In the course of investigations into the cause of an obscure pathological condition of the tea bush, it became necessary to make pH determinations of certain soils. Electrometric apparatus and a suitable centrifuge for clearing the solutions were not available. Considerable difficulty was experienced in making the determinations with accuracy by indicator methods owing to two causes. First, the turbidity of the soil solutions made comparison with standard buffer solutions somewhat difficult; secondly, the colours developed in the soil and buffer solutions with some indicators were different in hue, as distinct from shade or tint. This rendered exact matching quite impossible. The latter difficulties also arose when the drop ratio method was used instead of standard buffer solutions. The errors resulting from these causes were believed to be unduly large, and it was felt that greater accuracy would be attained if these difficulties could be overcome.

Non-breeding groups, I, II and III, each with six high-potassium (HK) and six lowpotassium(LK) Chokla ewes were given water once in 24, 48 and 72 h respectively. In the next summer, seven ewes (4 HK and 3 LK) from each group I, II and III were switched over to a watering schedule of once in 24, 72 and 96 h respectively and were naturally bred. All the animals were maintained on grazing alone.

Water deprivation for 72 h caused 18·8 and 19·2% body weight loss in HK and LKewes respectively; an overall average maintenance of weight loss in LK ewes was significantly higher than in HK ewes from the same group. There were significant differences in water intake due to treatments only. The HK and LK ewes from groups I and III showed a similar trend.

Pregnant ewes of HK and LK types given water once in 96 h lost 21·7 and 23·8% of their body weights respectively. Corresponding weight loss in aborted ewes were 23·8 and 33·3%. Two ewes, each from 3 LK and 4 HK animals aborted owing to water deprivation for 96 h. The water intake reached 30 and 36·5% of body weight in LK and HK pregnant ewes given water intermittently.

The wool attributes of non-pregnant ewes did not indicate a significant influence of blood potassium types. Four out of five ewes of the LK phenotype died during 3 years, irrespective of watering schedule.

The skeletons of most of a group of lame buffalo from an area around Pasir Puteh and of some of a group of similarly lame animals from an area S.W. of Pasir Mas were poorer than those of a control group from around Kota Bharu. Analyses of blood and liver indicated that the defective mineralization of the skeleton was caused by a shortage of phosphorus rather than of calcium or copper.

Evidence for a relationship between lameness and the quality of the skeleton was not strong and further study including a feeding experiment is needed to establish the validity of this.

Between 1953 and 1955 a series of field experiments have been carried out in Great Britain to assess the effect of sowing date on the extent and the rate of emergence of a number of varieties of maize.

The range of sowing dates was from late March till May. Records were kept of the soil temperatures, these will be reported later, and in certain experiments the water content of the soil was maintained at field capacity. In all experiments a northern flint variety and a southern dent variety were sown, in the first year only flint × dent hybrids were also grown.

There was an increase in final emergence with the later sowing dates. The northern flint varieties were superior to the southern dent varieties, while the flint × dent hybrids occupied an intermediate position. The lower final emergence of the southern dent variety was most marked at the earlier sowing dates.

Differences between varieties in the speed of emergence, taken as the number of days from sowing until half of the surviving seedlings had emerged, was observed at several centres. The open-pollinated varieties usually emerged more slowly than the flint × dent hybrids. There was a very marked difference between early- and late-sowing dates in speed of emergence.

It was possible in the second year to compare seed of high quality with that of low quality as determined by the ‘cold test’ of germination capacity. The lowquality seed gave greatly reduced final emergence, the experiments stressing the need for the adoption of a standard ‘cold test’ for maize seed, especially of that intended for sowing in north-western Europe.

The high final emergence of the northern flint varieties suggest that a gene source for resistance to soil pathogen attack is readily available. The possibilities in north-western Europe for expansion of growing grain maize would be greatly strengthened by development of varieties capable of growth at low temperatures. The experiments suggest that until such varieties are available little advantage in time of emergence will be gained by sowing maize before late April in Britain.

Carcass measurements were made on 24 Rambouillet lambs of different live weights but of the same age, and the lambs divided into 3 groups of 8 according to live weight. Group I, with the lowest mean live weight, had the lowest dressing percentage, relatively heaviest head and feet and lightest pelt, while group III, with the highest mean live weight, had the highest dressing percentage, the relatively lightest head and feet and the heaviest pelt of the three groups.

Group I contained the lowest percentage, and group II, of medium live weight, the highest percentage of muscle, while the relative weights of bone and fat tissue were similar. Group III contained the highest percentage of fat tissue and the lowest percentage of bone. The differences in the relative weights of the edible internal organs between the three groups were not significant.

Testis weight was relatively much greater in Group III than in the lighter animals. While dressing-out percentage increased with body weight, the increase was not equally distributed between fore and hindquarters. Hindquarters were relatively larger in group II than in group I; but the forequarters accounted for the greater part of the differences between groups II and III.

