Mon O45 at rates of 4 and 6 kg./ha. was shown to increase total dry matter in the stem of the sugarcane variety M13/56, optimum response occurring at 9–12 weeks after application. The increase in dry matter was mainly due to an increase in sucrose, since the chemical had no effect on fibre and decreased reducing sugars. The site of action appears to be in the top 16 internodes. Possible modes of action of the chemical are discussed.

A field experiment was conducted for two years to study the influence of type of seed bed and various mulcheson yield and nutrient uptake by pearl millet, and on moisture conservation, under the semi-arid conditions of Delhi. A flat seedbed stored more moisture, gave significantly higher yield of pearl millet, and increased the uptake of N, P and K, compared withridge and furrow beds. Mulches were effective in conserving moisture, with straw mulch significantly better than dust mulch inits effect on crop yield and nutrient uptake.

The effect was investigated of seasonal differences between winter and spring on the development of parthenocarpic and fertilized fruits in two squash cultivars, Zucchini Elite F1 and Bushy White. The former had stronger parthenocarpic characteristics than the latter. The effect of night temperature on growth of the parthenocarpic fruits was most pronounced, both rate of growth and final weight increasing with decreasing temperature. Whereas long days inhibited development of parthenocarpic fruits, the heaviest and longest fruits were obtained under normal day-length conditions.

Boron deficiency in cotton occurs widely in northern Nigeria, where its extent and severity appear to be increasing, particularly under intensive agriculture. The deficiency may be aggravated by fertilizer application, specially nitrogen. Soil boron status varies greatly but is generally very low and often less than is considered necessary elsewhere. Superphosphate containing added boron corrects deficiency safely and satisfactorily.

Cotton varieties differ in their sensitivity to boron deficiency. Breeding for tolerance of deficiency offers some scope for yield increases under the prevailing non-intensive conditions under which most of the crop is grown in northern Nigeria, but cannot be considered a complete solution to the problem.

A study was made of the nitrogen fixing systems of various forage legumes and their rotational effect on yield of subsequent cotton crops, as well as of yields of the different legumes. Phillipe-sara, clitoria and lubia out-yielded all the others. Nitrogen yields of the various forage legumes showed that they are active fixers of atmospheric nitrogen, but yields of cotton following the various legumes showed wide seasonal variability and were neither significantly nor consistently different in different seasons. On the other hand, the increase in cotton yield due to fertilizer nitrogen was highly significant, indicating a comparatively small end-of-season contribution of cut legumes to soil nitrogen. It was therefore difficult to differentiate between the legumes on the basis of any consistent ability to influence yields of following cotton, suggesting that the choice of a legume in the rotation should depend primarily on economic considerations.

Field experiments conducted in two localities in two growing seasons on the effect of inoculating haricot bean showed that a local strain of Rhizobium significantly improved nodulation and usually increased the nitrogen content of plants. In three out of four experiments, increases in seed yield were obtained ranging from 20–145 Per cent (significant in two cases). Inoculation was better than 43 kg. N/ha. of combined nitrogen but not better than 86 kg. N. Soil inoculation gave better early nodulation than seed inoculation, but the difference diminished in the later stages of plant growth.

Maize yields were significantly affected by the nature of the previous crop. Maize following groundnuts significantly outyielded maize following cotton, which in turn significantly outyielded maize following sorghum or cowpeas, and this order was largely independent of the nitrogen fertilizer regime applied to the maize. Analyses of soil and crop showed that groundnuts increased nitrogen availability in the topsoil, but there was little evidence of any similar advantage after cowpeas.

The Sudanese local onion cultivar Wad Ramli has a markedly long rest period (60 days) and a long dormant period of up to six months. It has high dry matter (16 per cent), high soluble solids (15 per cent) and strong pungency, factors which contribute to its good storability under conditions that are usually adverse for good storage.

Beans collected from immature pods of cocoa progency C77 × C23, as early as 15 weeks after pollination, successfully produced seedlings as vigorous as those from mature ripe pods. Seedlings produced by beans from 21-week-old pods were the most vigorous, with vigour based on the integral of all measured growth parameters (leaf number, leaf area, seedling height, girth and root weight). There were close correlations between these growth parameters on the one hand and bean maturity and seedling age on the other, the relations with the former being curvilinear and with the latter linear. Seedling age and bean maturity accounted for between 87–99 and 42–96 per cent respectively of the variations in growth parameters. Multiple regression equations are presented for quick estimations of leaf area.

The world grain situation and shortages of fertilizer place the agricultural industry even more to the forefront of policy and planning in low-income tropical farming areas. Planning must be positively directed toward eliminating the major constraint of inaccessibility to markets. The narrowing of alternative agricultural opportunities as accessibility decreases is indicated for a sample of farm-family households; low-income farmers isolated from the services sector arc particularly susceptible to the constraint of ‘scarcity of season’ which in turn is aggravated by the economic cost of ill-health when this coincides with the period of heaviest agricultural work. The problem which arises is one in which farmers rely on topping-up farm income with income from non-farm activities. Unless a two-to-threefold net income over any other combination of income-earning opportunities can be assured, small-scale producers largely persist in treating farming simply as a way of life by which the subsistence needs of the family can be met without recourse to new input forms.

Intercropping maize with pigeon peas, in a mixed stand or in alternate rows, significantly reduced the grain yield of maize but not of pigeon peas. Maize grown alone produced the maximum grain yield ha.−1 week−1, whereas maize and pigeon peas grown in alternate rows produced maximum proteins ha.−1 week−1 and absorbed the maximum amounts of potassium, calcium and magnesium. Pigeon peas grown in a pure stand produced minimum grain yield and proteins ha.−1 week−1, and absorbed minimum amounts of nutrients. The problem of intercropping maize with pigeon peas under optimum nitrogen fertilization is discussed.

The object of the study was to find whether loss during combine harvesting was correlated with pod shattering propensity of soybeans. Mechanical pod shattering methods tested included vibration, impact, centrifugation, pod traction and compression. The influence of variety and moisture content on mechanically-induced pod shatter and on header losses was studied. The pod suture compression method was simplest to perform and, with respect to crop moisture, gave results indicative of machine harvest shatter levels. Such a standardized mechanical shatter index may prove a useful criterion in soybean breeding selection for harvest shatter resistance.

Tall local sorghum and new dwarf varieties were compared, both as sole crops and when intercropped with an early cereal, in a replicated experiment, and at five sites in observation plots. Dwarf varieties were superior both as intercrops and as sole crops, and intercropping was better than sole cropping for all varieties. In the experiment 27 per cent more total grain yield (sorghum + early cereal) was obtained when dwarf varieties were used instead of tall. When the sorghum was intercropped, increased yields per plant came largely because there were more grains per head.

Close spacing between and within rows significantly increased the biological and agricultural yields of cowpea without exerting clearly differential effects on the three test cultivars of different forms. It is suggested that low yields of cowpeas commonly observed in southern Nigeria could be due largely to low planting density. A six-fold increase in yield of beans can be achieved by halving the current spacing of 90 by 30 cm. provided the crop is protected from field pest damage.

Four sesame varieties were tested at three plant populations to study varietal and population effects on some attributes of vegetative growth. Significant differences between varieties were detected and planting density was found to modify both areas and dry weights of leaves.

A phenol colour reaction test was found to be useful for classifying rice varieties. The degree of colouration varied between varieties and could be explained by differences in the enzyme activity, expressed as phenoloxidase and peroxidase. Light, temperature and aeration appeared to influence colour development, but age and crop location did not. A concentration of 1.5 per cent was found to be suitable.