Drying rates of stem internodes of S. 24 perennial ryegrass and S. 37 cocksfoot, some with leaf sheaths and laminae attached, were measured in controlled conditions of air speed, temperature and relative humidity after exposure for 60 sec to dry heat, steam, steam containing petroleum ether vapour, and petroleum ether vapour only. The last treatment was most effective in increasing the drying rate, but a similar effect was obtained by splitting the stem internodes longitudinally or by removing from the larger plant fragments (internodes with leaf) the leaf sheaths and laminae. Observations on leaves with a scanning electron microscope confirmed that the steam and petroleum treatments acted on the surface waxes thus reducing the cuticular resistance to water loss. The presence of internal tissue resistance was demonstrated by anaerobic treatment of ryegrass leaves and stem internodes to disrupt cell protoplasts. The ensuing increase in drying rate was clearest in stems which have a low surface area to volume ratio. The results suggest that the combination of both mechanical damage and thermal or chemical surface treatment could form the basis for more effective methods of increasing the drying rate in the field of crops cut for conservation.

Excretion of D.M., N, Ca, P and Mg in faeces, and N, P and Mg in urine were measured at intervals over 12 months in breeding Scottish Blackface sheep grazing hill pastures. These values were used with data on reproductive performance and body compositional changes, to calculate the energy, nitrogen and mineral balances. The sheep were: 11 6½-year-old with sound mouths (SM), 16 6½-year-old with broken mouths (BM), 16 5½-year-old with all permanent incisors clipped to gum level (CM) and 16 2½-year-old (Y). An energy supplement was given at the end of gestation and during early lactation. All faeces were collected and creatinine was used as an internal marker to estimate urine volume.

Faecal D.M. output ranged from 443 to 662 g/day, with highest values in November and lowest in May. Average values for the BM sheep were lower than those for the other groups but when output was expressed as a power function of body weight, the values for the Y sheep were 15% higher than those for the other groups. Faecal excretions of Ca and P in January and February were very low and the values for P were half the expected endogenous faecal loss.

Urinary output ofN ranged from 6·0 g/day in February to 22·2 g/day in August and the corresponding urinary urea N: total N ratios were 0·24 and 0·69. Urinary Mg output was highest in late summer and early winter but urinary P showed no consistent trends.

The estimated daily intakes of DOM (g) were 936 in November 1969, 599 in January, 414 in February, 1075 in May, 1150 in August and 946 in November 1970.

The loss of energy from the body between mating (November) and mid-lactation (June) ranged from 9·5 to 16·8% of the total calculated ME requirements in the Y and BM sheep, respectively. Maintenance requirements averaged 204 kJ/kg body weight/day and the value for the Y sheep was 12% higher than the mean for the older sheep.

Nitrogen and mineral balances were calculated for February, May, August and November. The sheep were protein-deficient in winter, not from a shortage of crude protein in the diet but because of its low digestibility (34%). Intakes of Ca and P in winter were low and a real possibility of a P deficiency exists. Estimates of the concentrations of N and of minerals in the herbage consumed by the sheep were made and compared with those obtained for cut herbage from the same pastures. It would appear that the sheep selected herbage of a higher protein content than that of the cut herbage. Herbage selection was greatest in November.

Winter vigour, winter burn, freezing damage and early spring yield were measured in 24 perennial ryegrass varieties which varied in their degree of winter adaptation. Winter vigour and winter burn were negatively correlated due to senescence in the dormant varieties. Cold resistance, measured in a freezing test, was also negatively correlated with winter burn but was independent of spring yield. Spring yield was positively related to winter vigour but negatively related to winter burn. The more dormant varieties which sustained most winter burn were better able to survive freezing.

A canonical variate analysis showed that the first two canonical variates accounted for 87·8% of the total variation. Interpolation from the means of the four characters suggested that the first canonical variate represented adaptation to winter conditions. A generalized model based on these findings is proposed and its use in the formulation of grass breeding strategies discussed.

Six opaque·2 (O2) inbred lines and the single, three-way and double-cross hybrids derived from them were compared for emergence at low temperatures with their analogous normal inbred lines and hybrids. The results demonstrate that there is an increasing difference in emergence between the o2 and the normal forms with an increase in the period of incubation, the o2 types being inferior, in general, to the normal.

A treatment of seeds with fungicides like Quinolate V4X, TMTD–Lindan and Vitavax 75W before sowing improved the cold tolerance of both the o2 and normal analogues, but the o2 forms remained far below the level of the normal.

