Proximal colons taken from lambs up to 3 weeks after birth were shown to transport both sodium and chloride from lumen to blood when incubated in vitro.

Sodium transport fell into three phases during postnatal development. The first covered the period from birth to 3 days of age when sodium transport was high and equal to that calculated from measurement of short-circuit current. The second was seen in 5- and 7-day-old lambs where the short-circuit current was low and the net transport of sodium was negligible. The third was seen in 2-3-week-old lambs where sodium transport was high, but the short-circuit current was low.

Chloride absorption by colons taken from 1-day-old lambs appeared to be in exchange for an anion, possibly bicarbonate. Chloride absorption by colons taken from 3-week-old lambs appeared to be electrogenie or coupled directly to the transport of sodium.

A possible explanation for the failure of electrolyte absorption by colons taken from 5- and 7-day-old lambs is discussed.

Designs are given for factorial experiments with three, four or five factors at two levels each, using thirty-two plots in a 4 × 8 lay-out on the ground. The effects of both rows and columns can be eliminated from the estimate of error. Provided that three-factor interactions can be ignored, information can be retained on all two-factor interactions.

A practical adaptation of a method devised by Miss Glynne for testing indoors the immunity or susceptibility of potato varieties to wart disease is described. The method consists of infecting by summer sporangia the young sprouts of the tubers under test. Extensive test has given such satisfactory results that there is little doubt that the method is infallible.

The writer wishes to render his grateful thanks to Mrs N. McDermott, who has been actively associated with him throughout the work described and who is largely responsible for the technique employed; to Miss M. D. Glynne, of the Rothamsted Experimental Station, for her many helpful suggestions; to Mr W. H. Parker, Director of the National Institute of Agricultural Botany, Cambridge, for his assistance and advice; t o Dr R. N. Salaman for supplying material for test, and to Dr G. H. Pethybridge for his kindness in examining tubers sent to him.

The results of an interim examination of the experiments at Rothamsted and Woburn on the effects of nitrogen, phosphate and potash on a six-course rotation of crops are reported.

It has become apparent that the main aim of the experiments, to relate the effects of the fertilizers to weather conditions, is not being fully realized. This is in part a consequence of the design, which has inherently low accuracy and results in low responses to phosphate and potash. In addition, faulty randomization and, at Woburn, fertility irregularities and pest damage have further reduced the accuracy attained.

The faulty randomization also seriously affects the estimates of experimental error given by deviations from smoothed response curves. Alternative estimates of error are provided to overcome this difficulty.

The mean yields and mean standard responses over the period 1931–55 are presented.

There is very little year-by-year variation in the responses to phosphate, but the responses to nitrogen and, for some crops, the responses to potash show sufficient variation to justify further analysis. As a first step the regressions of the responses to nitrogen on winter rainfall and on rainfall during the growing season and, for the root crops only, the regressions on sowing or planting date are briefly considered.

The responses of Leucadendron ‘Safari sunset’, on its own roots and grafted on ‘Orot’ rootstock, to a range of fertilization regimes were studied. The experiment was conducted during the summer of 1994, at Bet Dagan, Israel, and included three levels of compound NPK, two levels of P, and two NH4[ratio ]NO3 ratios.

Ungrafted plants fed without P yielded fewest marketable branches and had the lowest fresh and dry weights. Increasing the P concentration in the irrigation water to 10 mg/dm3 improved the yield, whereas increasing the NPK level reduced the number of marketable branches and the fresh and dry weight yields. Lowering the NH4[ratio ]NO3 ratio in the irrigation water significantly reduced the yield.

The grafted plants were significantly better than the ungrafted plants under all the treatments examined. The superiority of the grafted plants was more evident under conditions of P deficiency and non-optimal pH.

