Soya bean, Bengal gram and lentil plants were grown under field conditions and sprayed with suspensions of different strains of Rhizobium. Irrespective of crossinoculation groups beneficial effects were similar to those observed in nitrogen-free sand culture with respect to dry weight, chlorophyll and N contents. The beneficial effects of spraying Rhizobiumstrains compared favourably with seed treatment by appropriate Rhizobium strains and application of urea. Both an ineffective strain and a mutant strain of R. japonicum showed similar beneficial effects. Acetylene reduction by the Rhizobium-leaf association ranged from 497 to 890 nmol/g leaf/h. The ectosymbiotic association of Rhizobium with foliage of legumes, thus, may meet to a large extent the nitrogen requirement of such plants.

1. The effects of seed size in the swede crop on germination, emergence, growth and final yield were studied during the period 1959 to 1962.

2. The germination percentage was similar for all sizes of seed, but the emergence percentage was slightly poorer for ‘large’ and ‘small’ seed than for ‘graded’ seed.

3. Leaf area in the early stages of growth was proportional to the seed size, but as the season advanced the plants from small seed grew at a relatively faster rate than those from large seed, so that at harvest the relative yield difference, although still in favour of large seed, was much smaller than the relative difference in seed weight or seedling leaf area. It was shown that the relatively faster growth rate from small seed was not due to a later onset of inter-plant competition.

Pomegranate peels (PP) and mango leaves (ML) were analysed for nutrients and tannin contents. In an in vitro test, ten diets were prepared; six contained 2, 4 and 6% of PP or ML, three diets supplemented with mixed levels of PP and ML (1 + 1%, 2 + 2% and 3 + 3%) and control diet free of them. Gas was measured after 3, 6, 12, 24, 48 and 72 h of incubation. Methane and rumen parameters were estimated. In an in vivo experiment, 40 Ossimi lambs were divided into four groups; the first was control, other groups (T1, T2 and T3) fed diets containing 6% PP, 6% ML or mix levels (3% PP + 3%ML), respectively, for 2 months. Results showed that PP and ML were rich in tannins. In the in vitro test, a maximum reduction in gas, methane and NH3-N was in 6% PP, 6% ML and mixed levels (3% PP + 3% ML). In the in vivo experiment, there were no differences in growth and digestibility of DM and nutrients between treatment groups. Only a lowered DM intake and protein digestibility in lambs fed 6% PP. Gas and methane emission was decreased significantly in lambs fed 6% PP, compared to other groups. TVFAs and NH3-N were decreased for treatment groups. Also, all treatments did not show any pathological changes in liver function or on oxidative stress markers. In conclusion, PP and ML can be used in sheep diets at inclusion levels of 6% and mixture without detrimental effects on general health of Ossimi lambs.

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.

1. An investigation has been made into the changes that take place in the free amino-acid pattern when kale-water slurries are allowed to ferment under conditions of (a) aeration, (b) anaerobiasis and (c) partial sterilization with sulphur dioxide.

2. It has been found that, with aerated mixtures, the loss of free amino-acids is virtually complete within 2 weeks, while there is only a slight loss with the anaerobic mixtures. With mixtures containing sulphur dioxide no loss of amino-acids occur.

3. The formation of α-amino butyric acid possibly from threonine has been noted.

1. Following an examination of weaning weight with respect to litter size, it is concluded that no general relation between the two exists. Although a significant regression of weight on litter size was found, it appears probable that in herds where the relation between fertility and milk yield is different, such a regression will not necessarily be found.

2. A sampling experiment was carried out to determine the extent to which a sample might be expected to represent the whole litter. A correlation of 0·96 was found between the mean growth rate of samples consisting of the four pigs nearest the average at weaning and the mean of the whole litter. This represents a loss of 8 per cent of the information. With three or two pigs chosen in the same way the loss was greater. Samples of four pigs chosen at random did not give results significantly different from those of the four pigs nearest the average. The choice of the heaviest four pigs resulted in a loss of 15 per cent of the information.

