During the period 1942–50 some thirty-seven multifactorial field experiments have been carried out to determine the conditions under which weeds in fibre flax can be selectively controlled by herbicides. In order to assess the direct effects of treatment on flax, some experiments have been undertaken in weed-free crops, while others have been sited in weed-infested crops so that the increases in productivity following on weed suppression could be evaluated.

In almost all experiments, the total crop weight, the yield of de-seeded straw and the amount of scutched fibre per plot were determined, while in a proportion seed yield was also measured. Where weeds were present, counts were made to establish the degree of control.

The preliminary experiments demonstrated that sulphuric acid, ammonium sulphamate and ammonium thiocyanate were far too toxic to flax. An examination of a range of cupric salts suggested that the most promising compound was cupric chloride, while of the formulations of dinitro-o-cresol investigated only the sodium salt appeared to be sufficiently selective. It was also found that in terms of fibre production sodium 2-methyl-4-chlorophenoxyacetate was less toxic than sodium 2:4-dichlorophenoxyacetate. In consequence, the bulk of the investigations have related to determining the optimal conditions for the use of cupric chloride, sodium dinitro-o-cresylate and sodium methylchlorophenoxyacetate.

For all three compounds it has been observed that flax is least liable to injury at a height range of 2–6 in. There are limitations to the amounts which can be safely employed, namely, 20 lb. of cupric chloride or 6 lb. of sodium dinitro-o-cresylate applied in 100 gal. of spray solution per acre. With sodium methyl-chlorophenoxyacetate the corresponding limit is 1 lb./acre, and the evidence suggests that the crop may be injured if the volume of application is reduced below 25 gal./acre.

Within these limitations of concentration volume and stage of development of the crop, the suppression of annual weeds has led to significant increases in the yield of straw, seed and scutched fibre. Larger gains resulted from the use of sodium methyl-chlorophenoxyacetate and sodium dinitro-ocresylate. This superiority over cupric chloride is in part attributed to the wider range of weed species which are killed by the two sodium salts and in part due to the greater liability of crop damage if the limits on amount and time of application are not strictly observed.

The results have also clearly established that for fibre flax the weight of total crop, the yield of straw, the amount of seed or plant height cannot be taken as reliable criteria for the evaluation of herbicides, for while all these may be little affected by treatment yet there may still be large reductions in the amount of recoverable fibre. A preliminary anatomical examination of the internal changes in the stems of flax has shown that when treatment with dichlorophenoxyacetic acid is delayed, a marked but localized curvature of the stem results and in this zone fibre formation is abnormal: thus breakages either during pulling or processing may occur at this point of weakness.

1. A simple inexpensive anemometer is described; the instrument is intended for general husbandry use.

2. The essential part of the apparatus is a 1 in. diameter electrically heated duralumin spherecapping a mercury-in-glass thermometer.

3. Charts are given relating wind-speed to sphere temperature, ambient temperature and heat input to the sphere. No further calibration is required.

Supermarkets in the U.K. want uniform heads of crisp lettuce weighing at least 450 g and preferably 600 g but it is difficult to meet these requirements consistently throughout the season because there can be considerable variation in head weight both between and within sowings. In the butterhead lettuce crop the synchronization of seedling emergence, which was responsible for a large proportion of the variation in head weight at maturity (Gray, 1976), was improved by fluid sowing pre-germinated seed (Gray, 1978a, 6). Finch-Savage & Cox (1983) have also shown with butterhead lettuce that pre-germinated seed emerged earlier and produced earlier-maturing, heavier heads than dry seed and that the addition of sodium phosphate to the gel further advanced maturity and increased head weight. Therefore, fluid sowing pre-germinated seed of crisp lettuce in a gel containing phosphate might be expected to reduce variation in seedling emergence and to improve head weight and the uniformity of head weight at maturity.

A breeding programme initiated at Oak Park, Carlow, in September 1965, in which perennial ryegrass plants, instead of being widely spaced as traditionally used in grassbreeding, were planted 9 x 9 in apart, is described. At this density, plants were individually distinguishable throughout three growing seasons yet gave a complete ground cover of herbage on which was imposed two contrasting systems of defoliation. Data on ear emergence, dry-matter yields, persistence and some quality components agreed with data obtained from swards by other workers.

This paper reports a continuation of previous work on the mineral constituents of ewe's milk, in particular copper, iron, manganese and zinc. Milk taken at weekly intervals from four groups of Clun Forest and Suffolk x Clun Forest ewes was studied over lactations varying from 6 to 12 weeks. The copper content showed a marked decline as the lactation advanced, while there was no consistent trend in iron content. Maximum, minimum and mean values for iron and copper are given for the sheep in each group.

