Experiments on outdoor bush tomatoes cv. Sleaford Abundance were conducted during 3 years to compare seedling establishment from fluid-sown pre-germinated seeds with that from conventionally sown dry seeds and to compare the effects on ripening and yields of these establishment methods with transplanting. Fluid-sown pre-germinated seeds emerged about 15 days earlier than conventionally sown dry seeds from sowings made in late April (mean soil temperature at seed depth from sowing to emergence ranged from 9 to 11.5 °C) and about 6 days earlier from sowings made in mid-May (mean soil temperature ranged from 12 to 15 °C). The percentage seedling emergence from pregerminated fluid-sown seeds was, on average, 57% from the earlier sowings and 65% from the later sowings, 34 and 24% higher, respectively, than from dry seeds sown conventionally. Plants from fluid-sown pre-germinated seeds were about 50% heavier than those from dry seeds at all stages of growth up to flowering. Crops established by fluidsowing started to ripen 7 days earlier than those established from dry seeds, when averaged over sowing dates and years. Yields of ripe marketable fruit > 35 mm in. size from crops established from pre-germinated seeds were 35·2 t/ha, averaged over sowing and planting dates, 37% higher than from dry seeds though 51% lower than from transplants. In the two years with good growing seasons crops fluid sown in late April gave as good yields as those transplanted in late May and early June, after the last frosts, though in the cool wet year yields from fluid-sown crops were considerably lower than those from transplanted crops. Yields of ripe, marketable fruit from ‘bare-root’ plants raised from pre-germinated seeds in unheated Dutch-light structures were, on average, 48·5 t/ha, 25% higher than from plants raised in soil blocks in a heated glasshouse.

The purpose of this work was to determine the relative importance of mass flow and diffusion in supplying nutrients to wheat plants and to calculate nutrient uptake rates by roots (inflow). Winter wheat was grown in the field and measurements of plant Na, K, Ca, Mg, P, S and N contents, root length, plant water uptake and soil solution concentration made at regular intervals during growth. The apparent contribution of mass flow to plant uptake of nutrients between mid- April and mid-June was greater than the measured plant uptake for sodium, calcium, magnesium and sulphur (14, 9, 2 and 4 times respectively); however, only 50 % of the measured plant uptake of nitrogen and potassium and 5% of the phosphorus was supplied in this way. There were some 7 day periods when mass flow was able to supply the measured uptake of nitrogen and potassium, and it is possible that for these nutrients the importance of mass flow and diffusion may change during growth. Mean inflows (uptake in mol/cm root/sec) were calculated from sowing until mid- June. Inflow decreased for all nutrients from high initial values to low values during the winter and rose again in mid-April and May before falling in June. The increase in inflow in mid-April was concomitant with increased shoot growth but the precise factors controlling plant demand for nutrients and uptake in the field are still ill-defined.

In an earlier paper (Little, McLean & Winter, 1977) we reported a technique for the measurement of the phosphorus content of the diet consumed bygrazing cattle, which recently has been used successfully to measure the dietary intake of phosphorus by sheep grazing Mitchell grass (Astrebla spp.) pastures in western Queensland (Beale & McMeniman, 1978). In this technique, phosphorus of salivary origin is distinguished from that of plant origin in samples extruded by oesophageally nstulated animals by prior labelling of salivary phosphorus with the isotope 32P following the intravenous infusion of Na2H32PO4. The difference in specific activity between saliva and extruded bolus is used as the basis of the calculation of the phosphorus content of consumed herbage. Oesophageally nstulated animals may graze experimental pastures for an hour or more while samples are collected from them. It is important to have an accurate measure of saliva speoific activity, representative of that secreted during the grazing period; therefore, application of the technique is facilitated if the rate of change in saliva specific activity during collection periods is slow and linear.

Two hundred and ten Finn–Dorset ewes were mated to ten rams, five Suffolks and five Texels, in 2 years, to evaluate Texel rams as fat lamb sires. Three hundred and ninetyseven lambs were born and used in the study until the 6th week of age, after which 155 lambs were available for the rest of the experiment. From 6 weeks of age they were grazed with their dams and weighed weekly until slaughtered at 30 kg (females) or 36 kg (males) live weight. Carcasses were assessed by the Meat and Livestock Commission and a random sample of 16 left sides were fully dissected.

Fertility and prolificacy of the ewes were 95 and 190% respectively, and were not affected by sire breed. Texel-sired lambs did not differ from Suffolk in birth weight, weight at 6 weeks, growth rate from 6 weeks to slaughter, overall growth rate or age at slaughter. Except for growth rate from birth to 6 weeks, sex difference was significant (P < 0·05) in all growth estimates.

No significant breed or sex difference was found in dressing percentages or carcass weight for age. Mean dressing percentage was 47·4 ± 3·48 and 47·5 ± 3·78 for Texel and Suffolk crosses, respectively. Texel cross carcasses had significantly (P < 0·05) lower fat scores and males did not differ from females. Texel cross carcasses had significantly (P < 0·05) higher lean and bone percentages, but significantly (P < 0·01) lower total fat percentage.

Apart from demonstrating the capacity to produce leaner lambs compared with Suffolk, the results suggest that Texel sires offer the possibility of producing heavier carcasses without excess fat production.

