Seasonal development of roots under perennial and annual grass pastures

1994 ◽  
Vol 45 (5) ◽  
pp. 1077 ◽  
Author(s):  
AM Ridley ◽  
RJ Simpson

Studies in the field and in a rhizotron were conducted to examine the root growth of Phalaris aquatica L. (phalaris), Dactylis glomerata L. (cocksfoot) and Lolium rigidum Gaudin (annual ryegrass). Root and tiller development of the perennial grasses in autumn was also studied. In the field, annual ryegrass developed a more extensive surface rooting system than phalaris and cocksfoot by spring in a favourable season. Early root development of annual ryegrass was poor where the first rains of the season did not occur until winter. Growth rates of annual ryegrass roots at depth were similar to phalaris in mid spring in the rhizotron. Phalaris had a higher proportion of live roots than cocksfoot prior to the first autumn rain. Cocksfoot did not regenerate a substantial new root system until it developed secondary tillers, about a month after initial rains. Collectively, these studies indicated that the seasonal development and extent of the root systems of cocksfoot and phalaris were different.

1960 ◽  
Vol 38 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Wray M. Bowden

Chromosome numbers and voucher specimens are recorded for some collections of the tribe FESTUCEAE Dumort., mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1a) Arctagrostis arundinacea (Trin.) Beal var. arundinacea, 2n = 28, 2n = 29, and 2n = 30; (1b) Arctagrostis arundinacea (Trin.) Beal var. crassispica Bowden, 2n = 56; (1c) Arctagrostis latifolia (R.Br.) Griseb., 2n = 56. (2) Beckmannia syzigachne (Steud.) Fern., 2n = 14. (3) Brachyelytrum erectum (Schreb.) Beauv., two vars., 2n = 22. (4a) Bromus ciliatus L., 2n = 14; (4b) Bromus inermis Leyss., two subspecies and two vars., 2n = 56; (4e) Bromus kalmii A. Gray, 2n = 14; (4d) Bromus porteri (Coult.) Nash, 2n = 14; (4c) Bromus tectorum L., 2n = 14. (5) Catabrosa aquatica (L.) Beauv. var. laurentiana Fern., 2n = 20. (6) Dactylis glomerata L., 2n = 28. (7) Distichlisstricta (Torr.) Rydb., 2n = 40. (8a) Dupontiafisheri R.Br, subsp. fisheri, 2n = 132; (8b) Dupontia fisheri R.Br, subsp. psilosantha (Rupr.) Hultén, 2n = 44. (9) Eremopoa persica (Trin.) Roshev., 2n = 28. (10a) Festuca altaica Trin., 2n = 28; (10b) Festuca baffinensis Polunin, 2n = 28; (10c) Festuca brachyphylla Schultes, 2n = 42 and one collection, 2n = 44; (10d) Festuca elatior L., 2n = 14; (10e) Festuca obtusa Bieler, 2n = 42; (10f) Festuca prolifera (Piper) Fern. var. lasiolepis Fern., 2n = 50; (10g) Festuca rubra L., 2n = 42; (10h) Festuca saximontana Rydb., 2n = 42; (10i)Festuca scabrella Torr. ex Hook., two vars., 2n = 56 and 2n = 28. (11a) Glyceria borealis (Nash) Batchelder, 2n = 20; (11b) Glyceria canadensis (Michx.) Trin., 2n = 60; (11c) Glyceria grandis S. Wats., 2n = 20; (11d) Glyceria melicaria (Michx.) Hubb., 2n = 40; (11e) Glyceria pulchella (Nash) K. Schum., 2n = 20; (11f) Glyceria striata (Lam.) Hitchc, 2n = 20; (11g) Glyceria × gatineauensis Bowden (G. melicaria × G. striata), 2n = 30; (11h)Glyceria × ottawensis Bowden (G. canadensis × G. striata), three nothomorphs, 2n = 42, 2n = 46, and 2n = 48. (12) Lolium rigidum Gaud., 2n = 14. (13a) Phippsiaalgida (Sol.) R.Br., 2n = 28; (13b) Phippsia concinna (Th. Fries) Lindeb., 2n = 28. (14) Pleuropogon sabinei R.Br., 2n = 42. (15) Schizachnepurpurascens (Torr.) Swallen, 2n = 20. (16) Torreyochloa fernaldii (Hitchc.) Church, 2n = 14.