Manganese was determined in the milk from two groups and zinc in. that from one group of ewes. There were significant differences in weekly manganese content in both groups, but no consistent trend as lactation advanced. Zinc content showed no significant differences from week to week, but the milk of one ewe was consistently very much lower in zinc than that of the other five sheep.

Safflower (Carthamus tinctorius L.) is an important oilseed crop in India. A severe leaf spot disease caused by Ramularia carthami Zaprom. was observed in 1983 and investigations were carried out in order to analyse the role of environmental factors in disease development. High temperature and normal relative humidity, with dry rainless days, favoured disease development. Studies on the nature of in vivo resistance and susceptibility to R. carthami showed that growth of the fungal germ-tube was slower on resistant than on susceptible safflower cultivars, where the germ-tube extended with or without branching and penetrated infected leaves through the stomata. Of the four safflower cultivars evaluated, none were entirely free from the disease, but on the basis of lesion number and size, cultivar IGFRI-116 was rated as highly resistant.

There are few studies about the ability of CROPGRO-Tomato model to simulate tomato growth under field conditions as a function of both local weather and soil conditions. The aim of this work was to calibrate the CROPGRO-Tomato model, included in the Decision Support System for Agrotechnology Transfer (DSSAT) software, for the Thomas F1 indeterminate tomato cultivar grown under open field conditions at two locations in the Czech Republic with different soil and climate conditions. Additionally, this paper focuses on modelling the impact of compound weather events (CEs) on the growth characteristics of the hybrid field tomato variety. The genotype file, including the main parameters of crop phenology and plant growth, was adapted to the Thomas F1 indeterminate tomato cultivar. The CROPGRO-Tomato model was calibrated by inputting the soil characteristics, weather data and crop management data and then by adjusting the genetic coefficients to simulate the observed Leaf Area Index (LAI) and Above Ground Biomass (AGB) from transplanting to harvest under the farmers' field conditions. The comparison of the LAI simulated by the model and measured under field conditions showed adequate representation with the root mean square error of 0.86 and 1.11 m2/m2. Although there was a good fit for LAI and AGB between the simulated and measured data during the first part of the growing season, increasing differences were found in the growing season with cool-wet and/or hot-dry thresholds of CEs.

The half-carcasses from twelve Dorset Horn x Border Leicester-Merino lambs (3-5 months old) were used to investigate the relationships between the weight of the carcass and its cuts and their chemical composition. The specific gravity of the whole carcass and of the cuts was also measured.

Half-carcass weight and chemical composition were highly correlated. Weight could be used to predict the chemical composition with a reasonable degree of accuracy. The loin, the leg, the leg plus loin and the residual were shown to be highly correlated with the chemical composition of the halfcarcass. The loin and leg plus loin are the most convenient to use.

Analysing Hammond's data on the growth of limbs in the sheep, Huxley (1932) found a post-natal simple negative heterogony, or allometry, as in the latest terminology (Teissier, 1937), of the whole limb relative to the body. As lambs, and the young of most other grazing mammals, are born with relatively long limbs enabling them to follow their dams (Hammond, 1932), the same author pointed out that the leg must have exhibited positive allometry during foetal development.

Having possession of a sufficient body of measurements on the skeletal development of female calves of the Chianina breed, a very tall beef and draft breed of cattle of Central Italy, I investigated the course of growth of height at withers relative to the growth of the length of the trunk (from shoulder to ischium). The growth of height at withers can be considered as a sufficiently reliable measure of the growth of forelimb length owing to the fact that the two principal angles in the limb (scapula-humerus and humerus-radius) do not change very much with age (Engeler, 1935).

It was found that the growth of forelimb length in this breed of cattle exhibits a simple negative allometry relative to the growth of trunk length. This simple allometry, with growth constant about 0·78, holds from birth until over the age of 3 years, that is, throughout practically the whole post-natal growth.

Lack of data after this age leaves open to further research the course in the ultimate period of development.

I thought it would be of some interest to compare various breeds of cattle differing rather widely in the absolute values, as well as in the proportions of height at withers and trunk length at birth and in later life.

