Effect of defoliation frequency and summer irrigation on survival of perennial (Lolium perenne) and biennial (Lolium multiflorum) ryegrass in the subtropics

1997 ◽  
Vol 37 (5) ◽  
pp. 537 ◽  
Author(s):  
D. J. Donaghy ◽  
J. M. Scott ◽  
W. J. Fulkerson
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Seed Set ◽  
Seedling Recruitment ◽  
Early Summer ◽  
Pasture Production ◽  
Second Year ◽  
The Impact ◽  
Tropical Grass

Summary. The present study investigated, in a subtropical environment, the timing of defoliation treatments in spring and summer irrigation management on the survival of perennial (Lolium perenne cv. Yatsyn) and biennial (L. multiflorum cv. Noble) ryegrass in a mixed ryegrass–white clover (Trifolium repens) pasture over the first summer, and seedling recruitment the following autumn. Defoliation options were related to various ryegrass plant development stages such as the number of leaves per tiller attained during regrowth, stem elongation and seed set. The criterion for timing of frequent defoliation was 1 leaf/tiller regrowth and infrequent defoliation 3 leaves/tiller. Both pasture types were defoliated either frequently or infrequently at specific times from sowing to mid summer. Half the plots were irrigated from 30 November to 6 April while the remaining plots were not irrigated over this period. There was no survival of biennial ryegrass plants into autumn of the second year and pasture production was entirely from seedling recruitment of seed set in the previous spring. The maximum seedling recruitment (plant population 89% of spring in establishment year) was achieved by infrequent defoliation in mid spring and then cessation of defoliation until mid summer to allow plants to set seed. However, this resulted in a production loss of 3094 kg dry matter/ha of ryegrass and clover. In contrast, production of perennial ryegrass in the second year was reliant almost exclusively on individual ryegrass plants surviving the summer, as there was little seed set and virtually no seedling recruitment. There would appear to be 2 contrasting defoliation requirements to optimise perennial ryegrass persistence. Infrequent defoliation from sowing to early spring (22 March–2 September) and frequent defoliation in early summer (19 November–3 February) resulted in maximum plant survival and minimum tropical grass incursion. Frequent, compared with infrequent, defoliation up to 2 September decreased root dry matter in February by 45% to 1.66 g dry matter/plant. However in early summer, frequent defoliation maximised survival, presumably by reducing shading by tropical grasses, and preventing a closed canopy which encourages ‘rust’ infestation of the ryegrass. Irrigation of ryegrass over summer, in situations likely to become waterlogged, will only be of benefit in dry years and if scheduling is frequent enough to benefit ryegrass rather than tropical grass. These results highlight the importance of maintaining an infrequent defoliation interval to maximise persistence of perennial ryegrass in the subtropics. More frequent defoliation may be necessary in late spring/early summer to reduce the impact of leaf rust.

scholarly journals Pasture renewal on Bay of Plenty and Waikato dairy farms: impacts on pasture production and invertebrate populations post-establishment

2013 ◽  
pp. 227-234 ◽  
Author(s):  
K.N. Tozer ◽  
G.M. Rennie ◽  
W.M. King ◽  
N.R. Mapp ◽  
N.L. Bell ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Insect Pests ◽  
Dairy Farms ◽  
Pasture Production ◽  
The Third ◽  
Second Year ◽  
The Impact ◽  
Sampling Times ◽  
Clover Content

The impact of renewal on pasture production was determined by monitoring renewed and unrenewed pastures on five farms in each of Bay of Plenty and Waikato for 3 years, excluding the year after sowing (establishment). Renewed pastures produced an additional 1.5 t dry matter (DM)/ha averaged over both regions in the second year after establishment and 1.9 t DM/ha in each of the third and fourth years. Renewed pastures also had greater clover DM content in spring and summer and lower broadleaf weed DM content in winter. Perennial ryegrass tiller densities were similar in renewed and unrenewed pastures in both regions. There were fewer white-fringed weevil, black beetle and total nematodes in renewed pastures on at least one of the sampling times. It was concluded that higher clover content, fewer weeds, and fewer insect pests contributed to greater DM production in renewed pastures. Keywords: Pasture renewal; dairy pastures; pasture persistence; DM production; regrassing

Low rates of phosphorus fertiliser applied strategically throughout the growing season under rain-fed conditions did not affect dry matter production of perennial ryegrass (Lolium perenne L.)

