Soil, water and leaf analyses were carried out on samples from irrigated orchards in the Jordan Valley. Analysis of the soil for available phosphorus and potassium gave meaningful results. Analysis of the irrigation water showed that a high sodium and chloride content caused an increase of these ions in the soil, which led to undesirable effects such as chlorosis. Irrigation water class C3–S1 should only be used if there is an annual precipitation of about 300 mm. Leaf analysis showed changes in the composition of leaves with age, but only potassium varied significantly between varieties. Standards of leaf, soil and water composition are suggested for the growing of citrus.

Thirty Dorset Horn ewes were put to the ram four times in two years; four ewes lambed four times to produce 22 lambs, and 21 ewes lambed three times, producing 100 lambs with satisfactory birthweights. The minimum interval from parturition to conception was 32 days and there was no decline in the liveweight of the ewes. Another 37 ewes were run with a teaser ram from 1 January to 1 August 1964 (when it was replaced by a fertile ram) and from 15 April to 31 August 1965 when it was again replaced by a fertile ram. There was a marked decline in oestrual activity in Flock 2 from the middle of March until the middle of July.

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.

This paper summarizes the results of a series of NPK experiments conducted in the past on mature tea in north-east India.

The fixation of nitrogen in root nodules of pigeon pea, Centrosema pubescens and Styloxanthes gracilis were studied, and the transfer of nitrogen to other parts of the plant. Fixation reached a maximum of 14·5, 10·3 and 4·6 mg. per day per plant respectively, and the rate of transfer of nitrogen from the nodules was at a high constant rate throughout the experimental period. With pigeon pea and Centrosema younger plants seem to be more efficient fixers of nitrogen than older on, but the reverse was true with Styloxanthes.

Supplementary irrigation experiments were conducted on a Clansthal sand and a Windermere clay. Irrigation treatments were based on the application of 1 inch of water when the soil moisture deficit reached 2·5, 3·5, 4·5 and 5·5 in. in 7 ft of soil on the sand, and 1·00, 1·75, 2·50 and 3·25 in. in 2 ft of soil on the clay. Each experiment included a dryland control and soil moisture was estimated weekly in each plot with a neutron probe. The results showed that there were significant linear increases in yield with increasing quantities of water applied. The crops exploited soil moisture to a depth of 6 ft in the sand and 3 ft in the clay, even with the maximum water treatments. Under dryland conditions, on the sand the crop exploited soil moisture to the wilting point only in the surface foot of soil, but on the clay the crop extracted moisture held at tensions greater than 15 bars in the top 3 ft of soil. The conclusions are that, where available water for supplementary irrigation is limited, heavy soils should be irrigated in preference to sandy soils, and that the most efficient use of both rainfall and irrigation water is achieved when 1 cusec is used to irrigate about 200 acres.

The failure of overdrilling techniques to improve poor pasture and the development of the dipyridylium herbicides, particularly paraquat, for controlling grass species, prompted research into oversowing techniques in 1963 and 1964. Rotary cultivation, although giving better establishment than any other oversowing technique, did not always reduce the more persistent weed grasses such as Agrostis spp., and so failed to produce a perennial rye-grass dominant sward. This was believed to be due to various factors such as unsatisfactory herbicide pre-treatments, the interval between spraying and cultivation, the high moisture content of the soil when cultivated, as well as the greater resistance of rhizomatous grass species to paraquat. In the absence of paraquat, rotary cultivation was able to establish a satisfactory number of seedlings. In both experiments, however, the subsequent botanical composition was considerably influenced by pasture management.

Experiments were conducted during three crop seasons to determine the effects of lindane and carbary1, applied to the irrigation water or incorporated in the soil, on the control of insects, on the nitrogen status of the soil and plant, and on grain yield of lowland rice. In two crop seasons the highest grain yield was obtained from three applications of lindane to the irrigation water and carbaryl sprays at 7- to 10-day intervals, and in the third season from 20 kg/ha. carbaryl incorporated in the soil without any lindane treatment or carbaryl spray. In two seasons, soil-incorporated carbaryl at 20 kg/ha. active ingredient gave a significantly higher yield than the no-insecticide control, and in one season the increase in grain yield was just below the significant level. Most of the grain yield increase with 20 kg/ha. carbaryl incorporated into the soil was caused by better control of stem borer and leafhopper and a significant reduction in virus infection.

Faeces of different birds and animals were analysed for sulphur and nitrogen. Chick faeces contained the highest amount of sulphur while farmyard manure gave the highest value for mineralized S after incubation. There was a high degree of correlation between the total S and total N.

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.

Two types of design are described, in which the number of plants per unit area varies systematically within any one plot in the field, the plant arrangement being held constant. Any desired range of spacing can be covered in either design and the calculations necessary to establish specific sets of dimensions are given. In addition descriptions are given of the laying-out, planting (or sowing), management and recording of experiments using these designs.

Twenty strains of Eragrostis curvula, together with E. plana, Chloris gayana and Digitaria smutsii, have been compared on the basis of (a) herbage yields and (b) nitrogen, phosphate and potash composition and yield, from broadcast stands in a randomized block experiment over two seasons. The strains of E. curvula were grouped into types for which the names Curvula, Robusta Blue, Robusta Green, Robusta Intermediate, and Chloromelas were used. Significant differences were demonstrated in herbage yield between certain of these types, but there were no clear differences in nitrogen content. Chloris, Digitaria and the three Robusta types had the highest phosphate and potash content, whereas the Chloromelas type and E. plana were intermediate and the Curvula type was lowest in these constituents. Robusta Green, Robusta Intermediate and Curvula types had the highest nitrogen yield, Robusta Green and Robusta Intermediate types the highest phosphate yield, and Robusta Intermediate and Robusta types the highest yield of potash. The superiority of types other than Curvula (Ermelo and Tanganyika strains), and the need for research on the types, has been demonstrated.

Dormancy of six varieties of paddy, of three maturity groups, was studied under six seed-treatments. One type showed no dormancy but others showed dormancy in varying degrees 15 days after harvest. Dormancy was completely broken either by removing the kernels from the glumes, or by puncturing the glumes, or by putting acid-treated seeds in an atmosphere saturated with oxygen. The germination percentages were also significantly increased when seeds were treated with N/10 sulphuric acid solution for four hours, or when seeds were put in atmospheres saturated with oxygen. Speed of germination did not improve, as in the case of seeds germinated after four months of harvest, except in cases where the kernels were removed from the glumes or the glumes were punctured. The causes of dormancy of rice seeds were assumed to reside in the flowing glumes (lemma and palea), and different seed-treatments improved the germination of rice seeds by increasing the permeability of the glumes to oxygen and/or reducing the resistance of the tough glume covers over the germinating embryos. The magnitude of the treatment effects differed with variety. These studies suggest methods of improving germination.

Essential features are described of a computer programme, written in F.A.S., for the evaluation of 1 : 1 and 4 : 1 confidence limits of expected ‘twenty-day’ totals of rainfall. The paper deals briefly with the availability and utility of the programme to agricultural research workers in Africa.

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.