bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of plant spacing and application of nitrogen fertilizer on herb and essential oil yields of palmarosa (Cymbopogon martini Stapf. var. motia)
Authors: Rao E. V. S. Prakasa , Singh Munnu , Rao R. S. Ganesha 
Published: March 2009

SummaryA field experiment was conducted for 2 years during the crop seasons of 1980–2 to study the effect of diverse plant spacings and rates of nitrogen application on the yields of herb and essential oil of palmarosa (Cymbopogon martini Stapf. var. motia). The results indicated that at closer plant spacings of 30 × 30 cm (110 000 plants/ha) and 45 × 30 cm (74000 plants/ha), palmarosa responded to higher amounts of N fertilizer (240 kg N/ha/year). It was suggested that a plant spacing of 30 × 30 and 45 × 30 cm and application of 240 kg N/ha/year result in high essential oil yield of palmarosa.
A study of interaction of additive, dominance and epistatic gene effects with micro- and macro-environments in two tomato triple test crosses
Authors: Singh R. P. , Singh S. 
Published: March 2009

SummarySixty families of each of two tomato triple test crosses (S 120 × EC 61747 and EC 31513 × Pusa Ruby) were raised in completely randomized blocks in two replications with two fertilizer levels. Perkins & Jinks' (1971) analysis was used to detect and measure the interactions of additive, dominance and epistatic effects of genes with micro- and macro-environments for flowering time, maturity period, number of branches, final height, number of locules, number of fruits per plant, yields per plant and weight per fruit. Additive and dominance gene effects were almost equally sensitive to micro- and to macro-environments. The j and l type epistasis was more sensitive to the environments than the i type epistasis.
Excretion patterns of 3-hydroxy-4(1H) pyridone (DHP) by steers fed a high energy and a high-fibre diet supplemented with Leucaena leucocephala
Authors: Elliott R. , Brandon Janelle R. , Kenny G. J. , Evans T. R. 
Published: March 2009

SummaryDaily supplements of dried Leucaena leaf meal (500 g/head) were offered for 3 weeks to steers in metabolism cages. The steers had previously been fed diets of oaten chaff (5 kg/head/day) ormclasses and urea (4·5 kg/head/day) with restricted forage (2 kg/head/day). Excretion rates of the primary degradation product of mimosine, 3-hydroxy-4(1H) pyridone (DHP) by steers fed the two diets were compared. These compounds appeared in urine on the 1st day after Leucaena feeding had commenced and output remained fairly constant after 4 days. Mean weekly urinary outputs (g) of DHP from steers fed the oaten chaff or molasses + urea diet were 13·45 and 7·50 respectively. These levels corresponded to 0·23 and 0·13 of the amounts ingested. When steers were fed the molasses + urea diet, DHP continued to appear in urine up to 5 days after Leucaena had been withdrawn from the diet. On the oaten chaff diet no DHP was detected after 3 days following withdrawal of Leucaena.The effects of casein or formaldehyde-treated casein supplements on the output of urinary DHP by steers fed oaten chaff plus Leucaena was evaluated in a second experiment which ran concurrently. The animals were fed the test diets for 3 weeks before collections were made. Mean DHP outputs (g/day) from animals fed the control diet, control diet plus casein or control diet plus formaldehyde-treated casein were 1·89, 2·21 and 2·44 respectively.These results confirm substantial degradation of DHP and that the extent of degradation can be affected by the dietary regime in which Leucaena is fed.
The analysis of the lactation curve into maximum yield and persistency
Authors: Sanders H. G. 
Published: March 2009

An attempt has been made to analyse the lactation yield into its two components, maximum yield and persistency; the latter has been defined as the ratio of lactation to maximum yield, and has been measured by a S.F. calculated from , where R is the mean ratio for the month of calving concerned.Whilst, when corrections for external factors are applied, maximum and persistence are equally constant throughout the cow's life, these factors cause wider individual fluctuations with persistency; maximum yield is subject to a more rigid limit and may be largely determined by the area of the mammary gland, but persistency seems to be chiefly a nutritional factor—that is to say, it depends on the success of the mammary gland in competing with the other tissues of the body for the available nutriment. This leads to the view that persistency is higher in the dairy type of cow; it also appears to be associated with high constitution, for very definite positive selection is apparent with persistency, as compared to marked negative selection for maximum—this is attributed to pathological attrition falling more heavily on cows with high initial yield and low persistency.
The effect of seed rate on the yield of potatoes
Authors: Boyd D. A. , Lessells W. J. 
Published: March 2009

