THE EFFECT OF COMPANION GRASS AND SEED RATE ON THE PRODUCTIVITY OF A TALL-FESCUE SWARD

The effects of sowing from 10 to 50 lb/acre of tall-fescue seed on plant establishment and on the annual and seasonal distribution of DM yield of tall fescue and its companion grasses were measured through two growing seasons. Increasing the seed rate increased plant numbers per unit area and decreased per cent establishment. Adding Scots timothy as a companion grass depressed both plant number and per cent establishment. S37 cocksfoot and New Zealand perennial ryegrass reduced both still further. Total annual dry-matter production was relatively unaffected by varying either the seed rate or the companion grass. The contribution of tall fescue to total production was highest when sown alone and was successively reduced by timothy, perennial ryegrass and cocksfoot. When sown alone there were only slight differences in contribution of tall fescue due to seed rate. With any companion grass the contribution from tall fescue increased with increasing seed rate. Early growth was not reduced by modifying seed rate but was reduced by all the companion grasses. It is concluded that increasing the seed rate of tall fescue above 30 lb is not justified, that Scots timothy can be sown at 3 lb/acre with tall fescue without affecting total production or early growth of the mixture, with the advantages of control of unsown species and improved palatability of the herbage.     

SEASONAL TILLER POPULATIONS OF GRASS AND GRASSJCLOVER SWARDS WITH AND WITHOUT IRRIGATION

The number of tillers per unit area of pure swards of S23 and S24 perennial ryegrass, S37 cocksfoot, S48 timothy and of a S23 perennial ryegrass/white clover sward, were examined at intervals of 4 weeks during a period of two years. The monthly appearance of new tillers and the death of tillers of S23 and S24 ryegrass and S48 timothy were followed for 15 months. The studies were made with and without irrigation.
The number of tillers varied with season through the year. Tiller numbers increased rapidly in late winter or early spring, and then declined until midsummer. Numbers rose again between June and August. This seasonal pattern of tiller numbers was most marked in ryegrass and timothy and least in cocksfoot. The effect of irrigation on tiller numbers was variable, and usually small in relation to the overall seasonal fluctuations in tiller numbers, but dry soil conditions could delay an increase in tiller numbers between June and August. The relationship between seasonal fluctuations in tiller number and root growth of swards is discussed.     

SOME EFFECTS OF GRAZING MANAGEMENT ON THE YIELD AND ITS COMPONENTS OF SOME PASTURE GRASSES

A study was made to determine the effects of grazing to a height of 1 in. when the swards reached heights of 3 and 9 in. on the dry matter production, LAI, tillering and rate of leaf production of new and old tillers in the spring–summer and autumn–winter seasons of 3 pasture species growing in association with white and red clovers. In both seasons the herbage yield under 9–1 management was higher than that under 3–1 and was significantly greater in the spring-summer season. Differences in DM production between cocksfoot, tall fescue and Ariki ryegrass failed to reach significance.
Light utilization under the 2 management systems was considered to be inefficient. In the autumn-winter period there was a linear relationship between the LAI and DM production in all treatments.
The rate of leaf production per tiller was significantly higher in cocksfoot than in ryegrass and tall fescue in both seasons.
New tillers had a significantly higher rate of leaf production than old tillers in the spring-summer period, but not in autumn-winter. The numbers of grass tillers and rooted nodes of clover were significantly higher under 3–1 than under 9–1 and were influenced by season.     

Comparative defoliation tolerance of temperate perennial grasses

The defoliation tolerance of cultivars of four temperate perennial pasture grasses, perennial ryegrass (Lolium perenne, cv. Yatsyn1), phalaris (Phalaris aquatica cv. Australian), tall fescue (Festuca arundinaceae cv. Demeter) and cocksfoot (Dactylis glomerata cv. Porto), was determined under controlled conditions over a period of 12 weeks. Undefoliated plants were compared with defoliated plants, where only half of one leaf was left intact at the initial defoliation, and leaf regrowth was harvested every 3–4 d. The growth responses measured were plant tiller number, dry weight, relative leaf regrowth rate, root:shoot ratio, sheath:stem ratio and specific leaf weight. All species showed morphological adaptations that potentially increased their ability to tolerate defoliation (e.g. increased allocation to shoot at the expense of roots and lower specific leaf weights) but cocksfoot was found to be the most defoliation‐tolerant and perennial ryegrass the least. The adaptation that favoured cocksfoot most strongly was high sheath:stem ratio, which, it is proposed, allowed it to maintain photosynthesis and a level of carbon supply sufficient to support regrowth throughout the experiment. The strategy of perennial ryegrass which favours leaf growth and leads to rapid leaf turnover rates made it particularly susceptible to defoliation under the conditions of this experiment. This highlights the likely importance of defoliation‐avoidance responses in explaining the well‐known grazing resistance of this species. Phalaris and tall fescue showed responses that were intermediate between the other two species. The importance of defoliation‐avoidance mechanisms and implications for grazing management are discussed.     