3. The slight difference between the results from the random sample and the sample of the four average pigs indicated that there must have been only a small correlation, between weaning weight and subsequent rate of growth. An analysis of post-weaning rate of growth showed that the intra-class correlation of pigs of the same weaning weight was 0·15. Individual weight at weaning would therefore appear to be of slight value in estimating subsequent performance.

4. Intra-litter correlations of growth rate for litter classes eight and nine were found to be 0·3 and 0·5. These values are higher than those found by others, probably as a result of the inclusion of the pre-weaning period in the calculation of the growth rates. There would appear to be grounds for believing that at least a fifth of the individual variance may be accounted for by additive gene effects.

Nuclear magnetic resonance (NMR) micro-imaging techniques have been employed to study noninvasively the spatial distribution of mobile protons (1H) around the cotyledonary node of flax (Linum usitatissimum) plants of two differing growth morphologies. The gross anatomy of the tissues of the stem can be discerned as a result of differences in their mobile 1H contents. The technique produced excellent images of the complex changes in stem structure that occur at the point of origin of side shoots. Detailed structure within the xylem could be visualized and the presence of fibre bundles deduced as dark areas amongst tissues of higher 1H signal intensity.

As a result of the non-invasive and non-destructive nature of NMR-imaging, the images obtained have been compared to micrographs obtained by conventional histological techniques on the same plant tissue. In general, the two approaches produce comparable results, but the NMR images are influenced by the relaxation properties of the protons as well as their concentration. Paramagnetic species, such as Mn2+ ions, produce enhanced relaxation rates of protons in their vicinity and an apparent increase in proton density at short recycle times. Thus an NMR image can yield both chemical and structural information. Some of the advantages and disadvantages of this technique over conventional histological methods are discussed.

In 14 experiments made from 1968 to 1970 yields of, percentages of N in and amounts of N removed by the grain were compared: (1) when N was injected, either as aqueous ammonia (with or without a combine-drilled ‘starter’ dose of N) or as aqueous urea, or when broadcast as ammonium nitrate (‘Nitro-Chalk 21’) and: (2) when comparable liquid (14–6–8) and granular (20–10–10) NPK compound fertilizers were applied, either over the seed bed (sprayed or broadcast), or combine-drilled. All were applied to give 63 or 126kgN/ha.

Barley yields were increased significantly more by combine-drilled than by broadcast PK (0–20–20) fertilizer, especially when only 32 kg P2O5 and K2O/ha was given. N was better combine-drilled than broadcast when 63 kg/ha was given, but not with 126 kg/ha. Soil analyses suggested a limiting value for P.

Yields and N recoveries were largest when one-fifth of the N was combine-drilled (as 6–15–15) and the remainder injected as aqueous ammonia in bands 30 cm apart and 12 cm deep. Injecting all the N, either as aqueous ammonia or as urea, gave yields a little smaller than this, but still larger than from broadcasting ammonium nitrate.

The liquid NPK fertilizer gave smaller yields than the granular one in the two dry springs (1968 and 1969), but similar yields in the cool wet one (1970), both when applied over the seed bed and when combine-drilled. The smaller yields with the liquid fertilizer were associated with a severe check and loss of plant when it was combinedrilled (presumably caused by urea) and poorer growth after it was sprayed (presumably through loss of N to the air and greater dispersal of P in the soil). The single amount of each fertilizer increased yields more when combine-drilled than when broadcast, but not the double amount, which, especially as liquid, was safer when surface-applied. Effects of site and season upon mean yields were large.

Eighty-nine Fayomi pullets were classified into three major classes High, Medium and Low according to the intensity of egg laying. Six birds in each class were slaughtered. The major body organs were dissected and weighed. The number and diameter of the visible oocytes were recorded. The dressing out percentage was obtained. The results were as follows:

1. During the first year of laying, the averagenumber of eggs laid per day was 0·50, 0·42 and 0·24 eggs for the High, Medium and Low classes respectively.

