bluuebunny/crossref_metadata_2025 huggingface dataset:
Lead pollution of London soils: a potential restriction on their use for growing vegetables
Authors: Davies B. E. , Conway Deirdre , Holt Sarah
Published: March 2009

Great Britain relies heavily on imported food and Cantell (1977) has estimated that within urban areas there are over 100000 ha of dormant land (i.e. derelict and awaiting development) for which the most fundamentally valuable temporary use is growing food, since such land, Cantell claims, could yield 25 million tonnes of potatoes or 4 million tonnes of carrots annually. The national waiting list for allotments exceeds 100000 and, according to Thorpe (1969), vegetables are grown on nearly all (98·3%) urban allotments. Underlying the case for encouraging the agricultural or horticultural use of dormant land is the supposition that, once cleared of junk, urban soils differ little in potential quality from farmland. But this is not necessarily so: Purves & Mackenzie (1970) have reported that vegetables grown in Scottish urban soils were contaminated by trace metals as have Warren, Delavault & Fletcher (1971) in Canada, Beavington (1973) in Australia and Davies (1978) in England. Lead, is one of the commonest urban pollutants and many countries set limits on the concentration permitted in food. In Great Britain the present
limit is 2 mg/kg (fresh weight) but it is planned to reduce this to 1 mg/kg.
Control of potato cyst-nematode, Globodera rostochiensis, in a three-course rotation
Authors: Whitehead A. G. , Tite D. J. , Fraser Janet E. , French Eileen M.
Published: March 2009

Potato cyst-nematode, Globodera rostochiensis, was controlled in a three-course rotation (potatoes-sugar beet-barley) by treating the soil with an effective nematicide before growing susceptible Pentland Crown potatoes, or by growing Maris Piper potatoes, resistant to the nematode. In moderately infested sandy loam, Maris Piper potatoes grew and yielded much better in soil treated with a nematicide than in untreated soil. Maris Piper outyielded Pentland Crown only in years with ample rain in August. Sugar beet and barley in some years yielded better after Pentland Crown than after Maris Piper potatoes. Yield loss in Pentland Crown due to potato cyst-nematode varied greatly in the same field. The nematode was controlled better by 5·6 kg oxamyl/ha, or by 448 or 672 kg dazomet/ha, than by 448 kg Telone/ha. Large soil populations of G. rostochiensis declined faster under sugar beet and barley than small soil populations did, suggesting action of a predator or pathogen.
The cell walls ofEragrostis tef: variations in chemical composition and digestibility
Authors: Morris E. Jane
Published: March 2009

Teff(Eragrostis tef)was cut at various stages of growth and divided into leaf, stem (including leaf sheath) and inflorescence. Cell walls were isolated from the leaf and stem fractions and their composition determined. Acetyl groups and individual sugars were determined by gas-liquid chromatography.

Recoveries of cell walls from the same fresh weight of leaves or stems were similar at each stage of growth, but increased with maturity.

Throughout the growing season the leaf cell walls differed in composition from those of the stem. At the start of growth the leaves had a lower content of xylose and acetyl groups but were otherwise similar to the stems. However, with increasing maturity and the production of a flowering stem the stem cell wall composition changed much more than that of the leaf cell walls, with a marked decrease in the content of arabinose and an increase in the content of lignin and acetyl. Over the same period the leaf cell walls showed a smaller increase in acetyl content and decrease in arabinose and uronic acid, but were otherwise unchanged.

Digestion of the cell walls with a fungal cellulase preparation showed that although the two cell wall types were equally degradable while the grass was in the vegetative state, the digestibility of the stem cell walls decreased well below that of the leaves with the onset of maturity and the production of a flowering stem. This was confirmed byin vivoincubations of the cell walls in nylon bags.
Comparison of the effects of potassium fertilizer on the yield, potassium content and quality of 22 different vegetable and agricultural crops
Authors: Greenwood D. J. , Cleaver T. J. , Turner Mary K. , Hunt J. , Niendorf K. B. , Loquens S. M. H.
Published: March 2009

Sixty-one experiments with 15 levels of K fertilizer in the presence of excess N and P fertilizer were carried out on adjacent sites of the same field. Yield was always related to level of K fertilizer by a ‘diminishing returns’ type curve, and a derived equation, which defined relative responsiveness in terms of a single parameter, fitted the data for each crop very satisfactorily. Although the responsiveness of many of the crops was similar there were marked differences and the optimum levels of K (defined as the level at which a further 10 kg/ha increased yield by 1%) varied from 0 to 360 kg/ha, depending on the crop. Responsiveness was largely independent of the plant family to which the crop belonged, but was related to the mean plant weight atharvest; the larger the weight the less reponsive the crop. No general relation existed between responsiveness and duration of growth.

The % K in the dry matter of leaves (including stems) at harvest of crops receiving the optimum levels of K fertilizer was mainly determined by the family. It was generally between 0·9 and 1·1 for the Amaryllidaceae, between 1·1 and 1·2 for the Leguminosae and between 1·9 and 2·5% for the Cruciferae. The difference between the % K in the dry matter with the optimum level of K fertilizer and that with no fertilizer was proportional to responsiveness. Percentage K at harvest was a good indicator of the extent to which crop growth was restricted by lack of potassium.

