Comparative growth of wheat, barley, and annual ryegrass (Lolium rigidum) in monoculture and mixture

1996 ◽  
Vol 47 (3) ◽  
pp. 449 ◽  
Author(s):  
RD Cousens

The growth and development of wheat, barley, and annual ryegrass (Lolium rigidum Gaud.) were studied in monoculture and in additive mixtures at two sites of contrasting climate and soil type in New South Wales. Although smaller, annual ryegrass paralleled the behaviour of the two cereals in monoculture in all respects. The phenological development of all three species was more rapid at the wheatbelt site (Forbes) than on the coastal plain (Camden); yield loss was also greater at Forbes. The early growth rate of barley was greater than that of wheat or ryegrass at both sites. As a result, barley was more able to suppress ryegrass in mixtures and to maintain its yield than wheat. Sensitivity analysis of a growth simulation model suggested that the early rate of leaf production was likely to be influential in determining the magnitude of biomass reduction at anthesis; relative phenological development and height growth dynamics appeared to have little effect.

1985 ◽  
Vol 25 (4) ◽  
pp. 922 ◽  
Author(s):  
D Lemerle ◽  
AR Leys ◽  
RB Hinkley ◽  
JA Fisher

Twelve spring wheat cultivars were tested in southern New South Wales for their tolerances to the recommended rates and three times the recommended rates of trifluralin, pendimethalin, tri-allate and chlorsulfuron. Recommended rates of these herbicides did not affect the emergence or grain yield of any cultivar. However, differences between cultivars in their tolerances to trifluralin, pendimethalin and chlorsulfuron at three times the recommended rate were identified. The extent of the reduction in emergence and/or grain yield varied with herbicide and season, and there was also a herbicidexseason interaction. Durati, Songlen and Tincurrin were the most susceptible cultivars to trifluralin, and Teal was the most tolerant. Yield losses from trifluralin were more severe in 1979 than in 1980 or 1981. The differential between cultivars treated with pendimethalin was smaller and more variable; Tincurrin was the only cultivar with a yield reduction in more than one season. Durati, Songlen and Shortim were the only cultivars affected by chlorsulfuron. A reduction in crop emergence of a cultivar treated with trifluralin or pendimethalin did not correlate consistently with any grain yield loss, and reductions in emergence were always greater than yield loss.


1975 ◽  
Vol 26 (4) ◽  
pp. 647 ◽  
Author(s):  
K Helms

Seedlings of six cultivars of Trifolium subterraneum were tested during germination for resistance to Kabatiella caulivora, and gave results comparable with those obtained with seedlings inoculated by spraying at 1–4 weeks after sowing. Advantages of the method were that a large number of seedlings could be screened under uniform conditions with the minimum of time and space. Within the more susceptible group of cultivars, Woogenellup and Bacchus Marsh were usually more susceptible than Yarloop and Mt. Barker; these in turn were more susceptible than Clare, and Clare more susceptible than Daliak. For all cultivars except the highly resistant cultivar, Daliak, there was a correlation between the rate of trifoliolate leaf production and susceptibility to the disease, the most susceptible being those with most leaves expanded at the time of inoculation and with most leaves present at the time of harvest. Physiologic specialization in isolates of the pathogen from different parts of Australia was demonstrated. In general, one isolate from South Australia was more pathogenic than a group of isolates from South Australia, Victoria and Western Australia; these in turn were more pathogenic than one isolate from New South Wales, which was somewhat atypical in culture, and one from Victoria which was markedly atypical in culture.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 634-639 ◽  
Author(s):  
Deirdre Lemerle ◽  
Birgitte Verbeek ◽  
Neil E. Coombes

