The study of climate deals with the analysis of seasonal levels of various meteorological factors which influence us through the aerial environment. Short-term deviations from the expected climatic pattern are described as weather. In agriculture, a knowledge of both climate and weather is an essential basis for the adoption of any farming system and practical farmers all over the world have discovered, by trial and error over long periods of time, patterns of farming suited to their respective climatic areas. In many cases today these farming patterns are no longer economically feasible or socially acceptable and, with the present urgent need for increased agricultural production in the developing countries, there is not time for a leisurely approach to the problem of modifying the systems or finding new ones.

Ten weighable containers, the same size as 4-gallon petrol tins, were located in a plot 80 metres from the leading edge of a 2-acre field of irrigated alfalfa growing under advective conditions in the Sudan. Evapo-transpiration from alfalfa growing in these containers was compared with evaporation from a series of small evaporimeters level with the top of the plants and from a standard U.S. Class A evaporation pan, and also with estimates of evaporation calculated by the Penman formula. Evaporation from the free water surfaces in evaporimeters or pan was always greater than from alfalfa in the containers when the crop was 25 cm. high or less, but lower when the crop was more than that height, whilst the figures calculated by the Penman formula were much lower than either. Cumulative water losses were also recorded from containers where the soil was kept wet or allowed to dry out, and these were compared with evaporimeter losses up to the stage where no further water was being lost from the dry containers.

The effect of available water on yield (e.g. Waring, Fox and Teakle, 1958) and of nitrogen on yield and quality (e.g. Waring and Teakle, 1960) have been examined for wheat grown on black earths of the Darling Downs in Queensland. However, the joint effect and individual contributions of nitrogen and water to this effect in the field appear to have been neglected. Further, the condition known as mottled wheat, described by Wood (1960), is an important problem in the wheat industry, and it was felt by the authors that this condition was the result of a water-protein yield complex. It was therefore decided to examine the effects on yield, total protein and mottling of applications of nitrogen and water in a soil where these were deficient.

Pot experiments were used to test the effect of incorporating various organic materials in the soil on the nodulation of peas (Pisum sativum). Only farmyard manure gave a consistent increase in the number and weight of nodules, and also in plant growth, increases which were also produced by the aqueous extract of farmyard manure, although none of these increases were as large as those obtained by the addition of a combination of P and K fertilizers or activated vermiculite. Field beans (Vicia faba) and French beans (Phaseolus vulgaris) in general reacted in the same way as peas.

The dry-matter and organic-matter digestibilities of eight samples of fodder maize and five samples of maize silage were measured, using sheep. The maizes were harvested and ensiled in such a way that comparisons could be made between the digestibilities of either the same maturity types, harvested on different dates, or of different maturity types harvested on the same date, or of maize and silage made from similar material. The total range of organic matter digestibility for all types of maize on all dates was within the range 70·6 to 75·2 per cent. The digestibilities of maize silages were found to be slightly lower than those of the original materials.

Three Nigerian vegetables, Solanum melongena, Solanum nodiflorum and Vernonia amygdalina were analysed for oxalate, cyanide, minerals and food value. The edible leaves were low in oxalate and so involve no danger of oxalate toxicity, or decrease in their nutritive value due to the presence of oxalic acid. The content of hydrocyanic acid was also negligible and would, in any case, be lost during cooking. Aluminium contents were very high and could possibly be regarded as constituting a toxic level. The calcium content would provide about 4–7 per cent of the daily requirement for adults, who could depend solely on these vegetables for their daily iron requiretnents. The leaves were also good sources of protein. All these factors make the vegetables important dietary components in Nigeria and they could serve as a protein supplement, especially in villages where children can not get enough protein from meat, milk and cheese.

An experiment is described on the establishment of cocoa on clear-felled land, using various ground covers on which 22 NP:KMg factorial treatments were later superimposed. Growth of cocoa was improved in mulched and clean-weeded plots and the unshaded trees began bearing two years after planting, which is exceptionally early for young cocoa in Ghana. In the third year responses to NP fertilizer were obtained and in the following year yields were very high, up to 2170 pounds dry cocoa per acre. This was partly responsible for K deficiency, particularly in plots without mulch and KMg, which led to declining yields especially on the NP plots. Significant increases were thence obtained from the KMg fertilized plots. Mulching at the rates used in this experiment is too expensive and uneconomic, but K fertilizer applied at rates higher than the present rate of 75 lb K2O/acre/annum may be needed on Ghanaian forest soils if they are clear-felled for growing unshaded cocoa.

The pattern of yield and productivity of a typical Raphia swamp is described and suggestions are made for improving the crop by selection

The effect of grass mulch on groundnut yield and shelling percentage has been studied at three locations in the Gambia. Yield increases have been mainly attributed to physical factors but residual increases were found for only one year after application. Mulching gave rise to significant increases in exchangeable soil potassium, in percentage potassium in the plant at harvest and in total potassium uptake by the plant. In the absence of response to potassium fertilizer, increased uptake was ascribed to luxury consumption. It was suggested that reduced shelling percentage from mulched plots was due to potassium-calcium antagonism.

Use of substituted phenoxyacetic acids as yield stimulants for Hevea brasiliensis has been mainly limited to applications below the tapping cut rather than above. Although the above-cut application of these stimulants has exhibited some advantages with respect to yield, its use has been limited due to undesirable bark renewal characteristics. This paper describes studies with a method of above-cut application of stimulant which appears to eliminate the previous disadvantages. Reduced concentrations of growth regulator, applied at frequent intervals in combination with a disease preventive measure, resulted in favourable yield responses, bark renewal characteristics and application economics. Subsequent bark renewal was apparently directly proportional to the concentration of stimulant applied and it was thus possible to control the degree of bark regeneration. The above-cut method shows promise of being particularly effective with systems of reduced intensity tapping on certain clones.