In a trial laid out to compare the effects of liquid digested sludge with equivalent nitrogen and phosphate fertilizers as ‘Nitra-shell’ and superphosphate, growth data, and data of grain and straw yield were obtained.

Liquid digested sludge increased the dry weight and shoot number at the ‘tillering’ stage, and dry weight and ear number at the flowering stage, more than equivalent fertilizer.

By 13 May, sludge-treated plants had absorbed more nitrogen than fertilizer-treated plants. By 19 June this was reversed for the sludge-treated plants had then absorbed 81% of the nitrogen absorbed by fertilizer-treated plants; ripe grain from sludge plots had a lower nitrogen percentage than grain from fertilizer plots.

1. A small-scale plot experiment was conducted at the Hannah Institute for the 3-year period 1963–65, to study the comparative effect of applications of various mixtures of dung and urine (slurry treatments) on the yield and quality of an established S23 ryegrass and S100 white clover sward.

1. In glasshouse experiments, apterous and alate Myzus persicae Sulz. and Aphis fabae Scop, settled more readily on some sugar-beet plants than on others.

1. The main objectives of the breeding programme were to develop two types of soyabeans:

(a) High yielding, non-shattering, resistant to lodging, determinate in habit, with pods formed 5-6 in. from ground level, for mechanical harvesting.

(b) High yielding, non-shattering but with no qualifications as to habit, for hand harvesting by African farmers.

An account of the breeding programme carried out on twelve crosses is given. The breeding method used was a combination of the bulk and pedigree methods.

Yellow rust of barley has been observed more frequently at Cambridge in the period 1960-65 than the previous five years. The disease occurs in most parts of England but appears to be prevalent and more damaging in the south and west of the country. The increased incidence of the disease is probably associated both with the greatly increased acreage of barley now being grown and with the introduction of more susceptible barley varieties.

Two isolates of Puccinia striiformis differing in virulence characteristics have been found to be representative of the population of the pathogen in England. These isolates are similar to, if not identical with, physiologic races 23 and 24 which are widespread in continental Europe.

A survey of the seedling resistance to P. striiformis of the currently cultivated barley varieties showed that, of the twelve varieties tested, nine were susceptible to both isolates of the pathogen and three were susceptible to one isolate and resistant to the other. No varieties were resistant to both isolates.

Field experiments were done at Rothamsted each year from 1940 to 1948 to compare arange of organic manures with farmyard manure and with fertilizers. Eight kinds of farmyard manure (FYM) made under controlled conditions from the same quantity of feedingstuffs, sewage sludges from 7 sources, composts of sewage sludge with straw from 4 sources, 5 types of town refuse, cut-bracken stacked over winter, and peat, were tested on potatoes at single and double dressings. All organic manures were compared with and without fertilizers supplying 0.6 cwt. N, 0.6 cwt.P2O5and 1.0 cwt. K2O. The soils were heavy loams, farmed in normal rotations; a fresh field was used each year. Residual effects were measured on cereals grown in the year after the potatoes.

1. An experiment was started in 1959 to measure effects on grazed permanent grass of ammonium sulphate, calcium nitrate, superphosphate and muriate of potash; yields and N, P and K contents of the herbage were measured from 1961 to 1964.

2. Applying 1.5 cwt. N/acre per year (in four bi-monthly doses) consistently increased yields. The first and fourth cuttings yielded less with 3.0 cwt. N/acre per year (also in four bi-monthly doses) than with 1.5 cwt. N/acre, but the second and third cuttings yielded more; the total additional yield from 3.0 cwt. N was small. Yields were increased equally by ammonium sulphate (providing that lime was also applied) and calcium nitrate.

3. Yields were increased more by P than by K; the increase from P was greater when N was also applied.

1. The availability of K in potassium metaphosphate was investigated in an experiment with large pots using a red sandy soil, low in exchangeable potassium. Potatoes were grown. The effects of potassium metaphosphate in three different granule sizes, applied at two rates, were compared with those of equivalent potassium chloride and potassium sulphate.

2. Characteristic deficiency symptoms appeared in plants receiving no K and the crop responded to K fertilizer in potassium concentration, yields of tubers, and dry matter, and starch concentrations.

3. Potassium metaphosphate, regardless of granule size and of application rate, was as effective as potassium chloride and potassium sulphate in giving normal development of potato plants, high potassium uptake in the foliage, and yield of tubers.

1. Some of the effects of stress, fasting and ACTH injections in pregnant ewes were investigated.

2. A 6-day fast produced a relatively mild hypoglycaemia and hyperketonaemia without inducing pregnancy toxaemia.

3. Stress of transport produced an immediate slight rise in plasma cortisol; 4 hr. later the plasma cortisol had returned to the pre-stress levels.

4. A combination of stress and fasting produced severe hypoglycaemia, hyperketonaemia and subacute pregnancy toxaemia, but there was no increase in plasma cortisol levels.

5. Daily injections of ACTH resulted in a fourfold increase in plasma cortisol and prevented the development of hypoglycaemia, severe hyperketonaemia, and pregnancy toxaemia in pregnant ewes subjected to stress and fasting.

6. Changes in plasma concentrations of NEFA, urea, proteins, catecholamines and insulin were also investigated.

In an experiment in which plots of S24 perennial rye-grass grown at a 2 in. spacing were subjected to pretreatments involving two different nitrogen levels and three different cutting frequencies it was found that subsequent regrowth was most strongly related to total stubble weight. Other significant correlations were obtained with root weight, tiller number and weight of water-soluble carbohydrates in roots and stubble.

The relationships between cultural treatments and sward condition, and between sward condition and regrowth are discussed in the light of the results from this and other experiments.