The influence of wheat variety on the dose-response of annual ryegrass to diclofop-methyl (POST) was examined in the field in 1992 and 1993 in southern New South Wales, Australia. The aim was to determine if planting a strongly competitive variety of wheat improved control of annual ryegrass at reduced doses of diclofop-methyl. Suppression of ryegrass was dependent on herbicide dose, season, and wheat variety. In the absence of herbicide, dry matter (DM) production of annual ryegrass at 300 plants m−2at anthesis was 500 g ha−1with Dollarbird and Katunga compared to 1000 g ha−1with Rosella or Shrike in 1992. In 1993, DM was approximately 150 g ha−1with Dollarbird or Katunga, and 350 g ha−1with Shrike or Rosella. Ryegrass DM was reduced by diclofop-methyl to a greater extent, relative to the weedy unsprayed controls, with less competitive varieties Rosella and Shrike than with the more competitive Dollarbird or Katunga. Diclofop-methyl at 0.28 kg a.i. ha−1reduced DM of ryegrass growing with Katunga to less than 100 g m−2in 1992, compared to more than 200 g m2with the other varieties. In 1993, diclofop-methyl was more effective on ryegrass, and the same dose reduced ryegrass DM to almost zero in all varieties. Grain yields in unsprayed weedy controls of Dollarbird and Katunga were reduced approximately 20% by annual ryegrass compared with yields achieved with herbicides in both years. Yields of Rosella and Shrike in the unsprayed controls were reduced about 40% in 1992 and 60% in 1993. Only small increases in grain yields of all varieties occurred from diclofop-methyl doses above 0.13 kg a.i. ha−1. Poorly competitive varieties were dependent on herbicides to achieve grain yield potential and had a greater risk of weed survival when herbicide efficacy was reduced. In contrast, strongly competitive varieties, likely to retard build-up of weed seed in the soil, are less dependent on herbicides to achieve grain yield potential, and therefore result in reduced weed control cost.


1972 ◽  
Vol 20 (4) ◽  
pp. 411 ◽  
Author(s):  
KHL Key ◽  
J Balderson

The distribution of Psednura pedestris and the northern race of P. musgvavei was studied in relation to habitat in the heathy vegetation of the sandy coastal plain near Evans Head, N.S.W. The density of both species was in general very low, corresponding to an average of only one specimen captured per man-hr; in a few patches it rose to several times that figure. The distribution of the two species was in the main mutually exclusive in a mosaic pattern reflecting the mosaic distribution of the respective preferred habitats, pedestvis occurring on the margins of swamps and musgravei on somewhat better drained sites. However, at three locations mixed populations were found in the ecotone between the two habitats. At one of these, which was studied in detail, the zone of overlap was never wider than 12 m, and the highest density of each species occurred within a 2-m strip on either side of a median line related to a prominent habitat feature. The situation is compared and contrasted with that in parapatric species and races of morabine grasshoppers.


2006 ◽  
Vol 46 (9) ◽  
pp. 1151 ◽  
Author(s):  
J. C. Broster ◽  
J. E. Pratley

Charles Sturt University commenced herbicide resistance monitoring in 1991. A random survey in 1991 to determine the level of resistance in annual ryegrass (Lolium rigidum) to selective herbicides across the south-west slopes region of New South Wales found that 30% of samples were resistant to at least 1 herbicide. A subsequent survey of commercially available ryegrass seed found that 58% of these samples were resistant to at least 1 herbicide. As a result of these findings, a commercial testing service was established and has since received samples from a large proportion of the southern Australian cropping belt. Seventy-seven percent of samples tested were resistant to Group AI, 40% to Group B and 22% to Group AII herbicides. Lower levels of resistance were found to Group D (8%), Group C (1%) and Group M (0.4%) herbicides. The correlation between resistance in Group AI and AII herbicides was lower than expected given that these herbicides are considered to have the same mode of action. Within the Group AI herbicides the observed response of the samples was consistent across herbicide formulations. Resistance to clethodim varied from observed responses to other Group AII herbicides. The variation in resistance levels (and degree of multiple resistance) in each Australian state is discussed in relation to environmental conditions and cultural practices. The size of this dataset allows for the analysis of the relationships present among herbicide resistant annual ryegrass.