This paper, which forms part of a series of investigations on the potato crop, presents evidence obtained from experiments reported in the literature on the relation between seed rate and yield of maincrop potatoes. The available experiments are sufficient to indicate what is the average relationship between seed rate and yield, but are insufficient to demonstrate any clear differences between different parts of the country, soil types or even different varieties.Using this average relationship, optimum seed rates are presented for a range of prices of seed and produce. These optimal rates are compared with estimates from surveys of the actual amounts planted by growers in different parts of the country.Provided the optimum seed rate is attained the precise combination of seed size and spacing distance appears to be of minor importance; that is, a grower should aim to plant at the optimum seed rate regardless of seed size. There is, however, an upper limit of spacing between sets which should not be exceeded however large the seed may be.The optimum rate of planting at 1952 prices of ‘A’ or ‘H’ certificate seed is estimated to be 16–17 cwt. in most of the main potato-growing areas of the country, though it may be a little higher where a grower has a market for once-grown seed. Surveys indicate, however, that the normal planting rate of certified seed is over a ton to the acre in these districts.For a grower's own once-grown seed, on the other hand, for which the cost is not more than the price received for ware, the optimum seed rate is at least one ton per acre, whilst the average weight of seed actually planted is only about 17 cwt. per acre. It is estimated that the average loss per acre due to this failure to plant at the optimum seed rate amounts to 20–25s. per acre planted with certified seed and 10–15s. per acre for once-grown seed.
Studies on the environmental physiology of cattle in Tanganyika I. Preliminary observations on the seasonal diurnal variations in the rectal temperature of local Zebu cattle
Authors: Hutchison H. G. , Mabon R. M. 
Published: March 2009

1. Ten local Zebu cows representative of Africanowned cattle in Central Tanganyika, maintained under good African husbandry conditions, were temperatured twice daily over a period of 134 days from 23 July to 3 December, whilst the general meteorological environment was recorded.2. The period of observations was divided into four parts, during two of which differential planes of nutrition were maintained between two groups of animals, the first and last parts being control periods when the plane of nutrition was common to all animals.3. The diurnal variation in rectal temperature wasapproximately 99·0–102·5° F., arange of 3·5° F., whilst the atmospheric shade temperature varied about 12° F., from 64 to 76° F. at commencement of observations, and from 71 to 83° F. at the warmest period of the observations.4. The variation within morning rectal temperatures was greater than that within afternoon rectal temperatures.5. The low rectal temperatures in the mornings reflected inadequate nutritional level to maintain body temperature, as they were significantly increased by a moderate supplementary ration.6. Supplementary feeding did not affect the afternoon temperatures.7. Daily mean rectal temperature of the cows in the morning was verysignificantly negatively correlated with atmospheric temperature.8. Rectal temperatures of ten cows' temperatures at 2 hr. intervals from 07.00 to 21.00 hr., over a period of 7 days, was positively correlated with direct sun temperatures taken 4 hr. before rectal temperatures.9. Rectal temperatures were positively correlated with the dew-point in the morning, but were unrelated with the lower dew-point in the afternoon.10. It is suggested that afternoon temperaturing of experimental animals of local Zebu type under African husbandry conditions might be more informative for clinical purposes than the customary morning temperaturing, owing to the lower variation.11. It is tentatively suggested that the thermoregulatory system of local Zebu cattle may be regarded as operating a micro-adjustment mechanism to compensate for immediate variations in micro-climate, superimposed on a macroadjustment mechanism to extend the limits of operation of the micro-adjustment in accordance with seasonal trends of the macro-climate.12. Further data are being collected to clarify these tentative conclusions.
Changes in propionate and glucose metabolism during synchronization of oestrus in ewes
Authors: Wilson S. 
Published: March 2009

