Comparative germination patterns of annual grasses in north-eastern Victoria

1970 ◽  
Vol 10 (45) ◽  
pp. 401 ◽  
Author(s):  
AA McGowan

The seasonal distribution of germination of Lolium rigidum, Vulpa bromoides, Hordeum leporinum and Bromus mollis was measured under field conditions. The study was conducted in north-eastern Victoria from February to August in 1966 and 1967. Although 49-97 per cent of seed of all species had germinated by the end of April, the proportions of Lolium and Volpia that emerged after April (36 and 45 per cent respectively) were greater than the analogous proportions of Hordeum and Bromus (18 and 13 per cent respectively). These differences in germination pattern are considered to be of potential importance in explaining the incidence of annual grass weeds in winter cereal crops, but of little significance explaining the persistence of these grasses in grazed pastures. Less th-an one per cent of the original seeds remained viable on or in the soil by late winter.

1974 ◽  
Vol 14 (67) ◽  
pp. 167 ◽  
Author(s):  
PS Cocks

The responses of three annual grasses (Lolium rigidum, Vulpia myuros, and Hordeum leporinum) to nitrogen fertilizer were studied at three densities. Total herbage and nitrogen uptake were measured at four harvest dates. The response of the three grasses to nitrogen depended on their density. At low density both Lolium and Hordeum had greater dry weight increase than Vulpia, but at high density Vulpia responded as well as Lolium and better than Hordeum. By comparing the nitrogen responses at similar amounts of available herbage it was seen that, over a wide range of availability, both Lolium and Vulpia had greater absolute response than Hordeum. It was concluded that nitrogen response would probably be greatest on swards of Lolium or Vulpia that have a particular amount of available herbage.


2009 ◽  
Vol 60 (11) ◽  
pp. 1088 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
R. D. Cousens ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
...  

A field experiment was established in a southern Australian temperate pasture to investigate the effects of identity and proximity of perennial grasses on the demography of the annual grasses Vulpia spp. (V. myuros, V. bromoides) and Hordeum leporinum (barley grass). Annual grasses were grown either alone or in mixtures, at different distances from rows of Dactylis glomerata (cocksfoot) and Phalaris aquatica (phalaris). Dactylis had a greater suppressive effect than Phalaris on Vulpia and Hordeum. Biomass, tiller production, and panicle production of annual grasses increased linearly with increasing distance from the perennial row. Tiller and panicle production were greater for Vulpia than Hordeum. The estimated rate of population growth (λ) for annual grasses was greater in Phalaris than in Dactylis and in Vulpia than in Hordeum, and increased with sowing distance from perennial grass rows. It was estimated that λ, when seeds were sown directly adjacent to a row of perennial grasses, was 1 and 0.4 for Vulpia and Hordeum, respectively, within Dactylis stands, and 7 and 3, respectively, within Phalaris stands. However, 15 cm from the row, λ reached 50 and 39 for Vulpia and Hordeum, respectively, within Phalaris stands, and 39 and 16, respectively, within Dactylis stands. In grazed, dryland pastures, perennial competition alone is therefore unlikely to prevent population growth of annual grasses, especially in systems heavily disturbed by grazing or drought. However, Dactylis showed more promise than Phalaris in limiting the abundance of these weeds.


1973 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
PS Cocks ◽  
CM Donald

The germination and establishment of Hordeum lepovinum Link and Lolium rigidum Gaud., two Mediterranean annual grasses, were studied under controlled conditions. Results were related to the ecology of these species as pasture plants in southern Australia. Seeds of the two species germinated over a similar range of constant temperatures (8-30�C); Hordeum germinated much more rapidly than Lolium at all temperatures. Lolium has a marked requirement for alternating temperatures for maximum germination, while Hovdeum has a weak or nil requirement. Both species withstood prolonged wetting at high temperatures without germinating or losing all viability. Prior soaking and redrying before germination increased the rate of germination of both species. Light rains which fall before the first germinating autumn rains usually wet the seed only for short periods and this further increases the advantage of Hordeum over Lolium in rate of germination. Hordeum germinated and established much more readily on the soil surface than did Lolium, even though Lolium absorbed water more rapidly. The success of Houdeum was due both to its rapidity of germination, which allowed it to establish before the soil surface dried out, and to its ability to germinate at high moisture tensions. Because of these features Hordeum leporinum has the potential to germinate earlier, more rapidly, and more freely than Lolium rigidum in the autumn of the Mediterranean region of southern Australia.


Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 375-379 ◽  
Author(s):  
Thomas J. Peters ◽  
Russell S. Moomaw ◽  
Alex R. Martin

The control of three summer annual grass weeds with herbicides during establishment of forage grasses was studied near Concord and Mead, NE, in 1984, 1985, and 1986. Three cool-season forage grasses, intermediate wheatgrass, tall fescue, and smooth bromegrass, and two warm-season grasses, big bluestem and switchgrass, were included. The control of three major summer annual grasses, green foxtail, barnyardgrass, and large crabgrass, was excellent with fenoxaprop at 0.22 kg ai/ha. Slight to moderate injury to cool-season forage grasses and severe injury to warm-season grasses were evident. Sethoxydim at 0.22 kg ai/ha and haloxyfop at 0.11 kg ai/ha controlled green foxtail and large crabgrass, but not barnyardgrass. Sulfometuron-treated big bluestem and switchgrass plots had the best forage stand frequencies and yields and, at the rate used, sulfometuron satisfactorily controlled green foxtail but only marginally controlled barnyardgrass and large crabgrass.


1992 ◽  
Vol 6 (4) ◽  
pp. 938-948 ◽  
Author(s):  
Chester L. Foy ◽  
Harold L. Witt

Field experiments were conducted during 1982 to 1988 in Virginia to evaluate BAS 517, CGA 82725, clethodim, cloproxydim, fenoxaprop, fluazifop, fluazifop-P, haloxyfop, paraquat, quizalofop, SC-1084, sethoxydim, sethoxydim plus thifensulfuron, and terbacil for control of annual grasses in alfalfa. Herbicides were applied to alfalfa and grasses 2 to 30 cm in height after the first and/or second cuttings. Overall, the herbicides were highly effective in controlling fall panicum, giant foxtail, barnyardgrass, and large crabgrass. Alfalfa yields were not increased with herbicide treatments in several experiments. Only paraquat, applied later than recommended after cutting in one experiment, and sethoxydim plus thifensulfuron at one location reduced alfalfa yields.


2021 ◽  
pp. 41-48
Author(s):  
Halina A. Kamyshenka

The results of a statistical assessment of the influence of changing weather and climatic conditions of the territory of Belarus on the productivity of the main winter cereal crops are presented in order to build computational models of productivity. The calculations were made with respect to the climatic component as a predictor, taking into account the deviations of air temperature and precipitation from the long-term climatic norm of months that have the most significant effect on the yield of the studied crops. For winter rye and wheat, adequate models of yield variability have been built. The research results are relevant for solving forecasting problems.


2016 ◽  
Vol 67 (10) ◽  
pp. 1054 ◽  
Author(s):  
Eva Beoni ◽  
Jana Chrpová ◽  
Jana Jarošová ◽  
Jiban Kumar Kundu

