The effect of different cutting practices on the carbohydrate root reserves of Finnish red clover was studied. Cutting causes a rapid decrease in the insoluble sugars. The minimum is reached in about 12–15 days, independently of the time of cutting. However, the initial carbohydrate level is reached much more quickly in autumn than in June-July. The carbohydrate content of the roots in autumn is higher the later the second cut.

Cutting does not significantly affect the content of sucrose and other soluble sugars, the values for which are very low during June-August, but rise towards autumn.

1. The nutritive value and chemical composition of hybrid Napier, Napier and Jowar grasses and also a leguminous fodder, berseem, were studied using adult kumaoni steers.

The data obtained from 360 progeny families produced by crossing 40 F2 plants from each of three wheat crosses HD 2009 × HD 1949, Raj 821 × WH 147 and NP 876 × HD 1949, to three testers (the testers being the two parents of each original cross and their F1 in each case) were subjected to triple test cross analysis for detecting and estimating additive, dominance and epistatic components of genetic variation and interaction of these components with environment for plant height, spike length, number of tillers per plant, number of spikelets per spike, number of grains per spike, 1000-grain weight, number of days from sowing to heading and to maturity, grain yield per plant and grain yield/above ground dry matter ratio (harvest index). Epistasis was an important element for plant height, number of tillers per plant, number of grains per spike and grain yield per plant in all three crosses. Both the i type and j and l type epistasis were equally important. In general, the magnitude of additive component was larger than that of dominance component. The additive gene effects were more sensitive to environmental change than the dominance gene effects. Similarly, j and l type epistasis was relatively more sensitive to environment than the i type epistasis.

Thirty-two weaned Kenana bull calves were adequately fed to maximize growth and serially slaughtered at predetermined live weights of 100, 200, 300 and 400 kg. Eight animals were slaughtered at each slaughter point and the left side of each carcass dissected into individual muscles, bone, fat, tendons and fascia. Individual muscles were grouped into nine muscle groups and the distribution of intermuscular fat was studied in four anatomical regions. Huxley's (1932) allometric equation was used to describe the development of carcass tissues.

Relative to overall carcass side growth, fat was the fastest developing tissue, followed by muscle and bone tissues in descending order. The muscles of neck + thorax and abdominal muscles exhibited the fastest rate of growth relative to overall total side muscle growth, and the distal muscles of both limbs exhibited the slowest rate of relative growth. Relative to the rate of side fat deposition throughout the experiment, subcutaneous fat was deposited at a faster rate than intermuscular or kidney + channel fat. Intermuscular fat was deposited at different rates in the anatomical regions of the carcass.

The development of muscle groups was further examined in three arbitrary phases of the test period and revealed significant differences between phases in the rate at which each muscle group developed. Similar changes in the intensity of the rate at which fat was deposited in the subcutaneous region and between the muscles of the carcass or sites were evident.

Kenana cattle compare favourably with foreign dairy and beef breeds of cattle in muscle:bone ratio. Further studies are needed to evaluate the efficiency of meat production from Kenana cattle under different systems of management.

As reported in Part 1 (Gaili & Nour, 1980) a study was conducted to investigate the development of body components in Kenana cattle and to evaluate the potential of the breed for meat production. This paper is an account of the data which were obtained on the development of carcass tissues.

Many biological experiments and almost all quantitative genetic studies draw conclusions from differences between families. Such differences are caused as much by heritable as by non-heritable sources. This paper investigates the impact of seed quality on the expression of quantitative variability among 20 highly inbred lines of Nicotiana rustica using ten seed categories representing different pollination times, seed sizes, seed positions in the capsule and seed maturity. Analysis of variance revealed that while the mean performance of the inbred lines remained more or less the same across all the seed categories, their individual performances differed widely, showing a highly significant interaction between lines and seed categories. This interaction accounted for up to 12% of the total variation and was largely attributable to late pollinations and immature seed. Seed categories were also the main source of heterogeneity among the within-line variances, but only immature seed lowered the correlation between the inbred means. In general, seed quality affected the developmental characters much less than the traits measured at or after flowering, and the expression of genetic variation was not critically affected by seed size or position. Immature seed, on the other hand, generated the highest level of unreliability in the comparative performance of lines and such seeds should therefore not be used in quantitative genetic experiments under any circumstances. Further implications of seed quality effects on the interpretation of genetic components are discussed in detail.