Author(s):  
Н.В. АЛДОШИН ◽  
А.С. ВАСИЛЬЕВ ◽  
В.В. ГОЛУБЕВ ◽  
А.А. ЦЫМБАЛ

Проблема и цель. Целью настоящей работы являлась разработка эффективной конструкции перемешивающего устройства для приготовления посевного материала травосмесей, а также лабораторные исследования результативности работы смесителя. Методология. Для достижения цели объектом исследования выбран экспериментальный смеситель семян, позволяющий осуществлять высококачественное перемешивание семенного материала многолетних трав, отличающийся различными размерно-массовыми параметрами. В ходе проведения исследований была разработана и изготовлена работоспособная конструкция смесителя, защищённая патентом РФ, позволяющая осуществлять высококачественное перемешивание семян, характеризующееся также низким травмирующим воздействием на смешиваемые компоненты. Это, в частности, подтверждено результатами определения основных посевных характеристик – лабораторной всхожести и энергии прорастания, значения которых, как правило, только возрастали, что связано с оказываемым физическим воздействием на достаточно плотные семенные оболочки семян трав, способствующим в условиях достаточной влагообеспеченности улучшению их прорастания. Определение эффективности разных способов приготовления травосмесей осуществлялось инструментально при помощи литровой пурки, для чего до начала и после окончания процесса смешивания проводили определение натуры семян перемешиваемых культур. Результаты. Выявлено, что оптимальным эксплуатационным режимом для приготовления травосмеси, состоящей из клевера лугового, овсяницы луговой, тимофеевки луговой, а также ежи сборной и овсяницы луговой является восьмиминутное смешивание с частотой вращения рабочего органа 16 об/мин; смеси, состоящей из райграса пастбищного, ежи сборной, мятлика лугового – 12 минут при 16 об/мин; из райграса пастбищного, клевера ползучего, клевера лугового, тимофеевки луговой – 10 минут при 12 об/мин. Заключение. Реализуемая тенденция изменения объемной массы травосмесей в зависимости от режимов работы экспериментального смесителя объясняется, прежде всего, различными геометрическими параметрами перемешиваемого материала, что практически нивелирует возможность унификации процесса смешивания для смесей семян многолетних трав в целом. Следующим этапом является исследование качества полученных кормов в зависимости от пропорций перемешиваемого материала. Problem and purpose. The purpose of this work was to develop an efective design of a mixing device for preparing seed of grass mixtures, as well as laboratory studies of the efectiveness of the mixer. Methodology. To achieve the goal, an experimental seed mixer was chosen as the object of the study, which allows high-quality mixing of seed material of perennial grasses, difering in diferent size-mass parameters. During the implementation of the research work, it was developed, a workable design of the mixer was made, protected by a Russian patent, which allows high-quality mixing of seeds, which is also characterized by a low traumatic efect on the mixed components, which, in particular, is confrmed by the results of determining the main sowing characteristics- laboratory germination and germination energy, the values of which, as a rule, only increased, which is associated with the physical efect exerted on the sufciently dense seed coat of grass seeds, which, under conditions of sufcient moisture supply, improves their germination. Determination of the efectiveness of diferent methods of preparation of grass mixtures was carried out instrumentally using a liter purr, for which, before and after the end of the mixing process, the nature of the seeds of the mixed crops was determined. Results. It was revealed that the optimal operating mode for preparing a grass mixture consisting of Trifolium pratense L., Festuca pratensis Huds., Phlum pratense L., as well as Dactylis glomerata L. and Festuca pratensis Huds. is an eight-minute mixing with a working speed of 16 rpm, from Lolium perenne L., Dactylis glomerata L., Poa pratensis L.-12 minutes at 16 rpm; from Lolium perenne L., Trifolium repens, Trifolium pratense L., Phlum pratense L. – 10 minutes at 12 rpm. Conclusion. The realizable tendency to change the volumetric mass of grass mixtures depending on the operating modes of the experimental mixer is explained, frst of all, by diferent geometric parameters of the mixed material, which practically negates the possibility of unifying the mixing process for mixtures of seeds of perennial grasses as a whole. The next step is to study the quality of the resulting feed, depending on the proportions of the mixed material.