THE DIGESTIBILITY OF THE LEAVES AND STEMS OF PERENNIAL RYEGRASS, COCKSFOOT, TIMOTHY, TALL FESCUE, LUCERNE AND SAINFOIN, AS MEASURED BY AN IN VITRO PROCEDURE

Determinations of the in vitro digestibilities of leaf-blade, leaf-sheath and stem fractions of the grasses cocksfoot, perennial ryegrass, timothy and tall fescue and of the leaves and stems of lucerne and sainfoin have shown that all parts of the plant have a high digestibility at early stages of growth. With increasing maturity, however, the digestibility of the stem falls off at a much faster rate than that of the leaf; in grasses, leaf-sheath digestibility declines at an intermediate rate. The decline of digestibility is associated with a reduction in the content of water-soluble and protein constituents in the plant, and with a reduction in the digestibility of fibre. This may provide a biochemical basis for the selection of forage plants of high digestibility in plant-breeding studies.     

A COMPARISON OF BROADCAST AND WIDE-ROW SPACED GRASSES WHEN MANAGED FOR FOGGAGE PRODUCTION

A small-plot trial comparing perennial ryegrass, cocksfoot, timothy and meadow fescue sown broadcast and also in 21 inch rows was conducted at Auchincruive from 1954 to 1957. The cutting treatments were arranged so that measurement could be made of both summer and winter production.
Of the four species, cocksfoot was the most suitable for foggage production. Perennial ryegrass suffered severely from winter killing. Timothy and meadow fescue, although persistent, did not yield as much as cocksfoot.
Total dry-matter production over three years was higher from the cocksfoot rows than from the broadcast stand. For ryegrass and meadow fescue, broadcasting gave higher yields than row sowing while timothy showed no significant difference between sowing methods.
During the winter, all species showed a loss of dry matter. Losses for ryegrass, cocksfoot, timothy and meadow fescue were respectively 34%, 17%, 18% and 24%. Broadcast stands averaged 11% greater loss than the rows.     

COMPARATIVE PRODUCTIVITY OF HERBAGE VARIETIES ON UPLAND PEAT

The productivity and persistence of 27 varieties of herbage plants were compared, following sowing on a blanket peat after ploughing. Yields were estimated from 3–5 cuts per year for 5 growing seasons. The top yields in each year ranged from 2510 lb/ac. in the 5th year when no nitrogenous fertilizer was applied up to 4700 lb/ac. in the 3rd year when given 174 lb N/ac. Such levels are slightly less than half the level expected on lowland, but livestock output on hill land is far lower than on lowland. Varietal differences were significant, with red fescues, especially S59 smooth-stalked meadow grass, S170 tall fescue, S143 cocksfoot, Yorkshire fog and S53 meadow fescue giving top yields and persistence. Aberystwyth varieties were in all cases superior to other varieties. S50 timothy and S23 perennial ryegrass were persistent but production was low. The conclusions are compared with those of other investigators.     

Soil moisture and growth of contrasting varieties of Lolium, Dactylis and Festuca species

Varieties of Italian, perennial and Italian × perennial ryegrasses, tall fescue and cocksfoot were used to determine the effects of soil moisture on grass growth. Weather conditions were monitored and herbage accumulation, leaf extension rate, leaf appearance rate and tillering were recorded under natural (control), covered and irrigated treatments.
Water deficit reduced crop growth rate in the spring and drought was the major factor influencing crop growth rates in all varieties during the summer. The ryegrasses appeared most sensitive to drought, and particularly poor recovery growth was exhibited by the Italian ryegrass RvP and the hybrid ryegrass Snowdon.
Leaf extension rate and leaf appearance rate were both reduced by increasing soil water deficit. Herbage accumulation was increased by irrigation when potential soil water deficits were greater than 100 mm. When water deficits were large, irrigation increased leaf extension more than leaf appearance or tiller number. Increasing moisture deficit had a greater effect upon tiller number than on leaf extension.     

THE EFFECT OF METHOD OF SOWING ON THE ESTABLISHMENT OF GRASS SEED CROPS

Methods used by growers to establish seed crops of perennial ryegrass, cocksfoot, timothy and meadow fescue have been examined. While satisfactory establishments were obtained by sowing perennial ryegrass broadcast, cocksfoot, timothy and meadow fescue should be sown in rows, especially if they are to be sown under a cover crop.     

