The goals of this study are to analyse the impacts of 1.5 and 2.0°C scenarios on UK winter wheat using a combination of Global Climate Models (GCMs), crop models, planting dates and cultivars; to evaluate the impact of increased air temperature on winter wheat phenology and potential yield; to quantify the underlying uncertainties due to the multiple sources of variability introduced by climate scenarios, crop models and agronomic management. The data used to calibrate and evaluate three crop models were obtained from a field experiment with two irrigation amounts and two wheat cultivars that have different phenology and growth habit. After calibration, the model was applied to fifty locations across the wheat-growing area of the UK to cover all the main growing regions, with most points located in the main growing areas. Four GCMs, with two cultivars and five planting dates, were simulated at the end of the century. Results of this study showed that the UK potential wheat yield will increase by 2–8% under projected climate. Farmers will need to close such a gap in the future because it will have implications in terms of food security. Future climatic conditions might increase such a gap. Adaptation measures (e.g. moving the optimal planting time), along with climate-ready varieties bred for future conditions and with precision agriculture techniques can help to reduce this gap and ensure that the future actual UK wheat production will be close to the potential.

Thirty-two milk-fed Murrah buffalo calves of 3 weeks of age were randomly allotted to four dietary groups: milk, concentrate-berseem hay in the ratios 1:1 and 1:3, or berseem hay alone. Milk intake was gradually reduced and completely stopped after the sixth week of age in the groups given dry feeds. Two calves from each group were slaughtered at 6, 9, 12 and 15 weeks of age. In addition, four buffalo calves were slaughtered at 21 days of age for comparison.

Observations on ruminal tissue weight, content weight and the ruminal capacity indicate that the ruminant stomach of buffalo calves weaned on dry food after the sixth week of age becomes structurally developed by 9 weeks of age, whereas the rumen remains underdeveloped in calves fed milk to 15 weeks of age.

A relationship between grass N yield and total N supply was derived using data from experiments on grass-white clover swards. This relationship was very similar to that found previously using a larger pool of data from clover-free grass swards. The quantity of N released underground by the clover was estimated to be around 50% of the annual N yield in clover herbage. This is a much lower estimate than that reported by earlier workers.

Bastard Trenching as ordinarily performed consists of two distinct operations; loosening the lower spit of soil, and digging into it farmyard manure or other fertilising material. A considerable volume of data has been accumulated to show the effect of the addition of farmyard manure to soil, but little is known of the effect of loosening the bottom spit, either on the soil or on the plant.

A number of herbicide treatments involving the use of trifluralin, preforan and igran were compared together with hand weeding as methods for the control of weeds in a cultivar of Phaseolus vulgaris sown on 19 January 1972.

Favourable increases in yield of beans were obtained by combinations of preforan and igran which were associated with an increase in the number of pods produced per plant. Hand weeding failed to give a significant increase in final yield.

Within 14 days from sowing there was an appreciable weed cover in the control and hand-weeded plots but little evidence of weeds in the herbicide-treated plots. At 41 days there were still no significant differences between the control and the plots to be hand weeded. There was, however, a considerable reduction in percentage cover of weeds on the herbicide treated plots. Trifluralin and preforan were equally effective in reducing weed cover.

Triple superphosphate (21.6% P), potassium metaphosphate (25.0% P) and magnesium ammonium phosphate (19.0% P) were compared as phosphate fertilizers alone and in combination, and as powders and granules, in two experiments on acid soils. Basal nutrients were adjusted to allow for the amounts of N, K, and Mg in the test fertilizers. Immediate effects of the fertilizers were measured by early potatoes and barley, and residual effects by radishes and ryegrass.

All powdered fertilizers, alone or in combination, were equivalent to powdered superphosphate for early potatoes. The value of granular fertilizers for potatoes increased with the proportion of superphosphate in the mixtures. Superphosphate equivalents of the granular fertilizers were: magnesium ammonium phosphate, 14%; potassium metaphosphate + magnesium ammonium phosphate, 36%; potassium metaphosphate, 53%; superphosphate + potassium metaphosphate + magnesium ammonium phosphate, 54%; superphosphate + magnesium ammonium phosphate, 60%; superphosphate + potassium metaphosphate, 81%.

Residues from powdered fertilizers, applied to potatoes, were equivalent, for radishes, to residues from powdered superphosphate. Residues from granular fertilizers were more effective for radishes than residues from powders.

All powdered fertilizers were equivalent to powdered superphosphate for barley cut green. Granular magnesium ammonium phosphate, either alone or mixed with potassium metaphosphate, was slightly less effective than powder.

Residues from all powdered fertilizers applied to barley were equivalent for ryegrass. Residues from granular fertilizers, especially potassium metaphosphate and magnesium ammonium phosphate, produced more grass than residues from powders.

