The water content and turnover of six pairs of identical twin cattle were measured in the Kenya highlands. Three pairs were stall fed, and one twin of each pair received water daily. Their water turnover averaged 14.21./24 hr. while the others watered each 4 days had an average turnover of 12.41./24 hr. These stall-fed animals used 74-132 ml./kg.0.82/ 24 hr., about one-third the water turned over by grazing cattle (261-364 ml./kg.0.82/24 hr.). There was little relationship between estimates of water intake measured from the trough and that derived from tritium dilution.

Members of each grazing pair differed in weight by an average of 4.2% and their total body water by 5.9%, whereas the water turnover differed by only 2.2% amongst the twin pairs.

1. An account is given of the occurrence of copper deficiency in crops grown on the Fenland peats and glacial sands of East Anglia. Copper deficiency in the crops appears to be due to actual deficiency of available copper in the peat and sandy soils. The level of copper extracted from soils by an acid solution (pH 4.0) of the ammonium salt of E.D.T.A. provides a useful indication of soils deficient in copper, though the occurrence of the deficiency and its severity in crops is influenced by other soil factors, level of water-table in peats, species of crop and weather during the growing season.

2. Of the crops grown on the peat and sandy soils of East Anglia the most susceptible to copper deficiency are cereals. Visual symptoms of deficiency are described as these provide an important aid in diagnosis.

Evidence is provided that T. ambiguum, in common with other legumes, responds to inoculation with an effective strain of Rhizobium both in the field and in the glasshouse. There were consistent differences between the responses of 2x, 4x; and 6x: chromosome races to inoculation. Grass plants grown alongside effectively nodulated T. ambiguum plants gave significantly higher yields than those grown with ineffectively nodulated plants. The higher percentage germination associated with inoculation may be due to an effect of the skim milk used as inoculum carrier.

We wish to thank Professor P. T. Thomas and Mr W. Ellis Davies of the Welsh Plant Breeding Station, for their interest and advice, and Professor A. H. Bunting, of Reading University, for reading and correcting the manuscript.

The inoculation of legumes is often carried out using skim-milk as the carrier for the nodule bacteria. Increased germination due to inoculation has often been reported but in this investigation the effects of the skim-milk and the bacteria have been separated. The results indicate that the early establishment of T. ambiguum was stimulated by the skim milk rather than the nodule bacteria. The mechanism of this effect is thought to be due to extra N present in the milk and possibly to an enhanced nitrogen-cycle in the inoculated soil and evidence is produced of increases in certain freeliving nitrogen fixing and nitrifying microorganisms.

At Saxmundham Experimental Station in East Suffolk a four-course rotation experiment testing fertilizer treatments has continued with only minor modifications since the 1899/1900 crop year, the crops being wheat, roots (mainly mangolds), barley and either beans, peas or clover. Factorial combinations of nitrogen (N), phosphorus (P) and potassium (K), with two additional treatments testing farm-yard manure and bonemeal, are applied annually to the same plots regardless of crop.

All crops, particularly mangolds and sugar beet, yielded badly without P. N was as important as P for cereals, but had little effect on mangolds and sugar beet unless P was also applied; its effects on the legume yields were slight. On this heavy soil K had little effect on the yield of any crops except the legumes.

The rotation II experiment at Saxmundham, which ran from 1899-1952, was designed to show how limited quantities of FYM, N and P could best be allocated to the crops of a four-course rotation; there were also tests of additional quantities of N and P. Both FYM and P fertilizer gave large increases in the yield of all crops, but the profitability of the rotation as a whole proved to be little affected by which crops received FYM or P fertilizer. The rates of N tested were too small to provide any information relevant to current farm practices. The optimal dressing of P fertilizer at 1965 prices was 0.5-0.6 cwt. P2O6 per acre.

1. The yield and composition of milk from twenty Border Leicester x Cheviot ewes offered dried grass cubes, dried grass cubes and hay, hay or grazing was determined over a lactation period lasting 10 weeks. Milk yield was estimated by weighing the lambs before and after each suckling on one day each week. Samples of milk for analysis were obtained at fortnightly intervals by hand milking the left side of each udder before the mid-day suckling by the lambs.

2. Ewes receiving dried grass cubes and suckling twins and those receiving dried grass cubes and hay reached mean peak milk yields of 3470 and 2680 g./day, respectively, at 2-3 weeks after parturition, whilst the yields of the remaining ewes declined continuously from the beginning of lactation. The mean milk yield over the lactation of ewes receiving dried grass cubes and suckling twins was 2785 g./day, of those receiving dried grass cubes and suckling singles 1821 g./day, of those receiving dried grass cubes and hay 2119 g./day and of those receiving hay 1177 g./day. The yield of milk energy was highest for all ewes during the first week after parturition.

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.

Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.

1. Male-sterile plants were discovered in the progeny of an open-pollinated plant which had undergone a much higher level of natural crossing than any of a group of fifty plants drawn from the same population.