At harvest crops receiving the optimum levels of K fertilizer contained between 29 and 220 kg/ha of K, but uptake increased asymptotically to a maximum as K applications were raised to higher levels. Maximum uptake for nearly all crops was almost double the uptake with the optimum fertilizer application.

Percentage recovery of 100 kg/ha of added K fertilizer varied between 8 and 70%, roughly in proportion to the total crop dry weight, which varied between 1 and 15 t/ha.

Effects of level of K fertilizer on crop quality were also measured and over the practical range of applications the effects were generally small.

The differences between the K requirements of crops are discussed and it is argued that the responsiveness of one crop relative to that of another would be expected to be similar on a range of soils.
The value of nitrophosphate for spring-sown cereals
Authors: Cooke G. W. , Widdowson F. V.
Published: March 2009

Thirteen experiments on spring cereals were carried out from 1952 to 1954 to compare broadcasting with combine-drilling for nitrophosphate and for mixtures of superphosphate plus equivalent nitrogen. Broadcast nitrophosphate was of little value; drilled dressings were much more effective. Superphosphate drilled with the seed produced consistently higher yields than broadcast superphosphate. Superphosphate plus equivalent nitrogen gave higher average yields than nitrophosphate both when broadcast and when drilled. When the dressings were broadcast, superphosphate was markedly superior to nitrophosphate, but when the fertilizers were drilled with the seed, average yields with superphosphate were only a little higher than with nitrophosphate.

Nitrophosphates may be substituted for mixtures containing water-soluble phosphorus for cereals providing that they are drilled with the seed. Since nitrophosphates do not make cereals grow as rapidly as does superphosphate, even when drilled with the seed, such materials may give poor crops in conditions where the plants need a rapid start. The nitrophosphate tested contained rather more than one-quarter of its phosphorus in water-soluble form; the improved early growth observed where nitrophosphate was combine-drilled may have been largely due to this fraction of the fertilizer.
Bloat investigations
Authors: Ferguson W. S. , Terry R. A.
Published: March 2009

An account is given of experimental work carried out at Jealott's Hill on bloat.

Bloat was produced in dairy cows and sheep by dosing with lucerne juice. Sheep proved convenient test animals and were used in most of the tests described.

Parenteral and intravenous administration of the flavone quercetin, which inhibits the activity of smooth muscle, did not cause bloat even in the presence of cyanide. It is unlikely that flavones are concerned in bloat.

Fractionation of bloat-provoking lucerne juice showed that activity was retained after (a) precipitation of chloroplastic material, and (b) passage of clear juice through an anion or cation exchange resin. This suggests that the bloat-provoking factor is non-ionic and not adsorbed on resins—properties shown by saponinis.

Dosing sheep with lucerne saponins, four other saponins, egg albumin and a synthetic foaming compound failed to produce bloat.

Two household detergents and a number of surface-active agents did not relieve bloat, but foam-breaking compounds were very effective.

A synthetic inorganic saliva and cow's saliva did not prevent bloat in sheep and from the single test made with cow's saliva it is not possible to say if it increased the severity of bloat.

It is concluded that the formation of a stable foam is a major factor in lucerne bloat and that food constituents, other than saponins, and the physical condition of the rumen ingesta probably influence the stability of the foam.
Observations of nutritional and seasonal changes in the fleeces of some masham sheep
Authors: Byder M. L.
Published: March 2009

1. An experiment was carried out in summer when sheep do not normally shed their wool fibres to see if a poor diet would induce fibre shedding. Observations were then continued for a year to follow seasonal variations in the fleece.

2. The two experimental sheep lost about a quarter of their body weight during the nutrition experiment. Measurement of areas tattooed in the skin showed that there was a reduction of about 5% in these areas.

3. Histologieal observations of skin samples showed that there was very little fibre shedding during the nutrition experiment. This suggests that poor nutrition alone will not cause sheep to shed their fibres. More fibre shedding took place during the winter even though the sheep were well fed, suggesting a seasonal stimulus for shedding.

4. ‘Brushes’ which are normally formed when fibres shed in primary follicles were also seen in secondary follicles.

5. Observations were made during the nutrition experiment of the blood vessels in the skin and glycogen in the outer root sheaths of the follicles. No changes were seen in either the numbers of vessels, or the amount of glycogen present.

6. The weight of wool produced per unit area per day was determined at each sampling time during the whole year. The experimental sheep behaved differently from the controls in their wool production during the nutrition experiment. Thereafter all sheep behaved the same, and seasonal fluctuations in wool production were found.

7. The mean length and mean diameter of the wool produced was determined at each sampling time throughout the year.
The nutritive value of roughages for sheep II. The relationship between the gross digestible energy and the chemical composition of silages
Authors: Walker D. M. , Hepburn W. R.
Published: March 2009

1. The relationship existing between the gross digestible energy content and the chemical composition of twenty-four silages has been studied with nine Cheviot wether lambs over a period of 8 months.

2. Silages were made from grassland herbage and varied widely in the chemical composition of the ingoing material.

3. Each silage was fed to a group of three lambs for a 10-day preliminary- and a 9-day collectionperiod. Faeces and urine were collected in metabolism crates.

4. The silages were analysed for volatile acids and bases, for proximate nutrients and for some of the more precise chemical constituents as suggested in the scheme of analysis of Ferguson (1948).