1. Methods, buildings and equipment used for milk production in Caernarvonshire, Hertfordshire, Pembrokeshire and Wiltshire have been ascertained by a random sample survey carried out in 1948–9.

2. The results showed marked differences between counties in practically every respect which are summarized in thirty-two tables.

3. The value of this survey and some points in its planning and execution are critically discussed.

Estimates of inbreeding effects in a landrace are necessary in order to acquire information on the presence of different types of gene action for important traits. Twelve lines with different levels of inbreeding coefficients (F=0, 0·25, 0·50 or 0·75) were developed from three phenotypically selected families of a winter squash landrace (Cucurbita moschata Duchesne) between 2000 and 2002 in the area of Thermi-Thessaloniki, Greece. During 2003, a field experiment was established at this location to evaluate the lines. The agronomical characters measured were: the number and weight of total commercial fruits, days to first female blossom, seed weight, size of pollen grains and water-stress tolerance. Comparisons were also made of morphological characters, the dry matter, the total soluble solids and the pH of fruits. Lines with inbreeding coefficient F=0·50 were found to have the highest values for most of the measured characteristics. Significant family×inbreeding interactions were found, revealing different trends for the linear, quadratic and cubic components of each family with inbreeding coefficients. Three F=0·50 lines selected from within each representative family were evaluated along with four winter squash landraces from the C. moschata collection of the Greek Gene Bank, during 2004 in the area of Thermi. These F=0·50 lines showed a superior performance of three components contributing to yield, indicating that one generation of selfing improved the agronomic performance maintaining concurrently the substantial characteristics of the landrace.

A study designed to investigate the effect of K nutrition on the yield, components of yield and on macro- and micronutrient concentration of maize showed no significant effect of K on yield in forest alfisols derived from basement complex rocks and in savannah alfisols derived from sandstones in the tropics. Potassium addition significantly decreased lodging, but had little influence on cob length, ear weight, shelling percentage or moisture content.

Ear-leaf N and K were significantly increased, while Ca and Mg were decreased by K application. All the micronutrient concentrations (Zn, Fe, Mn, Cu) were significantly increased by K application in the forest and savannah zones. Yield was positively correlated with ear-leaf N on both soils.

1. Soil samples were incubated at 60% W.h.c. at 20° C. and leached after 8 and 20 weeks. On subsequent incubation, the rate of nitrate production in the leached samples was greater than that in unleached control soils. The increase in nitrate production seems to be due to an increased rate of ammonification.

2. Adding 100 p.p.m. of nitrate nitrogen to the soil before incubating had no effect on mineralization.

3. Adding a leachate of incubated soil to new soil samples reduced the rate of mineralization on incubation. This reduction is not due to nitrate or any other anion, since deionized leachate was equally effective.

Quantifying reasonable crop yield gaps and determining potential regions for yield improvement can facilitate regional plant structure adjustment and promote crop production. The current study attempted to evaluate the yield gap in a region at multi-scales through model simulation and farmer investigation. Taking the winter wheat yield gap in the Huang-Huai-Hai farming region (HFR) for the case study, 241 farmers’ fields in four typical high-yield demonstration areas were surveyed to determine the yield limitation index and attainable yield. In addition, the theoretical and realizable yield gap of winter wheat in 386 counties of the HFR was assessed. Results showed that the average field yield of the demonstration plots was 8282 kg/ha, accounting for 0.72 of the potential yield, which represented the highest production in the region. The HFR consists of seven sub-regions designated 2.1–2.7: the largest attainable yield gap existed in the 2.6 sub-region, in the southwest of the HFR, while the smallest was in the 2.2 sub-region, in the northwest of the HFR. With a high irrigated area rate, the yield gap in the 2.2 sub-region could hardly be reduced by increasing irrigation, while a lack of irrigation remained an important limiting factor for narrowing the yield gap in 2.3 sub-region, in the middle of the HFR. Therefore, a multi-scale yield gap evaluation framework integrated with typical field survey and crop model analysis could provide valuable information for narrowing the yield gap.