2. Some male-sterile plants produced a few viable pollen grains under some conditions but these rarely permitted self-fertilization. A few plants had both sterile and fertile tillers. Male sterility was not transferred by grafting. No effect on the proportion of fertile plants could be found, when progenies were observed early and late in the season, sown in the autumn and spring or grown at contrasting plant densities.

3. Inbred lines, unrelated to the male-sterile plants and their derivatives, varied greatly in their ability to restore male fertility. Some lines maintained the sterility almost completely, two consistently gave all male-fertile offspring, but the majority were partial restorers.

1. A method of producing hybrid beans with the aid of a cytoplasmic male-sterile is described.

2. Most of the requirements of large scale production of hybrid seed can be met: use of genetic markers showed that the male sterility allowed 100% cross fertilization; there was no evidence of a deficiency of insect pollinators near Cambridge; and fertility restoring lines are available.

3. The importance of being able to maintain a high level of sterility in the female parent line is emphasized. Methods of improving the proportion of sterile plants in the sterile phase of an inbred are discussed. The tolerable level of fertility in progenies of sterile parents depends on the level of sterility necessary in the female parent of the final cross. Five inbreds are being handled with less than 2% of fertile plants in their sterile phase.

1. A series of three field experiments, concerning the effects on growth, development and yield of sugar beet of extension of the growing season by transplantation, were carried out in 1962, 1963 and 1964. The first two experiments were subject to sequential sampling programmes for growthanalysis purposes, but in the third only yield data were recorded.

2. Root yield increased with advance in planting date and increase in plant population in all 3 years. Nitrogen had no effect on root yield in any year. There was no consistent interaction between time of planting and plant population in their effects on root yield. The advantage for transplanting over field sowing ranged from 4 tons washed beet per acre in the case of an early field sowing (20 March) to 10 tons in a late one (23 April). There were no treatment effects on the concentration of sugar in the roots. The roots of transplants were more globular in shape and fanged than were those of field-sown beet.

1. The metabolism of 137Cs in dairy cows has been studied after single oral and intravenous doses and during twice daily oral dosing for 28 days.

2. Gastrointestinal absorption of 137Cs was about 70-80% of the oral doses.

3. After 28 days continuous feeding the mean concentration of 137Cs in milk was 0.84% daily dose/1. and the body burden of the isotope varied between 5.7 and 8.2 times the daily intake.

4. When feeding of 137Cs stopped the concentration of the isotope in milk fell by a factor of five in 8 days, by a factor of ten in 16 days, by a factor of twenty in 32 days, and thereafter exponentially with a half-life of 30 days. The concentrations of the isotope in muscle decreased at first rather slowly but finally also exponentially with a half-life of approximately 30 days.

1. Broad bean plants caged with bees produced more seeds per pod, more seeds per plant, heavier seeds and a greater weight of seeds per plant than plants caged without bees. They also had more mature pods at the first harvest but the total number of pods picked was about the same for cages with and without bees. The flowering season of plants caged without bees was extended.

2. Field bean plants caged with bees had more seeds per pod and more seeds per plant than plants without bees.

3. For both crops, plants in the open had about double the number of pods, beans and weight of beans as plants in cages.

From May 1963 to April 1964 seasonal changes in soluble nutrients were followed in soil samples taken monthly from plots having none, PK, and NPK fertilizers in experiments at Rothamsted and Woburn. Phosphorus, potassium and magnesium concentrations in equilibrium extracts of the soils made with 0.0lM-CaCl2 solution were determined. Exchangeable P was determined with an anion exchange resin. Samples were taken under five arable crops growing in rotation, and under permanent grass on the two soils.

1. In four different years, swards of perennial rye-grass/white clover were treated with nitrogenous fertilizer (0, 30 or 60 lb. N per acre) in mid-February to produce an early growth of grass. The effect of the time of the first cut, taken in March or April, on the annual yield was studied.

2. The total annual yield was reduced when an increasing quantity of grass was removed at the first cut because this interfered with the development of inflorescences and reduced yield at the second cut.

3. Fertilizer treatment increased early growth and advanced by 2-14 days the date in spring at which the yield was adequate for grazing; this improvement improvement was small compared with the extent to which this date was affected by differences in the weather from year to year.

4. The response in total annual yield to N averaged 17.2 and 14.9 lb. of dry matter per lb. N respectively for the 30 and 60 lb. N per acre applications. The highest responses were measured when little or no grass was removed at the first cut. Where a larger crop was removed at the first cut the response to N was reduced; exceptionally it was negative.

While the leaf resistance of many of Knight's B genes in a Sakel background is now much lower than that found in his original studies, that of B9K has remained unimpaired and this gene still segregates as a major gene. It is proposed to ascribe to the weak gene transferred by Knight from Wagad 8 (G. herbaceum) to Sakel the symbol B11, as gene homology tests between this gene and other B genes indicate that is non-homologous with them. The strong effect of environment on the expression of B11 was confirmed and it was noted that in Upland stocks B11 was much more effective than in Sakel, whereas the opposite was true of B9K.

While the leaf resistance of Bm Sakel is high its stem resistance is of a low level and it suggested that leaf, stem and boll resistance may be under the same control in some genetic systems but not in others.