1. The results of five experiments, comparing the wool production of worm free and infected sheep, are described.

2. Worm-free sheep produced (a) 12·0–38·8% higher total fleece weights and (b) 17·2–43·2% more clean, dry wool per unit area than infected sheep. None of the infestations was higher than occurs naturally in the field, but the greatest effects were associated with a low level of nutrition.

3. It is suggested that the precise effect of worm infestation on wool production will depend upon the age of the host when first infected, the size of the infestation and the rate of wool growth at the time when the infestation is at maximum.

The extent to which proteins fed to ruminants are degraded in the rumen is determined by their rate of degradation and retention time in the rumen. It is known that retention times in the rumen are much longer for poor quality than for good quality roughages. Thus, it is possible that protein supplements may be more extensively degraded when fed with poor than when fed with good quality roughages. The present experiment was designed to determine the relationship between retention times of roughages and a protein supplement fed with them.

In oven-dried whole plants from three regrowths of four varieties of Panicum maximum, leaf and stem of normal and stunted oats at three stages of first growth, leaf and stem of rape and the whole plant of millet, cell wall ranged from 14 to 77% of the organic matter. In vitro digestible cell wall ranged from 13 to 46% of the organic matter and was closely related to the cell wall (residual standard deviation, ± 2·5). In 16 legume hays the average in vitro digestible cell wall was 22·1% of the forage organic matter compared with an average value of 20·5% found previously from in vivo digestibility experiments with legumes. An unsatisfactory feature of the in vitro digestibility determination was that in silages and low quality grass hays, the digestible cell wall was low relative to known in vivo values for these forage types. The separate determinations of cell wall and in vitro digestible cell wall would add to the confidence that can be placed on estimates of in vivo digestibility from laboratory measurements. Often, the determination of cell-wall content is sufficient for this purpose.

Fusarium solani f. sp. fabae Yu & Fang was isolated from root-rotted field bean (Vicia faba)plants at the Research Farm, Hudeiba Agricultural Research Station, Northern Province, Sudan. This is the first record of this fungus on field beans in the Sudan. Cultural and morphological characteristics of the fungus on potato-dextrose agar (PDA) and the symptoms caused are described.

A replicated trial of 18 families of Navy-bean breeding lines in the F4 generation was grown at Cambridge. The selection-index technique was used to investigate means of improving the efficiency of simultaneous selection for four criteria, namely yield, seed shape (numerical scores from ‘good’ to ‘poor’), early maturity and increased height of pod tips. Relative economic weights were chosen. The yield components and a range of characters describing plant type were measured making 15 characters in all, and combinations of these were included in 32 indices.

It was predicted that simultaneous selection would be limited by adverse correlations between some of the four selection criteria, especially early maturity and height. The estimated efficiency of selection would hardly be improved by including information on the yield components. Combinations of the plant type characters, on the other hand, were predicted to provide considerable additional advance amounting to a 10% improvement when information on total number of nodes and inflorescences and hypocotyl diameter was included.

It was concluded that the time involved in collecting yield component data would be better spent collecting information on a limited number of plant type characteristics in future trials, and that an ideal plant was one with reduced branching and a few heavily podded inflorescences borne on a tall plant with a strong base.

The concentration of nitrogen, phosphorus, potassium, sodium, calcium and magnesium was measured in the dry matter of sugar beet from four field experiments (1966–9). All combinations of four amounts of nitrogen fertilizer (0–1·8 cwt/acre), four plant populations (8800–54000 plants/acre) and irrigation were tested, which gave a wide range of plant size and yield. Nutrient concentration and uptake by the crop were also greatly affected by the treatments.

Nitrogen fertilizer and irrigation increased uptake of nitrogen by the crop but increasing the plant population had little effect on uptake and decreased the concentration of nitrogen. Sugar yield was related to the total nitrogen concentration in tops and roots and to uptake. There were optimal values of nitrogen concentration for maximal sugar yield, but the optima were greatly affected by plant population. Leaf colour was a good guide to nitrogen concentration.

Phosphorus concentration was affected little by the treatments but cation concentrations were greatly affected. In general, uptake of all the elements was increased by all treatments – the exception was sodium, which decreased as the plant population increased but this was balanced to somo extent by increased potassium uptake.

