Nine experiments in the East of Scotland were completed in the years 1966, 1967 and 1968 to test the response of potatoes grown for ware to five levels of a 15½–15½–21 fertilizer applied at rates of 0, 4, 8, 12, 16 and 20 cwt per acre.

1. Mean yield of ware tubers increased up to the highest fertilizer level.

2. Mean yield of small tubers increased only up to the 8 cwt per acre level and then declined.

3. Dry matter content of ware tubers decreased with increasing levels of fertilizer.

4. Increasing fertilizer levels lowered soil pH. At one site this was associated with a significant reduction of common scab on the tubers.

One of the most common complaints of users of palm nut kernel cake is that it is liable to become rancid on keeping. Rancidity developing in an oil-seed residue like palm nut kernel cake is likely to be due to splitting of the fats of the cake by a fat-splitting ferment or enzyme— a lipase—formed under certain conditions. The resting seeds do not contain lipase, but they are likely to contain a zymogen from which under suitable conditions lipase is formed.

The 65 spring and 14 winter cultivars of barley on the 1981 U.K. National List were examined electrophoretically for allozyme variants of phosphoglucoisomerase (PGI). Two different banding patterns were observed, a ‘fast’ and a ‘slow’ migrating type. With the exception of six spring cultivars in which the ‘slow’ type was found, all the cultivars were classified as ‘fast’. F2 progeny of crosses between ‘fast’ and ‘slow’ plants were used to interpret the banding patterns as resulting from the dimeric isozymes of two alleles (allozymes) each producing a triple band pattern, the faster two bands of which were considered to be ‘secondary’ or artefact bands. With the notable exception of Dragon and its sister line RPB 1115–75 all of the other ‘slow’ cultivars and breeders' selections were found to have the ‘slow’ cultivar Midas in their breeding history. Midas was bred using material from three ‘fast’ cultivars and a γ-ray mutant strain, the irradiation which produced this strain being regarded as the likely cause of the ‘slow’ isozyme. Unlike all the other cultivars tested, Midas was found to be a mixture of genotypes comprising 73% ‘slow’ and 27% ‘fast’ plants, a ratio which was most probably due to founder effects caused by the breeders' selection programme. In the light of the present investigation and other reports it is concluded that it is not an uncommon occurrence to find plants with different electrophoretic banding patterns within inbred cultivars.

This result has serious implications for cultivar registration as there is a possibility of selecting electrophoretically distinct plants from within existing registered cultivars. It is concluded therefore that the protection afforded to plant breeders under Plant Breeders' Rights schemes could be seriously threatened by the use of electrophoretic characters for cultivar registration except in some specific incidences where it may be possible to apply appropriate safeguards. The implications for plant breeders of the existence of isozymes of PGI, of possibly different efficiencies, within commercial cultivars of the genus Hordeum are also discussed.

Two dormant varieties of rice were harvested three times at intervals of 7 days after grain development and the seeds were subjected to different sunning and controlled humidity storage treatments. Germination percentages and moisture contents of the grains were recorded at intervals of seven days after harvest.

It was noted that the dormancy of the dormant rice seeds was broken early when the seeds were subjected to continuous sunning from sunrise to sunset, followed by the treatment where the seeds were preserved under 0 % humidity conditions at room temperature. There was no break of dormancy of rice seeds when the seeds were preserved under 94 % humidity conditions.

It was further noted that when the age of the seeds at the time of a germination test remained the same, the earlier the harvest, the earlier was the break of dormancy; and when the lapse of time after harvest remained the same at the time of a germination test, the later the harvest, the better was the germination.

It is suggested that dryness of the seeds helps in the early break of dormancy and wetness retards or completely stops the dormancy-breaking reactions. On drying, the kernels of rice seeds shrink in volume more than the glume covers resulting in an air-space between the glumes and the kernels. This air-space helps air-diffusion in and out of the seeds, resulting in quicker oxidation-reaction processes or possibly embryo respiration, and consequently the dormancy is broken early. Increase in temperature accelerates such reactions. It is further suggested that the dormancy of rice seeds depends on the interactions between the ‘embryo-sensitivity to inhibitors’ and the ‘state of oxidation-reaction processes’ inside the seeds.