Nine high-oil varieties of sunflower were evaluated for their reactions to salinity during emergence in salinized soil culture ranging from 0 to 12·80 mmhos/cm under controlled temperature of 27±1 °C. The varieties were Louck, Vniimk-8931, Chernianka-66, Record, Armarisky, Peredovik, Orizont, Mhjak and Zarea.

Soil salinity decreased the percentage of emergence in all varieties of sunflower. The rate of decrease in emergence of some varieties was greater than others. Among varieties tested Vniimk-8931 (a tall variety) and Chernianka-66 (a dwarf variety) showed the highest and the lowest tolerance to salinity at 7·60 mmhos/cm, respectively. For electric conductivities above 7·60 mmhos/cm, the nine varieties of sunflower could be classified in three categories. Vniimk-8931, Record, Louck, Peredovik and Armarisky as high salt tolerant, Mhjak and Orizont as medium salt tolerant and Chernianka-66 as low salt tolerant varieties.

The seasonal changes in plasma concentrations of albumin, globulin, transferrin, urea, Ca, P and glucose were measured in 59 Scottish Blackface sheep grazing a hill pasture. The sheep were classified according to age and state of permanent incisor dentition into four groups. Sheep were slaughtered at mating (November), mid-lactation (June) and in the late dry period (November), and the changes in plasma constituents related to changes in body composition. A protein-free supplement was offered during late pregnancy.

Another group of sheep was used in the subsequent year to investigate the significance of helminth infections on such pastures.

Plasma albumin concentration fell from 32·0 g/1 in all sheep in early pregnancy to 17·5–19·5 g/1 in late pregnancy and early lactation in 5½- to 6½-year-old animals. Younger animals (2½ year old) maintained higher (23·0 g/1) levels at these latter times. The extent of the decrease in plasma albumin concentration of the groups was related to the loss of N from their soft tissues during the same period.

Plasma volume increased from 2·10 to 2·491 between early pregnancy and midlactation (45 and 66 ml/kg body weight respectively). The increase in volume was considered to account for the reduction in the concentration of plasma globulin which took place during this period.

Plasma urea-N concentrations were extremely low (50—60mg/l) between February and April and had fallen from their highest values (240 mg/1) in August to 150 mg/1 by the following November. It is argued that the fall in albumin concentration which occurred in early pregnancy, coupled with the extremely low urea-N concentration, reflects a very low digestible crude protein intake during most of pregnancy.

Transferrin concentration followed a similar seasonal pattern to urea. The concentration was extremely low in February (2·2–2·4 g/1), highest in August (3·45 g/1) and had fallen by November (3·0 g/1). The value of transferrin as a nutritional index is discussed.

Regular dosing with anthelminthic of sheep on these pastures had a beneficial effect on plasma albumin concentrations, particularly during critical nutritional periods, namely late pregnancy and lactation.

Plasma glucose, Ca and P concentrations were of no value in monitoring the nutritional status of the animal with respect to these nutrients.

In a dry area of Southern Tanzania with a single rainy season irrigation during the six-month-long dry season (May-November) doubled the total annual yield of tea and at the same time evened its distribution over the year to some extent. Other factors including low temperatures limited growth rates during the period June-September despite irrigation, whilst a lull in production in November appeared to be unrelated to external factors. Roots were traced to depths of about 4·3 m and by the end of the dry season unirrigated bushes were drying the soil below 3m. In general total yields decreased with decreasing frequency of irrigation and quantity of water applied but because these plants were deep rooting they could withstand deficits up to 100 mm without a reduction in yield, equivalent to a loss of about 25% of the total available water in the profile. There was some evidence that the most economical use of water occurred when the soil was not rewetted to field capacity at each irrigation, although yields were then less. Irrigation also reduced the incidence of a stem canker, Phomopsis theae. The implications of these results to the tea industry of East Africa are discussed.

One hundred and sixty-eight wool samples were collected from commercial flocks of Karadi sheep raised in the five provinces of northern Iraq. The wool characteristics dealt with were staple and fibre length, crimps, fibre diameter, medullation, fibre strength and elongation.

The results showed that the Karadi wool is a long type of carpet fleece with average staple and fibre lengths of 19·3 and 23·5 cm, respectively. It had an average fibre diameter of 48·1 μ and contained 19·45 % medullated fibres. The number of crimps per 2 cm was 2·4. Average fibre strength and elongation were 24·8 g/5 cm and 31·8 % respectively. Phenotypic correlations between wool traits were studied.