Apparent recoveries of P by the four crops ranged from 24% to 32% and were more from granules than from powders. Residues from all fertilizers increased 0.5M-NaHCO3-soluble P in soils, and mean yields of ryegrass, the final test crop, increased by 3.2 to 5.1 cwt dry matter/acre/ppm NaHCO3-soluble P in the soils.

Hairiness in wool of Suffolk sheep as a fault was found to be associated with other defects like coarseness of wool fibres, hairiness of the britch, and the occurrence of pigmented fibres. The presence of these various defects was studied in the lamb's tail at docking time, and subsequently evaluated and correlated with the fleece.

The tails were graded according to the nature of the fibres and the spread of halo hairs from the tip to the base into four principal grades which by further subgrading could be made into seven grades. The results were as follows:

(1) There was wide variability in grades of tails within each flock.

(2) Average grade of tails followed in general the mean quality of the adult fleece.

(3) When Border Leicester were crossed with Welsh Mountain the tails of the two reciprocal crosses were found to be of hairy type of tail and nearly like the Welsh Mountain type.

(4) The percentage of coloured tails in the least hairy grades was found to be inversely related to the quality of the tail grade and indirectly to the fleece quality.

(5) The diameter of the wool fibres on the base of the tail is highly correlated with the diameter of fibres from the britch regions or mean fibre diameter from four regions of the body (mid-shoulder, midside, hip and britch).

(6) The mean diameter of the wool fibres obtained from four different parts of the tail was correlated with those of the britch regions only.

(7) The diameter and variability of fibres increased from shoulder to britch in the body and from base to tip in the tails.

(8) The britch and tails of two groups of sheep, one group characterized by coarse and the other by fine britch and tail wool, were studied histologically. There were significant or highly significant differences in the following characteristics in the britch of the two groups: (a) total number of follicles, (b) primary follicles with no medulla, (c) total number of secondary follicles, (d) secondaries with no medulla, (e) secondaries with large medulla. The only type of follicle where a significant difference was found in the tail was in the number of secondary follicles with no medulla.

White clover cultivars Sacramento ladino, Sonja and Aberystwyth S.184 were assessed for dry matter (DM) yields, clover content and herbage quality in monostand and in 50:50 mixtures with grasses under cutting at Truro, Nova Scotia and Charlottetown, Prince Edward Island between 1986 and 1989. Grasses were: orchardgrass (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), timothy (Phleum pratense L.) and reed canarygrass (Phalaris arundinacea L.). Dry matter yields ranged from 6158 to 11645 kg/ha and were highest in white clover/orchardgrass and white clover/timothy at Truro, and in white clover/timothy at Charlottetown. Sonja and Aberystwyth S.I84 outperformed Sacramento white clover in herbage DM and clover yield in all years at both locations. First-cut herbage contributed 39 and 29% of total yields at Truro and Charlottetown, respectively. Clover yield was highest in first-cut Sacramento/orchardgrass, but dropped by up to 73% in white clover/timothy associations over a 2-year period. Crude protein ranged from 14·4% in clover/timothy to 23·4% in clover/reed canarygrass and was positively correlated with clover content. It was concluded that choice of clover cultivar as well as grass is an important consideration in maximizing herbage yields and quality in the Atlantic region.

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)

Organic matter (O.M.) = dry matter (D.M.)–ash.

If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.

Two experiments were conducted to study the influence of heat treatment of Vicia faba beans on the productive performance of laying hens fed diets containing large proportions of the beans. In the first experiment, the effects of extruding and pelleting the beans were studied while in the second experiment the effects of autoclaving at 121 °C for 30 min the cotyledons and hulls of the beans were evaluated. Hyline-W36 layers were used in the first experiment while two strains (Shaver-288 and Dekalb) of birds were used in the second experiment. Each experiment lasted 5 months during which data on egg production, egg weight, feed intake, mortality and body-weight gain of birds were collected. The results obtained indicated that heat treatment (extruding, pelleting and autoclaving) of the beans, cotyledons and hulls had no beneficial effect on the productive performance of laying hens fed on diets containing large proportions of the heated beans, cotyledons and hulls. Egg-size reducing factors appeared to be concentrated in the cotyledons rather than the hulls of the beans.

In cases of anaemia in cattle and sheep, of infectious origin, parasitic origin, or due to simple haemorrhage, the phosphorus partition of the blood reveals an “unknown fraction,” confined to the corpuscles, and evidently nucleoprotein. It is determined by difference between the total phosphorus and the sum of total acid-soluble and lipoid phosphorus. It is associated with the appearance of nucleated red cells (normoblasts and Jolly bodies) and vanishes as they disappear. The amount may make up a considerable proportion of the total P.

