Many of the papers submitted to this Journal fall far short of the standard of presentation that editors are entitled to expect. This tends to sour the all-important relation between editor and author, making unnecessary work for the former and perhaps even prejudicing acceptance of the latter's paper. The author, typist, editor and copy-editor have specific roles to play in preparing copy for the compositor and this article explains those roles, in the hope that the explanation may help authors to present their papers in the correct form.

An experiment was conducted during the minor season in Sierra Leone to determine the optimum planting date for a photo-insensitive cowpea cultivar and study the relations between total rainfall and soil moisture available at different growth stages. Cowpeas planted in early September produced the tallest plants and higher grain yields than from other planting dates, since they benefited from 90% of the season's rainfall and made use of stored soil moisture. Average weekly rainfall or soil moisture in the top 15 cm of soil, recorded from planting to 50% flowering, can be used to predict cowpea grain yield.

Field measurements with a pressure chamber showed that the water potential of tea shoots was more closely related to the atmospheric saturation deficit than to the amount of water in the soil. Records for shoot growth and weather then revealed that, within a narrow range of mean temperature, the weekly rate of shoot extension was inversely related to mean saturation deficit measured at 1400 h. During periods when saturation deficit did not rise above 20 mbar, the rate of shoot extension varied linearly with mean temperature above a base temperature of 12.5–13.0°C. These correlations suggested that seasonality of shoot growth in tea can be explained largely by the independent effects of temperature and humidity. The effect of mean air temperature on the rate of shoot extension was confirmed in a glasshouse built over an established crop.

Ethephon (ethrel) sprayed once on to pineapple inflorescences at the onset of flowering, at rates of 400, 800 and 1200 ppm, suppressed anthesis, with the highest suppression from the latter concentration. Suppression was associated with failure of flowers to open; where flowers did open they were usually short, shrivelled and devoid of nectar. One application was sufficient to affect anthesis for the following 16 days. Ethephon-treated plots had a significantly lower incidence of ‘fruit collapse’ (a disease caused by Erwinia chrysanthemi entering via the open flowers). Highest control (2·3% incidence) was achieved with ethephon at 1200 ppm compared with 7·0% in the control (P < 0·01). A highly significant correlation was established between disease incidence and the mean number of open flowers.

Low levels of zinc are reported in flooded rice grown on alkaline clay soils in the Lake Chad basin, north-east Nigeria. Zinc was added at 0, 5, 10 and 20 kg/ha to sample plots. For the untreated plots, the mean levels of zinc in young rice leaf and ‘available’ zinc in the supporting soil, using the alkaline extractant method of Trierweiler and Lindsay (1969), were 18·2 and 0·33 ppm respectively; corresponding mean levels for plots with 20 kg/ha added zinc were 36·5 and 1·54 ppm. There is a correlation between the two variables of r=+0·61 (P<0·01). Levels of nitrogen, phosphorus, potassium, magnesium and calcium in the rice leaf are also reported.

An investigation for 2 years at Kano and 1 year at Samaru evaluated the effects of plant density on vegetative growth, development and dry matter production and distribution of five varieties of groundnut. Growth and branching of individual plants were reduced at high populations but more dry matter was produced per unit area. Dense plants, particularly Spanish 205, developed a larger leaf area earlier in the season and were presumably able to make better use of light. Varieties F439.4 and 439.2 suffered the least reduction in the number of vegetative branches but the extra branches contributed few useful reproductive nodes.

The yield data from a series of fire-cured variety × fertilizer trials in Malawi are presented. Variety was not important in determining total yields though it was in influencing the distribution of grades. Fertilizer had a large effect upon yields, particularly upon the Cutter and Leaf grades, but environment had by far the greatest influence. High levels of applied fertilizer could not be relied upon to replenish a depleted soil so that it produced yields comparable to those from a soil with well-maintained fertility. Application of fertilizer produced a beneficial change in the grade distribution within the crop.

