Phaseolus vulgaris (cv. Provider) was assessed as a vegetable and seed crop in southeast England. Experiments were designed to simulate ‘pick your own’ harvest systems which are becoming increasingly popular. Edible pods were removed on either one or two occasions at varying developmental stages, remaining pods being left to produce seed. The yield of edible pods increased considerably as pod removal was delayed but subsequent seed yield was reduced. However, depodded plants showed compensatory increases in mean seed weight so that seed yield reduction was less than expected.

Results are discussed in relation to decline in seed moisture content and the dual use of this crop for vegetable pod and seed. It is concluded that dual use is not convenient for large-scale agricultural operations. ‘Pick your own’ programmes utilize the potential of this crop more efficiently than present mechanical harvesting systems.

Interest is increasing in the Navy bean (or baked bean) as a breakcrop from cereals in southern England. As little experimental work has been carried out on the fertilizer requirements of this crop in the U.K. we undertook a trial in 1973 to investigate its response to four levels of nitrogen.

A field experiment was carried out at the Wye College Farm during 1988 and 1989. The aim was to study the effects of three rates and timings of nitrogen fertilizer application on the grain protein content of spring wheat cv. Axona. Results demonstrated that timing of fertilizer application was more important than the rate of nitrogen used. Grain protein development and final grain protein contents are discussed in relation to the seasonal variations experienced during the 1988 and 1989 growing seasons in South East England. Due to the early February sowing in 1989, grain protein content was not affected by the summer drought. Thus, the advantage of early sowing of spring wheat to reduce the detrimental effect of early summer drought on the grain protein content is emphasised.

Two varieties of oil-seed rape were drilled in 1979–81 at a range of seed rates. Percentage establishment, plant weight, height, and the ratio of seed to total aboveground dry matter were lower in high-density plots. Seed yields were not increased when the seed rate was raised from 9·0 to 13·5 kg/ha (Expts 1 and 2) or from 4·5 to 18·0 kg/ha (Expt 3) owing to a compensating reduction in the number of pods per plant. Seed quality and 1000-seed weight were not influenced by the seed-rate treatments.

Three spring oil-seed rape cultivars were drilled on five dates during 1979 and 1980. Delayed drilling (1) reduced seed yield, (2) increased the main stem contribution to seed production, and (3) increased the percentage of damaged pods at harvest. The results indicated that cultivars similar to those used in this trial should be drilled between the 3rd week of March and mid-April.

The results of experiments in which Navy beans (cv. Purley King) were precision drilled at the beginning, middle and end of May in 1972, 1973 and 1974 suggest that the optimum time to sow is mid-May when soil temperatures at 10 cm depth have reached 12–13 °C. Earlier sowing usually led to a reduced plant stand and low yields whilst in 1972 and 1974, two exceptionally cool years, later sowing resulted in lower yields following a reduction in 1000-seed weight.

Despite contrasting weather conditions acceptable yields of seed were obtained in all 3 years from mid-May sowings although cool wet conditions in the autumn of 1974 curtailed drying of the seeds below 30% moisture content. Accumulated temperatures (Ontario units) were successfully used to predict stages in crop development and the data used to demarcate the areas in England most suitable for Navy-bean production.

The roles of leaves, stems and reproductive parts in 14CO2 fixation and its subsequent movement in winter oil-seed rape, cultivar Jet Neuf, were investigated in two field experiments carried out on the Wye College Farm. The relative importance of these organs changed with time. At early flowering the leaves were the most important photosynthetic organs (66·8% 14CO2 activity). Midway between flowering and maturity the stems became the major supplier of photosynthates, a role eventually taken over by the developing siliquae (pods).

These data stress the importance of keeping all photosynthetically active surfaces free from disease if efficient resource utilization and higher yields are to be achieved.

Untreated and paclobutrazol-treated field-grown plants of winter oil-seed rape cv. Jet Neuf were exposed to 14CO2 at anthesis. Redistribution of labelled assimilate was followed in sequential harvests between exposure and maturity.

Labelled assimilates moved progressively from the leaves into the stem and reproductive parts. At maturity 9% of 14C fixed at anthesis had been mobilized into reproductive organs. Paclobutrazol increased the proportion of 14C translocated to the uppermost branches especially the terminal raceme.

It is suggested that stem reserves are valuable for yields commonly achieved in U.K. commercial practice.