EFFECTS OF WHITE CLOVER ON THE BOTANICAL COMPOSITION OF SWARDS OF RYEGRASS, TIMOTHY AND MEADOW FESCUE AND MIXTURES OF THESE THREE

Results are presented to show the effect of white clover (Trifolium repens) and of applied N on the hotanical composition of swards sown with perennial ryegrass (Lolium perernne), timothy (Phleum pratense), meadow fescue (Festuca pratensis) and mixtures of two and three of these species. White clover had a more favourahle effect on the growth of perennial ryegrass than on either timothy or meadow fescue both in terms of yield and in terms of tiller numbers. Tiller numbers of rough-stalked meadow grass (Poa trivialis) were increased and tiller numbers of Agrostis species were reduced by application of N and by inclusion of clover. Possible reasons for these effects are considered.     

Tiller production in cocksfoot (Dactylis glomerata) and tall fescue (Festuca arundinacea) growing along a light gradient

Pasture managers seek to balance leaf appearance with utilization to sustain sward productivity while meeting livestock nutritional needs. Achieving this in silvopasture must account for the influence of light and defoliation on tillering. We determined tiller production, as a function of light availability and clipping height, for two forage grasses adapted to cool, humid temperate conditions of the Appalachian region of the USA. Tiller production of cocksfoot (orchard grass) (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.) was greatest in unshaded and least in shaded sites, irrespective of residual clipping height. Juvenile plants produced more than twice as many tillers as mature plants, with differences accentuated by site, reflecting a shift in reproductive and resource‐use strategies. Trends in tiller production were as follows: cocksfoot > tall fescue; 10‐cm > 5‐cm residual clipping height; and unshaded > partially shaded > densely shaded sites. Tiller production reaches maximum earlier in the woodlot site, regardless of species or clipping height, than at the unshaded site. Plants at the wooded site extended leaves quickly, sustaining herbage production, but had less non‐structural carbohydrate and fewer tillers. Cocksfoot, but not tall fescue, sustained leaf and tiller production in the shaded sites, suggesting that cocksfoot is suited for use in silvopasture in this region.     

THE USE OF PERENNIAL RYEGRASS SOWN AT 1 LB. PER ACRE IN A STANDARD SEEDS MIXTURE

An attempt was made in a survey-type trial to combine perennial ryegrass with cocksfoot, meadow fescue and timothy together in the same sward, without the association being dominated by the ryegrass. It is concluded from this work that such non-dominant ryegrass swards can be obtained by limiting the seeding rate of the ryegrass to 1 lb. per acre in a seeds mixture sown at the rate of about 20 lb. per acre.     

THE DIGESTIBILITY AND VOLUNTARY INTAKE OF S22 AND H.1 RYEGRASS, S170 TALL FESCUE, S48 TIMOTHY, S215 MEADOW FESCUE AND GERMINAL COCKSFOOT

Pure swards of S22 Italian ryegrass, H.1 hybrid ryegrass, S170 tall fescue, S48 timothy, S215 meadow fescue and Germinal cocksfoot were each harvested at several stages of maturity during first growth in the spring, and in the subsequent regrowths. Each batch of herbage was fed to sheep in a digestion trial under conditions of voluntary intake. Results from the first growth herbages showed the expected fall in digestibility with increasing maturity. However, the digestibility of S22, H.1, S170 and S48 began to fall well before ear emergence, whereas the digestibility of Germinal fell only slowly up to the time of ear emergence, as had been found previously with S24 and S23 ryegrass and S37 cocksfoot. The rate of fall of digestibility in H.1 and S48 (0.4 units/day) also appeared to be lower than with the perennial ryegrasses and cocksfoot (0.5 units/day). The monthly regrowths within each herbage were of similar digestibility, but the mean digestibility of regrowths differed between herbages, being highest for S215 and lowest for Germinal and S170. The grasses with highest digestibility in the early Spring, in particular S22 ryegrass, were not, however, always the most digestible in the subsequent regrowths. The numbers of sheep fed on each herbage were insufficient to show whether there were significant differences in voluntary intake between different herbage species of the same digestibility. It is suggested that an intake/digestibility relationship, based on data from more animals, should be developed for each herbage species. Only if different relationships are found can it be concluded that factors other than level of digestibility have an effect on intake.     

