scholarly journals Effect of sward age on nitrate accumulation in ryegrass.

1976 ◽  
Vol 24 (4) ◽  
pp. 266-273
Author(s):  
A. Darwinkel

Two indoor trials were done with Italian ryegrass (Lolium multiflorum) and perennial ryegrass (Lolium perenne) to obtain more information about the nitrate-accumulating process of a new-sown grass sward. With an abundant NO3 supply for Italian ryegrass, NO3 accumulation in herbage decreased during 5 successive cuts after sowing, because of increasing NO3 conversion. In the same way the NO3 content in DM in perennial ryegrass was more in the first cut after sowing than in old plants from a pasture 5 years old. After sowing, a considerable part of the assimilate produced was used for stubble and root growth. With older swards these assimilates were increasingly retained in herbage, which is rich in organic N and to a lesser extent in stubble and roots, which are poor in organic N. Because of this, NO3 conversion is restricted in a new-sown grass sward and reaches a maximum in old sward of a permanent pasture, which almost exclusively produces herbage. Consequently nitrate is more apt to accumulate in new-sown grass than in old pasture. (Abstract retrieved from CAB Abstracts by CABI’s permission)

2016 ◽  
Vol 69 ◽  
pp. 252-257 ◽  
Author(s):  
K.C. Harrington ◽  
T.K. James ◽  
M.D. Parker ◽  
H. Ghanizadeh

The first cases of weeds developing resistance to glyphosate within New Zealand have recently been reported and investigated Both perennial ryegrass (Lolium perenne) and Italian ryegrass (Lolium multiflorum) populations have become resistant to glyphosate in several Marlborough vineyards due to many years of weed control using mainly just glyphosate Glyphosate is currently being used in many situations throughout New Zealand that could easily lead to further resistance developing such as in other perennial fruit crops on roadsides railways amenity areas waste areas fence lines and headlands of crops Following wide consultation as part of a Sustainable Farming Fund project strategies for resistance management in three systems (vineyard and orchards amenity and waste areas and crops and pastures) are suggested Adoption of these strategies will allow glyphosate to continue as a useful herbicide in New Zealand


2013 ◽  
Vol 66 ◽  
pp. 89-93 ◽  
Author(s):  
H. Ghanizadeh ◽  
K.C. Harrington ◽  
T.K. James ◽  
D.J. Woolley

Plants were obtained from two populations of Italian ryegrass (Lolium multiflorum) and three populations of perennial ryegrass (Lolium perenne) from different vineyards in Marlborough and Nelson that were suspected of being resistant to glyphosate following many consecutive applications of this herbicide over recent years Each population was multiplied by splitting out tillers and this was also done for plants taken from a population of each species from Manawatu pastures where they had not been exposed to glyphosate application A doseresponse experiment showed that four populations taken from the vineyards were about 10 times as resistant to glyphosate as those plants that had not been previously exposed to the herbicide The experiment was repeated and showed one perennial ryegrass population to have a 30fold level of resistance These are the first confirmed cases of glyphosate resistance within New Zealand


2021 ◽  
Vol 12 ◽  
Author(s):  
Claudio Cropano ◽  
Chloé Manzanares ◽  
Steven Yates ◽  
Dario Copetti ◽  
Javier Do Canto ◽  
...  

Self-incompatibility (SI) is a genetic mechanism preventing self-pollination in ~40% of plant species. Two multiallelic loci, called S and Z, control the gametophytic SI system of the grass family (Poaceae), which contains all major forage grasses. Loci independent from S and Z have been reported to disrupt SI and lead to self-compatibility (SC). A locus causing SC in perennial ryegrass (Lolium perenne L.) was previously mapped on linkage group (LG) 5 in an F2 population segregating for SC. Using a subset of the same population (n = 68), we first performed low-resolution quantitative trait locus (QTL) mapping to exclude the presence of additional, previously undetected contributors to SC. The previously reported QTL on LG 5 explained 38.4% of the phenotypic variation, and no significant contribution from other genomic regions was found. This was verified by the presence of significantly distorted markers in the region overlapping with the QTL. Second, we fine mapped the QTL to 0.26 centimorgan (cM) using additional 2,056 plants and 23 novel sequence-based markers. Using Italian ryegrass (Lolium multiflorum Lam.) genome assembly as a reference, the markers flanking SC were estimated to span a ~3 Mb region encoding for 57 predicted genes. Among these, seven genes were proposed as relevant candidate genes based on their annotation and function described in previous studies. Our study is a step forward to identify SC genes in forage grasses and provides diagnostic markers for marker-assisted introgression of SC into elite germplasm.


Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 292-294 ◽  
Author(s):  
W. O. Lee

Ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] was evaluated in field experiments at rates from 0.6 to 4.5 kg/ha for control of volunteer wheat (Triticum aestivumL. ‘Hyslop’, ‘Stephens’) in fall-planted perennial ryegrass (Lolium perenneL. ‘Cropper’, ‘Pelo’, ‘Pennfine’, ‘Omega’). Ethofumesate applied at 1.7 kg/ha or more in mid-November to wheat in the one-to three-leaf stage eliminated the wheat. Wheat was not eliminated when ethofumesate was applied preemergence soon after planting or when applied at the end of November to wheat in the four-leaf to four-tiller stage. In four experiments in which wheat was present, ethofumesate significantly increased perennial ryegrass seed production. In one experiment in which wheat was not present, ethofumesate did not affect perennial ryegrass seed production. Ethofumesate applied in the fall at rates to 4.5 kg/ha to newly-seeded perennial ryegrass or to well-established bentgrass (Agrostis tenuisSibth. ‘Highland’), Kentucky bluegrass (Poa pratensisL. ‘Newport’), and Italian ryegrass (Lolium multiflorumLam.) did not adversely affect germination of the following seed crop.


2021 ◽  
Author(s):  
Claudio Cropano ◽  
Chloé Manzanares ◽  
Steven Yates ◽  
Dario Copetti ◽  
Javier Do Canto ◽  
...  

Self-incompatibility (SI) is a genetic mechanism preventing self-pollination in approximately 40% of plant species. Two multiallelic loci, called S and Z, control the gametophytic SI system of the grass family (Poaceae), which contains all major forage grasses. Loci independent from S and Z have been reported to disrupt SI and lead to self-compatibility (SC). A locus causing SC in perennial ryegrass (Lolium perenne L.) was previously mapped on linkage group (LG) 5 in a F2 population segregating for SC. Using a subset of the same population (n=73), we first performed low-resolution quantitative trait locus (QTL) mapping to exclude the presence of additional, previously undetected contributors to SC. The previously reported QTL on LG 5 explained 38.4% of the phenotypic variation, and no significant contribution from other genomic regions was found. This was verified by the presence of significantly distorted markers in the region overlapping with the QTL. Second, we fine mapped the QTL to 0.26 cM using additional 2,056 plants and 23 novel sequence-based markers. Using an Italian ryegrass (Lolium multiflorum Lam.) genome assembly as reference, the markers flanking SC were estimated to span a ~3 Mb region encoding for 57 predicted genes. Among these, seven genes were proposed as relevant candidate genes based on their annotation and function described in previous studies. Our work is a step forward to identify SC genes in forage grasses and provides diagnostic markers for marker-assisted introgression of SC into elite germplasm.


1977 ◽  
Vol 89 (2) ◽  
pp. 425-435 ◽  
Author(s):  
J. H. Ollerenshaw ◽  
D. R. Hodgson

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.


1996 ◽  
Vol 127 (1) ◽  
pp. 57-65 ◽  
Author(s):  
D. Wilman ◽  
Y. Gao

SUMMARYFour grass species, three hybrids and three mixtures were grown in field swards near Aberystwyth. All swards were amply supplied with nutrients and were cut at 5-week intervals during the year of sowing (1989) and during the following 4 years. The order of the grasses in rate of establishment was: Westerwolds ryegrass > Italian ryegrass (Lolium multiflorum) > Italian ryegrass × perennial ryegrass, Italian ryegrass × meadow fescue, perennial ryegrass (Lolium perenne) > perennial ryegrass × meadow fescue, meadow fescue (Festuca pratensis) > tall fescue (Festuca arundinacea). During the sowing year as a whole, Italian ryegrass was the highest yielding grass, followed by Westerwolds ryegrass. During the remaining period (1990–93), as a whole, the highest yields were obtained from perennial ryegrass sown alone or in a mixture with tall fescue. Tall fescue sown alone was one of the lowest yielding grasses in the year of sowing, but developed to be the highest yielding in 1992 and 1993. Westerwolds ryegrass persisted least well, although some plants did survive until 1992. Italian ryegrass persisted better than Westerwolds and Italian ryegrass × meadow fescue persisted better than Italian ryegrass. Hybrid ryegrass and perennial ryegrass × meadow fescue persisted satisfactorily but with fewer tillers/m2 than perennial ryegrass or tall fescue. The yield of tall fescue in March was as high as that of Italian ryegrass in 1990 and 1991 and higher than that of any of the other grasses in 1992 and 1993; the tiller density of tall fescue was particularly high in March. The yield of mixtures (Italian ryegrass with perennial ryegrass, Italian ryegrass with tall fescue and perennial ryegrass with tall fescue) was, on average, 2·5% more than the mean of the component species when sown alone. When grown with ryegrass, tall fescue was not prominent initially but its proportion in the sward gradually increased.


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