Consideration is given to the prospects of producing F1 hybrid varieties of perennial ryegrass, Lolium perenne, and other herbage grass species for commercial use. In the light of the results of interpopulational hydridization in this and other crop species and of the technical and economic disadvantages inherent in other methods of F1 hybrid seed production, it is concluded that the development of interpopulational F1 hybrid varieties, by the field interpollination of parent populations, is a desirable and worthwhile breeding objective.

1. A study of the suitability of rations of predominately sorghum grain for the intensive finishing of steers is reported. Six groups, each of ten steers, 18 months old and of an average body-weight of 544 lb., were fed, according to a set schedule, increasing quantities of grain in the ration until two groups were each consuming rations containing 80, 90 or 100% grain. One of the two groups, fed each grain-to-roughage ratio, received 60 g. urea per head daily. Individual steers were slaughtered when they attained 900 lb. body-weight. A seventh group of ten comparable steers was slaughtered at the commencement of feeding in order to measure changes in body composition due to the nutritional treatments.

Oats grown in a pot experiment on two sandy loams were sampled at four stages of growth. Neither KC1 nor MgSO4.7H2O had any effect on yield but % Mg and total Mg uptake were consistently decreased by applying K and increased by applying Mg.Ca(NO3)2 increased % Mg more than did (NH4)2SO4, but yield and total Mg uptake were higher where (NH4)2SO4 was applied. The effects of fertilizers were similar on both soils.

The effects of applying (NH4)2SO4 and NaNO3 to the soil on % Mg in barley were compared in a field experiment on an acid loam to which several rates of limestone had been applied. Treatments had no effect on the % Mg in grain or straw at maturity. At four earlier stages of growth (NH4)2SO4 increased % Mg in the plants more than did NaNO3. Limestone slightly increased % Mg. Nitrification of NH4 in the soil was rapid.

Controversy exists in the literature concerning the validity of the nylon bag technique for investigating the nutritive value of feeds (Pidgen, Balch & Graham, 1980; Marten, 1981). Avariety of factors have been implicated in affecting results such as sample size, fineness of grinding and positioning of bags in the rumen. In addition basal ration has been shown to affect results (Lindberg, 1981 a, b; Siddons & Paradine, 1981). ørskov & Hovell (1978) showed that rate of digestion of hay in nylon bags was faster when the animals were fed on Pangola (Digitaria decumbena) hay rather than on sugar cane with its high sucrose content. In further work Ganev, ørskov & Smart (1979) reported that vegetable proteins degraded at a faster rate when incubated in nylon bags in sheep receiving dried grass rather than whole barley as their basal ration.

In two experiments the yield, digestibility, protein and cell wall contents of several autumn-sown triticale cultivars were compared with rye at defined growth stages. Yields at each growth stage were highest in the triticale cultivars. The content of leaf blade and sheath fell with increased maturity while stem and ear content increased. There were differences between cultivars in the contribution of individual stem internodes. Digestibility also declined with maturity for all plant parts, and differences were apparent between plant parts and between cultivars. Leaf blade showed a slow decline in digestibility whereas stem digestibility showed a rapid reduction so that, at growth stage 43, young stem internodes were of much higher quality than older ones. Spring-type triticales (A208 and A476) had the highest digestibility at stages from flag leaf emergence to anthesis. The relationships between digestibility, plant part contents and cell wall characteristics are discussed.

1. A mixture of sand and bentonite (after converting it to the calcium clay), containing 6 per cent, by weight of the latter, was found to be a suitable medium in pot cultures for the growth of grass. A good sward of perennial rye grass was established in the medium by suitable watering, manuring and cutting of the grass, within 11 weeks of sowing.

2. The mixture allowed of easy control of the moisture content, and appeared to possess a moisture-retaining capacity comparable with that of a natural soil.

3. The mixture is almost totally deficient in both nitrogen and phosphoric acid, and markedly deficient in potash and in some of the less common elements necessary for plant growth.

4. In view of the above properties and of the buffering action due to the presence of the bentonite, the mixture would appear to be suited to the more general study in pot culture of plant nutrition problems, and to offer several important advantages over either sand alone or natural soil for this purpose.