A survey of Barley yellow dwarf virus (BYDV) incidence in cereal crops in the Czech Republic over 4 years showed, on average, 13.3% BYDV-positive, randomly tested wheat and barley samples. The cultivated wheat and barley cultivars had different levels of susceptibility to BYDV infection. Field trials were performed with different barley and wheat breeding lines and cultivars, and resistance traits were evaluated after artificial inculcation by the viruliferous aphid vector Rhopalosiphum padi L. with BYDV-PAV. Our results showed high variability of visual symptom score (VSS) and reduction in grain weight per spike (GWS-R) in trials within the tested lines and cultivars. The barley line (WBON 96-123) and cultivars (Wysor, Travira) that contained RYd2 differed significantly from other cultivars in VSS. Line WBON 96-123 and cvv. Wysor and Yatzi showed the lowest GWS-R. Wheat line PSR 3628 and cvv. Altigo, Elan, Sparta, Aladin and Hewit showed significant difference from other cultivars in VSS. PSR 3628, Sparta, and Elan showed the lowest GWS-R. Similar results were obtained from BYDV titre analysis by RT-qPCR corresponding to the VSS and GWS-R traits. A low virus titre corresponded to low VSS and GWS-R. Hence, our results suggest that laborious and time-consuming GWS-R analysis could be replaced in some cases by qPCR-based BYDV titre analysis and, together with VSS evaluation, could enhance the efficiency of resistance assessment.


Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside

Field and greenhouse research was conducted during 1980 and 1981 to evaluate the effects of carrier volume, surfactant concentration, and treatment date on glyphosate [N- (phosphonomethyl)glycine] toxicity to annual-grass weeds and volunteer small grains. Glyphosate phytotoxicity increased as carrier volume was decreased from 190 to 24 L/ha. The presence of a surfactant in the spray solution did not influence grass control when glyphosate was applied in a carrier volume of 24 L/ha. When glyphosate was applied in 48 or 95 L/ha, the presence of surfactant resulted in better grass control than glyphosate without surfactant. When applied in 190 L/ha, glyphosate with 0.5% (v/v) surfactant gave better grass control than glyphosate alone or commercially formulated glyphosate. When glyphosate was applied to plants under water stress, little control was achieved regardless of plant growth stage. Glyphosate application to grass after head initiation also resulted in reduced control. Maximum weed control with glyphosate was attained when applications were made to seedlings growing actively because of adequate soil moisture and favorable temperatures.


2010 ◽  
Vol 3 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Matthew J. Rinella ◽  
Marshall R. Haferkamp ◽  
Robert A. Masters ◽  
Jennifer M. Muscha ◽  
Susan E. Bellows ◽  
...  

AbstractAuxinic herbicides, such as 2,4-D and dicamba, that act as plant growth regulators are commonly used for broadleaf weed control in cereal crops (e.g., wheat, barley), grasslands, and noncroplands. If applied at late growth stages, while cereals are developing reproductive parts, the herbicides can reduce seed production. We tested whether growth regulators have this same effect on the invasive annual grass Japanese brome. The herbicides 2,4-D, dicamba, and picloram were applied at typical field use rates to Japanese brome at various growth stages in a greenhouse. Picloram reduced seed production nearly 100% when applied at the internode elongation, boot, or heading stages of growth, whereas dicamba appeared to be slightly less effective and 2,4-D was much less effective. Our results indicate it may be possible to control Japanese brome by using growth regulator herbicides to reduce its seed production, thereby depleting its short-lived seed bank.


1970 ◽  
Vol 10 (42) ◽  
pp. 76 ◽  
Author(s):  
RT Parrott ◽  
CM Donald

A study was conducted at Adelaide of the ignitability of monospecific swards of four Mediterranean annual pasture plants under windless conditions throughout the normal field desiccation of the swards in the spring. For any individual species the ignitability depended almost wholly on the percentage of water or the very closely correlated percentage of dead herbage. Atmospheric conditions had no measurable influence on ignitability during desiccation. Trifolium subterraneum was much less ignitable at any particular level of moisture content than were the grasses. Lolium rigidum was more inflammable early in the desiccation process than was Hordeum leporinum of equal water content, presumably due to the greater continuity of dry leaf; but H. leporinum was ignitable much earlier in the spring because it matured and dried sooner than did L. rigidum. In the case of the grasses, only those firebrands that fell to or near the soil surface started a fire, whereas the more compact sward of T. subterraneum, when sufficiently dry, lit readily at the upper surface.


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