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.


1964 ◽  
Vol 4 (13) ◽  
pp. 141 ◽  
Author(s):  
EF Biddiscombe

Seven perennial grasses were evaluated for animal production and for persistence, when stocked heavily in summer or winter with young Merino wethers. The commercial strain of Phalaris tuberosa L., which is sown commonly in south-eastern Australia and is often low yielding during summer and winter, was taken as the standard. At first, the productivity of Bromus inernis Leyss. in summer and Dactylis glomerata L. (Brignoles strain) in winter was reflected in higher liveweight and wool yields for these seasons. This advantage over Phalaris was lost when the Bromus pasture weakened in the third summer and the Dactylis in the third winter. The latter sward revived by natural regeneration from seed, whereas P. tuberosa developed and maintained a dense sward of the original plants. On this evidence Bromus and Dactylis are possible replacements for Phalaris for specific seasonal purposes, but management to retain vigorous swards still needs study. These aspects are discussed.


1966 ◽  
Vol 46 (3) ◽  
pp. 233-241 ◽  
Author(s):  
S. O. Fejer

Floral induction was studied in New Zealand and Mediterranean varieties of Dactylis glomerata L. and their hybrids. Treatments of 1 month vernalization, or 1 month of cold short days, or 2 months of warm short days, when followed by long days, induced almost complete heading in the field for most materials. Early dates of heading, many fertile tillers of increased height, and heads of a large and branched type also were induced by these treatments as compared with the untreated control material. Certain cold treatments produced, at early vegetative stages, more growth than the control. It is inferred that earlier attempts to vernalize New Zealand Dactylis plants were unsuccessful because of the restricted root growth in pots and flats. Plant breeding implications concerning heterosis, genotype–environment interactions, and reciprocal differences in hybrids were discussed.


2000 ◽  
Vol 51 (7) ◽  
pp. 937 ◽  
Author(s):  
H. Wu ◽  
J. Pratley ◽  
D. Lemerle ◽  
T. Haig

Allelopathy has been receiving world-wide attention for its potential in integrated weed management. A newly developed screening bioassay, the ‘equal-compartment-agar method’ (ECAM), was used to evaluate seedling allelopathy against annual ryegrass in a collection of 453 wheat accessions originating from 50 countries. Significant differences in allelopathic potential were found in this worldwide collection, inhibiting root growth of ryegrass from 9.7% to 90.9%. Wheat seedling allelopathy also varied significantly with accessions from different countries. Wheat allelopathic activity was normally distributed within the collection, indicating the involvement of multiple genes conferring the allelopathic trait. Of the 453 wheat accessions screened, 2 distinct groups were identified. Condor-derivatives were more allelopathic than Pavon-derivatives, with an average inhibition of root growth of ryegrass by 76% and 46%, respectively. Research was further extended to investigate the near isogenic lines derived from Hartog (Pavon-derivative) and Janz (Condor-derivative). Hartog and its backcrossed lines were less allelopathic than Janz and its backcrossed lines, inhibiting root length of ryegrass by 45% and 81%, respectively. These results strongly indicate that wheat allelopathic activity might also be controlled by major genes, depending on the particular populations. The present study demonstrates that there is a considerable genetic variation of allelopathic activity in wheat germplasm. It is possible to breed for cultivars with enhanced allelopathic activity for weed suppression.