2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Growing Season ◽  
Dry Matter Production ◽  
Pasture Production ◽  
Lolium Perenne L ◽  
Matter Production ◽  
Extractable P ◽  
Intensively Managed

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.

The influence of grazing frequency and intensity on the vigour of Lolium perenne L. under subtropical conditions

1996 ◽  
Vol 47 (6) ◽  
pp. 975 ◽  
Author(s):  
FR McKenzie
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Grazing Intensity ◽  
Early Summer ◽  
Grazing Management ◽  
Lolium Perenne L ◽  
Continuous Grazing ◽  
Second Year

Lolium perenne L. (perennial ryegrass) exhibits poor persistence in subtropical environments. Grazing management may enhance the vigour and hence persistence of this species. Perennial ryegrass was subjected to various grazing treatments, and its vigour, indexed by etiolated growth, was evaluated over 2 years. Pasture and individual tiller vigour were monitored under 5 combinations of grazing frequency and intensity, applied rotationally, and 1 treatment of continuous grazing. The vigour of infrequently grazed plots was greater than that of frequently or continuously grazed plots; however, grazing intensity did not influence vigour. Seasonally, vigour declined during mid (December and .January) to late (February and March) summer of the establishment year and from early summer (October) to autumn (May) during the second year. Poor vigour in frequently grazed plots was associated with low growth reserves rather than a lack of active tiller growth points. Towards the end of the second year, however, a lack of active tiller growth points also limited vigour in frequently grazed plots. Tillers from infrequently grazed plots (regardless of grazing intensity) had greater vigour than tillers from the frequently grazed plots. To enhance the vigour of perennial ryegrass in subtropical environments, the frequency of grazing should be reduced, particularly in summer.

Tactical versus continuous stocking for persistence of perennial ryegrass (Lolium perenne L.) in pastures grazed by sheep in south-western Victoria

1999 ◽  
Vol 39 (3) ◽  
pp. 265 ◽  
Author(s):  
R. A. Waller ◽  
P. E. Quigley ◽  
G. R. Saul ◽  
G. A. Kearney ◽  
P. W. G. Sale
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seedling Recruitment ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fold Increase ◽  
Early Summer ◽  
Lolium Perenne L ◽  
Western Victoria ◽  
Tiller Density

The survival of perennial ryegrass (Lolium perenne L.) plants was studied in sheep pastures in south-western Victoria during the dry summer of 1996–97. Recruitment of perennial ryegrass seedlings into the pasture sward was also monitored in the autumn–winter periods in 1997 and 1998. The objective was to investigate whether a tactical stocking strategy, consisting of variable length summer, autumn and winter rotations and continuous stocking in spring, might increase perennial ryegrass tiller survival and seedling recruitment in the autumn, compared with continuous stocking all year. The grazing strategies were compared on 2 contrasting pastures: an upgraded pasture [sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year as applied fertiliser] and a naturalised perennial ryegrass pasture receiving 6 kg P/ha.year. Paddocks were grazed by Border Leicester × Merino ewes, mated to a terminal sire so as to lamb in September. Perennial ryegrass tiller density was higher on the upgraded pasture with a mean density of 7750 tillers/m2 in early summer which declined to zero live tillers by mid summer. Live tillers began to reappear before the opening rains and then increased after the rain. Mean tiller density in the upgraded pasture declined over the 2 summers, with only 2050 tillers/m2 being present 2 months after the opening rains in 1998. There were no effects (P>0.05) of pasture type or grazing strategy on the number of tagged tillers that survived the summer period. Only 12% of the vegetative tillers, randomly tagged in December 1996, survived to May 1997. More than half of the tillers (56%) that produced a seedhead produced daughter tillers which survived the dry summer–autumn period. A significant (P<0.05) interaction between grazing strategy and pasture type occurred with the number of perennial ryegrass seedlings that had established 4 weeks after the opening rains in 1997. There was a 5–11-fold increase in seedling numbers which regenerated in the tactically stocked, upgraded pasture compared with the other treatments. Seedling recruitment was considerably lower in the autumn of 1998, due presumably to an overall decline in perennial ryegrass density relative to annual grasses in 1997. A second experiment investigated the effect of excluding sheep from grazing at anthesis until seedhead maturation or until the opening rains, together with a mechanical seed dislodgment treatment at seed maturity. All exclusion treatments increased seedling recruitment 4–7-fold, compared with continuous stocking. The results suggest a possible mechanism by which perennial ryegrass density can be increased without expensive reseeding.

