bluuebunny/crossref_metadata_2025 huggingface dataset:
The growth and nutrient content of polybag oil-palm seedlings as affected by mulch materials and time of their application
Authors: Iremiren G. O.
Published: March 2009

Mulching polybag oil-palm seedlings with bunch refuse, shredded polythene, sawdust, grass, wood shavings and kernel shells ‘all-year’ or throughout the nursery period (May–May), in the ‘wet-season only’ (May-November), and in the ‘dry-season only’ (November–May) resulted in soil temperature differences which did not exceed 1 °C at 5 cm polybag depth. This was attributed to the high rainfall which reduced considerably the soil temperature differences between mulched and unmulched soil in the wet season and to the enhanced leaf canopy in ‘all-year’ and ‘wet season only’ mulchings which shaded soil in polybags in the dry season.

The mulch materials and times of their application significantly influenced growth variables like number of leaves, plant height and stem girth, and number of blast-affected seedlings at 6 months after sowing (wet season). By 12 months after sowing, all growth characters measured were similar in the various treatments, indicating compensatory growth at the latter half of the growing period (dry season).

N, P, K, Mg and Ca contents of seedlings were not significantly affected by either mulch materials or times of their application. The results emphasize that mulching for at least 6 months during the early or late nursery period and the use of various mulches may be beneficial to oil-palm seedling growth.
The use of biplots in interpreting variety by environment interactions
Authors: Kempton R. A.
Published: March 2009

Gabriel (1971) proposed a technique for displaying the rows and columns of a twoway table as a two-dimensional biplot so that any element of the table can be approximated by the inner product of vectors corresponding to the appropriate row and column. The technique is useful for investigating the pattern of response of varieties over different environments, and substantially increases the information available from the more familiar methods of regression and principal component analysis without need for additional computation.
Supplementary feeding of dairy cows on continuously stocked pasture
Authors: Jennings P. G. , Holmes W.
Published: March 2009

Two experiments were conducted with milking cows on continuously stocked perennial ryegrass pastures. In each a control group, T0, received 1 kg/day of a concentrate supplement and treatment groups T1 and T2 received 4 kg (Expt 1) or 5 kg/day (Expt 2) of a low quality T1 or a high quality T2 concentrate. In Expt 1 treatments were applied continuously for 14 weeks to a total of 30 cows. In Expt 2 a Latin square design for 9 weeks was conducted with 18 cows. The stocking rate of the pasture declined from 9·6 to 5·1 cows per ha (mean 6·7 cows/ha) from May to August (Expt 1) and was maintained at 3 cows/ha in August-October (Expt 2).

Supplements increased total intakes by 0·92 and 0·77 kg organic matter (OM)/kg OM supplied in the concentrates respectively for Expts 1 and 2. Milk yields increased by 0·6 and 0·5 kg/kg concentrate supplied and supplemented cows showed small increases in live weight. Differences in lactation milk yield just approached significance. Grazing times were only slightly reduced by supplements and bite sizes were lower than normal. There was no important difference in animal performance between the two concentrates. The total output from the pasture was 19·6t milk and 115 GJ of utilized metabolizable energy per hectare.

Reasons for the high supplementary effect of the concentrates and its implications for stocking rates are discussed.
An assessment of the hap initiator gene for haploid production in Hordeum vulgare
Authors: Powell W. , Wood W.
Published: March 2009

The production of haploids in large numbers is of great value to plant breeders and geneticists and this has led to the development of new techniques for haploid production (Nitzsche & Wenzel, 1977). In cultivated barley, Hordeum vulgare, there are four principal methods of isolating haploids: the culture of microspores, the isolation of embryos following the interspecific hybridization of Hordeum vulgare with H. bulbosum, ovule culture and the use of the haploid initiator gene (Kasha & Reinbergs, 1982). The present paper focuses attention on the use of the haploid initiator gene (hap) and compares this method with the H. bulbosum and microspore culture methods of haploid production.
Comparisons between the establishment, growth and yield of winter wheat on three clay soils, in experiments testing nitrogen fertilizer in combination with aphicide and fungicides, from 1980 to 1982
Authors: Darby R. J. , Widdowson F. V. , Hewitt M. V.
Published: March 2009

From 1980 to 1982 fungicide and aphioide sprays were tested in factorial combination with four amounts of nitrogen fertilizer, applied in one or two dressings to winter wheat, on three contrasting clay soils. These experiments were at Hexton (Burwell series) in Hertfordshire, at Billington (Evesham series) and at Maulden (Hanslope series) in Bedfordshire, following a 2–year break, an all-cereal rotation, and continuous wheat respectively. The nitrogen dressings were calculated after taking into account mineral N in the soil. In 1981 and 1982 soil density was measured by penetrometer. This showed compaction in soil at Maulden 28 cm deep which caused waterlogging in spring; this delayed growth which was not made good later.

At Hexton a small seed rate was used; plant losses during winter were proportionally larger than elsewhere. At Billington, the maximum number of stems occurred in March and elsewhere in April. Despite these differences in seed rate and number of plants, number of ears varied little, and each year the wheat at Hexton accumulated dry matter most rapidly. The growth rate there ranged from 20·0 to 21·8 g/m2/day during the linear growth phase as compared with 14·4 to 16·6 g/m2/day at the other two sites. Giving N in two dressings rather than in one increased dry-matter yield at all sites in May, but later this benefit remained static and so became a smaller proportion of the total. Fungicides increased post-anthesis dry-matter yield by 0·75 t/ha, most of which was incorporated in the grain.

Mean grain yields from 1980 to 1982 where nitrogen fertilizer was given were 9·86 t/ha at Hexton, 7·88 t/ha at Billington and 6–91 t/ha at Maulden. Additional nitrogen fertilizer always increased grain yield when fungicides and aphicides were given, but not where they were not. Grain yields in excess of 10 t/ha were achieved with numbers of ears ranging between 360 and 435/m2. The components of yield showed that grain yield was related to the number of grains per ear and 1000·grain weight, but not number of ears. Grain weight was increased by 3·1 mg by the fungicides.

The fungicides controlled the diseases eyespot (Pseudocercosporella herpolrichoides), Septoria spp. and yellow and brown rust (Pucdnia striiformis and P. recondita) where they occurred, but even where these diseases were absent or at very low levels the fungicides significantly increased grain yield. At Billington and Maulden take-all (Qaeumannomyces graminis) infected between 44 and 90% of the plants and sharp eyespot (Rhizoctonia cerealis) infected from < 1 to 20% of the stems because the wheat followed cereals. Yields of straw behind the combine-harvester were from 50 to 70% of those obtained from sheaves cut at ground level.
Physiology of bunch groundnuts (Arachis hypogaeaL.)
Authors: Choudhari S. D. , Udaykumar M. , Sastry K. S. K.
Published: March 2009

Twenty-nine bunch groundnut genotypes were grown in theKharifseason 1980 and the summer season 1981 at Bangalore. Growth and yield analysis showed that the total dry-matter accumulation was low up to 30 days after sowing and increased linearly up to the 86th day in theKharifand up to harvest in the summer season. There were significant differences between genotypes in leaf area indices (LAI), the leaf area duration (LAD) and LAD between pod initiation and harvest (LADP) in both the seasons. The mean LAI of genotypes did not vary much between theKharifand the summer seasons up to the 66th day. However, during the later stages of growth the LAD was higher in the summer. The higher biological yield and productivity in the summer was attributed to the high LAD and LADP during the later stages of crop growth. LAD and total dry-matter accumulation at harvest were significantly correlated both in theKharif(r = 0–75) and the summer(r= 0–81). The mean total number of flowers over all 29 genotypes did not vary, but total number of pegs formed per plant differed significantly between genotypes in both theKharifand summer seasons. The percentage of flowers which produced pegs was 72–2 in summer as against 51–2 inKharif.The primary branches contributed 86'7 and 90–1%to the total number of pods per plant in theKharifand summer seasons respectively. The contribution of the first four nodes of primary branches was 85%in both seasons. The number of fruiting points (nodes having mature pods) per plant, found to be the most important yield-determining component, showed significant variation amongst the genotypes in both theKharifand summer seasons. In summer, length of mature-pod-bearing zone (MPBZ), number of nodes in MPBZ and number of kernels per plant were higher than in theKharifseason. It is suggested that selection and breeding should concentrate on improving LAD and LADP, total dry matter per plant, more primary branches per plant, more pods in the distal nodes of primary branches and more fruiting points (nodes in MPBZ) per plant.
Game domestication for animal production in Kenya: the nutritional ecology of oryx, zebu cattle and sheep under free-range conditions
Authors: Stanley Price M. R.
Published: March 2009

Observations on oryx, sheep and cattle under natural grazing conditions in both a wet and a dry season are given and discussed.

Dry faecal outputs by the sheep and oryx were less in the wet than in the dry season. Output by the cattle was greater than both, and showed little seasonal difference. Faecal nitrogen concentrations showed no interspecific overlap, in the rank order sheep > oryx > cattle. All were greater in the wet season, and the rank order maintained.

Drinking water intakes were similar for oryx and sheep in both seasons. The cattle's water intake was greater in the wet season. Expressed as ml/kg W0·85/day, there were no overlaps in species' mean intakes, in the order cattle > sheep > oryx, in the ratio 100:57:24. In the dry season, the herd walked 16 km on non-drinking days, and a further 7 km on alternate days when receiving water. Under wetter conditions with more forage available, the herd walked only 11 km daily.

Slight interspecific differences in the times spent walking, feeding, standing and lying were found over a 48 h period. In the wet season less time was spent walking and feeding, with corresponding increases in the other activities. The oryx were notable in that rumination occupied far less of their daytime activity than for the sheep or cattle although the total times spent ruminating were similar.

The results are discussed in relation to differences in the species’ feeding habits and strategies of diet selection, combining the grazing results with observations from penned animals on a common diet. The intakes of water agree with the results from penned animals, confirming oryx's adaptation to hot, dry conditions. The advantages of a low water requirement, met by intermittent drinking, are discussed.

The possible detrimental effects on productivity of a regime of day-grazing and night-penning under hot conditions are discussed. In the light of these, some advantages to oryx of scheduling its rumination to the night hours are suggested.
Studies on the nitrification inhibitor, dicyandiamide (DCD), for increasing the efficiency of nitrogen applied to rice
Authors: Singh S. , Prasad R.
Published: March 2009

A field experiment, made during the rainy seasons oof 1982 and 1983 at the Indian Agricultural Research Institute, New Delhi, studied the effects of blending urea with dicyandiamide (DCD) on the yield and yield components of rice. DCD-blended urea was as effective as neem-cake-coated urea in respect of yield components as well as grain and straw yield of rice and when all the nitrogen was applied 10 days after transplanting both the materials produced significantly more grain and straw than prilled urea. Urea super granules (USG) were superior to DCD-blended, as well as neem-coated, urea.
Fat partitioning in British Friesian cows: the influence of physiological state on dissected body composition
Authors: Butler-Hogg B. W. , Wood J. D. , Bines J. A.
Published: March 2009

The influence of physiological state (pregnant, lactating, dry) on body composition and fat partitioning in Friesian cows has been examined. A total of 20 cows, four per physiological state, were slaughtered and their left half carcasses dissected into individual muscles, bones and fat depots. All body parts, including the internal organs and fat depots, were weighed at slaughter.

Muscle tissue and the internal organs showed some weight changes, consistent with a redistribution of tissue towards the udder and gut, and mobilization of muscle, but the major changes in weight associated with changing physiological state occurred in total body fat.

Intermuscular fat made the greatest absolute contribution to changing fat weight, but subcutaneous fat showed the greatest proportional change with changing physiological state. The order of depletion of fat depots during fat loss was approximately the reverse of the order of development found during developmental growth.

The distribution of subcutaneous fat between seven defined regions of the carcass was not affected by differences in total fatness in different physiological states. This, and the high correlation found between fat depth and total body fatness, confirms the view that measures of subcutaneous fat depth, e.g. by ultrasonics, should be useful predictors of the energy status of cows in varying physiological states.
Influence of growing various crops in five different fixed rotations on the changes in nitrate and total nitrogen content of soils
Authors: Sharma K. N. , Bhandari A. L. , Kapur M. L. , Rana D. S.
Published: March 2009

The results on the influence of various crops in five different fixed rotations on the ohanges in nitrate and total N content of soils are reported. Groundnut contributed largely to the accumulation of nitrate nitrogen in the soil profile (to a depth of 120 cm). Bajra fodder exhausted the soil nitrogen reserve to a great extent. Wheat and maize, in a rotation, reduced nitrate leaching to deeper soil layers. Summer moong also left a large amount of unabsorbed nitrate in the profile. Total nitrogen content of the soil decreased after the harvest of cereals. Maximum depletion occurred after the harvest of bajra crop. Potato (a crop which received a heavy dressing of N fertilizer) and legumes contributed to the soil N reserve. A balance sheet of N indicated net gains of total soil N in four of the five cropping sequences. A net loss of 75 kg N/ha was observed in bajra fodder-potato-wheat rotation.
The partition of carotenoids and vitamin A in the colostrum and milk of the cow and the goat
Authors: Chanda R.
Published: March 2009

The partition of carotenoids and vitamin A in the colostrum of nine cows and six goats and in the milk of three cows and two goats was determined using chromatographic and spectrophotometric methods. The following were the main results:

1. The content of β-carotene and vitamin A in the colostrum decreased rapidly during the first nine milkings in both the cow and the goat. The rates of decline were logarithmic. Logarithmic regressions also showed that the decreases in β-carotene were more rapid than those of vitamin A.

2. The heifers secreted more vitamin A in their colostral fat than did cows on the same ration. The vitamin A content of the colostral fat of goats was greater during the first lactation than in later lactations. There was no difference in the rates of decrease of the vitamin A content of heifer and cow colostrum, but the difference between the rates of decreases of colostral vitamin A of first and later lactation goats was significant.

3. The colostral fat of cows at pasture contained more vitamin A than that of cows on winter rations. There was no difference between the logarithmic rates of decrease in the two groups during the first nine milkings. The colostral fat of four goats receiving winter rations was richer in vitamin A than that of three cows treated similarly, and this superiority of the goat over the cow persisted throughout lactation.

4. There was no difference between the carotene content of the colostral fat of the first and later lactation cows. The yield of fat and β-carotene of the heifers was smaller than that of the cows. Cows at pasture secreted more β-carotene in their colostrum than the cows on winter rations. The presence of β-carotene was demonstrated in goat colostrum, although mature goat milk was free from any measurable quantity of carotenoids.
The analysis of the results of a rotation experiment on the use of straw and fertilizers
Authors: Patterson H. D.
Published: March 2009

An experiment, designed to test different ways of using straw with fertilizers, and involving a three course rotation of crops, was carried out at Rothamsted between 1933 and 1951. The methods of analysis developed for this experiment are described in the present paper and demonstrated using yields of potatoes.

Treatment effects of interest are given by the mean yields over all years and the linear regressions of yield on time. These estimates are straightforward but the evaluation of their errors is complicated by the existence of correlations due to the recurrence of treatments on the same plots. Further complications are introduced when, as frequently happens in long-term experiments, treatment effects show real variation from year to year. A method is given for estimating standard errors which include a contribution from this variation.

The various relationships between yields and the uncontrolled seasonal factors can also be examined; in the present experiment there is some indication that the effects of treatments on yields of potatoes are influenced by the dates of planting.

In other circumstances the analysis requires modifications, some of which are briefly considered.
The effect of ground water-level on the performance and yield of some common crops
Authors: Nicholson H. H. , Firth D. H.
Published: March 2009

1. Observations made on growing a series of crops in rotation over a range of static ground water-levels in a Fen peat soil are recorded.

2. The crops used show differences in their reaction to ground water conditions, and the seasonal incidence of rain has an overriding influence on their performance.

3. The effects of ground water-level may operate directly on the growth and development of a crop or may influence it indirectly through factors such as weed infestation, difficulties of cultivation, or the incidence of disease.
The effect of rate of wetting on water uptake and cohesion of soil crumbs
Authors: Emerson W. W. , Grundy G. M. F.
Published: March 2009

Short columns of air-dry soil crumbs were wetted at different rates and, after draining to a standard suction, the amount of water taken up by each column determined. It was found that this in the other under continuous grass. The extrapolated value of the cohesion of the grassland crumbs at zero rate of wetting was twice that of the arable, indicating an additional cohesive force in the grassland crumbs. The cohesion of the arable soil fell much more rapidly with increased rate of wetting than that of the grassland, probably because the roots in the grassland crumbs provide easy escape passages for the air.

The increase, with rate of wetting, of the amount of water held by a soil sample against a given suction is important, at least up to 200 cm. of water. This dependence of the pF curve on rate of wetting is of particular significance for laboratory studies of water movement in soils.
Ruminal ammonia formation in relation to the protein requirement of sheep: III. Ruminal ammonia formation with various diets
Authors: Annison E. F. , Chalmers Margaret I. , Marshall S. B. M. , Synge R. L. M.
Published: March 2009

1. Ruminal ammonia concentrations were measured in sheep receiving basal diets of hay and meals with various supplementary sources of protein. Ammonia production from groundnut meal was great and from maize products slight. Herring meal behaved in an intermediate way.

2. The extent of ammonia production from a given amount of protein-rich material was decreased when the amount of starch or cereal meal fed at the same time was increased.
On the composition of boar semen
Authors: Glover T. , Mann T.
Published: March 2009

1. Twenty ejaculates were collected from the same boar at weekly intervals; the composition of semen was studied by microscopic and chemical methods. The total volume of ejaculates varied from 240 to 500 ml., and sperm concentration from 50,000 to 177,000 cells/μl. Chemical analysis revealed 2·4–12·6 mg./100ml. fructose, 5·9–23·1 mg./100 ml. ergothioneine, and 32–156 mg./100 ml. citric acid.

2. The sequence with which the different parts of boar semen follow one another at ejaculation was studied by the method of fractionate collection. The earliest to be emitted was the ‘pre-sperm fraction’ from which sperm and seminal vesicle secretion were absent. The next was the ‘sperm-rich fraction’ which showed not only a high sperm content but contained also substantial quantities of substances derived from the seminal vesicles, i.e. fructose, ergothioneine and citric acid. The ‘post-sperm fraction’ consisted mainly of accessory gland secretions.

3. The analysis of semen fractions collected at very brief intervals has shown that whereas the secretion of the seminal vesicles accompanies the spermatozoa at ejaculation, it attains its maximum immediately after the bulk of the sperm has been ejaculated.
The effect of high air temperature on reproduction in the ewe
Authors: Yeates N. T. M.
Published: March 2009

Six Romney Marsh ewes exposed daily in a hot-room to temperatures averaging 105° F. dry bulb and 87° F. wet bulb for 2 months prior to the start of the breeding season all experienced oestrus and, as a group, at the same time of year as non-heated controls.

However, when maintained under daily hot-room treatment throughout the pregnancy period only one ewe lambed, suggesting an adverse effect of high temperature on gestation.

In a further experiment to confirm this, eight control ewes all lambed, average birth weight of lambs being 9 lb. 5 oz. Of six experimental ewes exposed to temperatures of 107° F. (dry bulb) and 92° F. (wet bulb) for 7 hr. daily during the last third of pregnancy, one failed to lamb and the lambs averaged 7 lb. 15 oz. A further six experimental ewes exposed to similar room conditions for the last two-thirds of pregnancy produced still smaller lambs, averaging 6 lb. 11 oz. at birth, and three ewes failed to lamb.

The yield of lamb per ewe was 9 lb. 5 oz. for controls, 7 lb. 13 oz. and 4 lb. 1 oz. for ewes exposed to heat during the final third and two-thirds of pregnancy respectively and, in the previous year's experiment, 1 lb. 2 oz. for those exposed throughout the pre-mating, mating and post-mating period.

It is concluded that although high temperature is apparently without effect on the incidence of oestrus in sheep, it is inimical to satisfactory gestation.
The occurrence of hybrid semi-lethals and the cytology ofTriticum machaandTriticum vavilovi
Authors: Sachs Leo
Published: March 2009

1. A semi-lethal gene combination has been found in hexaploid species hybrids involving some strains ofTriticum macha, but not in comparable hybrids involving other strains ofT. macha. The production of these semi-lethal hybrids can be explained by the interaction of two genes designated as maand mb.

2. The gene mais carried in some strains ofT. macha. The gene mbis carried in the third chromosome set of all other hexaploid species ofTriticum, inAegilops squarrosaand inAeg. cylindrica.

3. The semi-lethal gene combination has been found between species which would otherwise produce fertile hybrids and between species which would otherwise produce sterile hybrids. The semilethal gene combination occurs between species which do not overlap geographically.

4. The distribution of the genes maand mbshows that the gene maoriginated inT. machaand that the gene mboriginated inAeg. squarrosaand was introduced from there, during the course of evolution, into the hexaploid species ofTriticum(probably excludingT. macha) and intoAeg. cylindrica.

5. Meiosis in semi-lethal plants was comparable to meiosis in normal plants. But the semi-lethal plants showed a reduction in fertility, probably as a result of their poor vegetative growth.

6. The chromosomes ofT. machaandT. vavilovihave been no more structurally differentiated than the chromosomes of the other hexaploid species ofTriticum.

7. The present study has confirmed that the third chromosome set of the genusTriticumhas been phylogenetically derived fromAeg. squarrosa.
The effect of pregnancy and lactation in the ewe on the digestibility of the ration with a note on the partition of nitrogen in the foetus at full term
Authors: Head M. J.
Published: March 2009

1. Pregnancy and lactation had no effect on the digestibility of the dry matter and nitrogen-containing constituents of the ration of Cheviot ewes fed at a constant level.

2. The water consumption of the pregnant ewe was almost doubled during gestation.

3. The digestibility coefficients of dry matter and nitrogen in both pregnant and barren ewes fell considerably from November until the beginning of the following April.

4. The average nitrogen content of a normal fullterm Cheviot foetus was approximately 99 g.
Changes in Sudan Gezira soil under irrigation
Authors: Jewitt T. N. , Middleton K. R.
Published: March 2009

The effect of different amounts of irrigation water on the salts in Gezira soil has been studied by comparison of different rotations in two long-term experiments at the Gezira Research Farm. The conclusion is drawn that none of the rotations studied shows any evidence of salts rising or accumulating in the profile. There is some evidence of a removal of salts from a 6 ft. profile.
Ovulation and the passage of the ova through the fallopian tubes in the pig
Authors: Pomeroy R. W.
Published: March 2009

1. The rate of passage of ova down the Fallopian tubes in the pig has been checked on eighteen living sows by laparotomy and in fifteen sows and gilts at autopsy.

2. Both sets of observations suggest that the ova enter the uterus between 24 and 48 hr. after ovulation instead of 72 hr. as suggested by earlier workers.

3. It is suggested that the rapid passage of ova through the Fallopian tubes of the pig may be facilitated by the progesterone from the large number of corpora lutea in the ovaries of the pig.
Comparative studies of meat IV. Rates of fattening in relation to the deposition of fat and protein in the fatty and muscular tissues of meat carcasses
Authors: Callow E. H.
Published: March 2009

1. In the previous paper of this series (Callow, 1949) a special method of graphical analysis was developed in order to calculate the effect of different rates of fattening on the percentages of fatty tissue, muscular tissue and bone, etc., in a carcass. This method has been used in the present paper to calculate the effect of different rates of fattening on the deposition of chemical fat and protein in the fatty and muscular tissues of a carcass during fattening.

2. The method of analysis depends (a) on the choice of an arch-type carcass on mathematical and biological grounds, and (b) the use of partition percentages for defining the proportions of fat, protein and water laid down in the fatty and muscular tissues during an increase in carcass weight due to fattening.
Investigations in the Triticinae I. Colchicine techniques for chromosome doubling in interspecific and intergeneric hybridization
Authors: Bell G. D. H.
Published: March 2009

1. Sixteen colchicine treatments, involving five main methods of application and six concentrations, have been used on Triticum interspecific crosses, Triticum—Aegilops intergeneric crosses and Agropyron—Triticum intergeneric crosses.

2. The efficacy of the major treatments in terms of plant survival, plant fertility and ear fertility has been compared, and the most successful method of application has been found to be absorption through the cut leaves—i.e. capping cut-back tillers with a small glass phial containing colchicine.

3. Fertility induced by colchicine is not complete. In plants producing grain, every ear is not necessarily fertile, nor are all spikelets in fertile ears usually fertile.

4. Evidence has been obtained of differential cross response to colchicine action, and also of cross-group response to particular treatments.
Studies in selective weed control II. The control of annual weeds in spring cereals
Authors: Blackman G. E. , Roberts H. A.
Published: March 2009

As part of a general programme for the development of new techniques of selective weed control, numerous experiments have been carried out during 1943–7 on the eradication of annual weeds from spring-sown oats and barley. These multifactorial experiments consisted essentially of simultaneous comparisons of the relative merits of sulphuric acid, copper salts, dinitro-o-cresol and the two growth-regulating substances 2:4-dichloro-phenoxyacetic acid and 2-methyl-4-chloro-phenoxyacetic acid. All the compounds were applied as aqueous solutions or suspensions at a spray rate of 100 gal./acre.

Within groups of compounds, cupric chloride is more toxic than cupric nitrate, and this in turn is more toxic than cupric sulphate to such weeds as Raphanus raphanistrwn. Similarly, dinitro-o-cresol or its ammonium salt is more effective than the sodium salt for the control of R. raphanistrum and Galeopsis tetrahit. There is some evidence that sodium methyl-chloro-phenoxyacetate is slightly superior to sodium dichloro-phenoxyacetate for the control of Galeopsis tetrahit and Sinapis arvensis.

Between groups of compounds, as long as the weeds are in the young seedling stage there is little to choose between sulphuric acid, cupric chloride, ammonium dinitro-o-cresylate and the growth-regulating substances for the control of Sinapis arvensis, Raphanus raphanistrum, Thlaspi arvense and Polygonum convolvulus when the concentration ranges for the four groups are respectively 9–18, 1–4, 0·4–0·8 and 0·1–0·4%. Within these limits of concentration P. persicaria is best controlled with sulphuric acid and Atriplex patula by dinitro-o-cresol.

In general, there is a decrease in the toxic effects with increasing age. There are however complex interrelationships between weed species, compound and stage of development. Whereas for cupric chloride its effectiveness against Sinapis arvensis is little changed between the cotyledon and flowering stage there is with flowering a marked falling off in the efficiency of sodium methyl-chloro-phenoxyacetate. In the intermediate phase of development the growth-regulating substances are most toxic to Raphanus raphanistrum.

The results for crop yield demonstrate that sulphuric acid and cupric chloride are less selective than dinitro-o-cresol or the substituted phenoxyacetic acids, since for equivalent degrees of weed control smaller increases in grain production have often been recorded. These injurious effects are maximal at the higher concentrations and when spraying is delayed until after tillering is completed. There is a similar age trend for dinitro-o-cresol and the two growth-regulating substances, and in the case of the latter some indication of a concentration effect, i.e. the compounds are most selective at concentrations of 0·2% or less.

For the twenty experiments in which the yields were recorded the most appropriate herbicidal treatments have resulted in gains in yield over the controls ranging from 0·4 to 82·2% with a mean of 23·8.
The nitrogen status of soils Part I. The nitrification of some nitrogenous fertilizers
Authors: Owen O. , Rogers D. W. , Winsor G. W.
Published: March 2009

The rates of nitrification and the extent to which a number of nitrogenous materials are nitrified in soil have been studied. Of the substances used ammonium sulphate was most rapidly and most completely nitrified under these conditions. A reputedly genuine sample of Peruvian guano was almost as rapid as ammonium sulphate. At the other end of the scale was horn meal, which was nitrified most slowly and in which the percentage of nitrogen converted was lowest. On a basis of nitrification alone there appears to be no justification for the traditional view that hoof and horn is slow- and that dried blood is quick-acting. Two samples of bone meal showed very different rates of decomposition. This, and the anomalous behaviour of hoof and horn separately as compared with mixed hoof and horn, suggest that differences occur in the behaviour of different samples of what are nominally the same materials. Some of the commercial implications of these findings are discussed.
The nitrogen status of soils Part II. The effect of levels of application on the nitrification of some nitrogenous fertilizers
Authors: Owen O. , Winsor G. W.
Published: March 2009

1. Laboratory experiments in five soils to which hoof and horn materials were added at different concentrations have shown that the percentages nitrified throughout the transformation were largely independent of the level of application. The ranges of concentration used were 90–360 p.p.m., 150–350 p.p.m. and 100–300 p.p.m. nitrogen.

Similar results were obtained with dried blood in two soils.

2. Experiments in two soils with ammonium sulphate and in one soil with glycine, urea and guano showed a different response to level of application, the percentages nitrified at the different concentrations being widely different throughout the period of active transformation.

3. An explanation of the results is given on the basis of the relative rates of formation of ammonia and of its transformation to nitrate.

4. The importance of ammonia determinations in the interpretation of nitrification studies is emphasized.
Reversion of ferric iron to ferrous iron under water-logged conditions and its relation to available phosphorus
Authors: Islam M. A. , Elahi M. A.
Published: March 2009

It is known that acidic red lateritic soils are usually deficient in available phosphorus, and whenever any soluble phosphates are added to such soils they become fixed and non-available to plants. It is believed that added phosphates make insoluble compounds of ferric phosphates with iron salts in the ferric state. Since ferrous salts are more soluble than the ferric salts, it suggests itself that if in the soil we can keep the iron in the ferrous state or can effect the conversion of ferric salts into ferrous salts it may be possible to reduce the formation of insoluble iron salts with phosphorus and thus increase the amount of available phosphorus by reducing phosphate fixation. With this object in view red latoritic soils from Dacca Farm area were kept under water-logged condition and the effect upon the conversion of Fe3+ into Fe2+ state and the change of readily soluble phosphorus were studied from time to time.
Studies in oil-seed crops: II. An assessment of the interrelationships between plant development and seed production in linseed (Linum usitatissimum)
Authors: Blackman G. E. , Bunting E. S.
Published: March 2009

Records of plant development in some twenty-five multifactorial experiments were collected with the object of analysing the effects of nutrient level, density, spatial arrangement and variety on seed production in linseed. By sampling techniques estimates were made of plant density, the extent of basal branching, the number of capsules per stem, the number of seeds per capsule and the seed weight. The expected plot yields, calculated from these data, were in good agreement with the harvested yields.

In factorial trials, involving additions of nitrogen, phosphorus and potassium, only a change in the nitrogen level increased the yield of seed, and this gain was largely determined by an increase in the production of capsules and not by any alteration in either the number of seeds per capsule or the seed weight.

Over a range of density of thirty to eighty plants per square foot the number of capsules produced per plant was inversely correlated with density. When the distance between drills was maintained at 6–7 in. and the density varied by changing the seed rate then—on an area basis—both capsule production and seed yield were rarely affected since the product of plant number and capsules per plant remained relatively constant. On the other hand, if the rate of seed delivery in the drill was kept the same and the distance between the drills was the variable for density then with a narrow width of drill (4 in.) the increase in plant density more than offset the fall in capsules per plant.

Further experiments comparing drilling and crossdrilling did not wholly confirm the importance of spatial arrangement. There was, however, evidence that at densities over eighty plants per square foot, besides a further reduction in capsules per plant, the number of seeds per capsule was depressed. Varieties were characterized by differences in seed size, the number of seeds per capsule, capsules per plant and the ability to produce more capsules at high levels of nitrogen. The superiority of the yielding capacity of Royal could be ascribed to the high rate of capsule production. Such varietal differences in capsule production have not been reported previously, and since the number of capsules per plant is greatly influenced by varying density, the common practice of basing selection on spaced plants, may not give a true assessment of capsule formation at densities optimal for seed production.
Loss of nitrogen gas from water-logged soils
Authors: De P. K. , Digar S.
Published: March 2009

The investigation shows that when water-logged soils were treated with nitrogenous manures and fertilizers like oil cake, water hyacinth, ammonium sulphate and sodium nitrate, a large volume of nitrogen evolved as gas. This loss began 7–12 days after application of different treatments and was quicker from inorganic fertilizers than from organic manures. Besides loss as gas, a large amount of nitrogen was also lost in the drainage. The results suggest that if fertilizers like ammonium sulphate and sodium nitrate are applied to rice-fields by top dressing during the active vegetative growth of the crop, the loss nitrogen as gas will probably be greatly minimized.
The composition and nutritive value of hay grown in the east of Scotland and the influence of late applications of nitrogenous fertilizers
Authors: Moon F. E.
Published: March 2009

1. Examination of the composition of hay grown in the east of Scotland during the 4-year period 1948–51 has confirmed earlier work indicating the low protein content of this material. In addition, the digestibility of the protein was found to be low, particularly in the case of the seeds-hays, most of which contained insufficient digestible protein to balance the starch equivalent in meeting the maintenance requirements of cattle.

2. In nutritive value the seeds -hays were markedly inferior to samples from England and Wales examined by other workers, but very similar to mature ryegrass hay grown in Northern Ireland. The meadow hays examined were of similar starch equivalent but somewhat richer in protein, and this was associated with a higher digestibility of the protein; in consequence the ratio between digestible protein and starch equivalent was more nearly balanced for the maintenance feeding of cattle.

3. Applications of sodium nitrate or ‘Nitrochalk’ about 10–20 days before mowing produced very variable responses in the unusually dry season of 1949, but in other years significant increases in protein content were almost invariably obtained. Low protein seeds-hays of the type commonly found in the Lothians were more responsive to this fertilizer treatment than timothy meadow hay, and while increases in protein content of 20–30% were commonly obtained, when relatively heavy dressings of fertilizer (3 cwt. or more per acre) were used, increases in the region of 50% were sometimes recorded. In most years treatment about 10 days before mowing was fully effective in improving the protein content of the hay. Earlier treatment may be preferable in a very dry season, but in more normal years this may increase the yield of the hay and so diminish the effect on protein percentage.
Oestrus and some related phenomena in the buffalo
Authors: Hafez E. S. E.
Published: March 2009

1. Thirty-one buffalo-cows of different ages were tested for the symptoms and duration of oestrus, and the incidence of post-partum oestrus and conception. Clinical examinations of the vagina were also carried out.

2. The symptoms of heat were less intense than in cattle and there was no homosexual activity.

3. Pro-oestrus occurred in 43% of the cases with an average duration of 21.20 hr. whilst metoestrus occurred in 67% of the cases with an average duration of 19.20 hr. The average duration of oestrus was 28.47 hr.

4. The onset and cessation of oestrus were either abrupt or gradual. The phenomenon ‘split oestrus’ was observed intervening normal cycles. This was not characteristic of the individuals.

5. The average interval to post-partum oestrus was 43.80 days. The average number of silent heats per individual was 0.86. Conception took place after an average of 1.71 services whilst the breeding efficiency was 93% in the calving buffaloes.

6. Normal clinical changes in the vagina (temperature; nature and amount of secretion; picture of smear) were not reliable indicators of oestrus.

7. Further problems concerning reproduction in the buffalo are suggested.
Studies on the habits of Zebu cattle I. Preliminary observations on grazing habits
Authors: Harker K. W. , Taylor J. I. , Rollinson D. H. L.
Published: March 2009

In order to form a basis for any improvements of cattle and pasture management in East Africa it was decided to observe the grazing habits of the local cattle. A review of the literature shows that animals' habits can be influenced by temperature, but no record could be found to indicate the effect on the animals of elevation and an equable climate.

A summary is given of the results obtained during 720 cow-watching hours. Comparing these results with those obtained by other workers it is clear that Bos indicus cattle on a high-level plateau under tropical conditions have distinct and unique habits. On the average, during days with 12 hr. daylight 7·7 hr. were spent in grazing, 93% of this time being during daylight; 5·2 hr. were spent in ruminating, only 23% of this being during the hours of daylight.
Lucerne investigation I. Identification and classification of lucerne ‘varieties’ and ‘strains’
Authors: Zaleski A.
Published: March 2009

Detailed investigations on identification and classification of lucerne varieties and strains were conducted at Cambridge for four years, 1949–52, on lucerne sown in row plots and on twelve typical varieties planted out in replicated trials as single spaced plants, using 200 plants of each variety. A number of physiological and morphological characters were examined and the resulting data was analysed statistically.

The characteristics used for classification are those which showed considerable variation between varieties, but at the same time these differences were maintained consistently from year to year. They proved to be unaffected by a different way of growing the plants or by small differences in soil fertility or season. The results are shown in Tables 1–17, and three basic classifications with distinguishing features of types and varieties are given. The correlations established between various characters on twelve varieties are given under the heading ‘Correlations’ at the end of the results.

(a) The first classification into early, mid-season, late and extra-late types, based on the time of flowering, spring and autumn growth, gives a fair indication to the growers regarding earliness and productivity of various varieties.

(b) The behaviour of certain varieties from South America, and in particular Saladina, an Argentine variety, which is vigorous and productive under native country conditions but has lost this ability under Cambridge conditions, indicates plainly that classification based on these three characters can be applied only to the country under whose conditions it was established. Therefore any variety especially obtained from a country of extremely different environmental conditions and management system should be checked in these respects even if a description is given.
Semen characteristics and fertility in the bull
Authors: Bishop M. W. H. , Campbell R. C. , Hancock J. L. , Walton A.
Published: March 2009

1. Certain characteristics of bull semen have been examined at four artificial insemination centres in England. One hundred and twenty-one samples of semen, comprising 168 ejaculates from seventysix bulls of seven breeds, were examined. The semen from 119 tested samples was subsequently used to inseminate 4604 cows.

The following semen characteristics were studied: volume of ejaculate; concentration of spermatozoa; incidence of dead spermatozoa; incidence of morphologically abnormal spermatozoa; initial fructose concentration; resistance of spermatozoa to temporature shock; methylene-blue reduction; O2uptake; fructose utilization; visual evaluation of motility; impedance change frequency; and fertilizing capacity (conception rate).

A clinical examination was made of the reproductive organs of each bull.

2. Variations in the concentration of living spermatozoa and in the incidence of dead spermatozoa were found to account for most of the variations in the metabolic activity of semon: they also largely explained differences in physical activity as assessed by visual estimation of motility or by impedance change frequency.

3. Although the rates of methylene-blue reduction, O2uptake and fructolysis showed a close correlation with the numbers of living spermatozoa present, O2uptake and fructolysis per living cell decreased with increasing cell concentration.

4. Variations in metabolic activity showed no correlation with variations in the morphological characteristics of the spermatozoa, except in the case of spermatozoa with bent tails. These forms occurred in some samples as a result of staining treatment, but their incidence was positively correlated with the O2uptake and fructolysis per living cell.

5. There was evidence that highly active spermatozoa are more resistant to temperature shock than less active spermatozoa.
The influence of reproductive development upon the root system of perennial ryegrass and some effects upon herbage production
Authors: Troughton A.
Published: March 2009

The production of flowers in perennial ryegrass (Lolium perenne) has been associated with a reduction in root relative to shoot growth and the post-flowering period with the death of roots. Any effect that reproductive development has upon the root system does not appear to adversely affect subsequent shoot growth. In the present experiments, vernalized plants restricted to root axes present prior to flowering showed little difference in herbage production and length of life compared with unvernalized plants similarly restricted. Flower production did, however, limit the ability of plants to initiate main root axes. It would seem unlikely that the mid-summer depression of herbage growth is due to the effect of reproductive development upon the root system.