereas defoliation at the 2-leaf stage was adequate for plant recovery, but did not maximise regrowth. The results of this study showed that a defoliation interval based on the 4-leaf stage maximises water-soluble carbohydrate reserves, tillering, and leaf and root dry matter yields. The priority sequence for allocation of water-soluble carbohydrate reserves followed the order of leaf growth, root growth, and tillering during the regrowth period. Nitrogen energy reserves were found to play a minor role in the regrowth of cocksfoot plants following defoliation.


1995 ◽  
Vol 35 (6) ◽  
pp. 731 ◽  
Author(s):  
JL Jacobs ◽  
RJ Morris ◽  
J Zorrilla-Rios

Pasture was ensiled with increasing amounts of whole barley in stacks [0, 75 (SLB), 150 (SMB) kg/t fresh pasture] or in 200-L drum silos 10, 75 (DLB), 150 (DMB), 225 (DHB) kg/t fresh pasture]. All silages were well fermented with low pH values and low ammonia concentrations. The addition of barley significantly (P<0.05) increased the dry matter content of the resultant stack silages by 29% (SLB) and 54% (SMB) and significantly (P<0.05) increased residual water-soluble carbohydrate levels in the SMB silage compared with untreated stack silage. Incorporation of barley with pasture in 200-L silos significantly (P<0.001) increased the dry matter of the resultant silages and significantly (P<0.01) reduced effluent production by 55, 93, and 100% for DLB, DMB, and DHB compared with the untreated silo silage. Dry matter, nitrogen, and lactic acid concentrations in effluent did not differ significantly, although total losses of these components were significantly (P<0.01) higher in the untreated silage.| The stack silages were fed to beef steers (293 kg) and compared with silage diets containing equivalent levels of rolled barley mixed with untreated silage at feeding. Irrespective of method of feeding barley, animal performance improved compared with feeding a silage-only diet. At equivalent levels of barley inclusion, liveweight gains were higher and feed conversion ratios lower with the rolled barley diets. The results indicate that the addition of barley to low dry matter pasture during ensiling can reduce effluent production and the loss of soluble nutrients; however, it is likely that the grain will need to be processed to maximise subsequent animal production.


1998 ◽  
Vol 1998 ◽  
pp. 150-150
Author(s):  
J. K. Margerison ◽  
D. V. Illingworth ◽  
D. W Jackson

Increasing importance of home grown proteins has resulted in a renewed interest in grass-clover mixed swards. The objective of this experiment was to asses the effect of wilting on effluent production levels, polluting potential of the silage effluent, and silage quality in grass and grass-clover mixed swards.Perennial rye grass (G) and a grass clover mixed sward (0.75 perennial ryegrass, 0.25 white clover, GC) was cut in mid may. The G and GC was then precision chopped and ensiled in experimental silos at 0, 24 and 48 hours following cutting, with 5 replicate silos of each silage being made at each time period. The silage effluent was collected, the quantity produced was recorded and the biochemical oxygen demand and the chemical oxygen demand was measured. The silage was allowed to ferment followed by which the silage was sub-samples and composite samples 3 of each silage were analyzed for dry matter content, crude protein levels, neutral detergent fibre, water soluble carbohydrate, pH, lactic acid, acetic acid, proprionc acid, butyric acid, total volatile acid levels. The data were analyzed using the general linear model ANOVA in Minitab.


2018 ◽  
Vol 58 (6) ◽  
pp. 1043 ◽  
Author(s):  
A. Jonker ◽  
G. Molano ◽  
E. Sandoval ◽  
P. S. Taylor ◽  
C. Antwi ◽  
...  

Elevated water-soluble carbohydrate (WSC) concentration in the diet may affect rumen fermentation and consequently reduce methane (CH4) emissions. The objective of the present study was to determine CH4 emissions from male sheep (8 per treatment) in respiration chambers for 48 h and fed either a conventional diploid (CRG), a high-sugar diploid (HSG) or a tetraploid (TRG) perennial ryegrass cultivar, each offered at 0.7 or 1.0 kg dry matter (DM)/day during periods in early spring 2013 (P1), early autumn 2014 (P2) and late spring 2014 (P3). There was a significant (P < 0.001) interaction between cultivar and period for CH4 yield (g/kg DM intake). In P1 yield was 9% lower (P = 0.007) for sheep fed HSG than for sheep fed CRG or TRG, in P2 yield was 16% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG or HSG, and in P3 yield was 15% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG, with HSG-fed sheep being intermediate and not significantly different from either CRG or TRG. Despite there being a cultivar × period interaction, overall, CH4 yield was lower for sheep fed HSG or TRG than for sheep fed CRG (P < 0.001). There were no cultivar × level of feed offer interactions and, overall, yield of CH4 was 9% higher (P = 0.003) for sheep offered 0.7 than for sheep offered 1.0 kg DM/day. In each period, one or other of the high-WSC diploid (HSG) or tetraploid cultivars (TRG) gave lower CH4 yields than did the control diploid (CRG), suggesting that CH4 yield is reduced by characteristics of these cultivars. However, the effect was not consistently associated with either cultivar and could not be attributed to higher forage water-soluble carbohydrate concentrations.


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