Effect of defoliation management, based on leaf stage, on perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and cocksfoot (Dactylis glomerata L.) under dryland conditions. 1. Regrowth, tillering and water-soluble carbohydrate concentration

A field study was undertaken between April 2003 and May 2004 in southern Tasmania, Australia to quantify and compare changes in herbage productivity and water‐soluble carbohydrate (WSC) concentration of perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and cocksfoot (Dactylis glomerata L.) under a defoliation regime based on leaf regrowth stage. Defoliation interval was based on the time taken for two, three or four leaves per tiller to fully expand. Dry‐matter (DM) production and botanical composition were measured at every defoliation event; plant density, DM production per tiller, tiller numbers per plant and WSC concentration were measured bimonthly; and tiller initiation and death rates were monitored every 3 weeks. Species and defoliation interval had a significant effect (P < 0·05) on seasonal DM production. Prairie grass produced significantly more (P < 0·001) DM than cocksfoot and ryegrass (5·7 vs. 4·1 and 4·3 t DM ha^?1 respectively). Plants defoliated at the two‐leaf stage of regrowth produced significantly less DM than plants defoliated at the three‐ and four‐leaf stages, irrespective of species. Defoliation interval had no effect on plant persistence of any species during the first year of establishment, as measured by plant density and tiller number. However, more frequent defoliation was detrimental to the productivity of all species, most likely because of decreased WSC reserves. Results from this study confirmed that to maximize rates of regrowth, the recommended defoliation interval for prairie grass and cocksfoot is the four‐leaf stage, and for perennial ryegrass between the two and three‐leaf stages.     

THE EFFECT OF COMPANION GRASSES ON TIMOTHY PRODUCTION IN SWARDS CUT FOR CONSERVATION

To assess the effect of companion grasses on timothy productivity, swards of timothy sown alone or with one of eight companion grasses were harvested as for silage four times per year for two years. The companion grasses were: diploid perennial ryegrasses S24 and S23; tetraploid perennial ryegrasses Reveille and Taptoe; meadow fescues S215 and S53 and cocksfoots Trifolium and S143. Averaged over the N application rates (226, 339 and 452 kg N/ha per year) the total herhage yields of timothy/companion-grass mixtures were all significantly superior to that from timothy alone in the first year. Only perennial ryegrass S24 and the cocksfoot mixtures significantly outyielded timothy alone in the second year. Winterkill hecame evident in April of the second year and pure timothy and timothy/meadow-fescue swards were least affected. Over all swards, timothy DM increased hy a mean of 19% from the first to the second year, compared with a fall of 20% in total herhage DM. The contrihution of timothy herhage to the mixtures was very low with companions other than meadow fescue. Late-heading varieties were more compatihie than early-heading varieties, and tetraploid ryegrasses were more compatihie than diploid ryegrasses. It is concluded that if the inherently valuahle characteristics of timothy are to he exploited, it should not he sovm with aggressive companion grasses.     

Some differences between eight grasses within the Lolium-Festuca complex when grown in conditions of severe water shortage

Differences between eight related grasses within the Lolium-Festuca complex in conditions of severe water shortage were investigated. Transparent covers were used to restrict the access of rain to field plots of pure stands of Westerwolds ryegrass ( Lolium multiflorum var. Westerwoldicum), Italian ryegrass ( L. multiflorum ), hybrid ryegrass ( L. multiflorum × L. perenne ), perennial ryegrass ( L. perenne ), meadow fescue ( Festuca pratensis ), Italian ryegrass × meadow fescue, perennial ryegrass × meadow rescue, tall fescue ( Festuca arundinacea ) and three mixtures (Italian ryegrass with perennial ryegrass; Italian ryegrass with tall fescue; perennial ryegrass with tall rescue) grown in west Wales. Westerwolds ryegrass and Italian ryegrass died out after 12–15 months of exclusion of rain; meadow fescue, meadow rescue × ryegrass hybrids and perennial ryegrass died out after ≊ 2 years of exclusion of rain; tall rescue was still alive after 4 years of exclusion of rain. During the 2 years after the year of sowing, the loss of water from the top 1 m of soil was greater with tall rescue than with the other grasses. Tall fescue and perennial ryegrass had a low rate of leaf expansion, a small increase in length of exposed leaf sheath and a high weight per unit area of emerging leaf blade. Tall rescue had a greater number and weight of roots than the other grasses, particularly in the 50–100 cm layer of soil, on an adjoining, uncovered site. The order of suitability of the eight grasses for conditions of severe water shortage appears to be tall fescue > perennial ryegrass > perennial ryegrass × meadow rescue, meadow fescue, Italian ryegrass × meadow rescue, hybrid ryegrass > Italian ryegrass > Westerwolds ryegrass.     

