The growth characteristics of root systems were studied in the wheat varieties Chinese Spring' Hope and the chromosome substitution lines of Hope into Chinese Spring. The growth patterns varied considerably between the lines and this was due to the fact that the plants formed different numbers of tillers and grew for different periods of time. A correlation existed between the development of the shoot and root systems although some lines differed widely in their shoot root ratios. Differences between the lines in the early stages of growth were small and they reacted uniformly to different levels of phosphorus supply. The relation between shoot and root growth was also shown by the fact that the conclusions from genetical analyses were very similar. These showed that the method of control was largely additive in nature. It was concluded that variations in shoot and root characteristics were markedly influenced by single genes affecting the duration of the vegetative growth period as well as by polygenic systems.

Experiments with Sitka spruce (Picea sitchensis) seedlings grown on an acid sandy podzol at Wareham, Dorset, England showed that sulphur fertilizers improved the colour but not the height of the crop and increased sulphur concentrations in the needles above those considered by Ingestad (1962) to indicate sulphur deficiency for Norway spruce (Picea abies). Spruce seedlings grown on other soils (Oxford and Woburn) contained more sulphur than those grown at Wareham. Sulphur concentrations in transplants of both species were generally less when S-free basal fertilizers were used.

Radish (Raphanus sativus) experiments confirmed that Wareham soil was low in available sulphur. Increased yields were obtained from elemental sulphur treatments during the springs of 1968 and 1969, but not the summer months, when more sulphur may have been mineralized in the warmer soil. Wareham is in an area with less sulphur in the rain and atmosphere than most other parts of England.

The application of 2,4-D in combination with certain mineral nutrients was shown to produce a wide range of results on yield of the potato crop. Several variables were studied for their effects on the response of the crop to a commercially available compound of the above constituents (NCL).

While no environmental factors were shown to influence the response of the crop to NCL, the following factors did: time of application, potato variety, time of harvest, plant population and the presence or absence of the parent tuber. NCL was shown to modify the growth pattern of the crop and to increase the efficiency of the leaf canopy.

Animal production in grazing experiments depends both on treatment and on stocking rate. Production at optimum stocking rate is the only valid measure of treatment effect and treatment comparisons should be based on this criterion. Since optimum stocking rates are unknown these comparisons cannot be made directly, instead they must be inferred from the results obtained with the stocking rates actually used. This requires that some form of production stocking rate relationship be postulated. This paper suggests a form for this relationship and considers its implications on experimental design and particularly on the number of stocking rates per treatment.

Crotonylidene di-urea (CD-urea) in a sandy-loam and two clay-loam soils decomposed slowly at 7°C, and from 8 to 15% was recovered as mineral-N after 24 weeks. At 25°C, it decomposed faster in the sandy-loam than the clay-loam soils; with 100 ppm N, a maximum of 86% was recovered after 16 weeks, and 80% of 1000 ppm N after 24 weeks. Recovery after 24 weeks ranged from 30 to 60% in the clay loams.

Ryegrass grown in pots produced more extra dry matter, containing more N, during 16 weeks when given ammonium sulphate than it did during 50 weeks with CD-urea.

Emergence trials of five different seed lots each of cv. Lincoln and Kelvedon Wonder at six centres provided 27 different sowing treatments. Although mean emergence between treatments varied, the rank order of the lots remained almost constant. The results of seedling evaluation and conductivity vigour tests correlated well with field emergence, with neither test superior to the other. Grades of vigour were established and related to the performance of the seed lots in the field trials.

In 1964 spring wheat and kale each were grown with 0·0, 0·5, 1·0 or 1·5 cwt N/acre. In 1965 barley measured residues. Without N and with 0·33 cwt N/acre the barley yielded more after wheat than after kale, but, with 0·66 or 1·0 cwt N/acre, more after kale. The residues of the N given for the wheat and kale increased barley yields.

In 1965 spring wheat, kale and Italian ryegrass each were grown with 0·0, 1·0 or 2·0 cwt N/acre. In 1966 and 1967 barley tested 0·0, 0·5 or 1·0 ewt N/acre in all combinations with previous treatments. In 1966 yields were largest after kale and smallest after ryegrass. Differences from the three crops were diminished by the N applied for them, and these N residues consistently increased yields. N given to the barley greatly increased yields, most after ryegrass and least after kale, and equally with or without fertilizer residues, but did not change differences from the crops. In 1967 yields were largest after ryegrass, but no larger after kale than after wheat. The residues of the N given for ryegrass increased yields. N given to the barley increased yields greatly, but most after kale.