In soil moderately infested with potato golden cyst-nematode, Globodera rostochiensis, nematicide treatments which lessened soil infestation when a susceptible potato crop was grown permitted a satisfactory second crop to be grown 3 years later without further treatment. In two experiments on heavily infested sandy loam on the same farm (Woburn Experimental Farm, Bedfordshire), aldicarb or oxamyl, incorporated in the seedbed in 1979 or 1980, greatly increased yields of Pentland Crown tubers and reduced the number of eggs left in the soil after harvest, but had little effect on a second crop of Pentland Crown potatoes grown 4 years later. Application of aldicarb or oxamyl to the seedbed before this second crop of potatoes increased yields and lessened nematode increase. The injection of 1,3-dichloropropene mixture (Telone II) into the soil in autumn at 224 kg/ha in one of these experiments did not enhance the nematode population control achieved by aldicarb or oxamyl alone.

Field investigations were carried out to study the effect of partial defoliation on dry-matter production and seed yield of urd bean. Partial defoliation during the vegetative and/or reproductive phase reduced seed yield. The severity of yield reduction was dependent on the stage of crop development and the degree of defoliation. The reduction of total dry-matter production by defoliation was accompanied by a decrease in crop growth rate and leaf/plant weight ratio. The net assimilation rate was higher in defoliated plants from 40 to 60 days after sowing. The reduction in seed yield due to defoliation was highly due to a reduction in the number of pods per plant, and also sometimes in the number of seeds per pod and in 100-seed weight.

Between 1946 and 1950 multifactorial field experiments were carried out to determine the potentialities and effectiveness of chlorinated phenoxyacetic acids for the selective control of weeds in linseed (oil flax). The initial experiments of 1946 demonstrated that treatment with sodium 2-methyl-4-chlorophenoxyacetate led to considerable increases in the yield of seed through a reduction of the weed population and the consequent decrease in weed competition.

The subsequent experiments were undertaken on relatively weed-free crops so that the direct effects on the crop of compound, formulation, and stage of growth at the time of application could be investigated along with differences in varietal response. Amongst the observations made were time of flowering, straw length, the yield of seed, capsule production, seeds per capsule and the weight, oil content, protein content and germination capacity of the seed.

At similar dosages sodium methylchlorophenoxyacetate is less phytotoxic than sodium 2, 4-dichlorophenoxyacetate while the parent acid and particularly the ethyl ester of the dichloro - compound are much more injurious. With sodium methylchlorophenoxyacetate the tolerance is greatest between the post-cotyledon stage and a height of 20–25 cm.; within this range of plant development dosages up to 3·5 lb./acre have no adverse effects on the yield of seed. Treatment within 2–3 weeks of flowering delays flowering and reduces the seed weight. When dichloro-compounds are employed there are additional effects, such as the formation of abortive capsules or a reduction in the number of seeds per capsule. Under some conditions the oil content and the germination capacity of the seed is depressed but the protein content is increased.

Carcass weight, bone weight, bone length, and bone weight per unit length were examined as possible indices of the weight of muscular tissue in lamb and mutton carcasses.

S1 maize varieties and varietal hybrids were tested in six locations ranging in altitude from 236 to 1600 m in Cameroon. The grain yields of highland varieties were observed to increase with each increase in altitude while the yields of the lowland varieties decreased with increasing altitude.

The highland × lowland S1 varietal crosses yielded the same as the lowland parental varieties in highland areas and better than highland parental varieties in lowland areas.

Average yields of all varieties per location increased by about 1·1 t/km increase in altitude. Eberhart & Russell's (1966) stability method found no stable variety while Francis & Kannenberg's (1978) genotype-grouping technique found five highland × lowland crosses to be relatively stable.

Number of days from planting to tasselling increased with increasing altitude by about 20 days/km increase in altitude. Highland and lowland varieties performed poorly outside their zones of adaptation because of high incidence of foliar diseases like leaf blights and rusts.

Cassia acutifolia Del., known in the Sudan as ‘Senna Makka’ and in commerce as ‘Alexandrian Senna’ (Tothill, 1948), is indigenous to the Sudan and grows wild in the Northern and Central Provinces. It is used locally as a laxative and itsactive ingredient senoside is extracted for pharmaceutical purposes in England, U.S.A. and Germany. The Sudan has been exporting pods and leaves of Senna for many years and the crop has been steadily growing in economic importance. The exported produce is obtained from wild or cultivated Senna plants. Recently a breeding programme has been initiated to provide improved varieties that can both meet the growers’ need for high yield and satisfy the market's demand for uniform high quality produce. Before a proper plant breeding programme can be established, the mode of reproduction must be known since crop breeding procedures are largely determined by the reproductive system. This paper reports on studies made to determine the breeding system in Alexandrian Senna.