5. A close relationship existed between the gross digestible energy contents of the silages and the lignin (Ellis) content.

6. The most accurate prediction of gross digestible energy was obtained by taking into account the content of lignin (Ellis), cellulose (Crampton & Maynard) and crude protein, in the silage.

7. In the case of hays (Walker & Hepburn, 1955) no increase in the accuracy of predicting gross digestible energy was obtained by estimating the lignin and cellulose content, rather than crude fibre alone. However, with silages the results give support to the opinion of Mitchell (1942) and Schneider et al. (1951) that analysis for more precise chemical constituents will increase the accuracy of predicting digestibility.

8. Crude fibre and cellulose were not related in any fixed way with the digestibility of energy. Crude fibre itself was digested to some 80% compared with 62% in hays.

9. Metabolizable energy was closely related to digestible energy.

10. The starch equivalents of the silages were calculated by conventional methods and also from the content of gross digestible energy.
The influence of copper deficiency on the fleeces of British breeds of sheep
Authors: Lee H. J.
Published: March 2009

The fleeces of Border Leicester, Romney Marsh, Lincoln and Dorset Horn ewes which were confined for 3 years to copper-deficient pastures at Robe, in South Australia, have been studied.

As the copper status of the untreated ewes fell, their fleeces revealed abnormalities identical with those encountered in similarly copper-deficient Merino and Merino crossbred sheep.

The crimp characteristic of each breed was lost and straight, ‘steely’ fibres were produced. The capacity for crimp formation returned immediately when the copper status was restored.

Ewes which received regular copper supplements grew normal wool throughout the experiment. Supporting analytical data are presented.

The absence of this specific lesion from the fleeces of copper-deficient British breeds of sheep elsewhere is discussed.
The effects of agronomy on the carbon and nitrogen contained in the soil biomass
Authors: Adams T. McM. , Laughlin R. J.
Published: March 2009

Soils of various agronomic histories were fumigated with chloroform, and the resultant increased production of CO2 and mineral-N measured and expressed as biomass C and the flush of mineral-N production (FN), respectively. Biomass C and FN contents of grassland soils were greater than those of arable soils, and significant correlations with macro organic-matter content were found. Biomass C contents varied from 7 to mg C/100 g soil in arable soil and from 31 to 222 mg C/100 g soil in grassland or woodland. The proportion of soil organic C that was contained within the biomass ranged from 0·3 to 4·0%, whilst FN comprised from 1·0 to 11·7% of total soil N. FNcontents ranged from 1·1 to 13·2mg N/1OOg soil for arable soils, and from 2·5 to 31·7 mg N/100 g soil for grassland and woodland. Application of organic manures increased biomass C and FN contents in grassland soil.
Interrelationships between stem and ear development in winter wheat: the effects of a Norin 10 dwarfing gene, Gai/Rht2
Authors: Brooking I. R. , Kirby E. J. M.
Published: March 2009

A field and a glasshouse experiment were carried out to assess in winter wheat genotypes the interrelationships between stem and ear development, and to relate these to number of grains and yield. Capelle-Desprez (gai/rht2) and Hobbit ‘s’ (Gai/Rht2) were used together with four F4 lines from the cross between them. Two of the lines were homozygous for gai/rht2 and two lines homozygous for Gai/Rht2. Within each pair of homozygous lines there was a contrast between a tall and a short genotype.

There were no consistent differences in shoot apex morphogenesis between the genotypes, and, in general, similar numbers of spikelets and floret primordia were initiated in all genotypes. This contrasts with the hypothesis that genotypes based on Norin 10 (Gai/Rht2) have a fundamentally different pattern of ear morphogenesis. The main differences between genotypes were in dry-matter partitioning to stem and ear prior to anthesis and these were associated more consistently with the dwarfing gene than with height per se. Gai/Rht2 genotypes partitioned more dry matter to the ear during its development and less to the stem and this was reflected in greater ear weight at anthesis, more fertile florets and grains per spikelet, a higher harvest index and higher grain yield than the gai/rht2 genotypes. Although similar numbers of floret primordia were initiated in all genotypes, assimilate partitioning during development determined the proportion which developed into fertile florets at anthesis.
Field studies on leaching behaviour of a highly saline-sodic soil under two modes of water application in the presence of crops
Authors: Dahiya I. S. , Malik R. S. , Singh Maharaj
Published: March 2009

The leaching behaviour of a highly saline-sodic, moderately permeable, sandy-loam soil was evaluated under continuous and intermittent submergence conditions in a longterm field study in the presence of rice and subsequent wheat and sesbania crops. Leaching curves with respect to both desalinization and desodification showed that leaching efficiency was considerably higher with intermittent than with continuous submergence. The curves were useful in determining the amount of leaching water needed for a given mode of water application to reduce harmful levels of salinity and sodicity to acceptable ones. Empirical equations were determined to fit the experimental data. Their comparison with another empirical equation from published bare-field data of this site showed that leaching efficiency under crops was higher than under fallow. From the desodification leaching curve, it is concluded that in reclamation of these soils there is no need of the application of any amendment like gypsum. The soil salinity and sodicity data recorded at different growth stages and crop yields showed that leaching during the rice growing season, under intermittent submergence without previous leaching, decreased salinity and sodicity throughout the top 100 cm of the soil to levels safe for the successful cultivation of rice and subsequently the relatively deep-rooted crops of wheat and sesbania.
True and apparent metabolizable energy of some indigenous feedingstuffs and finished feeds determined by modified rooster bioassay techniques
Authors: Ranaweera K. N. P. , Nano W. E.
Published: March 2009

The true and apparent metabolizable energy (TME and AME) of a range of indigenous feedingstuffs and finished feeds were determined by rooster bioassay techniques adapted to suit a small nutrition laboratory.