2. There were significant differences in the ovarian weight, length and weight of oviduct, these being highest in the High class.

3. The number of visible oocytes was some 200 in all classes. There were, however, differences between classes in the maturation rate of the oocytes as measured by the differences in the diameter of successive ones.

4. The weight of blood, feathers, head, wings and legs were higher in the Low than in the High; these are all early maturing organs.

5. The weights of the full alimentary canal and the empty gizzard were higher in the High than in the Low, this might be accounted for by a greater appetite and to intake of feed induced by the higher egg production.

6. There were no significant differences in the weight of the circulatory, excretory and respiratory organs which are needed for the physiological welfare of the birds.

7. The dressing out percentage was higher in the Low and Medium than in the High. This may be due to the greater drainage of nutrients required for high egg production.

The nitrogen content of oats depends chiefly on the nitrogen content (1·4–3·9%) of the kernel and the kernel content (64–81%) of the oats, the husk containing only 3–10% of the total nitrogen in the grain.

Varietal differences are significant but small in comparison with the overall variability: they reach 0·3% nitrogen in a few cases. Variation between random samples is largely due to soil differences, with region and harvest year responsible for smaller effects. The predominant factor governing nitrogen level in oats of all varieties probably is, as for wheat, the level of available nitrogen in the soil in late spring and early summer, just prior to heading and during development of the grain.

Within the variety there is a pronounced inverse correlation between nitrogen and oil content which is independent of grain size: the variability of the oil content within the variety is, however, smaller than the corresponding variability of the nitrogen content. At some localities environmental factors of soil and season, particularly the former, inhibit the filling out of the grains which then ripen prematurely to give small oats with lean kernels of high nitrogen content, and favour within the variety a negative correlation between grain size and nitrogen which otherwise might not be apparent.

Before proceeding to discuss the immediate subject of this communication, it may be well to recapitulate shortly the views on the general question of the meaning of strength of flours which I expressed in the last number of this journal. It may perhaps be remembered that I suggested that strength, as defined by Humphries and Biffen, to be the capacity of making large well-piled loaves, must be a complex of at least two factors. One of these factors, that which regulates the size of the loaf, I showed to be the power of continuing to evolve carbon dioxide gas throughout the later stages of dough fermentation. I described how to measure this property by incubating in a bottle at 40ºC. a mixture of 20 gms. flour, 20 c.c. water, and ½gm. yeast, the bottle being connected to a gas measuring apparatus, and the volume of gas given off being read from time to time. A number of experimental figures were given, which showed that the size of the loaf which a flour could make, was directly connected with the rate at which it gave off gas in the later stages of dough fermentation, at the time when it was ready for the oven.

Field experiments during the wet seasons of 1981–1985 determined the response of soya bean to the application of P, K and Mo at four locations in the Nigerian savanna. Soya bean was grown at factorial combinations of four rates of P (0, 13·2, 26·4 and 396 kg P/ha) and two rates of K. (0 or 41·5 kg K/ha) in 1981, but in subsequent years two or three rates of Mo (0, 0·5 or 1·0 kg ammonium molybdate/ha) were included in a randomized complete block design with three replications at all locations.

Significant yield increases due to the application of P were recorded in 10 out of 11 trials. Yield increases due to 13·2 or 26·4 kg P/ha were from 29 to 210% over the control. The effects of K and Mo application were not significant in 10 out of 11 trials and eight out of nine trials, respectively. Whereas P x Mo interaction effects were significant in three trials only, highest yields were recorded due to application of 26·4 or 39·6 kg P/ha in combination with 0·5 kg ammonium molybdate/ha.

Application of P increased the percentage of P in soya-bean leaves significantly and a range of 0·275–0·330% P appears to be the critical nutrient range of P in soya-bean leaves at full bloom stage. Application of K had no effect on K concentration in leaves.