The rate of water loss from cut grass of different species dried at 20°C

The water loss from tall fescue cv. S170, perennial ryegrass cv. S24, Italian ryegrass cv. R v P and timothy cv. S352 when dried as a thin layer under controlled conditions at 20°C and r.h. 50% is described. Comparisons were made on six occasions between mid-April and mid-June. Tall fescue dried faster than the other species and the time to reach a water concentration of 0·2 g water per g dry matter varied little between the six harvests. In contrast, the drying time for the ryegrasses and timothy increased to maximal values in mid-May and then fell. Drying time was dependent on the initial water concentration of the grass, the ratio of leaf to stem and on the amount of true stem exposed to the drying environment. The practical implications in relation to haymaking are discussed.     

GRAZING MANAGEMENT FOR SEED PRODUCTION IN LEAFY STRAINS OF GRASSES

Leafy strains of five grasses were grown for seed and subjected to various cattle grazing treatments between October and April for three harvest years. The grasses were: S.143 cocksfoot, S.215 meadow fescue, S.170 tall fescue, S.59 red fescue and S.23 perennial ryegrass. All but S.59 red fescue (row crop) were studied as row and broadcast crops. The plots were sown under an arable silage crop and received top dressings of nitrogenous fertiliser every year. Yield of seed, and also quantity of herbage in winter, were measured.
October grazing in the seeding year reduced the first crop of seed in all species except ryegrass. Grazing in December improved the yield of meadow fescue throughout the experiment, and of cocksfoot, tall fescue and red fescue after the first year. Several factors might operate to bring about this effect; suggestions are made for further investigation. Repeated grazing from December to March tended to reduce vigour, and so to offset the advantage of removing autumn-grown herbage. Grazing at intervals from December to late April seriously reduced yield in all species. Tall fescue and red fescue, early flowering species, were most seriously affected, meadow fescue and perennial ryegrass least. Cocksfoot and tall fescue yielded more seed when grown in 2-ft. rows than when broadcast. Meadow fescue and perennial ryegrass did not. The yield of meadow fescue was less affected by adverse conditions than cocksfoot.     

THE DIGESTIBILITY AND PRODUCTIVITY OF SELECTED HERBAGE VARIETIES

Much of the published digestibility data refer to swards grown in the south of Britain. In order to study digestibility curves in a more northerly latitude, several pure swards were established in the west of Scotland in 1962 and 1963. Varieties included S22 and Tetila Italian ryegrass, S37 cocksfoot, S170 tall fescue, S215 meadow fescue, Scots timothy, English broad red clover, and SI00 white clover. In addition to primary growth in vitro digestibility, the effect of various cutting managements on digestibility and productivity was measured. Flowerhead emergence was delayed, with the result that the digestibility curve was later than is reported from southern Britain. Highest yields of digestible organic matter were obtained from the less frequent cutting regimes, but the mean digestibility of the herbage was lower. Pre-dictibility of herbage digestibility is desirable as the basis of a reliable and planned herbage utilization programme, particularly for conservation.     

Micronutrient concentrations in common and novel forage species and varieties grown on two contrasting soils

We investigated differences between forage species with regard to micronutrients that are essential to sustain livestock health. Five grasses (timothy, perennial ryegrass, meadow fescue, tall fescue and cocksfoot), three legumes (red clover, white clover and birdsfoot trefoil) and four forbs (ribwort plantain, salad burnet, caraway and chicory) were grown on one micronutrient‐poor/low pH soil and one micronutrient‐rich/high pH soil (outdoor pot experiment). In addition, six grasses (timothy, perennial ryegrass, meadow fescue, tall fescue, Festulolium hybrid and cocksfoot) and one legume (red clover) were field‐grown on the micronutrient‐poor soil. Of the twelve pot‐grown species, herbage of chicory, red clover and white clover generally had the highest micronutrient concentrations (maximum Co, Cu, Fe and Zn concentrations were 0·23, 9·8, 233 and 109 mg kg^?1 DM, respectively), except for Mo, which was highest in the clovers (10·6 mg kg^?1 DM), and Mn, which was highest in cocksfoot (375 mg kg^?1 DM). Soil type had the strongest effect on plant Mo and Mn concentrations. We also investigated differences in micronutrients between varieties, but they were generally few and negligible. The results indicate that choice of forage species is of major importance for micronutrient concentrations in herbage and that soil type exerts a major effect through pH. Forage of chicory, red clover and white clover generally met the requirements of high‐yielding dairy cows with regard to most micronutrients; therefore, diversification of seed mixtures so as to include these species could increase micronutrient concentrations in forage.