Sodium sulphite is used in an optional way to remove insoluble proteins from neutral detergent fibre (NDF) residue. To determine whether the recovery of both NDF and insoluble nitrogen (N) in NDF solution (NDIN) are altered by its use, both parameters were measured in a set of 12 feeds, including cereal grains: maize (MG), rye (RG) and wheat (WG); cereal co-products: maize gluten feed (MGF), distilled dried grains from barley (DDGB) and wheat (DDGW) and wheat bran (WB); protein concentrates: rapeseed meal (RSM) and expeller palm kernel (EPK); dehydrated sugar beet pulp (DBP) and oat (OH) and ryegrass (RGH) hays. Associated effects on the in situ effective degradability (ED) of both NDF and NDIN were also studied in DDGW, WB, RSM, EPK, DBP, OH and RGH. Also, ED of acid detergent fibre (ADF) and its N (ADIN) were studied in hays. Errors due to microbial contamination in the rumen on the ED of NDF, ADF, NDIN and ADIN were also established in these last seven samples using 15N infusion methods. Three rumen and duodenum cannulated wethers were used in the study. The sulphite use in NDF solution led to reductions (DDGB, DDGW, RSM and OH) and increases (RG, WG, WB and DBP) of the NDIN proportion, as well as the contribution of crude protein to NDF. These variations were associated with irregular effects on NDF residues and on ED of both NDIN and NDF. As a consequence, sulphite use does not assure the reduction of the insoluble protein contamination and it may even increase it. This methodology may also alter the degradability estimates of NDIN or NDF. Mean ruminal microbial contamination in NDF was 7·0, 10·8, 13·3, 5·4, 12·0, 35·3 and 20·0 g/kg in WB, DDGW, RSM, EPK, DBP, OH and RGH, respectively. The associated contents of microbial N in NDIN were: 59·3, 29·9, 26·2, 19·8, 37·3, 441 and 150 g/kg, respectively. Microbial contamination in ADF and ADIN (g/kg) was 3·6 and 94·5 in OH and 1·7 and 41·2 in RGH. Not correcting this contamination led to consistent undervaluations of ED of NDIN and NDF in all tested feeds, although errors only reached significance for NDIN in hays and DBP. Microbial-corrected ED of NDIN was 0·685, 0·826, 0·481, 0·389, 0·166, 0·718 and 0·425 in WB, DDGW, RSM, EPK, DBP, OH and RGH, respectively, whereas values for ADIN were 0·504 (OH) and 0·469 (RGH).

1. The results of three uniformity trials with a U4 cotton at Barberton are reported. Two of these trials, carried out in a dry year, gave yields in the region of 400 lb. seed cotton per acre; the third, in a wet year, yielded over 1100 lb. per acre.

2. Results from the three experiments agreed closely in essential details regarding size and shape of plots.

3. In all three cases the percentage standard error per plot decreased rapidly as the plot was lengthened, but tended to increase slightly as the width of the plot was increased.

4. The standard error increased as the block size was increased by the addition of more plots, indicating the desirability of keeping the number of strains in a variety trial as low as possible.

5. With plots of the same shape the smallest plots were the most efficient, while with plots of the same size the efficiency increased as the plot shape became longer and narrower.

6. Two fertility contour maps are given, which illustrate a general patchiness in yield common to cotton crops in the Barberton district.

7. Details of the types of plot used at Barberton are given, together with the reasons for their adoption.

1. Comparative analyses of pyrethrum flowers have been carried out by the methods of Tattersfield, Seil, Ripert, Haller & Acree and Wilcoxon.

2. The methods were of value in indicating the relative richness in pyrethrins of the samples tested, but discrepancies were seen in the absolute values of the pyrethrins I and II recorded. Under present conditions and until a standard method of analysis is agreed upon, it would appear requisite to state the method employed in the evaluation of the flowers.