To increase the productivity of fields growing direct-seeded upland rice, which usually gives low yields because of weed competition, unsatisfactory establishment and exposure to intermittent drought, an experiment on intercropping of rice with blackgram was conducted in two seasons under rainfed conditions on a sandy loam soil. Blackgram, when intersown simultaneously in one row in every 30 cm wide space left between the stand of 10 cm apart paired rows of rice, reduced the yield of rice by 1·64 t/ha. When one row of blaokgram was intersown, 21 days after sowing of rice (after completing weeding) between the paired rows of rice, rice yield was reduced by only 0·24 t/ha compared with solecropping of rice with weeding. This system provided mean yields of 2·48 t/ha of riceand 0·95 t/ha of blackgram. The price of blackgram being high, it showed a mean monetary advantage of Rs. 2373/ha over sole cropping of rice. The blackgram reduced the weed population appreciably.

An attempt has been made in the investigation described in this paper to elucidate the nutritional characteristics of winter pasturage. The yield, composition and digestibility have been determined of pasturage produced by unrestricted growth over the following periods: (1) end of July 1932 to December 1932; (2) end of August 1932 to January 1933; (3) end of September 1932 to February 1933; (4) end of October 1931 to March 1932. In both years of experiment the winters were mild and open, and the conditions as a whole were such as to enable the nutritional possibilities of winter grazing to be studied under the most favourable conditions. In order to assess the influence of winter conditions on composition and feeding value the results in every case have been compared with data, obtained in investigations in previous years on the same pasture, for spring and summer herbage of comparable height, stage of growth and botanical composition.

Semen samples were collected from buffalo bulls by a.v. at intervals of 24, 12, 8 and 2 hr., four consecutive ejaculates being collected for each bull in every treatment. Semen qualities were measured in fresh and stored ejaculate at 4° C. for 48 hr.

1. (a) In fresh semen, the average initial values were 3·12 ml. for volume, 645 × 103 for concentration per cubic millimetre, 2134 × 106 per ejaculate, 7·25 for motility, 80·1% for live spermatozoa and 21·1% for abnormals.

(b) Volume, concentration and percentage of live sperm were not affected by successive ejaculations.

(c) Motility started to decrease after the third collection in most cases.

(d) Percentage of abnormals was highly affected irrespective of interval of collection.

(e) When the interval of collection was short, enlarged middle piece of spermatozoa and detached galea capitis were observed.

2. (a) In stored semen, the average values were for motility 3·12%, for live sperm 64·5%, and for abnormals 27·4%.

(b) Storage caused a decrease in motility and an increase in percentage of abnormals, while it had no effect on percentage of live sperm.

(c) The rupture of head membrane of spermatozoa was observed in stored semen.

1. Three contrasting varieties of spring oats were grown at six centres in England and Wales for three seasons, at two levels of manuring. They were harvested at two stages of ripeness, and both straw and grain were analysed for all treatments.

2. Varietal differences in composition between samples of straw grown under similar conditions and harvested at comparable stages of ripeness were negligible. In this respect there was no relationship between quality of straw and that of grain.

3. Differences in composition attributable to environment were very large. Crude protein content ranged from 1·9 to 7·6%, and crops grown under cool and wet conditions always yielded a better quality straw than those grown under the warmer and drier conditions in the south of England.

4. The chemical composition of oat straw changed very little between the early ‘binder-ripe’ stage and the fully ripe ‘combine’ stage, although physically it tended to become more brittle and less attractive in appearance. The grain also showed little change in composition between the two times of harvesting.

5. A spring dressing of 2 cwt. per acre of nitrochalk increased the protein content of the straw very considerably, but the response varied widely with conditions. The average increase at all centres over three years was 20%.