Wool samples were collected from 39 rams representing five breed groups of sheep: Merino (M), Ossimi (0), and the crosses between them, viz. ¾ Ossimi–¾ Merino (¾ O), ½ Ossimi–½ Merino (½ O) and ½ Ossimi–¾ Merino (¼ O) maintained at Sakha Experiment Station, Kafrelsheikh, Egypt, with the objectives of detecting the effect of the seasonal changes in normal light rhythm and temperature on wool fibre length and diameter. Animals were divided into two light treatments groups, the first consisting of four animals from each breed kept under continuous dim light conditions throughout the year and the second of three animals from Ossimi and four from each breed group kept inside an open pen free to sunlight and shade zones under daylight rhythm throughout the year. It was found that fibre length as well as fibre diameter in normal light exceeded that in dim light except in winter time. Breed groups showed different responses to the absence of light especially the Ossimi and the ¾ O whose fibre lengths were most affected. The breed groups had larger fibre diameters in normal light than in dim light except Merino and ¼ O. Seasonal changes in temperature had a highly significant effect on fibre length but not on fibre diameter. Higher temperature coincided with lower increases in fibre length. Season to season variation in wool growth seemed to suggest that the number of light hours per day and atmospheric temperature counteracted each other resulting in a non-significant seasonal pattern.

A method is described whereby solutions can be obtained from wheat leaves which are toxic to the spores of rusts. Precautions designed to minimize unknown variable factors affecting the activity of the solutions are described.

It was found that the uredospores used germinated better in extracts from Little Joss wheat infected with Tilletia tritici than in that from healthy plants, this being correlated with the relative susceptibility of the two kinds of plant under field conditions. On the other hand, no correlation was obtained as between four different varieties tested in the healthy state.

A method is described, by which solutions are obtained in which enzymic activity in the course of preparation is reduced to a minimum. It is found that solutions prepared in this way are non-toxic, if obtained from healthy living leaves, though present in decaying leaves. It is deduced that the toxic substances studied are formed in the course of autolysis.

It is found that, using the second method of preparation, solutions obtained from rusted leaves are toxic. An experiment is described in which modifications of the degree to which such toxins are produced by a given amount of rust infection are brought about by different nutritional treatments, excess of potassium and deficiency of minor elements being conducive to the production of toxins.

Experiments are described which demonstrate that the toxins produced by infection with Puccinia glumarum are toxic only to spores of that species, and not to those of P. triticina, and vice versa.

A long-term experiment designed to study the effects on crop yields of different basic methods of cultivation used in the preparation of seedbeds is described and the results of the first completed cycle of 4 years are discussed. Four basic methods of cultivation were compared, namely, ploughing, rotary cultivating, cultivating and discing. Each one of these was done, early and late, for each crop in two four-course rotations which differed only in the cropping of 1 of the 4 years when potatoes were used in one case and a 1-year ley in the other. Each crop in the rotation (winter wheat, sugar beet, barley, ley or potatoes) was grown at two levels of fertilizer application and provision was made in the design of the experiment for two different weed control régimes. The soil was fairly easy to work, being of the Milton series of river gravels.

As a result of the work described, the following conclusions have been drawn:

1. Ploughing was the most consistent method of providing a satisfactory basis for the final seedbed preparation but in some circumstances other methods were equally good. On average, ploughing led to the highest yields and discing the lowest, with rotary cultivating second and cultivating third in order of merit.

2. The yields of cereals grown after root crops were not dependent on the method of basic cultivation used.

3. The effects of the cultivations on the yield of winter wheat after the ley appeared to be due to the extent to which the regrowth of rye-grass was controlled, the plough being most effective in this respect.

Some misconceptions concerning the application of Griffing's fixed effects model I and mixed effects model B are discussed.

The proportion of sward area rejected for grazing under different stocking intensities in grass-white clover (Trifolium repens L.) swards continuously grazed by steers toconstant sward height was determined and the effect of these areas on clover stolon developmentwas investigated.

In a randomized block field experiment, grazing treatments imposed from 1988 to 1991 comprised target sward surface heights (SSH) of 5, 7 or 9 cm from April to July followed by 7 or 9 cm from July to October (i.e. six treatments). The percentage area rejected was higher in 9 cm than in the shorter swards, the proportion of the total areas rejected increasing generally over the year. Within the rejected areas in spring the number of branches on the main axes of white clover plants was only 17% and the mean number of nodes per branch was 14% of those in grazed areas. Corresponding percentages in summer in rejected areas were 56 and 46% compared with grazed areas.

In a glasshouse experiment involving stolons grown for 18–21 days, the difference between those from grazed and rejected areas in branch number per stolon and mean node number per branch was much reduced. Branching and rate of branch development (node number) were slower in stolons maintained under dark conditions.