The relationships between mid-silking date, mid-maturity date, spread of silking and spread of maturity were studied in four maize hybrids. Mid-maturity date and spread of maturity were positively related to mid-silking date. The spread of silking ranged from 13 to 18 days and the spread of maturity from 34 to 47 days in different hybrids. Grain moisture content at mid-maturity ranged from 40 to 35%. It was concluded that the common practice of harvesting grain crops at 40% dry matter is likely to result in appreciable loss of yield: variation in the proportion of mature kernels when the grain has reached 40% moisture may account for the large season to season variation in yield observed in commercial crops. The potential benefits of early flowering hybrids are briefly discussed.

A physical form of “ropiness” in milk has been described and shown to be due to the formation of thin films of casein and (or) lactalbumin at the milk-air interface.

The “ropes” are a form of the “mechanical surface aggregates” of Ramsden and may occur on appropriate surfaces, such as ordinary farm coolers whenever the rate of flow, the temperature and the acidity conditions are favourable.

A modification of Ramsden’s method demonstrating the formation of mechanical surface aggregates, in an hitherto unobserved form, has been described, viz. horizontal glass tubes in parallel which are especially suitable for opaque fluids.

The condition appears to be identical with that described by Aekma and Brouwer(2) who showed the occurrence of corpuscles in milk after violent agitation. These corpuscles probably consist of thin films of solid protein which as in the cases described by the author have formed at the interfaces of air bubbles and milk.

The phenomenon has been shown to be of importance in handling dilutions of milk in the course of bacterial enumeration.

A 2-year field study indicated that pearl millet yielded more when sown after fallow, cow pea and green gram than after maize. Preceding fallow, cow pea and green gram reduced the nitrogen requirement of pearl millet by 40 kg/ha compared with maize. Pearl millet responded linearly up to the highest rate of nitrogen (80 kg/ha). N applied to millet had no residual effect on the subsequent crop of chickpea. The chickpea yield followed the order fallow > green gram ≥ cow pea > maize. Chickpea responded to phosphorus up to 40 kg/ha. Green gram-pearl millet-chickpea proved the most profitable cropping sequence. Continuous cropping and application of nitrogen and phosphorus improved the organic carbon and available phosphorus but decreased the available potassium status of the soil.

There are three by-products obtained from the preparation of legume seeds for human consumption which are marketed as supplemental animal foods, namely, the seed-coats (testa) which are removed from beans, peas and lentils. They are known commercially by various names, “skins,” “shells,” “husks,” “hulls” and as “offals.” They are used extensively in the East for the nutrition of cattle, where dehusked legumes enter so largely into the dietary of humans. Bean, pea and lentil husks are all used for stock feeding in Britain, and it was the frequency with which pea husks were found in commercial sheep-feeding mixtures sent for examination, and the knowledge that considerable consignments of bean shells are from time to time imported, that led to this enquiry into their nutritive value. Previous to the adoption of the Foodstuffs and Fertilisers Act, 1926, bean husks were imported into Britain in larger quantities than is at present the case, some of them being ground and added to bean meal, a practice which one has reason to believe has now ceased. Bean husks are seldom fed as such to cattle in Britain, but in France they are given to dairy cows and horses. For cows they are mixed with beet pulp, oil cakes and bran with, it is stated, good results. For horses they are mixed with oats, and an informant, a farmer from Cambrai, mixes them in equal proportions with oats for his working horses, giving to each 30 litres per day. It is claimed that the addition of the husks causes a more complete mastication of the oats and that horses do well on the mixture.

(1) Animals on a calcium-deficient diet suffer periodically from loss of appetite though the ration is in every other respect satisfactory.

(2) The results of twenty-two digestion trials show no enhanced effect on the digestibility of the organic constituents of the food on adding calcium carbonate to a lime-deficient ration.