6. Under cool and moist conditions the composition of oat straw was comparable with that of meadow hay.

The present investigation was carried out to estimate the effects of genotype and sex on growth and laying performance and assess the variations in plasma constituents in the tested genotypes and their relations with productive traits after four generations of selection. Data of growth and laying performance on 1440 females and males of Japanese quail were taken from the three quail genotypes: maternal (MG), long shank length (LSG28) and control (CG) genotypes. Genotype significantly affected all studied growth productive traits, favouring selected genotypes. The LSG28 surpassed MG in total protein, albumin (Alb), globulin (Glob), triglycerides and Alb/Glob ratio and lowered both cholesterol and total lipids (TL). Sex significantly favoured females, which had higher body weight, longer shank length at 35 days of age and higher body weight gain during the period from 1 to 35 days of age. Females showed significantly higher concentrations of both Alb and TL than males. The MG exceeded LSG28 in fertility and hatchability per cent. Correlations for both growth and productive traits with plasma constituents revealed inconsistent trends in either magnitude or direction. Four generations of selection resulted in substantial phenotypic improvements in most growth and productive traits, as well as plasma constituents studied in LSG28, and favoured MG in maturity, days needed to produce the first ten eggs, higher egg production per cent and heavier egg mass.

Two experiments with growing pigs grouped in pens and three with growing pigs kept in metabolism crates were undertaken in order to determine young growing pigs'dietary requirement for phosphorus of vegetable origin, the relative potency and true digestibility of that source and the effect of dietary Ca concentration on its utilization. Much of the P was contained in wheat offal, and of this 900 g/kg total P was phytin-P.

In the first two experiments the responses to vegetable P were measured by pig live-weight gain, gain: feed ratio, several conventional carcass measurements and the weight, length and density, and the ash, Ca and P contents of the fourth left metacarpal, and also by the alkaline phosphatase activity of blood serum. No significant differences were found between treatments in terms of body-weight gain, gain: feed ratio, or the commercially important carcass characteristics. The requirement of pork pigs for P was measured by bone and serum enzyme characteristics when all the dietary P was of plant origin, apart from 0·3 g P/kg from casein. Under the conditions of this experiment this P requirement appeared to be met when the diet contained 5–6 g P/kg. The potency of vegetable P in Expts 1 and 2 and of wheat offal P in Expt 3 relative to feed grade dicalcium phosphate was 0·77, equivalent to a net retention of 0·4–0·5 as a proportion of that consumed estimated from growth and digestibility measurements. A true digestibility coefficient of 0·53±0·01 for wheat offal P was obtained in Expts 4 and 5. The effect of variation in dietary N and energy, associated with variation in dietary offal concentration, on the reliability of the potency estimates is discussed.

Increasing dietary Ca concentration caused a slight decrease in the digestion of wheat offal-P. The soaking of wheat offal in water for an average of 11 h before feeding increased P digestion in one of two experiments. In vitro evidence indicated that soaking initiated the hydrolysis of insoluble P compounds.

The present paper contains the results of investigations on silver-leaf disease which are a continuation of those previously described by one of us (1,2) in earlier numbers of this periodical.

Some time ago it was thought desirable to duplicate as far as possible in different localities the experiments conducted on this disease. Hence most of the experiments described in this paper have been carried out both at Cambridge and at the John Innes Horticultural Institution, Merton.

The dry-matter content of about 260 samples of potatoes was determined. The samples were collected over three seasons and from many types of soil.

The average dry-matter content of a variety varied from season to season, but it always bore an approximately constant relationship to the average value of other varieties.

Wet seasons led to potatoes low in dry matter.

The variation in the content of dry matter of potatoes in different seasons and from different soil types is not a direct effect of the water balance of the tubers.

The average content of dry matter of potatoes depends on the soil in which they were grown; fen and blackland gave potatoes with the lowest dry matter, followed by skirt, silt and warp, then loam and medium loam, then clay, and the highest dry matter occurred in stocks grown in sands, gravels or light loams.

The difference between the soils is discussed, and it is tentatively concluded that the factor responsible for the variation in content of dry matter of the potatoes is the available water content of the soils.