Differential leucocyte counts and plasma activities of the muscle enzyme, creatine kinase, have been determined in blood samples obtained from broiler chickens, immediately prior to and following road transportation from farm to processing plant for slaughter. These parameters are proposed as indicators of physiological stress based on previous findings.

Heterophil:lymphocyte ratios and plasma creatine kinase activities increased and eosinophil counts were decreased during the journey in birds tranported in both July and October when the curtain sides of the vehicles were open or closed respectively.

These findings are consistent with the presence of physiological stress during road transportation. The thermal microenvironments to which birds are exposed in transit are thought to represent one of the sources of this ‘transportation stress’.

Elemental sulphur (32 kg S/ha) and urea (30 kg N/ha) were applied to the foliage of different winter wheat cultivars, halfat flag leaf emergence and halfat ear emergence, in factorial experiments in 1986, 1987 and 1988. There were no clear visual symptoms of S deficiency, but there was evidence from soil analysis, grain S concentration and grain N:S ratio that the crops were marginally deficient in sulphur. Disease severity was generally negligible. Leaf senescence at the end of grain growth was delayed by sulphur in two of the three years, both with and without urea in 1987, but only with urea in 1988. Sulphur, both alone and mixed with urea, increased grain S concentration from early grain growth in 1986 and 1987, but not until the end of grain growth in 1988. Urea alone reduced yield in 1986 and 1987, but mixing S with the urea compensated for this phytotoxic effect. Yield was not significantly increased by S when compared with plots receiving neither urea nor S.

Hagberg falling number (HFN) is used to estimate alpha-amylase activity in wheat grain (Perten, 1964) and it is utilized by flour millers and the Intervention Agencies of the European Economic Community as a grain quality measurement for breadmaking (Anon. 1983). High nitrogen fertilizer application can lead to lodging and can decrease HFN (Brun, 1982). This may result from damp conditions around the ear encouraging germination, and therefore increasing alpha-amylase activity (Stewart, 1984). However, since nitrogen application can also delay maturity, it has been suggested that this influence could maintain high falling number (Anon. 1985). Pushman & Bingham (1976) found that increased nitrogen application decreased alpha-amylase activity, lending support to the previous suggestion, but contrasting with the results of Brun (1982).

Fungicide applications to wheat have been reported to maintain the green area of the leaves (Dickinson & Walpole, 1975; Stevens & Palmer, 1980). It is not known, however, whether the photosynthetic rate of the leaves is also maintained. It was therefore decided to investigate disease development, green leaf area and photosynthesis of the flag leaf of winter wheat in response to the fungicide propiconazole, which has not previously been reported to influence senescence in the field.

Urea (supplying 15 kg N/ha) applied to winter wheat (Triticum aestivum) at flag leaf emergence and again at ear emergence improved grain yield in only two, but increased grain nitrogen (N) in four out of five experiments. The size of the improvements in yield and nitrogen content differed over varying sites and seasons but were not affected by cultivar or propiconazole (250 g a.i./ha) plus tridemorph (500 g a.i./ha) fungicide applied with the urea. Breadmaking quality was assessed on grain from one site in 1985 and in 1986. The beneficial effects on loaf quality of urea and fungicide applied separately were reduced when they were applied as a mixture. In 1986 this negative interaction was associated with effects on sodium dodecyl sulphate (SDS) sedimentation volume, flour sulphur content (S), N/S ratio and dough resistance. The effect of urea also interacted with cultivar on SDS sedimentation volume in 1985 and dough resistance in 1986.