The AME and TME of some common feedingstuffs were similar to the values published elsewhere. The AME of two finished feeds were similar to their zero-N corrected metabolizable energy values determined by the conventional total collection method. The mean ±S.E. endogenous and metabolic excreta energy per bird for 24 h was 70·4 ± 2·94 kJ.
The effect of cold treatments on the curd maturity of winter-heading cauliflowers
Authors: Wurr D. C. E. , Kay Rosemary H. , Allen E. J.
Published: March 2009

In four experiments in different years, plants of four winter-heading cauliflower varieties with mean numbers of leaves and leaf initials varying from 9·5 to 16·5 were stored for periods of 14–24 days at different temperatures from 0 to 5 °C. Cold treatment tended to delay the time from sowing to 50% maturity but did not reduce the spread in the time of maturity of individual plants within a population. The reasons for this are discussed.
Urea-formaldehyde complexes and their hydrolysis by rumen ureasein vitro
Authors: Makkar H. P. S. , Lall D. , Sharma O. P. , Negi S. S.
Published: March 2009

Much attention has been given to the use of urea in ruminant feeds since the demonstration by Hartet al.(1939) that non-protein nitrogen (NPN) compounds could be a substitute for protein in ruminant rations. However, the high activity of urease in the rumen decreases the efficiency of urea utilization, because the rate of ammonia release from urea is much faster than the rate of its assimilation by rumen microbes for the synthesis of amino acids (Bloomfield, Garner & Muhrer, 1960). Moreover, if the concentration of ammonia exceeds a certain limit, it causes toxicity to the animals (Froslie, 1977). The efficiency of urea utilization can be increased if the rate of ammonia production is similar to the rate of its assimilation by rumen micro-organisms. This could be achieved either by decreasing the activity of the rumen urease or by modifications of urea in products which result in slow release of ammonia (Helmer & Bartley, 1971). Attempts have been made to increase the efficiency of urea utilization by complexing urea with carbohydrates (Danielset al.1971; Muhrer, Harris & Bloomfield, 1968; Shultz, Shultz & Chicco, 1972), sodium bentonite (Britton, Cooling & Klopfenstein, 1978) and carboxy resin (Huston, Scherton & Breuer, 1974). Formaldehyde is known to protect proteins from rumen degradation by its reaction with terminal amino groups (NH2), the e-amino groups of lysine and a number of other side-chain groups of proteins (Barry, 1976; Van Dooren, 1972). Urea contains two amino groups for undergoing chemical reaction with HCHO to give different complexes. Previous work in our laboratory has shown that urea could be complexed with HCHO (Lallet al.1980; Pal & Negi, 1977). However, in those studies excesses of urea and HCHO were not removed and this produced an artefact in the evaluation of the ureaformaldehyde complexes (UFCs). Moreover, whole rumen fluid was used forin vitroammonia formation from these complexes. No studies have been made so far in a well-defined system on the biochemical basis of the ammonia-releasing property of the UFCs. We report here the formation and isolation of UFCs, free from urea and HCHO and their hydrolysis with purified rumen urease (EC. 3·5.1.5). Evidence is adduced that UFCs are substrates for rumen urease and can act as slow ammonia-releasing compounds.
Effects of maternal nutrition and plasma progesterone concentrations on survival and growth of the sheep embryo in early gestation
Authors: Parr R. A. , Cumming I. A. , Clarke I. J.
Published: March 2009

Mature Merino ewes (n = 320) were fed either maintenance (100% M) or 25% maintenance (25% M) rations from the day after mating until embryos were collected at either day 11 or 21 after mating. On the 4th day after mating 223 ewes were ovariectomized and given 5, 10, 15, 20 or 25 mg progesterone/day (intramuscular) until embryo collection. A further group of sham operated ewes (n = 54) acted as controls. Despite live-weight losses of 10·7 and 15·8% from mating to days 11 and 21 after mating respectively, ewes on 25% M rations showed no evidence that embryonic survival was influenced by undernutrition. The embryos from ewes fed 25 % M rations were significantly (P < 0·05) smaller than those fed 100% M (crown-rump measurements were 5·93 ± 0·139 mm and 6·39 ± 0·116 mm at day 21 after mating in the 25 % M and 100% M groups respectively). Development, assessed by formation of the first pharangeal lobe and the fore- and hind-limb buds, was significantly retarded (P < 0·05) in the 21-day-old embryos from the undernourished ewes. Embryo survival in ovariectomized ewes receiving 5 or 10 mg progesterone/day was significantly (P < 0·05) lower than in ovariectomized ewes receiving 20 and 25 mg progesterone/ day at day 11 after mating. Embryo survival at both days 11 and 21 after mating increased with increasing doses of progesterone. Ewes fed 25% M rations had elevated (P< 0·001) concentrations of peripheral progesterone compared with those fed 100% M. This occurred when the progesterone was derived from either exogenous or endogenous (ovarian) sources, dismissing the possibility that changes in secretion rates could account for these observed differences. Differences in embryo growth and development were not related to these variations in the plasma progesterone concentration. Undernutrition restricted both growth and development to 21 days of pregnancy.
Absorption by sheep of calcium, phosphorus and magnesium from a poultry litter supplemented diet
Authors: Ben-Ghedalia D. , Tagari H. , Geva A.
Published: March 2009