SUMMARYPropionate and glucose metabolism were compared in two groups of Scottish Blackface ewes, one in which ewes had been fitted with vaginal pessaries impregnated with progesterone-analogue for the synchronization of oestrus and the other when ewes were in anoestrus. In ewes given the same amount of feed, the production rate of propionate increased significantly (P < 0·05) from 33 in anoestrous ewes to 44 gC/day in ewes with pessaries. The proportion of glucose-carbon apparently synthesized from propionate also increased significantly (P < 0·05) from 0·31 in anoestrous ewes to 0·44 in ewes with pessaries. The proportion of glucose-carbon apparently recycled was also significantly (P < 0·01) increased from 0·12 to 0·22. No changes were observed in glucose concentration, production rate or oxidation rate between the two groups of ewes.
The efficiency of pneumatic tyred tractors under farm conditions
Authors: Russell E. W. , Hine H. J. , Keen B. A. 
Published: March 2009

1. Increasing the ballast on pneumatic tyres, up to a certain weight, improves the tractor performance as judged by its speed, fuel consumption and wheel slip. Further increases beyond this point continued to decrease the wheel slip without having any marked effect on its speed or fuel consumption. No certain evidence was obtained that too heavy a ballast decreased the tractor's efficiency.2. The tyre load affects the maximum pull the tractor can exert while working reasonably efficiently, but this pull does not depend markedly on the speed of work. Wheel weights of about 12–13 cwt. seem to be the minimum required for optimum performance of the 36 or 28 in. tyres at pulls of 1800 lb. under fairly good ground conditions, and possibly a greater weight may be required by the 24 in. tyre.3. If the tractor is ploughing it is usually running tilted, and this tilt transfers sufficient weight on to the furrow wheel for it to work efficiently under most conditions. Additional ballast is, however, often necessary for the lighter land-side wheel.4. Tyre performance is much less dependent on inflation pressure than on ballast. Pressures below 10 lb./sq. in. were only of use in wet conditions when small amounts of additional ballast were not available. Pressures above 12 lb./sq. in. may allow excessive slip to take place and probably only need be used on the furrow wheel of a well-loaded tractor ploughing.
Growth rate and carcass quality in bacon pigs: A study of polynomial coefficients fitted to growth rate data
Authors: Donald H. P. 
Published: March 2009

1. An examination of carcass reports from two groups of bacon pigs (comprising eleven litters and seventy-five pigs) was made to determine whether the variation in growth rate of normally reared pigs was associated with differences in carcass measurements. The method adopted was to fit orthogonal polynomials to the third degree to the last 10–11 fortnightly weighings converted to logarithms.2. The residual standard deviation after fitting was about 2–4%. For present purposes, the fitting of second degree parabolae appeared adequate.
The effects of heat treatment and protein quantity on digestibility and utilization of milk substitutes by lambs
Authors: Penning P. D. , Penning Ines M. , Treacher T. T. 
Published: March 2009

SUMMARYThe effects of heat treatment, as measured by undenatured non-casein nitrogen (NCN gN/100 g total N), and of protein: energy ratio on the digestibility coefficients and utilization of milk substitutes by lambs were investigated.Twenty-four Finnish Landrace × Dorset Horn lambs (12 males and 12 females) were given milk substitute diets in which approximately 20 or 30% of the gross energy was supplied by protein (PE20 and PE30). NCN levels were approximately 7, 12, 18 and 5, 11, 16 for diets PE20 and PE30 respectively.All lambs were offered a daily allowance of milk substitutes containing 7·95 MJ of gross energy from 3 to 25 days of age, when they were slaughtered and the chemical composition of the empty body was measured. Gains in the chemical components were measured using the comparative slaughter technique.For each unit increase in NCN value there was an increase in the apparent digestibility coefficients of dry matter (D.M.), crude protein (CP) and ash of 0·13, 0·13 and 0·93 percentage units, respectively. The apparent digestibility coefficients of all the dietary components, except lactose increased by 0·24 (d.m.), 0·24 (CP), 0·63 (fat), 0·75 (ash) and 0·32 (energy) percentage units and the metabolizability by 0·24 units for each 1% increase in PE.Live-weight and empty body-weight gains increased with increasing PE and NCN. Lambs receiving diets PE20 had a daily live-weight gain 42 g less than those on diets PE30; increasing NCN from 5 to 18 gN/100 g total nitrogen, increased live-weight gain by 33 g/day.Increasing PE and NCN increased water gain and nitrogen retention; increasing PE also increased ash retention and decreased fat gain.Lambs on diets PE20 contained more fat and less protein, at the same empty body weight, than those receiving diets PE30.Efficiencies of conversion of dry matter and energy to live-weight gain, and energy and N utilization all increased with increasing NCN, but increasing PE did not affect energy utilization and decreased N utilization.Female lambs had lower growth rates than males (—14·5 g/day) and had a higher total fat gain (128 g).
The nature of the competition between cereal crops and annual weeds
Authors: Blackman G. E. , Templeman W. G. 
Published: March 2009