3. The Wilcoxon method has given higher figures for the pyrethrin I content than the Seil method. The degree of divergence between the results depended upon the richness of the flowers, and upon the excess of acid used in distilling the volatile acid in the Seil method. The relationship between the amount of the pyrethrin I acid present and the titration recorded in the Wilcoxon method was not a linear one.

4. The question of the solvent to be used for the initial extraction of the flowers has been briefly discussed.

In rainfed lowland rice areas of intermediate deepwater (15–50 cm), transplanting in greater depths of water (50–60 cm) with clonal tillers (double transplanting) from 20 or 40- to 50-day-old-transplanted crops of similar environment increased grain yield significantly compared with seedlings of the same age (60 or 80- to 90-day-old) from a nursery. The grain yield did not decrease significantly when the clonal tillers were removed at 20 or 40 days after transplanting compared with that of the undisturbed crop. The practice of double transplanting (clonal propagation) increased tiller production and the number of panicles, and the crop could tolerate better the greater depths of water and thereby give greater grain yield.

In a field experiment conducted from 1981 to 1984 on alluvial soil (Ustochrept) of Jalandhar, green manure (GM) of dhaincha, sannhemp, pearl millet and moong did not affect tuber yield in the 1st year but increased it in the 2nd and 3rd years. GM of dhaincha and sannhemp were more effective than the moong in reducing responses of potatoes to K. GM of pearl millet was as effective as the dhaincha or sannhemp in 1981–2 and 1982–3 when buried 55 days after sowing but was inferior in 1983–4 when buried 85 days after sowing and resulted in reduced concentrations of N and P in potato plants. GM of dhaincha, sannhemp and pearl millet increased concentration of K in potato plants and available K in soil. GM of dhaincha and sannhemp, in particular, increased soil available K by decreasing non-exchangeable K whereas GM of pearl millet increased soil available K without affecting non-exchangeable K.

Experiments were made over 2 years at two sites using three varieties to investigate the relationship between total yield, number of tubers > 1 cm and the yield of tubers in the 60–80 mmsize range. Regressionanalysisrevealed that yield of tubers in the 60–80 mm size range was a linear function of total yield and number of tubers > 1 cm. The effect of changes in tuber shape on this relationship is discussed.

The environmental and genetic control of reproductive growth was studied in S. 170 a variety of Festuca arundinacea Schreb. The variety had induction requirements for short days and low temperatures before inflorescence production could occur, but some genotypes became induced with only short-day treatments. Low temperatures and short days in controlled environment rooms were less effective in bringing about induction than winter conditions in an unheated glasshouse. Only non-additive genetic effects could be shown to be significant in the control of induction requirements. Field studies showed that all inflorescence characters were subject to genetic and genetic x environmental control, and they also indicated that seed weight per inflorescence and seed fertility were most likely to show a response to selection. Diallel analysis under glasshouse conditions showed that the seed fertility and 1000 seed weight of the parental crosses were subject to maternal control, but these effects were not detectable in the next generation. Genetic control of seed fertility and 1000 seed weight in the diallel progeny was mainly additive.

An investigation has been made into the effect of time of application of nitrogen as sodium nitrate to the turnip. Experiments were arranged on a statistical basis, and were carried out in sand culture. The life of the turnip up to harvest was arbitrarily divided into three equal light periods, and the fourteen possible combinations of high and low nitrogen applied in these periods constituted the treatments. The absolute amount of growth was largely determined by the level of nitrogen, but the relative proportion of growth was independent of this level. Tops developed earlier than roots, and the effect of difference in nitrogen level was more marked with the roots than the tops. For a high yield of roots it seems desirable to apply nitrogen, early, but for a high yield of tops it would be preferable to apply the nitrogen as post-seedling dressings. The chief effect of level of nitrogen on moisture content was confined to the period in which the harvest took place. A comparison of top/ root ratios also showed that high nitrogen in the early stages of growth stimulated root development.

We thank Mr J. F. N. Leonard for his help during this experiment.