The metabolizable energy values of eleven samples of field beans (Throws M.S.). representative of different generations, locations and soil types, were determined using 3-week-old broiler chicks. A mean ‘classical’ value of 2·40 ± 0·09 kcal/g (10·09 kJ/g) was obtained, together with a mean nitrogen-corrected value of 226 ± 0·11 kcal/g (9·47 kJ/g). There was a considerable variation within groups of samples classified according to generation, location or soil type, so that no distinct relationships were detectable. Supplementary analytical data relating to moisture, crude protein, oil and fibre of the samples are also presented.

Field experiments were carried out in which three different sowing techniques: sowing by hand, with a conventional seed drill and with a precision drill, were used to plant an indeterminate and a determinate cultivar of Vicia faba at two sowing dates and at three population densities in 1989 and 1990 in Southern Germany.

Delayed sowing reduced field emergence rates in both years. Hand sowing produced the poorest stands in some instances due to an insufficient sowing depth being achieved. Only at late sowing dates did precision drilling give greater field emergence rates than conventional drilling. During the early stages of growth, hand and precision sowing resulted in crops with the greatest light interception and dry matter production. However, these differences between sowing techniques decreased later on. Lodging was most severe in conventionally drilled crops, particularly at high population density. Thus, when lodging occurred, dry matter and grain yields decreased with increasing plant density in conventional sowings, although they tended to increase in hand-sown and precision-drilled crops. Overall, apart from this interaction, there was no significant effect of sowing technique on grain yield. Grain yields and dry matter production were generally higher in the indeterminate cultivar Herz Freya than in the determinate cultivar Ticol, but there were no differential effects of sowing technique.

Data are presented on the relationship between seed yield, its distribution and the duration of growth. A plant model is proposed to achieve earlier ripening as well as high yield. The possibility of achieving this model is evaluated.

The F1 and F2 progenies of a complete diallel cross between seven inbred lines of field beans (Vicia faba spp. minor) were studied in order to elucidate the possibilities for breeding for earlier ripening without sacrificing seed yield. In a space-planted field trial the inheritance of and relationship among yield and earliness characters were examined.

On average the F1 generation was superior to F2 in seed yield as well as earliness of flowering and ripening. General combining ability (g.c.a.) effects were highly significant for all the characters studied and very high narrow-sense heritabilities were found for most characters. Specific combining ability (s.c.a.) effects were significant for all characters except for number of inflorescences, and significant reciprocal effects were found for seed yield and date of anthesis.

Because of the importance of g.c.a. effects, the phenotypic correlations were mainly determined by, and therefore similar to, the additive genetic correlations in showing a positive relationship between yield and the duration of pre- as well as postanthesis growth. However, a relatively strong negative non-additive genetic correlation was found between yield and duration of post-anthesis growth.

Path analysis showed that 70–82% of the variation in post-anthesis growth was accounted for by the distribution of seed yield described by four yield components, thus supporting the hypothesis that the duration of post-anthesis growth is highly dependent on the distribution and size of the seeds.

Two possibilities for breeding earlier-ripening, high-yielding cultivars are suggested: (1) exploiting hybrid vigour in terms of earlier ripening and (2) reducing the duration of post-anthesis growth byselecting for more seeds per pod and more pods per inflorescence.

Three types of field instrument are described that are suitable for the automated and replicated in situ measurement of the soil properties: temperature, thermal conductivity and water pressure. Novel aspects of their design and construction are discussed, as are details of their installation and precautions necessary for successful use in the field. The principle of operation of each type of instrument is described and the method of controlling several instruments of the same type via a computer-based data acquisition system is indicated. Their accuracy and performance under field conditions are shown to be very adequate. Determination errors are approximately 0·1 K in the range 0–35 °C for temperature, 6–8% for thermal conductivity, and 1 mm water for water pressure, with a time constant of about 2 sec in a silty clay loam soil; reliability is measured as two sensor failures out of 236 over an operating period of several months. Examples are given of data collected during their deployment in an experiment to determine the physical effects of tillage on soil.

An account has been given of the different methods adopted for extracting protein material from the juice of the mangold root and subsequent purification of the crude material.

Three samples of protein have been isolated in different ways and their distribution of nitrogen determined by the van Slyke method.