In 1966 spring wheat, kale and Italian ryegrass each were grown without N and with 1·0 or 2·0 cwt N/acre, but on a more fertile field. In 1967 and 1968 barley tested 0·0, 0·5 or 1·0 cwt N/acre in all combinations with previous treatments. In 1967 yields were largest after kale and smallest after ryegrass. The residues of the N given in 1966 consistently increased yields when the barley was not given N, and after ryegrass when it was; but they decreased yields when N was given after wheat and kale. The barley needed 1·0 cwt N/acre after ryegrass, but less than 0·5 cwt N/acre after wheat or kale. In 1968 barley yielded most when it was not given N and then the largest yields were after ryegrass. The N given for the barley greatly decreased yields and the N residues decreased them further.

The amounts of N removed in the barley grain were well correlated with yields.

Wheat, ryegrass and kale were grown with ammonium sulphate (treated with a nitrification inhibitor) or calcium nitrate supplying 50 and 100 lb N/acre, and without fertilizer-N. Plants were sampled at various stages, dry weights measured, percentage N determined and N uptakes calculated.

Initially wheat and ryegrass grew better and took up more N with ammonium fertilizer than with nitrate. Final yields of dry matter did not differ between forms. Kale produced more dry matter with calcium nitrate than with ammonium sulphate. All crops produced more dry matter with fertilizer-N than without. Fertilized crops contained greatest weights of N 109 days after sowing, when wheat and ryegrass had more with ammonium than with nitrate and kale had less. The 50 lb N/acre as calcium nitrate produced the most wheat grain/lb of fertilizer-N.

During the period when growth and N uptake were fastest, wheat grew faster with ammonium than with nitrate, ryegrass grew similarly with both forms, and kale faster with nitrate; wheat and ryegrass took up N faster from ammonium sulphate and kale from calcium nitrate.

Mature wheat recovered 58% of the fertilizer-N from calcium nitrate and 43% from ammonium sulphate. After 21 weeks of growth, kale recovered more N from calcium nitrate (50%) than from ammonium sulphate (24%), whereas grass recovered about 40% from each.

Twenty-eight Hereford cross Friesian heifer calves aged 3 months were allocated in randomized blocks to two main treatments, namely, ovariectomy (spaying), performed by flank laparotomy, and anabolic steroid oral administration (Ethylestrenol). The cattle were tied in stalls and individually fed ad libitum on a ‘barley-beef’ type cereal mixture until slaughtered weighing approximately 340 kg.

Ovariectomy reduced overall rate of live-weight gain and food conversion efficiency but differences were not significant. Spayed heifers, however, grew significantly taller than entires. Although fat and bone proportions of the side were increased slightly, carcass grading and composition were not appreciably altered by ovariectomy.

Steroid treatment failed to improve performance but lean content of the side was slightly increased. This failure in response may have been due to incorrect dosage.

Quantity/potential relationships, between gain and loss of K by the soil and K potential (RT In ακ/⊧αca+Mg) were determined on twenty-seven Rothamsted and Woburn soils. K extracted by neutral N ammonium acetate, by H-resin and 0·5 M sodium bicarbonate (pH 8·5) were also measured.

The ability of an extractant to remove soil K is equated to a K potential (derived from the quantity/potential curve) which the soil attains on removing K equal to that taken out by extractant. Mean values for all soils were – 4995 ± 97 cal/equiv for the ammonium acetate, – 6081 ± 88 cal/equiv for the H-resin and – 4336 ±117 cal/equiv for the sodium bicarbonate extractants. For the first and last extractants the ability to remove K was less in rich than in poor soils.

Varying the ammonium ion concentration from 0·1 N to 1 N in ammonium acetate/acetic acid mixtures, N in acetate ions, did not greatly affect their ability to remove K.

The dry weight contributed to the grain yield of sorghum by different parts of the plant was measured by removing laminae and by shading the head. A Nigerian tall variety formed more dry weight after heading and had a larger leaf area duration than a short-season, hybrid sorghum, but its grain yield was smaller. Laminae contributed more than 80% of the dry weight formed after heading in the Nigerian sorghum but less than half of this went into the grain. The remainder went into the stem, mainly to replace respiratory losses, or accumulated in the rachis and branches of the head. Top, middle and bottom groups of laminae contributed 42, 22 and 12% respectively to the dry weight of the grain; the remaining 24% was contributed by the sheaths. In the short-season hybrid sorghum over 70% of the dry matter formed after heading was stored in the grain. Only about half of this came from the laminae; assimilation in the head and in the sheaths contributed about equally to the remainder.

