Low-cost methods for enhancement of seed longevity may facilitate biodiversity conservation especially in resource constrained situations. Longevity of 13 cucurbitaceous seed lots belonging to 12 species with mean moisture contents 9.3±0.7% was studied in hermetic storage (HS) and in a liquid consisting of 20% (w/w) CaCl2 in glycerol, following seed to preservative ratio of 1:1 (v/v), at ambient temperature for 24 years. The liquid preservative (LP) was not absorbed by the seeds over the storage period and was harmless to them, drying seeds to about 5% of moisture and maintaining them at this state throughout the storage period. The seeds lost viability in HS in 3.8±0.4 years, while in LP viability was lost in 14–16 years in eight species and the seeds were still viable in five species after 24 years. LP-preserved seeds and also fresh seeds of three species were planted under field conditions. The results validated the use of LP in seed storage for 24 years. The liquid preservation extended longevity of the cucurbit seeds at ambient temperature by drying them and probably maintaining them in oxygen-free environment.

Studies were carried out at Kalyani during 1982–83 and 1983–84 to evolve a multiple cropping system with cotton as the main crop. Cotton was intercropped with paddy, greengram, blackgram, peanut and soyabean in the rainy season, and these were also grown as solccrops followed by crops of peanut, lentil, chickpea, wheat and mustard, respectively, in the winter season. All plots were subsequently cropped with sesame in the summer season. There was an increase in total grain yield, land equivalent ratio (LER), area time equivalent ratio (ATER) and relative net return (RNR) values when legumes and cereals were intercropped with cotton. The yield of the winter crops grown with the help of residual soil moisture was in the order: chickpea > mustard > lentil > wheat > peanut. Sesame yielded best after the chickpea and blackgram sequence and yielded almost as well after the lentil and greengram. The greatest net return was obtained from the cotton and paddy (1:1) intercrop followed by sesame.

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.

The results of eight fertilizer experiments with cotton, conducted in several areas of Macedonia, were evaluated by leaf analysis to establish possible relations between leaf N, P and K and yield, as well as to estimate the adequacy ranges of those elements under local conditions. Such a relation between leaf N and yield does exist, and leaf N within the range 4·4–4·9% of DM is adequate. On the other hand, leaf P and K within the ranges of 0·20–0·29 and 1·5–2·6%, respectively, also seem to be adequate. These findings are in agreement with general experience in this region, where cotton seldom benefits from application of fertilizers other than nitrogenous.

An experiment to investigate the effect of planting pattern, time of planting the cowpea, and insecticide application on the yield of intercropped cotton and cowpea showed that insecticide applied to the cotton controlled cowpea pests best when the crops were planted in alternating single rows. I n wet seasons, delayed planting of the cowpea reduced its yield but its performance was better in alternating single rows than in other planting patterns. In drier seasons, cowpea yield was unaffected by time of planting and yields were similar with alternating single or double rows. Cotton yield was reduced by 47% when the planting pattern was changed to a one cotton:two cowpea row configuration.

The rapid loss of viability in extracted cacao beans prevents long storage or long periods of shipment of selected seeds. Beans partially dried in a stream of carbon dioxide or nitrogen and stored at 25 to 28°C remained viable up to 60 days whereas those dried in air lost viability within 45 days. Storage of artificially dried beans in the absence of air was detrimental to their viability. A moisture content of about 50 per cent gave a high percentage germination within 30 days and reduced deterioration of beans.

When agricultural experimenters send data to a statistics unit for analysis, they do not usually include a field plan of the experimental site unless specially requested to do so. But such a plan can be a great help to a biometrician: he can use it to check that the design used in the field was correctly described, and to arrange the plot residuals in the field layout as a way of detecting a fertility trend in the site and of relating anomalous values to particular locations on the ground. This paper gives examples of how a field plan can be used to the benefit of the experimenter.