Immunoglobulin concentrations were compared in Finnish Landrace and other lambs, born to ewes of their own and of different breeds, to determine if the superiority of the Finnish lambs in obtaining maternal immunoglobulin from colostrum, shown in previous experiments, is due to special qualities of the ewes or of the lambs. The groups compared were, respectively, Finnish lambs born to Finnish, Welsh Mountain or Border Leicester ewes; Finnish, Oxford Down and Soay lambs born to Finnish ewes; Finnish and Merino lambs born to Border Leicester ewes; and Finnish and Southdown lambs born to Welsh Mountain ewes. The immunoglobulin concentrations in the Finnish lambs were in every comparison significantly higher than in the other breeds, and were not related to the breeds of the dams.

The object of these experiments was to compare the effect of dung, artificial manures and lime on yield and botanical composition of meadow hay.

The soil is a light loam derived from a coal measures sandstone, and is naturally sour. The poor type of herbage it produces is typical of a large acreage of land in the West Riding.

The northern halves of the plots were limed, and the results obtained show striking differences between the limed and unlimed halves which must be taken into account in any comparison made between the different manurial treatments.

In an earlier paper the estimation of the total digestible nutrients (T.d.n.) to be expected in ruminant feedingstuffs has been described (Glover, J. Duthie, D. W. & Dougall, H. W. 1960). In a like manner the average T.d.n. in pig feeds can be estimated. The necessary equations have been obtained in earlier papers (Glover & Duthie, 1958A, b). They are, respectively

where C.p. and C.f. are percentage crude protein and crude fibre, respectively, in the dry matter of the feed, D.c.p. is digestible crude protein and N.r. the nutritive ratio. They can be used directly for the estimation of T.d.n. because by definition T.d.n. is D.c.p.(N.r. + 1); thus the T.d.n. to be expected at different levels of C.p. and C.f. can readily be calculated. Table 1 shows in abbreviated form some of the values that are obtained in the ranges 0–30% C.p. and 0–40% C.f., while Fig. 1 illustrates in detail the effect on T.d.n. of changing C.p. and C.f. levels of the diet. This figure shows clearly the very marked effect of increasing C.f. depressing the digestibility of the total nutrients in pig feeds, a fact which is already well known.

In a 2 × 4 factorial experiment, the laying performance of hens given diets with or without blood meal and four concentrations (0, 5·71, 11·43 and 17·14 g/kg) of added magnesium chloride was measured for 280 days. The inclusion of 50 g/kg blood meal in the laying diet reduced the rate of laying (P < 0·05), egg weight (P < 0·01), egg output (P < 0·01), food intake (P < 0·01), body weight gain (P < 0·01) and body weight at 457 days (P < 0·05). It increased the height of albumen (P < 0·05), Haugh unit score (P < 0·01) and shell colour intensity (P < 0·05) of fresh eggs. The inclusion of increasing dietary concentrations of magnesium chloride reduced (P < 0·01) the specific gravity of eggs but had no significant effect on any of the other egg quality or production characteristics. The dietary treatments had no significant effect on Haugh units of stored eggs.

A close relationship has been found between the decomposition of feeds in the macro-respirometer and their digestibility. The degree of nitrogen mineralization appears also to conform with certain aspects of protein digestibility. The various relationships are sufficiently close to suggest that the macro-respirometer can be used in a preliminary assessment of the digestibility of feeds.

This study sought to determine whether increases in live weight (LW) of steers implanted with Compudose 200®, a growth promotant that contains 17β-oestradiol, arose in part from increases in resistance of those steers to cattle ticks and gastro-intestinal nematodes (worms) to which the steers were exposed while they were growing. Half of a group of interbred Hereford × Shorthorn (HS) and interbred Brahman × HS (BX) steers was implanted with Compudose 200 on two occasions 200 days apart. Half of each of the implanted and nonimplanted groups in each breed was treated every 3 weeks to control cattle ticks and worms. All animals grazed together and were regularly monitored for parasite burdens and LW changes. Both breeds responded positively to Compudose 200, to which BX responded most, and to treatment to control parasites. Resistance to either ticks or worms was unaffected by the presence of the implant so that, within each breed, increases in LW gain in response to the implant were similar regardless of parasite control. Thus the increases in LW gain resulting from the use of Compudose 200 arose directly from the action of the implant on metabolism, not indirectly through any effect on resistance to parasites.