Two globulins and an albumin have been extracted from mangold seed, the two globulins being isolated very pure and an elementary analysis done. These two proteins differed in sulphur and nitrogen contents and different physical properties justified their being looked on as two distinct proteins.

Distributions of nitrogen by the van Slyke method revealed differences in the globulins, especially in their contents of arginine and histidine.

The similarity between the root and the seed proteins has been pointed out, and the root protein has been compared with animal proteins.

The production of specialty coffee has several factors and parameters that are added up in the course of production, so that the quality is expressed in the act of consumption. Based on this scenario, this study included the analysis of ten genotypes of arabica coffee, the materials being subjected to irrigated and rainfed water regimes, in a low altitude region, to identify responses for sensory and physical–chemical quality. The genotypes were evaluated in a split-plot scheme with a randomized block design, with three replications. Arabica coffee fruits were harvested with 80% cherry seeds and processed by the wet method. Subsequently, the characteristics related to physical–chemical and sensory analyses were evaluated. The genotypes of the Paraíso group showed great variability for the physical–chemical and sensory variables for rainfed and irrigated regimes. The genotypes of the Catuaí group, however, showed less variability for sensory characteristics in both cultivation environments and for physical–chemical characteristics in the irrigated regime. In the sensorial data set, the genotypes Catuaí 144 CCF and Catuaí 144 SFC (when irrigated) and Paraíso H 419-3-3-7-16-2, Paraíso H 419-3-3-7-16-11 and Catucaí 24-137 (rainfed cultivation), are more favourable to the production of specialty coffee at low altitude.

Sugar cane (Saccharum sp. hybrid cv. Co 1148) was planted in October alone and in association with potato (Solarium tuberosum cv. Kufri Chandramukhi), coriander (Coriandrum sativum cv. Sheetal), mustard (Brassica juncea cv. T59) and wheat (Triticum aestivum cv. K816) to find the optimum N dose in alluvial entisols of Lucknow, India. The yield of sugar cane was least in association with wheat and most with potato. The optimum N doses for sugar cane were 152, 175, 186 and 231 kg/ha when grown in association with potato, coriander, mustard and wheat respectively. The optimum N dose for sugar cane grown alone was 186 kg/ha.

Experiments made at Shika, Nigeria, over a period of 3 years showed that the drymatter response of Andropogon gayanus to applied N was curvilinear over the range 0–896 kg N/ha, with maximum yields being obtained at an application rate of about 500 kg N/ha. However, the highest return of dry matter per unit of fertilizer applied (14·4 kg D.M./kg N) occurred at 28 kg N/ha and there was only a modest increase in crude-protein content as N was increased, reaching a maximum of 10·5% at the highest level of N. Also, at both high and intermediate levels of N, A. gayanus was replaced by less desirable grasses.

May, the beginning of the rainy season, was found to be the most efficient time to apply N, although reasonable dry-matter responses were obtained by applying N in the dry season. ‘Nitro-chalk’ and calcium nitrate were more efficient sources of N than urea, sodium nitrate and, in the long term, ammonium sulphate.

1. Three trials are reported in which the grazing behaviour of separate groups of cows, one receiving supplementary food, either as conserved roughage, concentrate or fodder crop, was observed over 24 hr. periods. A fourth trial, assessing the effect of summer temperatures on unshaded milking cows, is briefly described.

2. In trials 1 and 2 the stall feeding of either conserved roughage or concentrate reduced grazing as compared with unsupplemented cows by approximately 10%.

3. Allowing access to a fresh ‘strip’ of a fodder crop at a set time each day, whilst not altering total grazing time, very markedly altered periodicity of grazing. Cows delayed grazing up to 3 hr. whilst awaiting a fresh ‘strip’.

4. Environmental temperatures up to 87° F. did not alter total grazing time as compared with grazing time when temperature reached a maximum of only 70° F.

5. The value of supplementary feeding of dairy cattle at pasture, at least where the intake of pasture is sufficient for maintenance and a low level of production, appears to be open to question.