Bracken-dominated hill pasture was treated with combinations of bracken and pasture herbicides and two reseeding techniques against a background of fertilization and liming. Picloram and dicamba gave high levels of bracken control and reduced carbohydrate levels in the rhizome. Both paraquat or reseeding with minimal cultivations increased yield of digestible organic matter by reducing competition from native weed grass species and promoting better establishment of ryegrass.

Three separate nitrogen balance experiments were made in three consecutive years. Comparisons of nitrogen retention were made between late-pregnant (15–20 weeks) Greyface (Border Leicester ♂χ Scottish Blackface ♀) ewes given a basal diet of hay and molassed sugar-beet pulp cubes (SBP, 1·25 em diameter x ca. 3cm length) and when given additional nitrogen supplied as urea contained in molassed sugar-beet pulp cubes (SBPU). Both sugar-beet pulp materials were adequately supplemented with minerals and vitamins. Supplementation with urea significantly increased nitrogen retention.

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.

The habit of growth of pigeon-pea cultivars was greatly affected by environmental changes. The effect was greatest in the highest yielding cultivar, Pant A2, for the characters plant width, number of pods/main branch, number of pods/plant, grain yield and plant weight. In the late-sown crop the ‘vegetative sink’ was affected more than the ‘generative sink’. T21 was the outstanding yielder under late-sown conditions. It is suggested that a rotation of mungbean–pigeon pea–wheat can be grown in 1 year, with profitable returns.

The deposition on soil of sulphur from the atmosphere through gaseous absorption, or particulate precipitation and deposition on vegetation and to other surfaces, is calculated to account for most of the atmospheric-S deposited in Britain; S collected in rainwater appears to amount to only one-sixth of the total deposition (Chamberlain, 1960). A knowledge of the amounts of S deposited is important agriculturally, particularly in areas far from industry, both where fertilizers are not used, and also when deciding how much fertilizer-S should be used relative to other nutrients. The technical problems of separating the amounts of sulphur deposited by gaseous absorption, particulate precipitation, and in rain are easier in a tropical climate which has well-defined wet and dry seasons and where atmospheric SO2 concentrations are smaller and vary less than in industrial areas.

A field experiment was made with sorghum hybrid CSH-1 during the rainy seasons of 1968 and 1969 on a sandy loam soil to study the influence of amounts and sources of phosphate fertilizer on phosphorus nutrition. Concentration of P in the crop and uptake increased with increasing amounts of phosphate and with increasing proportions of water-soluble P in triple superphosphate-dicalcium phosphate and triple superphosphate-rock phosphate mixtures. Relative effectiveness values were calculated from P uptake at harvest by a multiple regression method. For triple superphosphate, nitrophosphate (30% water soluble P), dicalcium phosphate and rock phosphate (from Jordan) the values were respectively, 100, 74, 61 and 22.

Three preliminary experiments at Cambridge (1904–70) indicated that several varieties and breeding lines of sugar beet differed in their response to fertilizers. Three factorial experiments were therefore made at Broom's Barn (1970–2) to measure response by four widely differing varieties of sugar beet (Sharpe's Klein ‘E’, Maris Vanguard, V.T.137 and Anglo-Maribo Poly) to nitrogen (0, 75 and 150kgN/ha), sodium (0 and 250 kg N/ha) and potassium (0 and 400 kg K/ha) fertilizers. Increases in sugar yield from 75 kg N/ha by each of the varieties were remarkably similar and giving a further 75 kg N/ha neither increased nor decreased the yield of any variety on average over the three experiments. The yield response to sodium and potassium was greatest in Sharpe's Klein ‘E’ and least in V.T.137; however, as with nitrogen, varieties responded inconsistently from year to year and the interactions were not statistically significant for data pooled over the three experiments. These experiments indicate that varietal differences in fertilizer requirement are unlikely to be important in commercial practice.

The flavour of meat from sheep grazing rape (Brassica napusL.) was compared with that from grass-fed sheep in a series of experiments. The occurrence of a strong and unattractive foreign flavour and aroma was confirmed but the intensity of flavour was not consistent. The intensity was apparently unaffected by cultivar, growth stage, length of grazing period or breed or age of sheep.

An investigation was undertaken to determine whether commercial milk replacers provide fermentable substrates for the yeast Torulopsis glabrata and thus produce ethanol in the stomachs of new born lambs and calves. Samples of stomach contents from calves in two small rearing units and a small number of farm bred calves, all being fed commercial milk replacers, were also examined. Ethanol was produced from certain replacers in all cases, and its association with Torulopsis glabrata was confirmed.