The effects of constant and varying heights of cut on the yield of Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (Lolium perenne L.)

1977 ◽  
Vol 89 (2) ◽  
pp. 425-435 ◽  
Author(s):  
J. H. Ollerenshaw ◽  
D. R. Hodgson
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Growth Habit ◽  
Lolium Multiflorum ◽  
Italian Ryegrass ◽  
The Mean ◽  
Second Year ◽  
Harvest Year ◽  
Prostrate Growth

SummaryThree constant and four variable heights of cutting were applied to swards of Italian ryegrass (Lolium multiflorum Lam.) cv. Aberystwyth S. 22 and perennial ryegrass (Lolium perenne L.) cv. Aberystwyth S. 23 for a period of 2 years. The treatments were initially given in the seeding year of the Italian ryegrass swards and first harvest year of the perennial ryegrass. The same swards were used throughout the duration of the two experiments. The three heights of cutting 3, 6 and 9 cm were defined by the mean lengths of tiller remaining after defoliation with a flail harvester.The yield of dry matter (D.M.) was relatively low from Italian ryegrass cut repeatedly to 3 cm because many plants died. Higher yields were obtained by cutting repeatedly to 6 or 9 cm but only when the grass at the end of the season was cut to 3 cm. Italian ryegrass produced more herbage by variable than constant heights of cutting, especially when a lax cut occurred in mid-summer.Perennial ryegrass gave higher yields of D.M. by constant low than high cutting, but there were no differences in yield when the constant high cut swards were closely defoliated at the end of each season. More herbage was produced by variable than constant heights of cutting in the second year, especially when several lax cuts occurred in the variable height of cut treatments.As perennial ryegrass had a very prostrate growth habit in swards which received several close cuts tillers were not defoliated too severely. In contrast, Italian ryegrass remained erect in growth habit even in swards which were closely defoliated and thus tillers were cut more severely than those of perennial ryegrass. The need to measure accurately the actual lengths of tillers after defoliation is emphasized in height of cutting treatments.

Effect of sowing time on the establishment and early production of tropical and temperate pasture mixtures under irrigation in south-eastern Queensland

1981 ◽  
Vol 21 (111) ◽  
pp. 410
Author(s):  
KF Lowe ◽  
TM Bowdler ◽  
JC Mulder
Keyword(s):  
Dry Matter ◽  
Temperate Species ◽  
Considerable Proportion ◽  
Tropical Species ◽  
Sowing Time ◽  
South Eastern ◽  
Early Production ◽  
Grass Establishment ◽  
Second Year ◽  
Tropical Grass

The most effective time to sow irrigated perennial pastures containing tropical and temperate species was investigated over three years at Gatton, south-eastern Queensland. Three mixtures were sown each month between September and June and in split sowings where the tropical species were sown in September or March, and the temperate species in May. Autumn sowings produced the most seedlings of sown species 40 d after sowing. Of the autumn months, May was the most suitable, with an establishment of 181 plants/m2 and a weed population of only 19 plants/m2. Tropical grass establishment was less than 8 plants/m2 from all sowing times. A considerable proportion of tropical grass sown in autumn appeared in spring. Split sowings were not as effective as autumn sowings and favoured the tropical species, which were sown first. Dry matter yield of sown species in the establishment year varied from 0.9 t/ha for February sowings to 12.0 t/ha for April sowings; weed yields varied from 5.8 t/ha for September sowings to 0.8 t/ha for May sowings. Tropical grass contribution was greatest from the split sowing in which the tropical species were sown in September. Temperate species yields were highest from May sowings. In the second year yields of temperate species declined substantially, mainly because of poor persistence of ryegrass. Although tropical grass yields increased in all treatments, this increase was not sufficient in the autumn sowings to compensate for the low ryegrass yields.