The effect of paclobutrazol (applied at several concentrations and timings) on stem length and the seed yield of oil-seed rape was explored in three field trials during 1981–4. Spring applications were most effective in reducing plant height, but they had an adverse influence on the yield components. Autumn applications increased seed yield in one season, but were less effective in the final trial when soil conditions were much drier at establishment. Data indicated that autumn treatments may increase the productivity of the uppermost racemes. Future studies must investigate the persistency of paclobutrazol in the soil, and its possible influence on subsequent arable cropping.

The response of three spring cultivars of oilseed rape to five levels of nitrogen fertilizer (0 to 200 kg/ha) was studied during 1978–9 (Scarisbrick, Daniels & Alcock, 1981). Sampling problems, practical difficulties of measuring yield components, and the high co-efficients of variation for these data were discussed. During the course of further investigations on the winter cultivar Jet Neuf (established on approximately 75000 ha in the U. K. during 1980–1) within-plot variability for plant weight was assessed in order to indicate the size of sample necessary to compare treatment means.

Phaseolus vulgaris is grown in the U.K. primarily for its edible immature pods (dwarf French beans). The possibility of also using this species as a combinable break crop in south-east England was investigated during 1972–80 when trials were undertaken on the nitrogen fertilizer requirement for commercial seed production.

The objective of this study was to examine the effect of the chemical growth regulator chlormequat on the yield and yield components of oil-seed rape. Although this chemical is widely used in wheat production systems, its use as a morpho-regulator for oil-seed rape has not been examined thoroughly. A few Eastern European experiments have been published. Voskerusa (1972) applied it at 2, 4, 6 and 8 kg/ha to winter varieties in Czechoslovakia. His results, which agree with those of Fabry & Hannich (1972), demonstrated reduced winter kill using an autumn application. However, studies on modern varieties such as Rafal, now widely grown in European Economic Community countries, have not been reported in detail.

Navy beans were precision drilled in 1973–5 at a range of plant population densities. Within each growing season the density treatments did not influence seed yield, but mean yields differed significantly between years. The results suggest that cultivars similar to Purley King can only be regarded as a reliable break crop in a season such as 1973 which was slightly warmer and drier in mid-summer than average. Although the rate of drying increased with increasing plant density in two of the growing seasons, no practical advantages are proposed.

Pre-anthesis stem reserve contribution to grain yield was assessed in two spring barley cultivars of contrasting height. It was greatest in the taller, but final grain yields were similar. Partitioning of total reserve capacity to various plant parts showed that the leaf and sheath below the peduncle were most important, followed by stem internodes which had increasing reserve capacity up to internode 4.

It is suggested that stem reserves are valuable for yields commonly achieved in U.K. commercial practice.

High grain yields were associated with large positive increases in stem dry weight after anthesis. This would indicate that the source capacity to boost yield is more than proportional to that required to fill the grain alone.

A glasshouse experiment in 1997 at Wye College, University of London, investigated the uptake of 35S-SO4 at two growth stages. When labelled S was applied at growth stage 24 on 20 January only 14% of available sulphur was detected in the plant parts. There was a progressive increase in uptake into the newly emerged leaves. The leaves, which emerged after the application of the radiolabelled sulphur solution was complete, imported sulphur from other parts of the plant. At final harvest the ears had become a major new sink and had imported 68% of the labelled sulphur.

When labelled sulphur was applied on 7 March at growth stage 41–45, an average of 93% of available sulphur was taken up during the 3 days exposure period. The major portion was quickly translocated and recovered from the aerial parts. At final harvest 53% appeared in the grain. The experimental results demonstrated that sulphur reserves can be remobilized to developing sinks. It is suggested that sulphate ions can be retained as a reserve pool by the plant until they are required by actively developing sinks.

A field experiment was carried out on soyabean (Glycine max (L.) Merr.) to measure the effect of planting date (soil temperature) on seedling emergence. Seeds were sown at weekly intervals on seven planting dates from April until the end of May in SE England in 1997. Planting date had no significant effect on final percentage emergence but had a highly significant effect on time to emergence. The coefficients of variation (c.v.) for the number of days to emergence (calendar days) were high (43–45%), and therefore not a reliable method for predicting emergence. Three accumulated heat unit (AHU) methods based on air and soil temperatures were compared with the calendar day method to determine the most reliable system for predicting seedling emergence. Accumulated soil temperatures above a base of 9·0 °C had the lowest c.v.s (8–15%) and were shown to be the most reliable predictor of emergence.