Quantitative information concerning preejaculation sexual preparation of bulls was published some years ago by Collins, Bratton & Henderson (1951), who concluded that about 40% more motile sperm could be obtained by imposing one false mount before ejaculation. It had been suggested that one false mount in bulls is essentially as efficient as two such attempts in terms of sperm output (Branton, D'Arensbourg & Johnston, 1952). More recently Hafs, Knisely & Desjardins (1962) have shown that bulls given a planned 5 min sexual preparation yielded 30% more sperm than those given no preparation. Similarly 10 min preparation resulted in a 12% increase in sperm output when compared with a 5 min preparation. These authors also showed that zero, one, two or three false mounts significantly affected motile sperm output.

The electrical potential difference between exuding sap of detopped sunflower plants and rooting media containing different NH4 ion concentrations was measured, together with the Na and K concentrations in root tissue and their fluxes in the xylem exudate. It was found that adding NH4 ions to the medium made the electrical potential difference less negative with respect to the external solution and decreased the water conductivity of roots. Moreover, fewer K and Na ions were transported to the xylem sap and the K concentration in root tissue after 3 h had decreased whereas that of Na had increased. These results suggest that the sunflower root acts as an efficient accumulator for Na rather than simply as a barrier to Na transport. It is suggested that NH4 ions caused a decrease in charge separation across one of the barriers where Na is actively transported so that adding NH4 ions to the medium increased Na accumulation in root cells. This barrier may have been at the symplast.

Reduced glutathione (GSH) is synthesized within blood erythrocytes from the constituent nonessential amino acids, glutamic acid, cysteine and glycine. The concentration of GSH in. erythrocytes can therefore be affected by the permeability of erythrocyte membranes to certain of these amino acids and their availability within the erythrocyte (Young, Ellory & Tucker, 1976; Smith, 1977). Alterations in the activity of the two enzymes responsible for GSH synthesis, γ-glutamyl cysteine synthetase and glutathione synthetase can likewise influence GSH concentration (Smith, Lee & Mia, 1973; Blume, Paniker & Beutler, 1974; Wellner et al. 1974; Board, Morris & Peter, 1976).

Until recent years large incidental additions of sulphate in fertilizers, especially superphosphate and ammonium sulphate, ensured that the major sulphur requirements of crops were adequately met. Increasing purity and concentration of commercial fertilizers, however, have largely eliminated such additions, with corresponding increase in the importance of available soil sulphate and atmospheric sulphur. The latter can readily be measured but its contribution to crops is more difficult to assess. To examine one aspect of this question, the effect of sulphur in rain on the yield and sulphur content of oats has been measured by comparing pot cultures grown in two environments, one with access to both gaseous atmospheric sulphur and rain sulphur and the other to gaseous sulphur only.

There are extensive areas in Scotland and other parts of Britain where, because of low soil cobalt status, the cobalt concentration of pasture herbage is below the 0–1 /fg/g D.M. regarded as the requirement for grazing ruminants (Agricultural Research Council, 1965). A common method of overcoming the effects of cobalt deficiency in livestock occurring within these areas is to apply cobalt sulphate to the pasture. Following work carried out by Stewart, Mitchell & Stewart (1941, 1942) and Stewart etal.(1946) the standard recommended application of cobalt sulphate for pasture has remained at 2 kg/ha for many years, an application generally expected to last for 3–5 years. However, in South East Scotland there are doubts about the adequacy of such treatment which has led to a reappraisal. Significant increases in uptake of cobalt by herbage following applications to land at this rate are not always observed and sometimes there is no appreciable increase in ‘available’ soil cobalt as determined by acetic acid extraction.

Khan, Ghosh & Sasidharan (1978a) and Khan, Sasidharan & Ghosh (1978b) have reported on Barmer goats' efficiency in water economy under the conditions of the Rajasthan desert, India. Some earlier reports also pointed to the superiority of dosert-adapted goats of other breeds in this respect (Maloiy & Taylor, 1971; Shkolnik, Borut & Choshniak, 1972; Dawson et al. 1975). Recently, Khan, Sasidharan & Ghosh (1978 c) have recorded evidence which indicates that Banner goats' management of the body's water balance is decidedly superior to that of desert sheep. However, just as these two species exhibit wide divergence in their behavioural responses to environmental stresses, they appear to exhibit physiological responses of different types in combating such stresses. In the present note, information on a few important indices of adaptation to water insufficiency conditions, namely, glomerular nitration rate (GFR) and blood and urinary urea concentrations in Barmer goats are presented.

It has been reported recently (Stott, 1974) that in cattle, reproductive efficiency is increased by keeping the animals under cool climatic conditions. However, in buffaloes very limited information is available. Roy, Sengupta & Misra (1962) have reported that all buffaloes exhibited oestrus and were inseminated in a group protected from direct sun radiation whereas in a non-protected group only one showed oestrus. There is no systematic information available on the effect of wallowing and showers on the oestrual behaviour of buffaloes. Therefore, the present investigation was undertaken to study the effect of cooling on oestrual behaviour in buffaloes.

Lipid production across the liver was measured in catheterized dairy cows in vivo in the fed state and during 6 days of fasting. Production rates were calculated from the lipid concentrations in arterial, portal and hepatic-venous plasma and from the rates of plasma flow in the portal vein and the hepatic veins.

There was a consistent net hepatic output of triacylglycerol and a net hepatic uptake of free fatty acids in the fed state.

In the fasted state there was a significant change to a net hepatic uptake of triacylglycerol and an increased hepatic uptake of free fatty acids. Both factors are likely to result in an accumulation of triacylglycerol in the liver.