In conclusion, I wish to express my thanks to Prof. T. B. Wood, F.R.S., for giving me the necessary facilities to carry out the work; to Mr H. R. Davidson, M.A., for placing the experimental animals at my disposal and also to Dr H. E. Woodman for his active interest and supervision at all stages of the work.

The quantitative relationships between “single value” properties and mechanical analysis of the soil are of some considerable importance in the textural classification of soils, and have received much attention since the original work on moisture equivalent by Briggs and McLane (1907). The empirical nature of the moisture equivalent, with the consequent trend towards standardisation of technique, has led to frequent re-examination of the relationship between the mechanical analysis and the “single value.”

Rapeseed and mustard cultivars aro morphologically determinate but the growth of the raceme, which is a corymbose type, is indeterminate. On the raceme flower opening proceeds acropetally in a sequential manner with one or two flowers opening each day. Thus there is a considerable time lag between first and last flower opening within the same raceme. In these oil-seed crops, besides leaves both pod wall and stems are photosynthetically active and the share of assimilates contributed by these three organs to the growing seeds has been estimated to be 37, 32 and 31%, respectively (Brar & Thies, 1977). A rapid decline in leaf area during pod filling in rapeseed and mustard (Chauhan & Bhargava, 1984) and rape (Allen & Morgan, 1972) cultivars has been observed. The assimilate supply to the pods developing at different periods may, therefore, differ owing to a decline in the leaf source as well as increasing intornal competition between pods. In winter oil-seed rape (Brassica napus), both mutual competition for assimilates and shading resulting from excessive pod production have been reported to cause heavy seed and pod losses (Mendham, Shipway & Scott, 1981). No information is available for rapeseed and mustard cultivars on how different components of the pod, such as its weight, seed weight, number of seeds and seed oil percentage, change according to their position on the terminal raceme. This information may be useful in deciding the appropriate number of pods on a raceme for optimum yield.

This group, which is concerned with the applications of mathematics to agricultural science, was formed in 1970 and has since met at approximately yearly intervals in London for one-day meetings. The thirtieth meeting of the group, chaired by G. J. S. Ross of the Institute of Arable Crops Research, Rothamsted, was held in the Wellcome Meeting Room at the Royal Society, 6 Carlton House Terrace, London on Friday, 3 April 1998, when the following papers were read.

The determination of in vitro dry-matter digestibility (DMD) of grass and pasture legumes under both temperate and tropical conditions is well established (Tilley & Terry, 1963; Minson & McLeod, 1972). One application of the in vitro DMD estimation of pasture samples is, together with an estimate of faecal output, the measurement of the herbage dry-matter intake of grazing cattle. Pasture samples are usually collected with oesophageal fistulated cattle. This technique is well documented and has been reviewed by a number of authors (Langlands, 1975; Minson et al. 1976).

In meat-type poultry breeding, pectoral angle (PA) is a conventional anatomical indicator for changes in body conformation and meat traits; its correlation to egg performance is however deemed controversial. In this context, we revisited, assessed and put forward evidence for the usefulness of this classic phenotypic variable and its specific integrative index of pectoral angle-to-body weight ratio (PA/BW). Specifically, we identified respective correlations and used them for distinguishing the major categories (production types) of diverse chicken breeds under the traditional classification model (TCM) and genotypic clustering models of the global chicken gene pool subdivision. Also, the usefulness of the supplementary integrative egg mass yield index (EMY) for this objective was demonstrated. Because of estimating the total mass of eggs laid (i.e. egg number times egg weight), EMY can serve as an indicator of egg production. Direct approximation of EMY values by PA and BW values did not lead to significant correlation dependences between these indicators in each of the four breed utility types according to TCM. However, using the ratio of PA to BW, instead of PA and BW alone, resulted in significant correlation of EMY with PA/BW, allowing for distinction between egg-type and non-productive breeds. The validity of the proposed correlation-based models was supported by PCA and Neighbor Joining clustering analyses. Collectively, we suggested that PA can be a potentially correlated trait for selecting hens and roosters in breeding flocks to boost egg yield. These results can also be applied to chicken breeding as well as conservation- and phenome-related research.