Field investigations were undertaken during the winters of 1971–6 to study the grain yield responses of lentil cultivars to seed inoculation with single and mixtures of Rhizobium strains. An effective symbiosis and consequent increase in the grain yield was associated with the efficacy of the strain. Inoculation with a superior strain produced 23–32 % more grain than no inoculation on loamy-sand soil and 46–90% more on sandy-loam soil.

In separate studies comprising inoculation and nitrogen treatments, the seed treated with an effective Rhizobium strain gave on average 43% more yield than no inoculation and the application of 25 kg N/ha alone gave the same yield as inoculation. Rhizobium inoculation plus 20 kg N/ha was the best combination for maximum yield under both loamy-sand and sandy-loam soils.

The effect of dwarfism on leaf number and size was investigated on six pairs of tall and dwarf nearisogenic lines of indeterminate autumn-sown white lupins (Lupinus albus L.). Dwarfism reduced mainstem height by 41% and first-order branch length by 22%. It also slightly decreased the number of leaves on the mainstem and first-order branches without affecting the time of flowering. Leaf size was not reduced. Logistic equations were used to analyse differences in the patterns of light interception by leaf canopies relative to thermal time from sowing during the growth of seven dwarf lines and three tall cultivars sown on different dates. The genotypes studied had long periods of low light interception during their early growth. No differences were found between most of the equation parameters for dwarf and tall genotypes. Only the proportion of light intercepted at flowering differed and this was explained by differences in flowering time. The dwarf character did not limit the ability of the crop canopies to intercept light. It is concluded that the character can be introduced into a wide range of genetic backgrounds without deleterious effects.

Seed production of annual medics was measured at four sites in Syria and Jordan between 1986/87 and 1988/89. Plots sown to medic in the first year were sown to wheat in the second year, and medic regeneration was measured in the third year. At three of the sites, adjacent plots were established in the second and third years and herbage production, and regeneration where appropriate, were measured in the third year. In this way, genotype × site interactions were used to assess medic adaptation to wheat/pasture rotations, continuous pasture and newly sown pasture.

Seed production was correlated with rainfall, the mean yield of 14 genotypes ranging from zero at 160 mm to 1 tonne/ha at 510 mm. Medicago polymorpha produced the highest yields, though not at the lowest rainfalls. Yields of M. rotata were also above average. There was, however, wide variation between species in seed weight, pod weight and seeds/pod.

Regeneration was better after wheat than after pasture. Herbage production was slightly better after pasture than after wheat, and both were greatly superior to that of newly sown pasture. After 2 years' germination, most genotypes retained more than half (mean 60%) and up to 99% of the seed produced in the first year.

Genotype × environment interactions were tested using analysis of variance (ANOVA), regression (Finlay & Wilkinson 1963) and principal component analysis (PCA). Because adaptation in pasture plants depends on many variables, PCA proved to be the most useful technique and the simplest to apply. ANOVA and regression were limited by their inability to process more than one variable at a time. Regression analysis is further limited by requiring a greater number of sites.

Based on seed production, seed survival, seedling regeneration and herbage production, certain locally collected genotypes of M. rigidula, M. noeana, M. polymorpha and possibly M. rotala, were adapted to conditions in Syria and Jordan. A similar methodology could be used to test pasture legumes throughout west Asia and north Africa

1. Ten experiments are reported in which the effect of high-level copper supplementation of pig rations on growth rate and food conversion was observed. In three of the experiments the study included observations on carcass quality.

2. In nine of the ten experiments a positive increase in the growth rate of the pigs receiving copper was recorded but the magnitude of this increase was markedly variable.

Experiments made with winter fodder crops, lucerne (Medicago sativa), berseem (Trifolium alexandrinum) and oats (Avena sativa) and summer fodder crops, cow pea (Vigna unguiculata), guar (Cyamopsis tetragonoloba), sunhemp (Crotolaria juncea) and pearl millet (Pennisetum americanum) showed that a sequential crop of Sudan grass yielded more after the legumes than after the cereal fodders, oats or pearl millet. The legume advantage was noted in the crop not given fertilizers but also when Sudan grass was given N fertilizer. The yield increase in Sudan grass grown after legumes was equivalent to 32–60 kg fertilizer N/ha applied to Sudan grass following pearl millet.

After harvesting the legumes more available N and NO3-N was present in the soil and the apparent recovery of fertilizer N by a subsequent crop was increased by the legume.