Mean growing point density over six sampling dates from summer 1990 to autumn 1991 was significantly higher in the 5 cm than in the 9 cm spring SSH treatment. Although rejected areashad only 34% of the growing point density of grazed areas in autumn, the latter comprised the majority of the total area in most sward height treatments and so reduced the overall effect of rejected areas on growing point density.

In most regions, sugar beet is normally sown as a spring crop. If sown in autumn the crop remains on the field over winter and may achieve fast re-growth in spring from assimilates stored within the beet, allowing earlier leaf growth and light interception in spring. The specific leaf area (SLA) (ratio between leaf surface and leaf mass) is mainly affected by leaf area expansion and consequently affects productivity in early growth stages. The aim of the present study was (i) to examine the SLA dynamics of autumn-sown sugar beet before and after winter and (ii) to develop an empiric approach describing SLA changes during the growth period. A field trial in northern Germany with three different sowing times (mid-April, mid-June and mid-August) and varying plant densities (148 000, 246 000 and 370 000 plants/ha) was carried out in 2009/10 to 2011/12. The average SLA of the canopy was the highest (>25 m2/kg) directly after emergence, then decreased until autumn (<13 m2/kg) and increased again up to 20 m2/kg during re-growth of winter sugar beet in spring. A stepwise multiple regression analysis revealed mean photosynthetically active radiation over 10 days before measurement (PARmean), leaf area index (LAI), mean temperature over 10 days before measurement (Tmean) and temperature sum since sowing (Tsum) as the main influences on SLA dynamics. The strongest correlation to SLA was shown by Tmean (r = 0·69) and the weakest by Tsum (r = −0·28). A multiple linear regression model was fitted to the dataset with Tmean, PARmean and log (Tsum) achieving an adjusted R2 of 0·64. This empirical equation is suitable for use in a crop growth model for winter sugar beet.

The activity of spermatozoa in bull semen can be assessed by measuring the frequency of impedance changes in the semen. Such measurements necessitate the passage of a small electric current through the semen. The field experiment described in this paper shows that this electrical treatment is harmless. Measurements can therefore be made on samples of semen which subsequently will be used in artificial insemination.

From time to time during the course of the present war, pig feeders have reported that they have experienced considerable difficulty when making use of extracted palm-kernel meal as a major constituent of the rations of bacon pigs. This has been attributed partly to the lack of palatability of the extracted meal, which leads to a reduction in food consumption and a consequent depression in the rate of live weight increase, and partly to its high fibre content, which causes the ration to be somewhat bulky and of lowered digestibility and nutritive value. The present experiments were designed to throw light on these somewhat contentious matters, since little guidance is to be obtained from the scanty references to this subject in the scientific literature dealing with animal nutrition.

(1) Removal of chlorine ions by soil from dilute hydrochloric acid solution has been shown to take place under the experimental conditions employed.

(2) Interaction between dilute acids and soil (free from carbonates) has been studied. The results show that hydrochloric acid, nitric acid, sulphuric acid, acetic acid, citric acid and phosphoric acid all react with soil. The state of equilibrium between the soil and the acid solution can be satisfactorily expressed by Freundlich's equation. The order of reactivity of the soil towards various acids does not follow any obvious rule.

(3) The various soil fractions do not show any fundamental difference in their equilibrium relationship with regard to an acid solution; the order of their power to react with acid following inversely the order of the size of particles in them.

(4) The experiments recorded seem to support the view that the interaction between soil and acids is a surface phenomenon.

Results of a 2-year studyin the rainforest and savannah zones of Nigeria todetermine the responses of yield, components of yield and nutrient content of maize to soilapplied zinc showed that Zn significantly increased yield in the new and old savannah soils, whereas significant yield response was recorded only in an old field of the forest zone. Ear weight was the only yield component significantly influenced by Zn treatments in the two zones. Application of 2·5 kg Zn/ha appears adequate for successful maize production in the savannah and old forest zones in the tropics.

Soil-applied Zn significantly increased ear-leaf N and Zn, but P concentration was significantly decreased. Grain yield was positively correlated with ear-leaf Zn.

The normal body temperature of the pigs used in these experiments showed an appreciably greater variability than has hitherto been considered normal for pigs, the limits being 98·3–104·80° F. and the variation is independent of environmental temperature, or season of the year. The average normal temperature of the adult hog is 101·7° F.

In fasting for from two to five days a reduction of body temperature was noted in a large majority of cases, amounting on the average to 1·7° F.

Whether the normal or fasting figures are taken, the mean body temperature is higher in youth (50 days) than in the adult hog by about 1·5° F.