Monthly partitioning of dry matter (DM) and nutrient contents of polybag oil palm nursery seedlings, planted at three spacings, showed that leaves and petioles accounted for about half of the DM up to 11 months. There was no spacing effect on the nutrient contents of seedlings, K being always higher than other nutrients followed by N, Ca, Mg and P in that order. Most of the nutrients were in the leaves and petioles, with a dramatic increase in the amount of nutrient taken up by the seedlings in November. Fertilizer rates and frequencies were deduced for an oil palm nursery based on the nutrient contents of seedlings.

The adaptability of rice varieties to crop seasons in Taiwan was evaluated for 106 varieties. Average grain yield was higher in the first than second crop seasons. Indica varieties yielded better than Japonicas, particularly in the second crop season, when temperatures are higher. In both the Indica and Japonica groups, varieties developed in Taiwan outyielded those from overseas. Japonica varieties from Japan were lowest yielders in both seasons. Some IRRI varieties were outstanding in the first, while several Ponlais and Taiwan Indicas appeared promising in the second crop seasons.

The pressure-chamber technique has been used for the first time to measure leaf-water potentials in chickpea under field conditions. Available soil-water contents at different depths for irrigated and non-irrigated crops are presented along with the diurnal variation in leaf-water status, to show that pressure-chamber measurements correspond closely with available soil water. Leaf-water potential has also shown differences in leaf-water status among different cultivars. The rapidity and ease with which measurements can be made in the field make the technique suitable for quick measurements of leaf-water status for chickpea.

Twenty-five cultivars of soyabean (Glycine max (L.) Merr.), differing in their origin, crop duration and seed size, were planted four times at bi-weekly intervals during the major rainy season at Ibadan, Nigeria and harvested at optimum maturity or two weeks later. Delayed harvest and intense rainfall during pod maturation were essential for selecting for resistance to field weathering, but 2 weeks' delay enabled susceptible and resistant cultivars to be identified. Percentage of infected seed had the highest correlation with potential germination at harvest (r=−0·869**) but may not be a suitable criterion for use in a screening programme. An alternative would be to screen cultivars for resistance to weathering on the basis of seed size and the proportion of smooth and clean seed, since these characters were highly correlated to potential germination (r=−0·562** and 0·632** respectively).

Methods are described for releasing HCN from cassava leaves and tubers by organic solvents and its spectrophotometric estimation as the red complex formed with alkaline picrate. Chloroform was the most efficient solvent, with toluene an acceptable alternative, using enough solvent to wet samples thoroughly to maximize cyanide yield. Cyanide content was concentrated in the veins and towards the base of leaves and declined linearly with leaf age. Release of HCN with solvent compared favourably with traditional homogenization/steam distillation with leaves and parenchymal tissue, but was unsatisfactory for tuber peel. The effective removal of HCN from cooked cassava leaves depends chiefly on release of enzymes by efficiently chopping them before boiling, which only slowly destroyed potential cyanide content of unchopped leaves.

Four hybrids of pearl millet (Pennisetutn typhoides) were screened for photoperiod sensitivity in a heated temperate glasshouse and the effects of 12 h short day induction on the reproductive development and plant morphology were examined. All the hybrids (BK 560, MBH 104, MBH 110 and ICH 105) responded to 14 short days by a considerable reduction in the time to anthesis, plant height and the final number of leaves produced, without any adverse effect on head development. In another experiment BK 560 required at least four short days for floral initiation and another four for subsequent development. Short day induction had no apparent effect on the rate of leaf appearance. The results were compared to those reported for millets in general and to millets grown in the tropics.

The change in seed oil percentage and 100-seed weight of Brassica juncea Varuna was studied as the crop matured during rabi 1977–78. Statistically, the oil percentage reached its highest value at 55 days from flowering, whereas the 100-seed weight was highest about 20 days later, when the pods were fully yellow. Oil yield (the product of oil percentage and seed weight) also reached its highest value when the pods were fully yellow. This information should enable the crop to be harvested at the proper physiological stage (yellow-podded) for maximum oil yield.