In continuation of earlier work, a study has been made of the factors controlling the competition between spring-sown cereals and annual weeds. During the years 1934 and 1935 some eighteen replicated trials were carried out in widely different localities. In six experiments, observations involving some 20,000 counts were made on the cereal development. Competition between Brassica arvensis (yellow charlock) and spring barley primarily reduced the number of tillers and fertile shoots; competition on the other hand with Raphanus raphanistrum (white charlock) diminished in addition ear size. The presence of R. raphanistrum in spring oats may decrease panicle size to the same extent as shoot number. In four out of six experiments the addition of nitrogen to both the weedy and clean crop had similar effects, greatly increasing tiller production in barley and both panicle size and shoot number in oats.In six experiments nitrogenous manuring raised the yield of the weedy crop (containing either B. arvensis, R. raphanistrum or Chrysanthemum segetum (corn marigold)) to or above the level of the clean crop; n i four the yield increases were greater in the weedy than in the weed-free crop. In one experiment doubling the amount of nitrogen applied to the weedy crop did not increase the yield of oats more than the single rate, although the final yield level was considerably below that of the weed-free oats. In four other experiments additional nitrogen did not raise the yield of the weedy crop; but in only one was the yield of the clean crop increased by nitrogenous manuring.
The practical application of age conversion factors to dairy cattle production (butterfat) records
Authors: Ward A. H. , Campbell J. T. 
Published: March 2009

1. From an analysis of the records from 702 cattle of predominating Jersey type tested for at least six consecutive years under normal and average herd conditions in New Zealand, the authors have attempted a detailed study of the nature of the increase in production according to age.2. They are unable to find any evidence supporting the theory that increase in production for dairy cattle operates as a percentage addition from early age to maturity.3. The evidence secured from an analysis of 702 Jersey records of six consecutive lactations commencing at 2 years of age, strongly suggests that the increase in production according to age can be summarized neither by a percentage addition nor a constant addition alone, but is best represented by a regression formula of the nature X = aY + b, where X equals the maturity production and Y the immature production.4. The strict regression formula will probably change according to the interpretation of “maturity equivalent”, but in general its application should lose little of the simplicity of the ratio form of conversion.
Differences in carbohydrate fractions between Lolium perenne and two tropical grasses of similar dry-matter digestibility
Authors: McLeod M. N. , Minson D. J. 
Published: March 2009

SUMMARYFour samples each of Lolium perenne, Chloris gayana and Setaria splendida grown under similar conditions and having similar in vivo dry-matter digestibilities with sheep were used in a comparison of the chemical composition of tropical and temperate grass. L. perenne had less lignin, crude fibre, neutral-detergent fibre, acid-detergent fibre and cellulose than the two tropical grasses but more neutral-detergent solubles. In vivo digestibilities of the cell-wall polysaccharides of the tropical grasses were not reduced by their higher lignin contents. The digestibilities of the cell wall were generally higher than the digestibilities for the dry matter and neutral-detergent solubles. It is suggested that the effect of lignin on the digestibility of cell-wall polysaccharides is dependent on the area of protection, and better predictions may be achieved if the cell wall is divided into two fractions, an unlignified fraction that is completely digested and a completely indigestible fraction containing all the lignin.It is concluded that differences may be found in the carbohydrate composition of temperate and tropical grasses but that these differences may not cause differences in the overall in vivo digestibility of the dry matter.
Stocking rate trials in Ankole, Uganda: II. Botanical analysis and oesophageal fistula sampling of pastures grazed at different stocking rates
Authors: Harrington G. N. , Pratchett D. 
Published: March 2009