Eight Morino lambs equipped with simple cannulac in the duodenum and terminal ileum were divided into two equal groups and used to study the net absorption of calcium, phosphorus and magnesium from concentrate diets supplemented by soyabean meal or by ensiled poultry litter. Mean net absorption of Ca, P and Mg for the soya-bean meal and poultry-litter treatments, respectively, was 31·6, 10·1; 34·7, 35·4; and 51·5, 41·6.

Irrespective of the diet, the small intestino was the major site for Ca and P absorption and the stomachs for the absorption of Mg. A large secretion of P in the stomachs was found with both diets; 8·50 and 9·32 g/day for the soya-bean meal and poultry-litter treatments, respectively.

The results of the present study support the view that poultry litter is a good source of P and Mg for sheep and can be used with deficient diets. Owing to the low rate of Ca absorption from the poultry-litter diet, it appears that at limited levels of inclusion, the extra added Ca would not be a detrimental factor.
The relationship of bovine mandibular cheek tooth development to age determined by post-mortem radiographic examination of cattle aged between 12 and 24 months
Authors: Andrews A. H.
Published: March 2009

Results of visual and radiographic development of the mandibular caudal teeth were obtained from 135 cattle between 1 and 2 years old. Age ranges for each stage of tooth development were obtained. Using visual assessment of second molar intra-oral eruption the maximum age range before animals could be differentiated was 8 months (1 year 3 months from 1 year 11 months). Animals showed different stages of development in all six teeth using criteria based on resorption of the temporary premolar teeth and crown and root formation in the permanent premolar and molar teeth. The maximum age range before animals could be distinguished was 5 months (1 year 6 months from 1 year 11 months) and at all other ages the age difference before differentiation was less.
Eating and rumination behaviour in sheep given silage made from the fibrous residue of broad bean (Vicia faba L.)
Authors: Fujihara T. , Nakao T.
Published: March 2009

It is generally recognized that there is a close relationship between the utilization of roughage feed and rumination behaviour in ruminant animals (Gordon, 1955, 1968; Pearce & Moir, 1964; Campling, 1966; Welch & Smith,1969; Sudweeka et al. 1975; Thomas, Kelly & Wait, 1976; Fujihara, 1981). Likewise, it is also well known that rumination behaviour is clearly affected by differences in the physical and/or chemical properties of the diet (Gordon, 1958; Campling, Freer & Balch, 1962; Balch, 1971; Ørskov, Fraser& Gordon, 1974; Osuji, Gordon & Webster, 1975; Morgan & Campling,1978; Harumoto & Kato, 1978a, b; Fujihara, 1980b). Recently, Fujihara (1980a, b) observed more efficient rumination in sheep offered fresh grass than hay, and suggested that the efficient rumination might induce an efficient utilization of dietary nitrogen when feeding fresh grass.
Statistical criteria for distinctness between varieties of herbage crops
Authors: Patterson H. D. , Weatherup S. T. C.
Published: March 2009

The paper examines the statistical properties of criteria currently used to determine the distinctness of herbage varieties and suggests alternatives.
Some effects of lime, nitrogen and soluble and insoluble phosphate on the yield and mineral composition of established grassland
Authors: Adams S. N.
Published: March 2009

Twelve factorial experiments made from 1977 to 1981 compared the effects of 0, 4 and 8 t CaCO3/ha, 0 and 360 kg N/ha/year as urea and 0 and 60 kg P/ha/year as either superphosphate or ground rock phosphate on the yield and mineral composition of established grassland on soils of pH 4·7–5·6 in Northern Ireland.

Lime did not increase yield whether urea was applied or not. It substantially reduced herbage Mn and, to a lesser extent, herbage P, Mg and Zn.

With lime, ground rock phosphate was almost completely ineffective in raising yield and herbage P content. Without lime, it had some value but was less effective than superphosphate.

Soil P extracted either by ammonium acetate at pH 4·2 or Olsen sodium bicarbonate reagent did not predict response to superphosphate. When the soil test values were adjusted for field bulk density, soil P extracted by ammonium acetate, but not by Olsen reagent, was significantly correlated with response.