The potassium potential which limits uptake of K by ryegrass, ‘the uptake potential’, was derived from the uptakes of K and from the quantity/potential relationships of a number of soils by a method which avoids exhausting the soil by cropping. This potential was – 5600 cal/equiv in Rothamsted soils, but the method was unsuitable for Woburn soils. In Rothamsted soils uptake of K was more closely related to quantity than to potential of K, but in Woburn soils it was equally well related to both. From 28 days until 82 days, when the initially available K had been used in most soils, diffusion in the soil seemed to control rate of uptake of K. On longer cropping, much initially nonavailable K was released, the grass still grew and the mean K potential had fallen to only –5189 cal/equiv in Rothamsted and –5336 cal/equiv, in Woburn soils.

Tritiated water (TOH) space was determined in sixty-one sheep of known age (3 days to 18 months). Representative samples of the minced carcass were subsequently analysed to determine body composition (water, fat, protein, ash and energy). The regressions of the weight of the various body components on TOH space and body weight reported here gave equations suitable for prediction. These were similar to equations derived from published results for adults. Combining data on young sheep and adults gave broadly based equations that could be used to predict the body composition of healthy sheep of all ages from 3 days to adults.

The effect of different spacings between and within rows on the pod yield of Ashford (semi-spreading, alternately branched type) and Barberton (upright, sequentially branched type) were studied.

The largest yield of Ashford was obtained at 60 cm x 15 cm spacing, while in Barberton the largest yield was obtained at 40 cm x 15 cm. It is suggested that the optimum spacing for these varieties varied because of differences in their growth habits.

Differences in yield were generally associated with differences in the number of pods and weight of pods per plant. An inverse relation between number of pods per plant and number of seeds per pod suggested internal competition between alternative sinks.

The number of flowers per plant decreased with closer spacing. The percentage of flowers which set pods ranged from 14 to 21%. Wider spacing increased the number of branches, total number of pods and the proportion of pods which matured, but did not affect the mean individual kernel weight.

Seventy-two (thirty-six hogs and thirty-six gilts) Large White type weaner pigs were individually and restrictedly fed four diets (as wet mashes) containing high levels (85% in the starter diets and 90% in the finisher diets) of either maize, sorghum, wheat or barley. Thirty-six pigs (nine per treatment) were slaughtered at 120 lb (54 kg approximately) live weight at the end of the period in which the starter diets were fed and the remaining thirty-six at 200 lb (90 kg approximately) live weight at the end of the period in which the finisher diets were fed.

In the starter period the growth rates and food conversion efficiencies of the pigs fed the barley- and wheat-based diets were similar but taken together were slightly superior to those of the pigs fed the maize- and sorghum-based diets. Based on determined digestible energy values the caloric efficiency of live-weight growth was significantly better for the barley-based diet than for all other diets. At a slaughter weight of 120 lb the killing out percentage of the pigs fed the maize diet was significantly higher than that of the pigs fed the barley and wheat diets. Iodine numbers of inner and outer backfats were significantly higher in pigs fed maize than in those fed sorghum and wheat and in those fed barley compared with those fed wheat. There were no other differences in carcass measurements or in the percentages of lean, fat and bone dissected from the carcasses. However, the pigs fed barley had (1) significantly smaller middle regions and (2) as percentages of the total tissue within the body, significantly less fat in the middle region but significantly more fat in the shoulder region, than did any of the other pigs.

In the finisher period the pigs fed the barley- and wheat-based diets grew significantly faster and converted their food and digestible energy of that food significantly more efficiently than did the pigs fed maize and sorghum. The caloric efficiency of live-weight gain was also significantly greater for the barley-fed pigs compared with those fed wheat. When slaughtered at 200 lb live weight, with the exception of backfat iodine numbers, where identical differences to those recorded at 120 lb were found, there were no significant differences in carcass measurements. On dissection the barley-fed pigs had significantly more lean and significantly less fat in the carcass than did any of the other pigs.

The vegetative growth, flowering and seed yield of three cowpea varieties—Adzuki, Mala and New Era—with contrasting yields, were compared in one field and two greenhouse experiments. In the field the plants were spaced so far apart that they did not form a closed stand, but were effectively individuals, like the potted plants used in the greenhouse experiments. In all experiments New Era yielded most followed by Mala, although the differences between these two varieties were not significant, and Adzuki least.

Seed yield and vegetative growth were not simply related. New Era with the highest seed yield had the largest vegetative dry weight, leaf area and leaf area duration (D), followed by Mala, with Adzuki always least in each parameter. However, the superiority of New Era in total dry weight and leaf area was much greater than in seed yield. Mala and Adzuki were more efficient than New Era in converting dry matter into seed. Large fractions of current assimilates moved from the leaves to the seed of Adzuki and Mala than of New Era.