Damage to barley grain cv. Golden Promise was induced in the laboratory by putting seed at 8·7, 14, 18, 22, 26 and 35% moisture content (MC) through a mechanical laboratory thresher for 10, 20 or 45 sec. The extent of visible external damage was greatest at 8·7 and 14% MC with reduced and similar levels of damage after handling at 18–35% MC. At moisture contents up to and including 26%, seeds could tolerate extensive mechanical damage with little effect on seed quality. Seed germination and seedling vigour were, however, reduced after handling at 35% MC despite similar levels of external damage to those seeds handled at 18, 22 and 26% MC. Samples of grain of cv. Triumph produced by whole-crop harvesting included mainly slightly damaged seeds with little effect of harvest moisture content, which ranged from 22·5 to 44%, on the incidence of damage. Seed germination and seedling vigour increased when seeds were harvested at progressively lower moisture contents, with the largest increase between 36% MC (56% germination, 6·1 vigour rating) and 29·5% MC (94% germination, 7·8 vigour rating). The seed quality of whole-crop harvested seed at 29% MC was similar to that of combined seed harvested at the same moisture content. It is suggested that 30 % is the maximum harvest moisture content at which commercially acceptable seed may be produced by the whole-crop harvesting method.

The last issue of this Journal (p. 132) contains a paper by Dr R. A. Fisher on the effect of Silica upon the growth of Barley at Rothamsted, which begins by stating that his data “show conclusively that the view previously rejected that the silicate acts by making available to the plant the actual reserves of soil phosphates must be regarded as strongly established.” Twice elsewhere Dr Fisher states that this erroneous conclusion of previous investigators is due to the fact that they had considered only the proportion of phosphoric acid in the ash and had overlooked the increase in the total phosphoric acid in the crop. As Mr Morison and I were the previous investigators in question I turned to our twenty-three-year-old paper with some curiosity to ascertain the grounds for this magisterial dismissal of our conclusions, for my remembrance of the subject did not tally with the opinion Dr Fisher attributes to us. Still less do I agree now that I have re-examined our original paper.

Response of rainfed barley to different methods of nitrogen application was studied on a loamy sand soil in 1974–5 and 1975–6. The nitrogen fertilizer was applied by broadcasting, side drilling, drilling below the seed and in solution. In a year of lower rainfall, applying the fertilizer below the seed or in solution produced significantly more grain yield than broadcasting or side drilling. In a year of higher and well-distributed rainfall, applying the fertilizer below the seed was significantly better than other methods of nitrogen application. The magnitude of the response to applied nitrogen increased with increase of crop season rainfall and its better distribution. Placing N below the seed improved water use. It was followed in order by applying in solution, side drilling and broadcasting in both the years.

The paper reports a laboratory study on miscible displacement of reactive solutes during leaching a highly saline-sodic soil rich in soluble sodium carbonate with solutions of calcium chloride. The effect of varying flow velocities, initial soil moisture content and concentration of calcium in the leaching water on the extent of carbonate precipitation and replacement of sodium by calcium from the exchange positions was studied in soil columns. The results showed that precipitation of soluble carbonates in the soil increased with increasing flow velocity, initial soil moisture content and concentration of calcium in the leaching solution. The results further showed that the calcium exchange capacity of the soil was reduced significantly and nearly proportionally with decrease in the degree of water saturation as a consequence of decreased water application rate and initial soil moisture content. In view of the results obtained, a simple model to describe calcium-sodium exchange under unsaturated flow conditions in saline-sodic soils under consideration has been proposed. Possible implications of the results in actual field situations is discussed.

The digestibility coefficients of old barley straw fed with a basal ration of oats, bran and maize to two adult horses and of the same straw after treatment by Beckmann's method were ascertained. The coefficients of the nitrogen-free extractives and the crude fibre of the untreated straw were 33·23 and 38·24 respectively and of the treated straw 54·14 and 63·71. There was a reduction in the digestibility of the small quantity of protein and fat.

Taking into account the 14·5% of dry matter lost during treatment, the starch equivalent value of the treated material was somewhat higher than that of poor quality meadow hay.

The digestibility coefficients were considerably lower for an immature horse previously maintained entirely on fresh grass.

A field study to optimize the nitrogen (N) top-dressing mode of panicle fertilization and improve rice yields was conducted in mid-eastern China. Japonica cultivar Yunongjing-6 was grown and panicle N fertilizer was applied at the beginning of the inverted fourth leaf stage using three different modes: manual broadcast application (BA) on the soil surface as a control treatment, deep application during ditching at a depth of 15 cm (DD) and manual BA on the soil surface during deep ditching (BAD). The activity of soil enzymes, including invertase, urease, phosphatase and catalase, was increased significantly at the jointing, booting and grain-filling stages with the DD and BAD treatments compared with the traditional BA mode. The DD and BAD treatments also increased basal internode and neck-panicle internode bleeding intensity. The DD treatment gave the highest crop yield, increasing the yield by 0.63 and 0.31 t/hm2 in 2011 and 2012, respectively, compared with BA. The results suggest that ditching during panicle N fertilizer application after sun-drying of the fields increases rice yields, most likely by improving the activity of soil enzymes and enhancing the physiological activity of roots and grain weight.