Herbage P in the first cut in 1978 was highly correlated with response to superphosphate; only sites with herbage P < 0·27% responded to P.
Intra-uterine insemination of ewes with frozen semen
Authors: Maxwell W. M. C. , Butler L. G. , Wilson H. R.
Published: March 2009

There have been a number of reports on the frozen storage of ram semen, and artificial insemination with frozen semen has been performed on an experimental basis in several countries. Intensive laboratory studies led to considerable progress regarding the freezing and thawing procedures (Salamon & Visser, 1972; Colas, 1975). However, fertility following insemination tends to be considerably lower than for fresh or chilled semen (Maxwell et al. 1980).
Response of green gram to potassium and zinc application
Authors: Singh B. , Badhoria B. S.
Published: March 2009

Green gram is one of the most important kharif pulse crops of India. It is of short duration, can fit well in crop rotation and, therefore, can be grown throughout the year. Information has been accumulating concerning the role of potassium and zinc in cereal crops but very little information is available regarding the nutrition of potassium and its interaction with zinc on the yield and quality of pulses. However, Malewar, Budhewar & Jadhav (1980) and Ghildiyal, Saini & Sirohi (1975) have reported significant positive effect of zinc treatment on growth attributes in green gram. The present investigations were, therefore, planned to study individual and interaction effects of potassium and zinc on growth, dry-matter and grain yield and quality of green gram.
Induction of lambing: comparison of the effects of prostaglandin, oestradiol benzoate and dexamethasone
Authors: Boland M. P. , Crosby T. F. , Gordon I.
Published: March 2009

In the first of two experiments 45 ewes were treated on day 141 of gestation with either prostaglandin F2a or saline. Doses of 10, 15, 20 or 25 mg PGF2a failed to induce lambing earlier than in control animals. A further 50 ewes were similarly treated on day 144; neither dose level of PGF2a nor day of administration had any effect on the interval from injection to lambing compared with controls. In a second experiment 159 ewes were randomly assigned to one of four treatment groups as follows: (1) 20 mg oestradiol benzoate (ODB); (2) 16 mg dexamethasone; (3) 15 mg PGF2a; (4) 2 ml saline. Ewes were injected on either day 143 or 144 of gestation and on each of those days animals were injected either in the morning or evening. The mean times to induction of lambing were 38·6 ± 20·8; 44·2 ± 18·1; 83·5 ± 39·8 and 82·9 ± 43·1 h for the four treatments respectively. Neither day nor time of treatment had any significant effect on the interval to lambing. Both ODB and dexamethasone induced parturition earlier than PGF2a or saline (P < 005).
Experiments to examine the significance of ammonia evolution from barley seedlings infected with the powdery mildew fungus, Erysiphe graminis f.sp. hordei
Authors: Jenkyn J. F. , Finney M. E.
Published: March 2009

Experiments using intact seedlings and detached leaves failed to confirm previous reports that ammonia gas is evolved from barley leaves during the establishment of infection by the powdery mildew fungus Erysiphe graminis f.sp. hordei.

In the experiments using intact seedlings infection did, however, lead to greater concentrations of ammonium nitrogen in the senescing leaves and, in one experiment, the subsequent evolution of ammonia gas from these seedlings. Losses of nitrogen as ammonia gas from crops are probably small, but it is possible that under some circumstances they may represent a significant proportion of the otherwise unexplained nitrogen losses and hence be important in experiments which aim to study the nitrogen balance of crop-soil systems.
The effect ofin saccorumen incubation of a grass silage upon the total and D-amino acid composition of the residual silage dry matter
Authors: Rooke J. A. , Greife H. A. , Armstrong D. G.
Published: March 2009

Grass silage was incubated in polyester bags in the rumens of Jersey heifers for 2, 12, 24 and 48 h. The total (D + L) and D-amino acid contents of the silage and of the silage residues remaining after rumen incubation were determined. In addition, the contamination of the silage residues by rumen bacterial protein was measured by using35S as a marker of rumen bacterial protein. The amino acid profile of the residual silage dry matter differed markedly after 2 h of rumen incubation from that of the original silage; thereafter progressive changes in the amino acid composition of the residual silage dry matter occurred between 2 and 48 h of rumen incubation. The D-alanine content of the original silage was higher than that of D-glutamic acid. Both these D-amino acids disappeared almost completely from the silage after 2 h rumen incubation; between 2 and 48 h rumen incubation the quantities of D-alanine and D-glutamic acid in the residual silage dry matter increased. The residual silage dry matter contained more D-glutamic acid than D-alanine and these acids were in a similar proportion to that found in rumen bacteria; thus it was concluded that D-amino acids in the residual silage dry matter resulted from contamination of the residues by rumen bacteria. Contamination of residual silage protein by rumen bacterial protein increased with length of rumen incubation; the extent of contamination was similar for each incubation time whether assessed using35S or D-amino acids as markers of rumen bacterial protein. However, this contamination by rumen bacterial protein did not markedly alter the degradability of silage protein calculated from the disappearance of silage N incubatedin sacco.
Studies on the Northern Rhodesia Hyparrhenia Veld:IV. The effects of nitrigen fertilizer and defoliation
Authors: Smith C. A.
Published: March 2009

Plot trials measured the effect of fertilizers and defoliation on Hyparrhenia veld.