Varietal differences in relative growth rate, net assimilation rate, or leaf area ratio were too small to account for varietal differences in seed yield.

New Era and Mala produced more flower buds than Adzuki. However, Adzuki developed the largest proportion of ripe fruits, but had more aborted seeds/fruit than New Era and Mala. Thus, increased flower production and fruit formation did not increase the production of mature seeds. Therefore, little would be gained by breeding or selecting for increased flower production. The heavier seeds of Mala and New Era compared with those of Adzuki contributed greatly to their larger yields. At the spacing of 3 ft x 1 ft used in the field, the leaf area index (L) and leaf area duration (D) were suboptimal, and closer spacing should increase yield.

The potassium quantity/intensity (Q/I) relationships, which relate change in exchangeable K content (Q) to change in activity ratio were measured in soil samples from manuring experiments at Rothamsted and Woburn. Within each experiment, Q/I curves for different K-manuring treatments were super-imposable on each other and on the curve relating exchangeable K to Io, the activity ratio at which the soil neither gains nor loses K. The distances on the Q axis between the curves were equal to the differences in exchangeable K.

The buffer capacity, dQ/dI, was related to the K saturation of the cation exchange capacity (CEC) by the equations

(Q and CEC in m-equiv/100 g)

Broadbalk and Hoosfield soil, and

for Barnfield soils (b= 3·08; m= 1·0) and for Woburn market garden soils (b =2·41; m= 0·6) but for soils from other Woburn experiments, dQ/dl did not vary significantly with Q/CEC.

Sections of muzzle skin were studied from twelve Murrah buffaloes including seven females and five males ranging from 1½ years to mature animals up to 7 years old. The 130–1350 μ thick epidermis of muzzle rested on a PAS positive, argyrophilic basement membrane. The stratum lucidum was lacking. The stratum granulosum could not be identified in some animals. In such animals, a wavy, deeply eosinophilic layer was seen in the area of stratum granulosum and stratum lucidum.

Lamellated nerve endings, 40–45 μ in diameter, and arteriovenous anastomoses, frequently appeared in the reticular layer of the muzzle dermis.

The muzzle glands were lobulated, compound tubuloacinar and resembled the salivary glands morphologically. Their acini were strongly PAS reactive and acidic mucopolysaccharide positive. While intercellular secretory canaliculi were present, myoepithelial cells could not be observed. It is suggested that fine bundles of striated muscle fibres which run perpendicular to the skin surface might function to expel gland secretions. Most gland-cell nuclei were intensely Feulgen reactive and the cells revealed a moderate alkaline phosphatase activity. The intralobular duct system of the muzzle glands consisted of PAS negative intercalated ducts and mildly PAS reactive striated tubules. The simple cuboidal to columnar epithelium of the striated tubule changed to pseudostratified columnar type toward the larger interlobular ducts which were lined by stratified columnar epithelium. Toward their opening, the excretory ducts had stratified squamous epithelium. The lumina of the ducts frequently contained PAS positive and colloidal iron reactive secretory mass.

When open flowers were removed from cowpea plants for periods between 3 and 12 consecutive days beginning from the first day of anthesis, more flowers opened on the deflowered than on the untreated plants, thus compensating for those removed. However, most of these extra flowers dropped prematurely.

In experiments in the greenhouse or on dry-season irrigated plots, deflowering for up to 9 days did not decrease the seed yield of the varieties Adzuki or Westbred. In an early-season field experiment, deflowering of Westbred did not decrease the seed yield unless repeated for 12 days. All periods of deflowering Adzuki decreased the seed yield, and the longest period gave the smallest yield.

Six field experiments (1963–8) in eastern England compared solid fertilizer with liquid fertilizer or anhydrous ammonia for sugar beet. Two glasshouse experiments investigated the interaction between depth of placement of fertilizer and soil moisture.

Yields of sugar were the same from broadcast solid and sprayed liquid in all the experiments, but nitrogen uptake by the crop was less from liquid than from solid. Three experiments tested placement of liquid 4 in to the side and either 2 or 6 in below the seed. Plants with deep-placed fertilizer consistently out-yielded those with shallowplaced fertilizer, but yields were never significantly different from broadcast solid fertilizer. Dry-matter yields of sugar beet grown in containers indoors showed that the crop responded to deep placement when the surface soil was watered infrequently.

With anhydrous ammonia injected during seed-bed preparation, sugar yield and nitrogen uptake were the same as with solid fertilizer in the seed bed, and were greater than with anhydrous ammonia injected in the ploughed land during early spring. A side-band injection of anhydrous ammonia before singling gave a crop containing as much nitrogen at harvest as, but less sugar than, nitrogen applied in the seed bed.