A field experiment was made with pigeon pea (Cajanus cajan (L.) Millsp.) at the Indian Agricultural Research Institute, New Delhi, during the rainy seasons of 1975 and 1976 to study the effects of plant type, plant population density and the application of phosphate fertilizer on growth and yield of pigeon pea. Cultivars BS-1 and UPAS-120 produced significantly more grain with 100 × 103 plants/ha, whereas the cultivar Prabhat produced most when 200 × 103 plants/ha were grown. Application of 13 kg P/ha increased most growth and yield attributes and increased the grain yield significantly over the control to which no P was given; however, no additional increase was obtained when 26 kg P/ha was given. The highest-yielding cultivar BS-1 benefited most from phosphate fertilizer.

Of recent years a disease of root-crops known to farmers in North Wales is one in which the heart or core of the root is converted into a soft putrid mass but which leaves the rind and mature foliage intact. The disease is prone to appear on land treated with lime as a preventive against the roots being attacked by Plasmodiophora brassicae or when the land has received a heavy dressing of nitrogenous fertilizers. It is common knowledge that nitrogenous manures have a tendency to force the crop and so produce watery, sappy roots which easily fall prey to disease. Recently it was brought to the writer's notice by one of the County Organizers for Agriculture in Wales that some of the farmers in his area were strongly disinclined to lime the land for root-crops because this treatment was favourable to the appearance of “soft-rot.” There is probably some modicum of truth in this contention, for as will be seen below, the writer in the investigation of the present disease found that the organism isolated refused to grow on any media which were not neutral or alkaline. The writer observed and investigated this disease on a crop of white turnips grown on the farm of the University College of North Wales and the land here had received a dressing of nitrate of soda. A casual glance at the crop did not show anything unusual, in fact judging from the amount of green foliage the crop looked very healthy. Closer examination however showed that the very young leaves at the centre of the crown had been destroyed thus forming a tiny wound into which one could push a probe without obstruction to the depth of some three or four inches. The fully expanded leaves very effectively concealed the wound and the disease seemed evidently confined to the internal tissues leaving the foliage and rind quite firm even up to time of harvesting the crop. Indeed the extent of damage was only fully revealed at the time of lifting when the harvester's knife lopped off the foliage only to discover that the roots were bad.

The incidence of oestrus in pregnant ewes has been reported previously by Williams et al. (1956) and Bichard et al. (1974). However, their investigations were not designed specifically to study such a phenomenon and the number of animals employed was small. None of the factors affecting oestrus occurrence was investigated. Under experimental conditions, vasectomized or aproned rams are sometimes used after the removal of fertile rams to detect embryonic failure in pregnant ewes. It is of interest to check on the validity of this method. This study was carried out to obtain an estimate of the incidence of oestrus in early pregnancy using relatively large numbers of fat-tailed Barki and imported Hungarian Merino ewes and to investigate the effect of year, breed of ewe and age of ewe on its occurrence.

Nine normal lactating Murrah buffaloes from the Punjab Agricultural University Dairy herd were used to assess the effect of showers and evaporative cooling on plasma oxytocin concentration, let-down time, milking time and milk yield in buffaloes. The animals were showered four times daily between 10.30 and 16.30 h or provided with evaporative cooling from 07.00 to 21.00 h. In the hot and dry period the oxytocin concentration in buffaloes given a shower was significantly greater than that of the buffaloes of the control group. In the hot and humid period there was a similar trend.

It is concluded from these studies, that cooling may increase the effective milk ejection reflex because the milk-ejection response to a given blood oxytocin concentration is different when the animal is heat stressed from when it is cooled.

The present communication is intended as a contribution to the study of the capacity of soils to retain moisture in equilibrium with the atmosphere. The experimental material with which it deals consists in part of the analytical data obtained in the investigation of one hundred soils of the county of Dorset, which has been carried out for the County Council, and in part of a series of determinations made for the purpose of elucidating this problem.