A field experiment was carried out at Harper Adams in Shropshire to investigate the effect of supplying the spring N application to winter wheat as different proportions of urea as a solution, rather than as conventional soil-applied solid urea, on N recovery in the above-ground crop, autumn soil mineral N and nitrate leaching over the subsequent winter. A solid ammonium nitrate treatment was also included to represent alternative commercial practice to solid urea. Treatments were repeated on the same plots over the 3 years 1992, 1993 and 1994. N recovery was measured in all 3 years by difference in N uptake between fertilized and unfertilized plots, and in 1993 for selected treatments, N was applied as 15N-labelled fertilizer to determine direct uptake of fertilizer N in the crop and soil. Both urea sprays and solid soil N applications were labelled with 15N. Urea sprays were split over several days to reduce scorch, whereas solid fertilizer was applied as a single dressing. For some urea spray treatments, apparent N recovery in the above-ground crop in 1992 and 1994 was less compared with soil-applied N treatments. These urea spray treatments were applied in the morning rather than the evening, and gaseous losses, most likely by volatilization, are suggested. In 1992 application of a large proportion of N as urea sprays, such that application of some N as urea solution was delayed to around GS 37, was associated with an increase in physiological N use efficiency. In 1993, there was no difference in direct or apparent recovery of fertilizer N in the crop or soil for N applied as ammonium nitrate, solid urea or as urea sprays. Mean nitrate concentration in the drainage water at 1 m was elevated for all N treatments in all years, but only in 1992 did nitrate concentration and leaching loss decrease with increasing proportion of N applied as urea sprays. It may therefore be possible to reduce gaseous losses by application of urea sprays under cool conditions in the evening and exploit the increased physiological N use efficiency for urea sprays applied later, such that total fertilizer N applied and N losses are reduced.

Supplying a proportion of the N requirement of a wheat crop via the foliage would potentially reduce immobilization of fertilizer N in the soil organic matter and N losses by leaching or denitrification. A field experiment was carried out at Harper Adams in Shropshire to investigate the effect on crop yield of supplying the spring N application to winter wheat as different proportions of urea as a solution rather than as conventional soil-applied urea, and to determine the physiological basis of any yield differences. A solid ammonium nitrate treatment was included to represent alternative commercial practice to solid urea. Treatments were repeated on the same plots over the 3 years 1992, 1993 and 1994. Solid fertilizer was applied as a single dressing, whereas urea sprays were split over a number of days to reduce scorch. Nitrogen as urea sprays produced similar grain yields to N applied conventionally to the soil as solid ammonium nitrate or urea, but effects on above-ground dry matter production and harvest index depended on the time of application. Application of a large proportion of N as urea sprays, such that some of the N as urea solution was applied later in relation to crop development, produced less above-ground dry matter, but compensated by increasing harvest index. It is concluded that application of N as urea sprays could be successfully used to substitute for soil-applied N fertilizer at stem extension in winter wheat without loss of yield. Extra application costs, however, are likely to outweigh any efficiency or environmental benefits, except where applications of solid N are made to dry soils.

Year × variety means of wheat grain crude protein content (CP) and Hagberg falling number (HFN) surveyed in the UK from 1974 to 1993 were investigated with a residual maximum likelihood (REML) analysis using variety, nitrogen fertilizer application (kg N/ha), average monthly temperatures (°C), and total monthly rainfall (mm) as fixed terms, and year as a random term. Annual variety means were weighted according to the inverse of their variances. The statistical significance of fixed terms as they were added to the model was evaluated by comparing the Wald test statistic with critical values of chi-squared. CP, except for 1976 which was associated with prolonged drought conditions, was best described with a model combining effects for variety (P < 0·001), nitrogen application rate (0·0143, S.E. = 0·00312, P < 0·001), July temperature (0·184, S.E. = 0·0582, P < 0·01) and May rainfall (−0·00952, S.E. = 0·00233, P < 0·001). A model describing HFN combined effects for variety (P < 0·001), August rainfall (−0·930, S.E. = 0·2579, P < 0·001) and June temperature (24·4, S.E. = 7·37, P < 0·001). These models were evaluated for describing CP and HFN of cv. Avalon grown on sandy-loam from 1982 to 1992 at one site. Correlation coefficients of 0·51 (P = 0·1) and 0·72 (P = 0·012) were obtained between observed values at this site and those predicted from the nationally derived models for CP and HFN respectively. Variety effects suggested that the varieties commonly used in the mid 1970s would give higher CP and lower HFN than their more modern counterparts if grown at similar levels of nitrogen and in the same climatic conditions.