SUMMARYBotanical analyses of trials grazed at 3·6, 2·4, 1·2, 0·8 and 0·6 ha/300 kg animal for 4 years are detailed. The two heaviest grazing pressures encouraged Brachiaria decumbens, a high quality grass, at the expense of Themeda triandra and Hyparrhenia filipendula. Rotational grazing allowed the weed grass Cymbopogon afronardus to regenerate after clearing more rapidly than did continuous grazing.Bullocks with oesophageal fistulas sampled pastures grazed at 2·4, 1·2 and 0·6 ha/animal at 4-weekly intervals for 12 months. The 0·6 ha/animal treatment was repeated on pasture cleared of the weed grass Cymbopogon afronardus. Cattle growth rates, both long term and at the time of sampling, were recorded.Cattle growth rates were greatest at 2·4 ha/animal but fistula sampling demonstrated that the diet was significantly lower in CP and higher in CF than the more heavily stocked treatments, which is contrary to the normal pattern. It is concluded that the differences in cattle growth rates at the different stocking rates were due to differences in dry-matter intake rather than the recorded differences in diet quality. The higher CP in the diet at the heavier stocking rates is ascribed to the increase of B. decumbens in the diet.An unexplained ceiling to cattle growth rates of ca. 0·5 kg/day, and a calculated drymatter intake of < 2·1% body weight/day, in the presence of unlimited forage of 10% CP and 55% apparent digestibility, makes it more economic to stock for maximum production per ha than per animal.
Experiments on the spacing of sugar beet: III. Further statistical considerations
Authors: Hey G. B. , Kemsley W. F. F. 
Published: March 2009

1. The distribution of the total weight of beet in small areas (2 yards by 1 yard) was examined and estimates made of the effects of missing beet on the final yield, and of the yield to be obtained with various percentage plants.2. The distribution of gaps over the field is found to be non-random. The percentage of gaps varies from block to block, but does not differ greatly between the spacings. Three methods were employed and gave consistent results.
The effect of soil characteristics on the zinc-copper interaction in the nutrition of wheat
Authors: Arora C. L. , Sekhon G. S. 
Published: March 2009

SUMMARYA pot culture experiment was conducted on 11 soils differing in their physicochemical characteristics to study the occurrence of Zn-Cu interaction in relation to plant growth and Zn and Cu concentrations of wheat. The nature of the interaction was found to vary with the soils and the amounts of applied nutrients. The plant growth showed antagonistic interaction between Zn and Cu when one of the two elements was added in low amounts. However, when the two elements were applied in large amounts, their concentrations in the plants increased but the plant growth was adversely affected. The applied Zn generally failed to affect the uptake of native or low amounts of applied Cu whereas the applied Cu decreased the uptake of native zinc in five out of 11 soils.The DTPA extractable amounts of Zn in experimental soils were not affected signicantly by Cu application and vice versa. The fact that the application of Zn or Cu may not affect or increase the uptake of each other may depend upon the soil characteristics and the rates of their application.
The phosphorus requirement of lettuce
Authors: Smith R. , Scaife M. A. 
Published: March 2009

SummaryThe optimal intensity of P supply for lettuce was investigated in a pot experiment with five soils, six levels of P application (0, 15, 30, 60, 120, 240 ppm) and three times of harvest (2, 3 and 4 weeks after emergence). The P adsorption isotherm for each soil was measured in 0.01 M CaCl2.All soils responded strongly to P application, the amounts required for maximum growth varying from 120 ppm on a sandy soil to 300 ppm on a moss peat. The differences in requirement were related to the P adsorption by the soil, and on all soils a solution P concentration of about 1 ppm resulted in maximum growth.The Optimal leaf P concentration in young lettuce was about 0·6%.