Production and forage quality of prairie grass (Bromus willdenowii) in comparison to perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) in subtropical dairy pastures

2000 ◽  
Vol 40 (8) ◽  
pp. 1059 ◽  
Author(s):  
W. J. Fulkerson ◽  
J. F. M. Fennell ◽  
K. Slack
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Seedling Recruitment ◽  
Forage Quality ◽  
Grass Species ◽  
Tiller Stage ◽  
Prairie Grass

A grazing study was conducted, over a 3-year period (1997–99), on the subtropical north coast of New South Wales, Australia, to compare the yield of prairie grass (Bromus willdenowii cv. Matua), tall fescue (Festuca arundinacea cv. Vulcan) and perennial ryegrass (Lolium perenne cv. Yatsyn), on a well-drained red krasnozem soil at Wollongbar Agricultural Research Institute (WAI) and on a heavy clay soil at Casino. The effect of grazing interval (equivalent to the time taken to regrow 1.5, 2.5 or 4 leaves/tiller) in spring, and forage quality of prairie grass in winter and spring was also assessed. At both sites, the dry matter (DM) yields of prairie grass over the establishment year and in year 2 were significantly (P<0.001) higher than for the other 2 grass species (mean for 2 years over the 2 sites was 23.8, 8.9 and 7.7 t DM/ha for prairie grass, ryegrass and tall fescue, respectively). In year 3, there was no production of tall fescue or ryegrass at the WAI site while prairie grass produced 11.3 t DM/ha although this was obtained from natural seedling recruitment after the sward was sprayed with a herbicide in February of that year. At the Casino site, ryegrass and tall fescue still made substantial growth in year 3 (3.1 and 2.1 t DM/ha for ryegrass and tall fescue, respectively) but this was significantly below the yields of prairie grass (5.5 t DM/ha). More frequent grazing of prairie grass in spring (equivalent to 1.5 leaves/tiller of regrowth) led to significantly (P<0.05) less plants surviving summer and less seedling recruitment in the following autumn. The annual yield of the 1.5 leaf treatment was significantly (P<0.05) lower than the remaining treatments but only in the third year of the study. Analysis of prairie grass forage samples, taken in June (vegetative sward) and November (reproductive sward), gave magnesium values of less than 0.2% DM which is below the concentration found in ryegrass and that recommended for dairy cattle. The Ca : P and K : (Ca + Mg) ratios in prairie grass improved, as a forage for dairy cows, with regrowth time up to 5 leaves/tiller. Metabolisable energy remained constant with regrowth time in June at 10.8 MJ/kg DM but fell significantly in November from 10.7 MJ/kg DM, immediately post-grazing, to 9.2 MJ/kg DM at the 4.5 leaves/tiller stage of regrowth. In contrast to observations in ryegrass, the water-soluble carbohydrate content of forage samples of prairie grass taken in November showed a substantial increase with regrowth time to over 12% DM at the 3 leaves/tiller stage of regrowth. The high productivity and forage quality of prairie grass obtained over a 3-year period suggests this grass species could be a suitable temperate perennial grass for subtropical dairy pastures. An appropriately long grazing interval in spring seems critical to optimise plant survival over summer and for adequate seed set for seedling recruitment the following autumn. If summer weeds and/or grasses invade to a significant extent, the large seedbank of prairie grass provides the opportunity to spray out the pasture in summer and rely on seedling recruitment to establish a new sward in autumn. The forage quality of prairie grass in winter and spring is similar to perennial ryegrass but the magnesium levels are substantially lower and stock grazing this type of pasture for extended periods would need to be supplemented with this mineral.

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