2019 ◽  
Vol 70 (4) ◽  
pp. 493
Author(s):  
William Higgisson ◽  
Sue Briggs ◽  
Fiona Dyer

Nitre goosefoot (Chenopodium nitrariaceum (F.Muell.) is a woody shrub that occurs at the edges of floodplains and other intermittently flooded areas across the Murray–Darling Basin. No studies have been conducted on the hydrological requirements of nitre goosefoot, and the species is not considered in watering requirements of floodplain species of the Murray–Darling Basin. This study investigated the effects of simulated rainfall and depth and duration of experimental flooding on mortality, leaf production, biomass and seed production of nitre goosefoot. Nitre goosefoot plants were grown from seeds collected near Hillston, New South Wales, Australia. The plants were subjected to the following 14 hydrological treatments: dry (no water applied), rainfall (simulating rainfall conditions at Hillston) and 12 combinations of three water depths (10cm, 50cm, 75cm) with four durations of inundation (5 days, 10 days, 20 days, 40 days). The study found that nitre goosefoot plants survived flooding, providing plants were not totally submerged, leaf production increased during flooding and after drawdown, and leaf production, biomass and seeding were highest under shallow flooding for approximately 1 month. The results of the study allow the hydrological requirements of nitre goosefoot to be considered in environmental watering programs.


1985 ◽  
Vol 36 (3) ◽  
pp. 361 ◽  
Author(s):  
RW Medd ◽  
BA Auld ◽  
DR Kemp ◽  
RD Murison

The influence of wheat (Triticum aestivum L.) planting arrangement and density on the competitive effect of the weed, annual ryegrass (Lolium rigidum Gaudin), was examined in field experiments over three climatically contrasting years on the central western slopes of New South Wales. Results for three experiments conformed to a common trend. Geometrical arrangement of the crop (rectangularities of 1 to 6.4) at any one of a range of crop densities had no significant effect (P > 0.05) on ryegrass competition, expressed as relative wheat grain yield reduction. However, the effect of ryegrass was substantially reduced by increasing wheat sowing density from 40 or 75 to 200 plants m-2. In analysing models of weed competition a reciprocal yield model (I/ Y = 0.0092 + 0.0037X, r2= 0.89) predicted yield reduction (Y, as per cent of weed-free controls), especially when used with the ratio of weed density to crop density (X), with residual sums of squares lower than for other models.


1998 ◽  
Vol 46 (6) ◽  
pp. 735 ◽  
Author(s):  
E. W. Pook ◽  
A. M. Gill ◽  
P. H. R. Moore

In most years between 1977 and 1992, insect defoliation was negligible in a regrowth stand of E. maculata Hook. on the south coast of New South Wales. However, leaf consumption by winter–spring infestations of cup moth larvae accounted for c. 6%, 19% and 4% of the total leaf loss from the canopy in 1989–90, 1990–91 and 1991–92, respectively. During the most serious infestation of 1990, cup moth larvae produced 0.56 t ha–1 of frass, equivalent to the consumption of c. 0.8 t ha–1, or c. 0.5 m2 m–2 of eucalypt leaf (c. 12% of winter leaf area index). In early November 1990, shortly after the infestation, an assessment of insect defoliation in the crown of a dominant tree revealed that (i) 47% of the leaf population was damaged, (ii) a larger proportion of older than younger leaves was damaged, (iii) the proportion of damaged leaves increased down the tree-crown profile, and (iv) 13% of the potential leaf area was missing. In the absence of further insect attack, the process of canopy renewal (leaf production and leaf fall) reduced the proportion of damaged leaves to 23% by June 1991.


1975 ◽  
Vol 15 (72) ◽  
pp. 102 ◽  
Author(s):  
GD Kohn ◽  
EG Cuthbertson

The influence of pasture topdressing with superphosphate and of stocking rate on the Chondrilla uncea population in a clover-ryegrass (Trifolium subterraneum-Lolium rigidum) pasture was measured in a grazing experiment at Wagga Wagga, New South Wales, over the period 1962 to 1966. Superphosphate application reduced final weed populations at all stocking rates. Continuous grazing maintained skeleton weed populations at a low level, but increasing the stocking rate from 5 to 15 sheep ha-1 had little influence on weed numbers. A management comparison at a high stocking rate-high fertilizer rate showed that rotational grazing increased the weed population compared with continuous grazing systems.


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