ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00988.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

The possibility of using microscopic characteristics of the leaf epidermis as aids to the identification of some British agricultural grasses in the vegetative condition has been investigated.The occurrence of the following types of differentiated cells on the leaf‐sheath was markedly affected by the stage of growth of the tiller: silica cells, silico‐suberose couples, cork cells, asperities and incipient asperities. These cells were frequently absent or confined to the base of the sheath in vegetative tillers, but they occurred over most of the sheath in culm leaves. Silica cells tended to preponderate in young tillers and silico‐suberose couples and cork cells in the reproductive stage. The inter‐nerve epidermis of the leaf‐blade was generally the least affected by growth stage; although less differentiated than the sheath, it was found to be the most useful location for identification purposes. Species separable on the basis of the above‐mentioned characters of the leaf‐blade were:—(a)Tall fescue (Festuca arundinacea) from meadow fescue (F. pratensis)(b)Heath‐grass (Sieglingia decumbens) from smooth‐stalked meadow grass (Poa pratensis)(c)Sheep's fescue (F. ovina), from mat‐grass (Nardus stricta) wavy hair‐grass (Deschampsia flexuosa) and bristle‐leaved bent (Agrostis setacea).Timothy (Phleum pratense), meadow foxtail (Ahpecurus pratensis) and bent (Agrostisspp.) were separable on the following characteristics, which were not affected by growth stage: the occurrence of crystal clusters precipitated by hot water in timothy and occasionally in meadow foxtail, but not inAgrostisspecies, the peculiar shape of undifferentiated cells of the nerve epidermis inAgrostisspecies, and the dense cover of asperities on the ligules ofAgrostissp

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00989.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

An experiment is described in which folding and sideways creep‐grazing was compared with a rotational grazing management for lamb production at pasture.The experiment was carried out in two years (1957 and 1958) using a stocking‐rate of 7 ewes and 12 lambs per acre from the birth of the lambs until they had all been sent for slaughter.The folding management produced more liveweight gain per acre (955 and 983 Ib.) than the rotational management (870 and 926 Ib.) and the mean carcass‐weights were higher.The biggest differences, in favour of the sideways creep‐grazing system, were in tbe quality of the carcass produced. Folding produced 74% and 77% grade A carcasses and the rotational management 43% and 53%, respectively, in 1957 and 1958.Worm‐infestation was considerably less under the folding management and parasite control appeared to be more efFective where the area reserved for lambs only was not expanded to include ewe‐grazed pasture as the season

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00990.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Three grasses, bromegrass, slender wheatgrass and reed canary grass were sown on irrigated land with Ladak alfalfa in varying ratios with the object of determining what effect different proportions of alfalfa to grass would have in preventing alfalfa domination. The total number of seeds, irrespective of the proportions used, was held constant at 2.5 per linear inch of row.The influence of alfalfa on total yield was such that no significant yield differences due to grasses were established. However, the relative stand of grass varied considerably in the different mixtures. Slender wheatgrass did not compete with Ladak alfalfa, and had nearly disappeared from all stands after five crop‐years. Smooth bromegrass swards were dominated by the alfalfa, partrcularly where small amounts of the griass were sown. Reed canary grass and alfalfa maintained strong stands at all ratios of seed mixtures.The best overall ratio of grass to alfalfa by seed numbers was about 2.5: 1, although a higher ratio of grass was found desirable where brome was the grass component.Ratio of grass seed to alfalfa seed offered some measure of control for alfalfa domination, but choice of grass species was more importan

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00991.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

The proximate and ash constituents of twenty weed species have been determined. These weeds are all common to north‐eastern England. Some are characteristic of hedgerow and roadside and a few species of arable land; the majority, however, usually occur in pasture and meadowland, or in other sites where they are freely accessible to stock. Exact locality, approximate stage of growth and date of harvesting are recorded.A comprehensive examination of their ash has been made and four trace elements of recognized importance,viz. iron, manganese, copper and cobalt, were determined.The weeds have been classified on the basis of a marking system, and it was found possible to place them in one or other of three fairly well‐defined groups,viz. high, medium or low apparent value.Reference has been made to earlier assessments of these weeds and probable values, as reflected by chemical analysis, have been discussed. Most of the weeds listed as being of high apparent value are known or could justifiably be assumed to be of good nutritive status; examples of such are dandelion, nettle, creeping thistle and broad‐leaved plantain. Ragwort, although ranked highly on the marking system used, is well‐known to be toxic to animals. Not all members of the group of medium apparent value are likely to be eaten to any appreciable extent and at least two are of doubtful wholesomeness. Among weeds of low apparent value, only bird's‐foot trefoil would appear to have much potential u

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00992.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00993.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Sowings of annual meadow grass (Poa annua) were made in pots of soil which had been treated with sheep urine, with urine diluted × 50, or with water as a control. The treatments were applied before, at, and after sowing.Urine, whether applied at sowing time, or eleven days before or after, significantly reduced the germination or establishment of the weed grass.Diluted urine tended to reduce the number of established seedlings when applied at or shortly after sowing.In a subsidiary experiment the number of viable seeds in soil taken from pastures which had received no urine for four years were compared with those from soil under pastures receiving urine. The difference was not significant

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00994.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Two leafy strains of cocksfoot, S143 and S37 were subjected to winter, spring and winter + spring defoliation; 2 cwt. per acre of nitro‐chalk was applied after each defoliation, in addition to the standard manuring for all plots.Winter grazing of leafy cocksfoot does not appear to depress the yield of seed appreciably when extra nitrogen is applied.Grazing of cocksfoot in mid‐April is likely to depress the seed yield substantially, especially if followed by a very dry summer.The reaction to hard defoliation by sheep may vary with the growth form of the cocksfoot strain.Grazing appeared to be more detrimental to seed yield than defoliation by cutting.During this investigation, prolonged frost which occurred during the early part of the year appeared to have an adverse effect on cocksfoot seed yi

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00995.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

The possibilities of the wilting process have been investigated, with the ultimate object of determining its effect on the quality of farm silage. Attention has been confined mainly to mild or partial wilting, rather than severe wilting, since the danger of ensiling excessively dry material, especially when it is not chopped, is well recognised.Preliminary field tests were conducted to determine the rate and extent of the fall in moisture content in long and in bruised herbage, wilted for periods not exceeding 24 hours. Subsequently the wilted silages were made in experimental silos and, finally, in trench silos on a farm scale. This first paper deals with the field trials. Results show that important reductions in moisture content can be obtained in all but very poor weather. In good weather, moisture content may easily fall from the 80% to the 70% level; in poor weather (cool, overcast, with occasional showers) moisture loss still occurs.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1959.tb00996.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY