bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of supplementary irrigation on rain-grown sorghum (Sorghum bicolor) in the Sudan
Authors: Farah S. M.
Published: March 2009

Effects of supplementary irrigation at three periods of grain sorghum development (a) from emergence to a time after floral initiation was completed (b) during heading and flowering and (c) from ending of flowering to maturity, during two seasons, were tested. Grain yield and its components and straw yield were significantly affected by the irrigation treatments, which were themselves considerably affected by rainfall.

The results suggest that water deficits during the three periods, as were specified in this study, had affected grain yield primarily through effects on number of grains during the first period and size of grains in the second period. Effects in the third period were apparently complementary to those of the first and/or the second periods, being either very substantial or negligible, depending on the rain conditions in these periods. Straw yields were mostly affected by irrigation during the third period, mainly as a result of development of late tillers.

High yields of rain-grown sorghum can be obtained if water deficits are avoided by supplementary irrigation during one or more of its growth periods.
Growth responses and serum enzyme activities in growing pigs resultant from supplementing diets based on aged barley with synthetic δ-α-tocopherol
Authors: Lawrence T. L. J. , Boyd J. W.
Published: March 2009

In group and individual feeding experiments of 98 days duration, a total of 96 Large White x Landrace 9-week-old pigs were fed diets (containing 0–09 mg selenium/kg) based on 85% of barley (containing 3 mg δ-α-tocopherol/kg), which had been stored aerobically for 1 year, with 0 (basal), 10, 20, 40, 80 or 160 mg/kg of synthetic δ-α-tocopherol added. In both experiments the tocopherol supplementation significantly improved growth rates over those obtained from the basal diet. Serum creatine phosphokinase and aspartate aminotransferase activities were not significantly affected.
Daily turnover of body water in growing, pregnant and lactating buffaloes subjected to restriction of water for drinking and wallowing
Authors: Ranawana S. S. E. , Tilakaratna N. , Srikandakumar A.
Published: March 2009

As part of their normal behaviour, buffaloes need to wallow in water or mud for a period of the day and, in general, show a greater affinity for water than other domestic ruminants. It has been reported (McFarlane, 1971) that buffaloes turn over more water than other domestic ruminants. This, in turn, should make them more susceptible to deprivation of water, even for short periods. Requirements for water are also known to change with the physiological state of animals. The experiment described in this paper was carried out to compare the effects on the daily turnover of body water in growing, pregnant and lactating buffaloes, under normal management, when denied wallowing and when drinking water was restricted.
The effects of oxalate in some tropical grasses on the availability to horses of calcium, phosphorus and magnesium
Authors: Blaney B. J. , Gartner R. J. W. , McKenzie R. A.
Published: March 2009

Horses fed various species of tropical grass hays containing more than 0·5% total oxalate were in negative calcium balance of up to 41 mg/kg live weight/day in mineral balance experiments. In most cases, a concurrent negative phosphorus balance of up to 22 mg/kg live weight/day was measured. These results were in contrast to those obtained when grass hays low in oxalate were fed. Magnesium balance was little affected by oxalate. The degree of negative calcium balance could not be reconciled with total calcium and total oxalate concentrations, but could be explained if a major fraction of calcium in the grasses was in the form of calcium oxalate crystals and if calcium in this form was unavailable for absorption. It is suggested that soluble oxalates exert a variable but smaller effect on absorption of the remaining calcium fraction of the grasses. In general, nutritional secondary hyperparathyroidism may occur in horses grazed solely on pastures in which calcium to oxalate ratios are less than 0·5, such ratios usually being found in grasses containing more than 0·5% total oxalate.
Triple test cross analysis in three barley populations under saline-alkali soil conditions
Authors: Tripathi I. D. , Singh M.
Published: March 2009

One hundred and eighty triple test cross families arising from three barley crosses (C 164 x EB 1556, BG 25 x NP 21 and BH 15 x RD 103) were grown in two blocks of a randomized-block design in saline-alkali soil prepared in micro-plots. The families were evaluated for number of days from sowing to heading, plant height, number of tillers per plant, ear length, number of grains per ear, 100-grain weight and grain yield per plant. The cross BG 25 x NP 21 showed epistasis only for number of days toheading and number of grains per ear; in contrast, epistasis was present in all traits in BH 15 x RD 103. In cross C 164 x EB 1556, epistasis was detected for plant height, ear length and number of grains per ear. Thus, epistasis appears to be related to specific cross combination. The ‘j and l’ type epistasis was more pronounced than the ‘i’ type. Early generation selection may be used for number of days to heading which Exhibited epistasis marginally with preponderance of additive gene effects, while for the remaining traits selection should be deferred till an advanced generation.
Studies on compatibility of nitrogen fixation by high-temperature-adapted Rhizobium strains and Vigna radiata genotypes at two moisture levels in calcareous soil
Authors: Rai R. , Prasad V.
Published: March 2009

Rhizobium strains adapted to high temperature, and genotypes of green gram, were used to study the symbiotic N2-fixation in a summer season at two moisture levels in calcareous soil. Different interactions between strains and genotypes were observedatthe two moisture levels. At both moisture levels, strain S4 with the green gram genotype S8 showed the greatest grain yield, nitrogenase activity, leghaemoglobin and ethanolsoluble carbohydrate of nodules.
Assessment of results from wheat trials testing varieties and application of nitrogenous fertilizer
Authors: Holbrook J. R. , Byrne W. R. , Ridgman W. J.
Published: March 2009

The analysis of two experiments involving the response of bread-making wheat to application of nitrogenous fertilizer is discussed. It is shown that a step function is required to determine the amount of applied N which optimizes the profit to be obtained from the crop. Varieties varied in their yield response to N and in the amount of applied N at which the ‘step’ took place and it is argued that trials of varieties at a common rate of N application or the reporting of results which are averaged over a number of rates cannot lead to very precise recommendations for growers.
The availability of calcium in three grasses
Authors: Armstrong R. H. , Thomas Brynmor , Armstrong D. G.
Published: March 2009

1. The availability of the calcium in three species of grass has been determined by a slaughter technique, using the rat as the experimental animal.

2. The calcium in both timothy and perennial rye-grass was found to be more available than that in cocksfoot, the differences between timothy and cocksfoot, and between perennial rye-grass and cocksfoot being of a significant order.

3. The grasses as a whole were found to be inferior to both the legumes and herbs in respect of calcium availability.

4. The significance of the high faecal calcium values found in rats receiving the cocksfoot diets has been discussed.

5. There was shown to be some indication of inverse relationships between fibre content and calcium availability, and between oxalic acid content and calcium availability.

No single one of the nine grassland plants so far investigated has proved to have a calcium availability which, when taken in conjunction with total calcium content, would be in the least likely to induce symptoms of deficiency in an animal fed on that species alone.
The reproductive performance of Red Sokoto goats in Nigeria
Authors: Adu I. F. , Buvanendran V. , Lakpini C. A. M.
Published: March 2009

An analysis has been made of the reproductive performance of Red Sokoto goat of Nigeria. Data are based on records of 140 kiddings from 96 does. Age at first kidding was 435 ± 18·9 days. The mean litter size at first kidding was 1·45. Prolificacy increased with parity, the kidding percentages from first to third parities being 141, 186 and 200 respectively. Doe weight was significantly correlated with litter size (r = – 0·27). Repeatabilities of litter size per doe kidding and of litter weight were negative. Heritability of litter size was 0·08 ± 0·02. Birth weights were low, the mean weight of kids during the 3 years ranging from 1·48 to 1·64 kg. Doe weight was related to litter weight in a manner such that litter weight as a proportion of doe weight tended to decline as doe weight increased. The ratio of litter weights of singles to twins at any given weight of the doe was 100:180. Kid mortality by 3 months of age was 30·8 %. Mortality among twins was only slightly higher than singles. However, mortality in kids born in multiple births (triplets and quadruplets) was much higher. Birth weights of surviving kids were significantly higher than of those that died.
The effect of time of planting on four bean (Phaseolus vulgaris) genotypes in Kenya
Authors: Fisher N. M.
Published: March 2009

Four genotypes of dry beans were compared at three planting dates during one season (April to June, 1976) and four planting dates during a second season (November 1976 to January 1977). Yield declined with delay in planting in both seasons but in the second season yields were lower at the first planting and declined less rapidly. Canadian Wonder was the most stable-yielding genotype and had highest mean yield though it may have been inferior to other genotypes at the two most favourable plantings. Its stability was attributed to drought escape and good field resistance to drought and disease. Mexican 142 was the least stable genotype. A black-seeded landrace yielded well in dry conditions in spite of its long duration.

The most important components determining planting date effects on yield were numbers of pods per plant and seeds per pod. Canadian Wonder had markedly more stable numbers of pods than any other genotype.

Cooler temperatures in July and August retarded crop development in the first season. For one planting of the second season, flowering was retarded by 7–10 days in all genotypes and this was apparently an effect of water shortage. No effect of water was apparent on the time taken from flowering to maturity.
The growth of pigs kept to one level of feeding, in two environments, and fed diets with and without an antibiotic
Authors: Lucas I. A. M. , Calder A. F. C.
Published: March 2009

1. Pigs housed in both a good and a bad piggery were kept to a medium plane of feeding on diets with and without a procaine penicillin supplement. Antibiotic improved neither efficiency nor rate of growth in either piggery during the period from weaning to 100 lb. live weight, nor from then to slaughter at 200 lb. live weight. The average temperatures during the first half of the experiment were 43 and 51° F. in the bad piggery and in the sleeping pens of the good piggery respectively. During the second half of the experiment these averages were 54 and 58° F. respectively.

2. Between weaning and 100 lb. live weight, pigs housed in the bad piggery grew 6% more slowly and 5% less efficiently than in the good piggery, but although the growth rates fitted in well with previous observations, neither difference was statistically significant in this experiment.

3. Between 100 and 200 lb. live weight pigs housed in the good piggery grew 3% less efficiently than in the bad piggery, but there was no difference in rate of growth. The difference in efficiency was statistically significant.

4. Carcasses from pigs housed in the good piggery were fatter than from pigs housed in the bad piggery. These fatter pigs also had higher killing-out percentages.

5. Although dietary antibiotic supplement had no effect upon growth rates or carcass measurements, it resulted in higher killing-out percentages.
Crop characteristics and the potential yield of wheat
Authors: Austin R. B.
Published: March 2009

The potential yield of the best varieties of winter wheat currently grown in eastern England is estimated to be in the range 12–14 t/ha (15% moisture, 10% protein, freshweight basis).

Increases in the leaf area index at anthesis, in the duration of the grain-filling period and in the light-saturated rate of photosynthesis of the leaves, slower decline in their photosynthetic capacity, and decreases in the respiratory losses of assimilated carbon would increase this potential yield. Such changes might be brought about by breeding or by improved agronomic practices.

The grain growth rates predicted by several published simulation models are shown to be in reasonable agreement with each other.
Effect of Rhizobium inoculation, mulch and nitrogen and phosphorus fertilizers on soya bean (Glycine max (L.) Merrill)
Authors: Sekhon H. S. , Kaul J. N. , Dhingra K. K.
Published: March 2009

A field experiment was conducted for 3 years to study the effect of Rhizobium inoculation, mulch and N and P fertilizers on soya bean. The application of wheat straw mulch helped greatly in lowering the maximum soil temperature but failed to increase the yield, particularly on the fields where soya bean was raised for the first time. Seed inoculation gave significantly greater yield than control (no inoculation and no mulching). The combination of mulch and seed inoculation, on average, produced 0·76, 0·43 and 0·84 t/ha more grain than inoculation alone in 1976, 1977 and 1978 respectively. A basal dose of 15 kg N/ha increased the yield when seed was inoculated but no mulch applied whereas the dressing of N did not prove beneficial when mulching was combined with inoculation. The grain yield, however, increased up to 180 kg N/ha in the case of mulch alone and control treatments. The response of soya bean to phosphorus application was inconsistent.
Inter-relationships between pasture growth and senescence and their effects on live-weight gain of grazing beef cattle
Authors: Ebersohn J. P. , Moir K. W. , Duncalfe F.
Published: March 2009

On 13 pastures grazed by beef cattle live-weight gain (range, 0·34–1·12 kg/head/day) was significantly correlated with non-green grass content of pasture. In turn, non-green grass in pasture was not significantly correlated with non-green grass in oesophageal extrusa. Live-weight gain was largely explained (adjusted R2 = 0·91) by non-green grass content of pasture, cell-wall content of green-grass leaf and pasture dry matter on offer in a quadratic model. The quadratic form was best understood in terms of pasture growth with which non-green grass content of pasture was significantly and negatively correlated.
The effect of level of nutrition during pregnancy and during lactation on lamb and wool production of grazing sheep
Authors: Coop I. E.
Published: March 2009

Seven different experiments over 3 years and involving a total of 1750 ewes have been designed to study the effects of high and low levels of nutrition during pregnancy and during lactation on grazing sheep. The trials were run as nearly as possible under typical fat-lamb producing conditions. Commencing with breeding ewes in average store condition before tupping, a live-weight gain of 25–40 lb. from tupping to lambing was adopted as a standard of a high level of feeding and a gain of ± 5 lb. was considered to be a low level of feeding. Differential feeding was obtained by keeping the ewes on high-quality pasture as a high level of nutrition, and by stocking heavily on poor pasture as a low level. Under these conditions the following results were obtained:

(1) Level of nutrition during pregnancy. The high level of nutrition during pregnancy increased birth weight by about 0.5 lb., but had little if any influence on the rate of growth and the weaning weight of the lambs, irrespective of the subsequent level of nutrition. The high level did not reduce ewe and lamb mortality and there was some evidence to the contrary when the high plane was applied early, leading to large live-weight gain.
Some observations on factors affecting myoglobin concentrations in muscle
Authors: Lawrie R. A.
Published: March 2009

1. The myoglobin contents of selected muscles in horse, pig, domestic fowl and pigeon, and in the foetuses of horse, pig, sheep and cattle, have been determined.

2. The order of increasing concentration of myoglobin in the adult animal (4 years) is given by the series heart, longissimus dorsi, diaphragm and psoas, the figures for draught horse being, respectively, 0·325, 0·465, 0·610 and 0·705% and for pig, 0·203, 0·280, 0·350 and 0·435%, and the ratios of these concentrations being the same in each animal.

3. In both draught horse and pig, it is shown that the concentration of the pigment rises rapidly from birth, and that, after 2 years in the horse, and 1 year in the pig, it remains fairly constant, except in the case of horse psoas and diaphragm where there is a slow, but significant, rise throughout life.

4. This relationship of myoglobin with age has been shown to be significant at a probability level of 0·1%.
Genetic variation in colour pattern of Wessex saddleback pigs
Authors: Donald H. P.
Published: March 2009

Mating Wessex Saddleback with Gloucester Old Spot pigs shows clearly that the former are of the three genotypes expected if the belt pattern is primarily determined by a single dominant gene (Be). Breeding tests and measurements of belt width agree in showing that homozygotes tend to have medium to wide belts, heterozygotes tend to have medium, narrow or broken belts, while pigs homozygous for the recessive are black. Crosses of Wessex with black-spotted pigs produce black piglings with or without wide symmetrical belts depending on the genotype of the Wessex parents.

Selection of breeding pigs with narrow belts maintains a high incidence of recessive blacks. Solid blacks which are nevertheless genetically belted may occur, but if so their numbers are likely to be very small.

Evidence is given which suggests that pigmentation in the skin and hair of Wessex × Large White pigs is much reduced if the Large White parents have blue eyes.
Responses of cotton to ammonium sulphate and superphosphate, and relationships between yield and some soil constituents in Tanzania
Authors: Le Mare P. H.
Published: March 2009

In 92 field experiments in Tanzania's major cotton-growing area south and east of Lake Victoria mean yield without fertilizer was nearly 900 kg/ha of seed cotton. The mean direct effect of 224 kg/ha of single superphosphate with 202 kg/ha of ammonium sulphate was 380 kg/ha of seed cotton; with twice as much fertilizer the increment was 525 kg. First and second residual responses made important contributions to the total effect of superphosphate. In most zones the response to each fertilizer was large but in Nassa response to superphosphate was small; in Nzega yields were small and there was no response to ammonium sulphate, perhaps because Calidea dregei caused abscission of bolls; on the acid soils of Ukerewe Island yields and responses to superphosphate were small.

Data are given to show the average amounts of plant nutrients in the soils most used for cotton. Correlations of yields with soil chemical data suggest that some soils lack enough calcium for large yields. A long-term experiment at the Ukiriguru research farm (Le Mare, 1972) showed that productivity of impoverished soil growing cotton every year was recovered and improved by lime with phosphorus and nitrogen fertilizers: the experiments throughout the cotton area indicated that those results were widely relevant.
Complete diets for dairy cows: the effect of energy concentration and change in energy concentration of a complete diet on intake and performance of lactating dairy cows
Authors: Phipps R. H. , Bines J. A. , Weller R. F. , Thomas Joanne
Published: March 2009

Ninety-two British Friesians (56 cows and 36 heifers) were divided into two groups during weeks 3–10 of lactation and received ad libitum either complete diet H (65% concentrates, 35% grass silage, 11·7 MJ ME/kg D.M.) or diet M (50% concentrates, 50% grass silage, 11·2 MJ ME/kg D.M.). In weeks 11· 20 half the animals of each group continued to receive the same diet (HH or MM) while the other half were changed from diet H to M (HM) or from diet M to L (ML). Diet L contained 35% concentrates, 65% grass silage and 10·7 MJ ME/kg D.M. The crude protein concentration of all diets was maintained at about 157 g/kg D.M. by the addition of soya-bean meal to diets M and L.

During weeks 3–10 the mean D.M. intake (kg/day), milk yield (kg/day), milk protein (g/kg) and live-weight change (kg/day) for animals on diets H and M were 15·0, 21·7, 33·3, 0·50 and 12·9, 20·2, 31·5, 0·35 respectively. Differences were significant for D.M. intake, milk yield and milk protein concentration. Although milk-fat concentration of cows given diet H (40·2 g/kg) was similar to that of cows given diet M (39·9 g/kg), heifers receiving diet H had a significantly lower value (37·0 g/kg) than those given diet M (39·8 g/kg).

When animals were changed from diet H to M or from M to L at week 11, D.M. intake, milk yield and milk-protein concentration decreased. However, milk-fat concentration and live-weight change were generally unaffected.

During the complete experimental period, weeks 3–20, animals on treatments HH, HM, MM and ML had mean D.M. intakes and milk yields of 15·3, 14·2, 13·2, 12·4 kg/day and 19·7, 18·5, 17·8, 17·0 kg/day. Milk-protein concentration, was closely related to D.M. intake, but only with heifers did diet H significantly depress milk-fat concentration. The highest live-weight gain was recorded on treatment HH (0·40 kg/day) and the lowost on treatment ML (0·29 kg/day) with intermediate values for treatments HM and MM.

In vivodigestibility coefficients of D.M. and organic matter for diet H (0·731, 0·757) were significantly higher than those of diet L (0·707, 0·734) with intermediate values for diet M. However, for acid-detergent fibre the digestibility coefficient for diet H was significantly lower (0·562) than for diet L (0·662). The digestibility coefficients for nitrogen in all three diets were similar.

Estimates of mean efficiency of utilization of ME for lactation were made on a weekly basis and were 0·56 and 0·64 for animals on diets H and M in weeks 3·10. During weeks 11·20 the mean values for animals on treatments HH, HM, MM and ML were 0·46, 0·53, 0·51 and 0·59, respectively.
Comparisons of growth and early yields of potato varieties of contrasting maturity classification at three sites
Authors: Griffith R. L. , Allen E. J. , O'Brien Susan A. , O'Brien P. J.
Published: March 2009

Six experiments which compared a range of contrasting varieties are reported. Two experiments were at a very early, coastal site in N. Pembrokeshire (Trefin), two at a site in South Pembrokeshire (Trefloyne) and two at a coastal site in N. Norfolk (Brancaster). No variety was in every experiment but several were in the majority of experiments. In some experiments sprout growth was manipulated by control of storage temperatures. A variety classified as early or second early produced the highest yields in all experiments but the yields of the best maincrop varieties were high and substantially better than many early varieties. The highest-yielding variety at the first harvest maintained this advantage throughout June and July. At two sites (Trefin and Brancaster) the highest-yielding variety was consistent from year to year but overall the ranking order of varieties for yields was inconsistent, e.g. Arran Comet was the highest-yielding variety at Trefin in both years and one of the lowest yielding at Brancaster.

The results suggest that it is unwise to attempt to rank varieties for early yields by an overall score. The maturity classification of varieties is not necessarily an accurate guide to the utility of a variety. A consideration of the physiological age of the seed and growing conditions provided some explanation of these effects and their implication for breeding are discussed.
Experiments on growing sugar beet under continuous illumination
Authors: Bell G. D. H. , Bauer A. B.
Published: March 2009

1. Growing young sugar-beet plants under continuous illumination before transplanting into the field induced stem elongation and anthesis in considerably greater proportions than in plants not exposed to continuous light exposure.

2. The technique of growing young plants under continuous light exposure during the winter offers a means of rapid multiplication of small seed stocks, and also of isolating the various physiological types comprising the population. In particular, the technique should make it possible to select types resistant to bolting.

3. Analysis of the glomerule populations obtained from the plants showing anthesis at definite dates indicates that there is a definite trend in the proportions of large, medium and small glomerules as the season progresses.
A critical survey of breeding wheat for baking quality
Authors: Frankel O. H.
Published: March 2009

1. For both genetical and methodological reasons, tests for quality, in the majority of breeding schemes, are not required at the early stages of the breeding process.

2. Reliability and definition of any one empirical test is not sufficient to safeguard against losses of valuable material.

3. It is suggested, therefore, that as a rule agronomically promising lines should be carried on to a stage where comprehensive tests, using a number of selected methods, can be carried out, preferably over a number of seasons. It may be questioned whether a combination of such tests as the wholemeal fermentation and the gluten swelling tests (Pelshenke, 1938a) would suffice. In the light of the available evidence a testing system might be suggested comprising baking tests together with such “indirect” and, better still, “analytical” methods as will afford accurate information of an analytical nature.

4. This review of the testing problem suggests the conclusion that empirical tests are limited in their significance and reliability, and that only an increased knowledge of the fundamentals can afford a truly scientific approach. It should be admitted that the plant breeder, with his insistence on empirical tests where fundamental knowledge was lacking, has side-tracked the cereal chemist from the narrow path of scientific approach all too often. It is questionable whether this has been to the ultimate advantage of wheat breeding.

5. Inheritance studies on quality should greatly facilitate the task of the breeder. They will become feasible and valuable only when the nature of the desirable characters and the true significance of the testing methods are clearly understood.
Distribution of manganese in the pea seed in relation to marsh spot
Authors: Glasscock H. H. , Wain R. L.
Published: March 2009

1. An outline of recent investigations on the cause of marsh spot in pea seeds indicates that the disease is caused by a deficiency of available manganese in the soil.

2. The symptoms of the disease are very briefly described.

3. The methods of analysis used by the writers for determining the amounts of manganese in whole peas and in different parts of peas are described.

4. As no loss of manganese was found to result from soaking the peas in water for 24 hr., soaked peas were used for dissection in preference to dry peas.

5. Referring to the diseased peas, the highest level of manganese was found in the peripheral tissues of the cotyledons, followed by the germ and seed-coat. Only slight traces of manganese were found in the healthy and in the necrotic tissue from the centre of the cotyledons. All parts of the healthy seed were richer in manganese than the corresponding parts of the diseased sample. In addition, the order of distribution was different; notably in that the tissue from the centre of the cotyledon contained a higher level than the seed-coat, and the germ a higher level than the outer layers of the cotyledon.

6. A given weight of small peas proved to contain less manganese than the same weight of large peas selected from the diseased sample. The reverse was found to be true for similar size groups selected from the healthy sample. These differences in the manganese content of size groups suggest that peas of uniform size should be selected for analysis when the relative manganese levels of different samples are to be tested.

7. It is suggested that migration of cell contents from the necrotic tissue of diseased peas may partly account for the differences in manganese content of healthy and diseased peas.
Studies on carotene in relation to animal nutrition: Part IV. Carotene balance experiments with cows and bullocks
Authors: Seshan P. A. , Sen K. C.
Published: March 2009

The results of carotene metabolism experiments with four cows and four bullocks have been discussed. It has been shown that under ordinary farm diet, cows may secrete milk with a fair amount of carotene and vitamin A potency and still themselves remain on negative carotene balance, so far as the current intake and outgo are concerned. Increased intakes of carotene are, however, followed by the increased carotene and vitamin A potency of milk. Experiments with bullocks on a carotene-low diet consisting of dry rations have shown that the faecal carotene elimination attains a constant value and the animals show a consistently negative carotene balance. When, however, two doses of berseem are superimposed on this basal ration, positive retentions of carotene are obtained, followed by a rise in the blood-carotene level. The experimental evidence points to the possibility of a part of the faecal excretion being the result of a withdrawal of carotene from the body reserves.
The comparative digestive powers of zebu and high-grade European cattle
Authors: French M. H.
Published: March 2009

1. With three different groups, each of two zebu and two zebu × Ayrshire grade oxen, and ten typical East African feeding stuffs, no significant difference was found between the average digestibility coefficients recorded with the zebu and the grade oxen.

2. The slight differences in feeding values were also of no practical significance.

3. Some of the zebu × Ayrshire cattle were 3/4 and others 7/8 Ayrshire but the higher grading to the European breed apparently did not affect the digestive powers.
The distribution of Br in the soils and herbage of north-west Pembrokeshire
Authors: Wilkins Carolyn
Published: March 2009

The Br content of soils and herbage from sites in north-west Pembrokeshire was determined. Topsoils had a range of Br contents from 10 to 515 μg/g, with a mean of 54 μg/g, subsoils ranged from < 1 to 455 μg/g, mean 47 μg/g, and herbage samples from 5 to 157 μg/g, mean 45 μg/g.

The topsoil Br content can be related to the loss on ignition and drainage status of the soil; the topsoil Br/loss on ignition ratio becomes smaller with increasingly poor drainage. It was found that the Br distribution in the soil profile is also related to drainage status, the topsoil/subsoil Br ratio increasing with increasingly poor drainage.

There is no clear relationship between soil Br and the amount of the element taken up by the herbage at the same sites.
The placement of fertilizers: I. Root crops
Authors: Lewis A. H.
Published: March 2009

Evidence is adduced to show that sowing the fertilizer in restricted zones or bands gives higher yields of swedes, sugar beet and mangolds than broadcasting and harrowing in fertilizers.

Sowing fertilizer in bands at one or both sides of the seed is the most satisfactory method of application. The bands should be about l½ in. from the seed and an inch or so below it. Placing the bands much further away than 1½ in. gives inferior results.

Sowing fertilizer in bands at both sides of the seed involves risk of bad sowing, as, on bad seed beds, clods may jam between the fertilizer coulters even if they are staggered. Sowing fertilizer in a single band at the side of the seed obviates this difficulty and sometimes gives higher yields. It is recommended that for swedes, mangolds and sugar beet, complete fertilizers should be sown in one band about 1 in. below and distant laterally about 1½ in. from the seed.

On soils very deficient in one or more nutrients, sowing fertilizer in a band below, but not in contact with the seed, gives very good results, but on most soils it is likely to lead to a poor stand of plant and low yields.

Sowing fertilizers in the drills in contact with the seed gives good results on soils acutely deficient in one or more nutrients, but it can only be recommended for specific fertilizers in restricted areas (e.g. super-phosphate can be used in this way for swedes on some soils in Wiltshire and Dorset) since it involves serious risk of impaired germination.
Nutrition of the bacon pig: XI. The minimum level of protein intake consistent with quick growth and satisfactory carcass quality (Part IV)
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The main object of the present investigation was to test the inference from the results of previous trials that a diet composed substantially of cereal and weatings, with a small percentage of lucerne meal or grass meal, and supplying 7% of white-fish meal up to 90 lb. live weight and no protein supplement at all thereafter, should provide all the protein needed for the maximum rate of growth in bacon pigs and the production of carcasses of satisfactory quality, when fed at the rates shown in the feeding chart in Table 3.

Two separate trials were carried out, and both the individual-feeding and group-feeding techniques were employed. In Trial I the control treatment A supplied the standard allowances of high-protein supplement, consisting of 10% of white-fish meal from weaning to 150 lb. live weight, and 5% of extracted soya-bean meal from 150 lb. to slaughter at about 200 lb. The white-fish meal in the rations of the pigs on treatment B was restricted to 7% up to 90 lb. live weight, and from this stage onwards the high-protein supplement was entirely omitted from the diet. The rest of the diet in both treatments consisted of barley meal and weatings, with a small percentage of lucerne meal, care being taken also to safeguard the animals against mineral deficiencies.
Dispersion studies on Gezira soil
Authors: Jewitt T. N.
Published: March 2009

1. The degree of dispersion on shaking of the heavy clay Gezira soil has been studied in relation to its initial moisture content when it is added to the water. A minimum dispersibility was found at about 7% initial moisture content. Such behaviour is different from that found with certain English soils by Puri & Keen.

2. Spontaneous dispersion was studied using the same soil, and by this method it was found that the dispersion decreases with increasing moisture content over a range of zero to 9% moisture.

3. This relation between dispersion and water content is discussed in relation to possible effects in the field of practice. Attention is drawn to possible seasonal and daily differences in the effect of rainfall.
The effect of the “gyrotiller” on crop yield
Authors: Garner F. H. , Sanders H. G.
Published: March 2009

1. In two experiments on heavy land (one continued for four, and the other for three years) gyrotilling has been compared with normal cultivations, and no significant increase in yield has been obtained, although in five out of seven experimental crops the actual difference was very slightly in favour of gyrotilling.

2. In two experiments on light land (one continued for three, and one for two years) gyrotilling has been compared with normal cultivations (ploughing and subsoiling, and also, in one case, ploughing alone), and in all five experimental crops there was a slight depression in yield, which was only significant in one case, connected with gyrotilling.
An apparatus and technique for measuring the respiratory exchange of fed sheep over periods of forty-eight hours
Authors: Lines E. W. L.
Published: March 2009

The gaseous exchange of the sheep can be measured in the apparatus described with considerable accuracy and good agreement obtained with the energy absorbed from a maintenance diet. The apparatus automatically compensates for diurnal changes in temperature and humidity, and maintains a constant rate of ventilation.

The precautions necessary to ensure that the metabolism as measured is a good sample of that of the animal when subsisting on the diet, consist of control of temperature and humidity within the chamber and training the animal so that it is free of psychic strain during the period of measurement. It was found that the sheep takes 14–20 days to adjust its energy turnover to a change in diet.

Modification in structure and operation of the Haldane-Carpenter gas analysis apparatus are described in detail.

The method of A. C. Andersen is used to compute the energy metabolism and respiratory quotient from the gaseous exchange and methane production.
Grass silage: A comparison of the changes involved in the ordinary, molasses and A.I.V. processes
Authors: Davies W. Morley , Botham G. H. , Thompson W. B.
Published: March 2009

The object of this communication is to give an account of an experiment, carried through in the autumn and winter season of 1934–5, designed to determine the changes in composition involved in making silage by the ordinary, molasses and A.I.V. processes. The changes in composition included those of both crude as well as digestible nutrients.
Investigations on the root nodule bacteria of leguminous plants: XIX. Influence of various factors on the excretion of nitrogenous compounds from the nodules
Authors: Virtanen Artturi Ilmari , von Hausen Synnöve , Laine Tauno
Published: March 2009

1. It has been shown experimentally that the excretion of nitrogen noted by us in cultures of inoculated legumes takes place from the nodule bacteria, probably from the intranodular ones, and not from the roots. No excretion of amino acids occurs in cultures of uninoculated legumes growing on nitrate nitrogen.

2. Our earlier hypothesis that the legumes receive their nitrogen nutrition from the nodules in the form of organic nitrogen compounds, particularly amino acids, is in perfect accord with our new observations concerning the process of excretion. All facts indicate that the amino acids concerned are primary products of the nitrogen fixation, and not breakdown products of proteins. Bond's valuable work along quite different lines produced results which support this conclusion. He, however, did not study the chemical nature of the nitrogen compounds in question.

3. The excretion of nitrogen occurs in media capable of absorbing the excreted nitrogen compounds (cellulose, kaolin, sand, soil). The demonstration of the excretion is not possible in water cultures except when very large quantities of water are used. On the basis of these facts a hypothesis is advanced to explain the nature of the excretion.

4. The term total fixed nitrogen has been used as an expression for the extent of nitrogen fixation, while the term extent of excretion is employed to indicate that percentage of the total fixed nitrogen which is excreted from the nodules.

5. The extent of excretion depends largely on the strain used for inoculation. With strains of apparently equal effectiveness in nitrogen fixation, the extent of excretion may vary considerably, so that actually such strains differ in their effectiveness.
Studies on the relation between cultivation implements, soil structure and the crop: III. Rolls: an account of methods employed in a study of their actions on the soil.
Authors: Culpin C.
Published: March 2009

An account is given of methods which have been employed in laboratory and field studies of the actions of rolls on the soil. These studies have revealed little that is remarkable or unexpected concerning the actions of rolls on the soil, but they have clearly demonstrated that the exact actions of rolls differ widely according to the circumstances in which they are employed. When rolling is carried out in field experiments, it is necessary to perform tests to measure the exact effects produced on the soil. In this way it should gradually become more apparent when and how rolling is likely to be beneficial.

Of the methods which have been described, the last two, viz. tests of the consolidation, moisture content and tilth by means of a sampling tube, and of the mechanical resistance to the penetration of a probe with the automatic “resistance” recorder, are well adapted to use in field experiments. These methods are being used in many field experiments involving cultivations, and it is hoped that it may at some time in the future be possible by such methods to relate cultivations and crop yields through a knowledge of the soil structure.
A study on the date of ear emergence in barley
Authors: Bell G. D. H.
Published: March 2009

1. The discrepancy between the results obtained by various workers concerning the inheritance of earliness or the time of ear emergence in cereals, suggests that this character needs further elucidation physiologically before genetic analysis can be properly undertaken.

2. A study of the ear emergence characteristics of varieties when grown under varying conditions indicates that the expression of this character is very much affected by the growing conditions, and the physiological basis must be understood before the various expressions of earliness and lateness are appreciated. It is therefore suggested that the genetic analysis should be conducted in conjunction with a physiological analysis and with a proper consideration and understanding of the effect of environment.

3. A series of crosses involving parental forms differing in time of ear emergence, and in some cases belonging to different physiological groups, has shown how differences in genetic behaviour can to some extent be correlated with the physiology of ear emergence of the parents.

4. In one cross involving similar types, no evidence of segregation or large genetic difference was obtained. In two crosses involving larger differences of similar types, evidence for a single major factor difference was obtained. In other crosses between different physiological types, and an unstable form, more complex genetic results including transgressive inheritance were obtained. Still other crosses superficially suggested a 3: 1 ratio in theF2, but the presence of a certain amount of transgression, and the behaviour of theF3, pointed to a more complicated relationship.

5. Two crosses involving different physiological types were studied in theF1and theF2when sown at different times in the spring by dividing the progenies into separate portions. It was shown that the behaviour of theF1and theF2of the same cross was materially affected by the sowing time.
A study of relationships of breed, time of mating, level of nutrition, live weight, body condition, and face cover to embryo survival in ewes
Authors: Cumming I. A. , Blockey M. A. de B. , Winfield C. G. , Parr R. A. , Williams A. H.
Published: March 2009

Embryo survival was studied in flocks of 500 Saxon Merino and 500 Border Leicester × Merino ewes introduced to rams in either summer or autumn. The ewes were fed 200, 100 or 25% of a maintenance diet from day 2 to day 16 after mating. Embryo survival was greatest in ewes fed the maintenance diet. There was no suggestion that live weight, face cover or condition score were important factors affecting embryo survival. Embryo survival in the twin ovulating cross-breds was higher than in the twin ovulating Merinos, but there was no significant difference in embryo survival in ewes with single ovulations. Embryo survival in ewes with twin ovulations was significantly higher at the autumn mating than in summer.
Influence of Size and Shape of Plots on the Precision of Field Experiments with Potatoes
Authors: Justesen S. H.
Published: March 2009

1. A uniformity trial with potatoes was used for investigating the effect of size and shape of plots on the precision of field experiments. Up to a certain limit the S.D. in per cent. of the mean decreases when the size of plots is increased; further increase of plot size increases the errors as a lesser part of the soil variation can be removed.

2. Two-row plots show less variation than either 1 or 3-row plots. This may be explained by row competition.

3. When the area to be used is fixed, smaller plots are more efficient than larger, owing to the greater number of replications in the former case. One exception occurs in the case where border rows are not harvested; here 4-row plots are more efficient than 3-row plots, owing to the fact that a larger part of the soil is included in the calculations when 4-row plots are used.

4. Long and narrow plots are more efficient than shorter and wider of the same size. The only exception is again explained by row competition.

5. In field experiments with potatoes fairly large plots should be used; at least 2 rows wide and preferably long and narrow strips.
Experimental Error and the Field-Plot Technique with Potatoes (With One Diagram and One Text-figure.)
Authors: Kalamkar R. J.
Published: March 2009

The present investigation consists of the statistical analysis of a uniformity trial with potatoes conducted by Dr Kirk. In this study the standard error in per cent. of the mean decreased slightly with the increase in the widths up to plots 5 rows wide, but any further increase in the width of the plot resulted in the higher standard error. The fertility contour map of the field is given in Fig. 1 to show graphically the effect of soil heterogeneity on the yield. The increased size of the plot resulted in the decreased efficiency in the use of the land when the entire plot was harvested; in other words, given a piece of land of certain size, it is advantageous to have a greater replication of smaller plots than a smaller number of larger plots. Four-row plots proved to be the most efficient when the border rows are discarded. The superiority of long and narrow plots over shorter and wider ones is demonstrated.

With the greatest pleasure I acknowledge my indebtedness to Dr Kirk, who supplied me with the data, to Dr Fisher for his valuable suggestions and to Dr J. Wishart for useful advice and criticism.
The Loss of Toxicity of Pyrethrum Dusts on Exposure to Air and Light
Authors: Tattersfield F.
Published: March 2009

1. Pyrethrum powders and dusts, prepared by grinding or by the incorporation of extracts of pyrethrum flowers upon absorbent earths, such as talc and kieselguhr, lose their insecticidal activity on exposure to light and air. The loss is more rapid in the case of artificially prepared dusts than with ground flower-heads.

2. Both light and air play an important part in the process of inactivation, as samples of kieselguhr-pyrethrum and talc-pyrethrum dusts stored in closed vessels in the dark or exposed to air in the dark are relatively stable; also samples exposed to light in an atmosphere of carbon dioxide, nitrogen orin vacuolose little of their toxicity under the same conditions of illumination; samples exposed in oxygen, however, rapidly lose their activity.

3. Both wet and dry oxygen were effective in destroying the activity of the dusts, but apparently at different rates, and there is some suggestion that the type of reaction may be different in the two cases.