N was the only nutrient limiting growth, and N fertilizer markedly increased the herbage yield and crude protein %. The herbage response was linear up to the highest rate used, 189 lb. N/acre, with a calculated N recovery of approximately 35%. Split fertilizer applications were only advantageous in one year out of three. The effect of N fertilizer steadily decreased at successive harvests after application, and the residual effect in a following season was transient. N fertilizers did not alter the botanical composition of the veld.
Seed ripening in grasses:II. Changes in free amino acid content
Authors: Stoddart J. L.
Published: March 2009

1. The free amino acid content of seeds Aberystwyth S. 143 cocksfoot (Dactylis glomerata L.), S.321 perennial ryegrass (Lolium perenne L.), S. 48 and S. 352 timothy varieties (Phleum pratense L.) was studied during ripening.
A study of magnesium and calcium metabolism in lactating ewes fed a semi-purified diet low in magnesium
Authors: L'Estrange J. L. , Axford R. F. E.
Published: March 2009

1. Lactating ewes, fed an artificial diet deficient in magnesium, showed no ill effects while they received an adequate supplement of magnesium acetate. Sudden withdrawal of the supplement resulted in acute hypomagnesaemia, hypocalcaemia and loss of appetite within 48-72 hr. One animal developed tetany within 3 days after withdrawing the supplement. Appetite and serum magnesium and calcium levels could all be restored by giving magnesium acetate supplement.
The persistence of tropical grass-legume associations under grazing in Brazil
Authors: Thomas D. , de Andrade R. P.
Published: March 2009

The persistence under a close intermittent grazing regime of eight accessions of Stylosanthes guianensis, Stylosanthes macrocephala and Stylosanthes capitata in combination with Andropogon gayanus (cv. Planaltina) and Brachiaria decumbens (cv. Basilisk) was evaluated in small plots on a low fertility acid oxisol in the tropical savannah region of Brazil. Five accessions persisted for four seasons with both grasses, although legume yields were lower in the B. decumbens associations.

S. macrocephala CIAT 1582 (CPAC 139), S. capitata CIAT 1019 (CPAC 704) and CIAT 1097 (CPAC 706) were the most productive accessions at the end of the experiment. The three accessions S. guianensis cv. Cook, S. capitata CIAT 1315 (CPAC 707) and CIAT 1405 (CPAC 846), which failed to persist, were destroyed by anthracnose (Colletotrichum gloeosporioides). This disease remains the primary factor limiting the use of Stylosanthes in the region. The value of small-plot grazing experiments is briefly discussed.
Physiological maturity in Aestivum wheat: visual determination
Authors: Singh V. P. , Singh M. , Kairon M. S.
Published: March 2009

Field experiments were conducted during the winter seasons of 1977–8 and 1978–9 at Agronomy Research Area of Haryana Agricultural University Farm, Hissar, to identify the visual plant characters that coincide with physiological maturity (PM) and 95% maximum grain dry weight (95% MGW) in wheat (Triticum aestivum L.) cultivars. The dry-weight accumulation data from three cultivars (WH-157, HD-2009 and UP-270) differing in many agronomic characters were fitted to polynomial regression equations to calculate time of PM and 95% MGW. The mean number of days from anthesis to 95% MGW and from anthesis to PM ranged from 31 to 36 and 38 to 43, respectively, depending upon cultivar. The time of 95% MGW preceded PM by about 7 days. Of the nine visual plant characters recorded during the grain-filling period, complete loss of green colour from the glumes occurred close to PM. Complete loss of green colour from the flag leaf most consistently coincided with the time of 95% MGW. Complete loss of green colour from the flag leaf could therefore be used as an indicator of the commencement of rapid decrease in grain dry weight and the final stage of grainfilling which ends when the glumes have lost the whole of their green colour.
The use of electrophoretic techniques to distinguish perennial ryegrass cultivars when sown in mixtures
Authors: Kennedy S. J. , Gardiner S. J. , Gilliland T. J. , Camlin M. S.
Published: March 2009

In research into competition between individual cultivars of one perennial grass species sown in mixtures, fixed matrix designs have been widely used because of difficulties in identifying the components inanatural sward.Extrapolation of results from such fixed designs to the sward situation is often difficult in any but the short-term context.

This paper describes the principles, requirements and use of an electrophoretic technique together with a mathematical concept which can be used to distinguish certain perennial ryegrass cultivars when sown in mixtures. Such methods have useful implications for the study of sward composition and competitive ability of ryegrass cultivars sown in mixtures. The number of samples required to study selected 2-way cultivar mixtures using this method is indicated.
The growth and activity of winter wheat roots in the field: the effect of sowing date and soil type on root growth of high-yielding crops
Authors: Barraclough P. B. , Leigh R. A.
Published: March 2009

The effect of sowing date on root growth of high-yielding crops (8–1 It grain/ha, 85% D.M.) of winter wheat (Triticum aestivum L. cv. Hustler) was measured at Rothamsted and Woburn in 1980 and 1981. Roots were sampled by coring on five occasions and changes in root dry weight and length were determined. The average growth rate between March and June was about 1 g/m2/day (200 m/m2/day), over 5 times that measured between December and March. Increases in root weight or length with time were generally exponential to anthesis when the crops had 101–172 g root/m2 (20–32 km/m2). September-sown wheat had more root than October-sown wheat at all times, but whereas early differences in length were maintained throughout the season, root weights converged between March and June. Overall, there was no significant difference in root dry-matter production between sites at anthesis, but there was a substantial difference between years. Differences in root growth between crops were reduced by plotting the amount of root against either the number of days from sowing or accumulated thermal time. Using che latter, root growth between December and June was reasonably linear although there was some indication of a lag below 500 °C days. Regression equations obtained for the relationships between root growth and accumulated thermal time also fitted previously published data and may provide general descriptions of root growth with time.