1. The Hutchinson-MacLennan method for determining the lime requirements of soils, when practised under suitable standard conditions, gives more reliable indications than are obtainable by the ordinary methods of chemical analysis.

2. The method gives indications which appear to be uniformly in excess of the actual requirement of the soil for lime as judged by economic standards: hence a correcting value seems advisable.

3. The correcting value for the soils of Canterbury Plains is about 0·10%.

4. The greater acidity and higher lime requirement of soils of the Southland Plains appears to be due to a combination of lack of natural under-drainage and high rainfall, which prevents aeration and oxidation of organic matter, so that “sour” humus accumulates in the soil.

The probable error on one pig calculated on the average daily live weight increase was found to be for cross-bred pigs about 7 per cent.; for pure-bred pigs from the same litter and each of similar live weight about 3 per cent.; for cross-bred pigs each of similar live weight but from different parents about 4 per cent.

The error is greatest in experiments of short duration and it decreases as the period of the experiment is lengthened. The decrease is slight if the experiment is prolonged beyond seven weeks.

The errors on 18 separate pens containing four pigs to each pen (the total initial live weight of each pen being similar) varied from 2·3 per cent, to 12·08 per cent., the average being 6·21 per cent.

The percentage probable error is relatively low when the pigs are fattening rapidly and high when the pigs are fattening slowly. The average daily increase of the quicker fattening female pigs when un-speyed appears to be depressed as a result of periodic sexual disturbances.

The stage of fattening does not appear to influence the probable error. Animals in the later stages of fattening show a greater range in their rate of fattening than animals in the early stages, see Fig. 2, p. 284.

Weekly weighing of individual pigs is recommended as it gives an indication of the health of each pig. It also enables each experimenter to discriminate between differences in the rate of fattening due to individuality and differences due to ill health, etc.

The rate of fattening of pigs is very variable, periods of rapid fattening are followed by periods of depression.

Gill in 1871 first pointed out that when an excess of basic lead acetate is added to a solution of invert sugar the negative rotation of the latter is greatly reduced owing to the formation of a soluble lead compound of laevulose. If sufficient lead solution is added the negative rotation may become a positive one; thus in one experiment quoted by Gill a negative reading of – 28° was transformed into a positive value of + 57°. The change of rotation was not, however, permanent and on removing the lead or on acidifying the solution the original rotatory power was restored. The change of rotation was attributed to an effect of the lead on the laevulose only; a solution of dextrose was practically unaffected by the presence of basic lead acetate. Since Gill's paper the effect of basic lead acetate as a source of error in sugar analysis has been the subject of numerous papers especially by Pellet, Svoboda, Edson, Prinsen Geerligs, Watts and Tempany and Eynon.

A statistical analysis was undertaken to study persistency of lactation in buffaloes, using the milk records collected on a herd of buffaloes belonging to the Ministry of Agriculture at Sakha Experiment Station. The number of buffaloes included in this report was 328 animals having 722 lactations. A formula was developed for estimating persistency of lactation in buffaloes and results obtained are as follows.

Plectranthus edulis is an ancient tuber crop, cultivated in Ethiopia, which produces stem tubers on stolons below the ground; however, agronomic and physiological information on this crop is scarce. Three field experiments were carried out at each of two locations (Awassa and Wondogenet, Ethiopia). Expt 1 dealt with the effects of breaking a seed tuber into different numbers of seed pieces before planting, Expt 2 assessed the effect of the weight of the seed tuber piece and Expt 3 investigated the effect of planting different numbers of seed pieces per planting hole. Cultivar Lofuwa was planted in Awassa, whereas cvar Chankua was planted in Wondogenet. Breaking seed tubers in Expt 1 resulted in more main stems/hill, more tubers and smaller individual tubers. In Wondogenet, the tuber yield also increased. Breaking did not affect the number of stolons/m2. Expt 2 indicated that when only one seed piece was planted per planting hole, smaller seed pieces gave fewer stems, fewer stolons and fewer tubers/m2, smaller tubers and lower tuber yields. Expt 3 showed that planting more seed pieces/planting hole gave more stems, more stolons and more tubers/m2, thus increasing tuber fresh yield/m2, whereas the mean tuber weight was not consistently affected. Across all experiments, the tuber yield increased when the number of main stems increased up to three main stems/m2. Higher tuber yields resulting from experimental treatments were either achieved by an effect on number of tubers alone or by combined effects on number of tubers and mean tuber weight, but not by an effect on mean tuber weight alone. The number of small tubers was high in all experiments. Breaking a seed tuber into two or three pieces before planting them in one planting hole consistently resulted in increased numbers of main stems and tuber yield.