Large soil monoliths, extracted undisturbed in 44-gallon oil drums, have been used to assess the available-water capacity, and the relation between the growth of sugarcane and soil water deficit for agricultural soils in Barbados. Constancy of field capacity was studied and the effect of cultivation on the storage of available soil water. Deep montmorillonite clays and oceanic soils had storage capacities greater than 20 cm. of water in an 80 cm. profile, whereas sandy or stony montmorillonite clays and most soils developed from kaolinite clays had capacities less than 11 cm. Cultivation significantly increased the water holding capacity of soils but this was rarely as great as for fabricated composts and the water was never so freely available. The data have been used in decisions about cultivation and irrigation, and as the basis for an ecological grouping of sugar estates according to their probable water balance.

The shoots of high, medium and low yielding clones of tapioca were examined to see whether yield was associated with morphological characteristics of the foliage and/or with leaf area development. The lowest yielding variety had the highest leaf area per stem, and vice versa, differences in leaf area being mainly due to differences in leaf size. Leaves of the highest yielding variety possessed attenuated lobes, which tended to have a more vertical mid-day orientation, whereas the lowest yielding variety possessed large broad-lobed leaves with more horizontal orientation. The intermediate variety had acutely attenuated lobes and showed a much more vertical day-time orientation. The relationship between the leaf properties and canopy efficiency is discussed.

Experiments were made in glasshouses, growth cabinets and growth rooms to study the differential responses of the broad bean to water stress during the vegetative and flowering phases of growth. Plants in the flowering phase proved to be more sensitive to drought than in the vegetative period, and there were different responses (Relative Growth Rate) to temperature at different stages of plant growth. Day length and temperature influenced the position of the earliest flower initials on the stem, and intensity of flower shedding was aggravated by high temperature.

Effects of rainfall on yield of cocoa from a large-scale experiment has been investigated at 10 and 12 sites, over seven years, in the Eastern and Ashanti regions of Ghana. There was a positive association between yield and rainfall at certain times of year, but a negative association at other times. Variation due to the regression of yield on monthly rainfall varied up to 23 per cent, while a maximum variation of 31 per cent accounted for the regression of yield on the total rainfall of February to April in the Eastern region.

At Ukiriguru, in Western Tanzania, three levels of sulphate of ammonia were compared on natural pastures on hardpan soils. Yields of dry matter were substantially increased by nitrogen fertilizer and at high stocking rates the growth of cattle on different treatments followed fairly closely the amounts of dry matter available.

Results of an investigation to select intercrops showed that cotton can be grown with more profit with groundnut or gora paddy than when grown alone. Growing food or cash crops along with cotton enables an early crop to be produced and the practice may help to extend cotton cultivation in Chotanagpur and Santhal Parganas, a potential cotton belt of the future.

Pot experiments with Malaysian rice variety Reyong-20 showed that sea water supplied at a concentration of 3 per cent increased yields of both grain and straw; a 6 per cent solution increased straw but not grain yields; yields were depressed at 9 and 12 per cent but tolerance of higher concentrations of sea water increased with age of the plants.

On a site in the Sudan Savanna, chemical properties of soils (except for phosphate) and the composition of cotton leaves were determined after fifteen annual treatments including dung, ammonium sulphate, single superphosphate and potassium chloride, in all combinations of three levels. In the soils dung increased C, N, cation exchange capacity, exchangeable Ca and Mg and pH, and decreased soluble Al and Mn; ammonium sulphate decreased pH, increased soluble Al and Mn, and decreased exchangeable Ca and Mg; potassium chloride had no obvious effects. In the plants dung increased P and reduced Mn; ammonium sulphate reduced Ca and Mg, and increased Mn; superphosphate increased P, Ca and Mg, and reduced K; potassium chloride increased K slightly. The most important results were the ability of ammonium sulphate to acidify the soil, as shown by soil properties and reflected in tissue composition, and the ability of dung to ameliorate these effects. Reduction of crop yield in the presence of adequate nutrient supply seems to have been due to excessive soil acidity.

Pods of bhindi (Abelmoschus esculentus) developed most rapidly for the first 11 days after the opening of bhindi flowers, after which development slowed down. Seeds matured in about 21 days after flower opening and attained up to 97 per cent germinability. Water potentials lower than −500 joules/kg. in the germination medium adversely affected germination of bhindi seeds. Seeds up to two years old but of > 1 density (i.e. those which sink in water) germinated better than lighter seeds which float.