Roots of September-sown crops reached 1 m depth by December but those of October-sown crops were not detectable at this depth until April. For most crops the distribution of roots with depth was reasonably described by an exponential decay function, with over 50% of the roots in the top 20 cm of soil at all times. At Woburn in 1981, a plough-pan restricted roots to the upper soil horizons for most of the season but apparently had little effect on the total amount of root produced. For one of the experimental crops an empirical mathematical function describing the distribution of roots with depth and time is presented.

Using the data from this and previously published studies, the relationship between grain yield and the amount of root at anthesis was investigated. Total root length was positively correlated with grain yield but nonetheless similarly yielding crops could have different-sized root systems. Total root dry weight was poorly correlated with grain yield.
Oestrous activity of Egyptian fat-tailed Ossimi ewes raised at different locations
Authors: Aboul-Naga A. M. , Aboul-Ela M. B.
Published: March 2009

Oestrous activity of three flocks of Ossimi, subtropical fat-tailed ewes was detected by teaser rams over a calendar year. The flocks were raised at north Delta, mid-Delta and middle Egypt.

The two Delta flocks showed irregularity in percentage of ewes coming into oestrus monthly, with a marked decrease in March, April and May, April being the lowest. On the other hand, the mid-Egypt flock showed consistent oestrous activity throughout the year, with small fluctuations.

The three flocks showed month-to-month variation in incidence of oestrus per ewe, with lower activity in the spring months. Neither of the two Delta flocks showed real regular oestrous activity in any month throughout the year, with high ewe variation. Some ewes showed regular activity throughout the year (16–20 cycles), whereas some others showed only 4–7 cycles per year.

There were two periods of the year with high frequency of anoestrus. The more intense was March–May while fewer ewes had an anoestrous period in July–August. This was the case in the three flocks but with varying intensity.

A period of more than 1 year of detecting oestrus affected oestrous performance of the ewes and should be avoided.
Hepatic xanthine dehydrogenase and plasma uric acid in broiler chickens fed various amounts of dietary methionine, protein and energy
Authors: Amubode F. O. , Fetuga B. L.
Published: March 2009

In four consecutive experiments, plasma uric acid (PUA), hepatic xanthine dehydrogenase (XDH) and body-weight gains (WG) of broiler chickens were measured under varying dietary methionine, protein and energy. In Expt 1, increases in WG with increasing dietary methionine peaked at 0·60%, a level where the initial decreases in either PUA or XDH reached a minimum. PUA and XDH in broiler finishers (Expt 2) decreased between 0·26 and 0·50% dietary methionine while WG improved between 0·26 and 0·50% methionine. XDH in the 18% protein and 0·68% methionine + cystine (MC) diet combination for Expt 3 was 66·4 μtmol/10 min/total liver weight, a value higher than either the 43·5 or 46·5 μtmol/10 min/total liver weight, respectively obtained in the 21% protein + 0·68% MC and 24% protein + 0·68% MC diet combinations. Both PUA and XDH, however, increased with increasing dietary protein when MC was either 0·76 or 0·84% diet. XDH in Expt 4 decreased between 11·7 and 13·4 MJ ME/kg diet that contained either 0·76 or 0·84% MC, tending not to vary between 13·4 and 15·1 MJ ME/kg diet. This enzyme activity remained essentially similar between 11·7 and 15·1 MJ ME/kg diet that contained 0·68% MC.
Efficacy of selected herbicide mixtures for weed control in sugar cane
Authors: Fadayomi O. , Abayomi Y. A. , El-Manhaly M. A.
Published: March 2009

Three trials were conducted over two cropping seasons, on portions of the production fields of the Nigerian Sugar Company sugar-cane estate, Bacita, to evaluate the efficacy of several herbicide mixtures for weed control in sugar cane using the varieties Co. 957 and Co. 1001. With a broad spectrum of weeds, early post-emergence applications of diuron + hexazinone (2·0 + 0·7 kg a.i./ha) followed by hexazinone + paraquat (0·5 + 0·3 kg a.i./ha) about 8 weeks after the first application gave satisfactory weed control that resulted in high cane yields. Addition of glyphosate to the mixture for the first application or its substitution for paraquat in the second application, or both, resulted in increased suppression of nutsedge. This was, however, more phytotoxic to the sugar-cane plants. Addition of pendimethalin to either diuron or hexazinone improved the control of grass weeds. Hexazinone-based mixtures were found to give longer-lasting weed control than the diuron-based mixtures. Both diuron and hexazinone were generally more selective on Co. 957 than on Co. 1001. The degree of weed infestation between 6 and 12 weeks after planting was inversely related to cane yield.
Effect of time and method of application on the relative efficiency of prilled urea and urea super granules for rice
Authors: Prasad R. , Singh S. , De R.
Published: March 2009

A field experiment was made on rice during the rainy seasons of 1982 and 1983 to study the relative efficiency of prilled urea and urea super granules (USG) applied broadcast or deep placed at different times. USG gave more, longer and heavier panicles with a higher percentage of filled grains than prilled urea. Deep placement of 60 kg N/ha as USG in two applications (half 10 days after transplanting and half at panicle initiation) gave the same grain yield as 120 kg N/ha of prilled urea applied half at final puddling and half at panicle initiation. Urea super granules, therefore, hold considerable promise as a nitrogen fertilizer for rice.