In a study of soil and water conservation systems for high-altitude Kenya farming, control of accelerated erosion in two arable crops per year for six years was achieved by contour-ploughing and tied-ridging. The Kikuyu red loam latosol lay on 10 per cent and 12 per cent slopes under rainfall of intensities often exceeding 2 inches per hour. Soil structure measurements showed progressive reduction in the acceptance rate of rainfall, but gulley erosion occurred only in the absence of ties. Six years of intensive arable cultivations were compared with rotations having two, three or four years of perennial grass ley, with and without protection by Nichols terraces. Runoff, measured through Parshall flumes, was heaviest from well-established grass immediately after intensive grazing. Productivity was highest under grass. With a basal dressing of one hundred weight of double supers, 10 acres of Cynodon dactylon carried 20 Zebu steers for seven months without supplementation and showed a liveweight gain of 1·1 lb per steer per day. Grazing was reduced by failures in establishment of short legs. The grass depleted soil moisture to wilting point to a depth of ten feet within six months of planting and annually thereafter. Water use was approximately the same as total rainfall. Results, applicable locally, indicate a limit of four years duration for arable and a minimum of five years duration for pastures. Terraces can only be replaced by a high standard of management and skilled cultivation.

Since the profitability of the geranium crop depends to a great extent on the total yield of oil per acre, methods of increasing this yield are of prime importance. Two trials were laid down to determine the responses to nitrogen, phosphate and cutting at various times during the year. Phosphate increased total weight of green material, nitrogen had little effect, and neither significantly affected the yield of oil per ton cut. Time of cutting influenced both oil and green material yields. Climatic factors producing higher yields of green material had the opposite effect on yields of oil per ton of material cut, and vice versa. Fertilizers had no discernable effect on oil quality, but there was an appreciable difference between oil produced after wet and dry periods.

Most oil palm pollen is produced by male inflorescences 2–3 days after anthesis, and this pollen is the most viable. When protected, pollen viability on female inflorescences is good up to 6 days, after which it declines. The majority of the pollen remains below the canopy, especially at bunch level. Results of quantitative evaluation of pollen dispersal showed that atmospheric pollen density is very variable and is governed by numerous factors. There is a marked diurnal variation, with highest pollen density during the afternoon and a negligible amount during the night and early morning. Rain causes an immediate drop in concentration, but pollen densities were influenced more by the number of days on which rain was recorded than by total rainfall. A relationship exists between pollen density, the number of male inflorescences in the vicinity, and rainfall, but the effects of relative humidity, sunshine and wind are obscure. Whilst pollen density drops rapidly within a short distance from the inflorescence, there is a significant dispersal over greater distances than previously thought.

Two groups of mature Marwari wethers were raced at 5 and to miles/hr respectively, for 30 minutes. Rectal temperature, respiratory frequency and pulse rate were measured initially, again immediately after the exercise, and subsequently four times at 20 minute interval. The rise in rectal temperature, respiratory rate and pulse rate in the animals raced at 10 miles/hr was 2·1°F, 86 and 22 counts/min. respectively. The corresponding values in the animals raced at 5 miles/hr were 0·9°F, 72 and 19 counts/min. The rise in rectal temperature due to stress was proportional to the degree of exercise. The magnitude of increase in the respiratory rate tended to be the same under both the treatments, and the trend in pulse rate was similar to that of respiratory rate.

The chemical composition of setts of cocoyam (Xanthosoma sagittifolium) varied in different sections. The highest concentration of N, P and fat occurred in the youngest part but crude fibre and Ca were highest in the oldest portions. Dry matter was lowest in the youngest section. Positive linear relations were found between N and K percentage, Ca/P ratio and age of the various sections of the corm, with the highest N/P ratio towards the middle portion of the corm. The high sprouting percentage of the youngest sections of the corm was attributed to both greater bud number per given area and to the short period of their dormancy. Better establishment in the field was achieved by using setts from the oldest section of the corm, probably because they were less vulnerable to decomposition by soil micro-organisms. Positive linear relations were established between P concentration and sprouting percentage. Setts from the two oldest sections of the corm produced plants with the greatest leaf blade area, total dry weight and dry weight of various organs and it is recommended that planting setts should be obtained from the less succulent section of the corm. There were also positive linear relations between Ca concentration of setts and dry matter production in the field, and between leaf blade area at time of harvest and corm yield.

On some estates in Malaya the incidence of Marasmius bunch rot reaches serious proportions through causes other than poor sanitation or pollination. In such areas fungicidal sprays may be of value in both therapy and prophylaxis. In laboratory tests, using the paper disc diffusion and liquid culture methods, 32 fungicides were tested for activity against Marasmius palmivorus to provide an indication of promising formulations for field trials. A number of compounds showed strong inhibition of fungal growth in both series of tests, and amongst these the organo-mercury preparations were outstanding, especially Antimucin WBR. Other promising fungicides included Fylomac 90, Seprisan, Hyamine, Izal, Thiram and PCNB. In field trials in which Antimucin WBR and Verdasan were used for treatment of partially-infected immature bunches, these fungicides checked disease development, with a significant reduction in losses through disease. The value of fungicidal sprays formerly recommended in estate practice, and their potential value in prophylaxis, are discussed.

Under the arid tropical conditions of the Sudan, where seasonal variations in photoperiod are small but where temperatures are high, there is evidence from the performance of both local and introduced onion varieties that temperature has considerable influence on bulbing. The onset of bulbing does not prohibit the emergence of bladed leaves under such high temperature conditions. The size of the onion plant may be an important factor in the bulbing response under conditions of high temperature and small variations in photoperiod.

Veld dominated by Hyparrhenia and other species, in a sub-tropical 38-inch rainfall area in Swaziland, was changed into a more productive sward of Eragrostis curvula and other seral grasses by the application of nitrogen, phosphorus and lime. Nitrogen had the greatest effect in terms of both herbage production and ecological change, but responses were increased by the addition of phosphorus and lime. There were indications of yield responses to zinc in the presence of lime, and to molybdenum, but trace element effects were generally small and inconsistent.

A field experiment was conducted to see if a successful crop of groundnuts can be raised in North Bihar (India) during summer in rotation with paddy. The experiment was designed to find a suitable variety, and the best time of sowing and digging. Three promising varieties of groundnut, one early-bunch and two late-spreading types, were included in the test. Emergence and flowering were rapid in the early-bunch variety as compared to the two late-spreading varieties. Though flowering was less in the bunch variety, the percentage of mature kernels was higher. The earlier the sowing and the later the digging, the greater was the pod yield in all cases. On the basis of these results and other practical considerations, the best combination seems to be to sow the early variety AK 12-24A about 15 January and to dig about 22 June.

Devices are described for calculating the available-water capacity of a soil from data on the characteristics of soil in each horizon.

Several methods of measuring and estimating the available-water capacity of soils with varying degrees of accuracy are described. The errors associated with the use of the different techniques on a wide range of soils have been calculated and suggestions are made regarding the choice of method for particular circumstances.