1995 ◽  
Vol 35 (5) ◽  
pp. 571 ◽  
Author(s):  
KF Lowe ◽  
TM Bowdler

The growth, persistence, and rust sensitivity of a range of temperate grasses were measured to assess their potential for irrigated pastures in the subtropics. Characteristics considered important for adaptation to the subtropics include a relatively even growth rate throughout the year, rust tolerance, and the ability to persist under humid conditions. Cultivars and experimental lines from Lolium perenne (perennial ryegrass), L. rnultiflorum (Italian ryegrass), Festuca arundiizacea (fescue), Festuca x Lolium (festulolium), Bromus spp. (prairie grass and bromes), Dactylis glomerata (cocksfoot), and Phalaris aquatica (phalaris) were sown at Gatton, south-eastern Queensland, in pure stands or mixtures of annual and perennial grasses, using high seeding rates, 50 kg N/ha.defoliation, and full irrigation throughout the year. As a group, the fescues were the highest yielding and most persistent over 2 years, with AU Triumph the highest yielding cultivar. Maru phalaris was the most persistent grass, increasing from a frequency of 85% at the end of the first year to 100% at the end of the second year. Perennial ryegrass yields were about two-thirds those of the fescues, with a frequency of around 70% after 2 years. Dobson was the best ryegrass, producing a greater proportion of its forage in summer and increasing its density over the 2 years compared with the other perennial ryegrasses. Mixtures of annual ryegrass and fescue cultivars produced yields equivalent to pure fescue swards, with production dominated by annual ryegrass in the first year and by fescue in the second. Matua prairie grass was high yielding, but under frequent cutting was not as persistent as the ryegrasses. Felopa festulolium was inferior to the perennial ryegrasses and fescues in yield, the distribution of that yield, and persistence. Weeds contributed 1-10% of total yield over 2 years. The experiment suggests that the fescue cultivars are the most productive temperate grasses for perennial irrigated pastures in the subtropics, although better animal performance would improve farmer acceptance. The addition of a ryegrass component to fescue swards increased yields during establishment but did not improve overall yields. Late-maturing cultivars are the highest yielding of the perennial ryegrasses. Rust sensitivity needs improvement as all the present lines are highly susceptible.


1968 ◽  
Vol 8 (31) ◽  
pp. 190 ◽  
Author(s):  
K Hoen

Observations on summer survival in sown swards of a number of cultivars of Phalaris tuberosa L., P. coerulescens L., Dactylis glomerata L., and Hordeum bulbosum L. were made at Wagga Wagga, New South Wales, in two consecutive years with widely different rainfall patterns. In both years survival was higher among reproductive plants than among vegetative plants, and in both types of plants the largest individuals had the highest survival rates. In the abnormally dry year 1965 only a number of cultivars of cocksfoot had adequate survival rates. Some agronomic practices aimed at maximum survival over the first summer are discussed.


2016 ◽  
Vol 2 (91) ◽  
pp. 74-79
Author(s):  
V.H. Kurhak ◽  
M.I. Shtakal ◽  
V.M. Shtakal

There showed the productivity, chemical composition of feed and the timing of mowing of grass and variety mixes of permanent grasses on drained peat soils of Left Bank Forest-Steppe of Ukraine. The presence of early rip­ ened seeded grass provides a uniform supply use mowed mass from middle May until the end of September and the productivity of lands, which ranges from 10 to 14 t/ha of dry weight, metabolizable energy – 100.0 – 130.0 GJ and feed units 7-11 t/ha. Additional manuring of N90 on the background Р45К120 is effective at the start of second year of use. On the organization of hay conveyors of different ripening time herbages is possible to extend the optimal tim­ ing of mowing of green mass to 25-35 days. Best among the early-maturing grass crops are Dactylis glomerata va­ riety Kyivska rannia-1 with Alopecurus pratensis variety Sarnenskiy ranniy or its mixture with Bromus inermis and Festuca pratensis. With medium ripening – pure sowing eastern fescue of variety Lyudmila, Phalaris arundinacea variety Sarnenski-40, Bromus inermis variety Arsen and their compounds. High productivity of late-ripening herb­ age is provided by the inclusion in the composition of grass mixtures of Phleum pratense L. variety Vyshgorodska and Dactylis glomerata of variety Ukrainka, and Agrostis gigantea Roth variety Sarnenska piznia. It is also possible organization hay conveyors of different ripening varieties of Dactylis glomerata varieties Kyivska rannia, Muravka, Ukrainka.


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