bluuebunny/crossref_metadata_2025 huggingface dataset:
Implications of daylength sensitivity in bambara groundnut (Vigna subterranea) for production in Botswana
Authors: Harris D. , Azam-Ali S. N.
Published: March 2009

Bambara groundnut (Vigna subterranea (L.) Verde.) is grown throughout southern and western Africa, primarily as a subsistence crop, but agronomic information is scarce. The rates of emergence, flowering and pod production were assessed for 20 weekly sowings between 16 October 1990 and 26 February 1991 at Sebele, Gaborone, Botswana. Daylength during this period changed from 12·7 h to 13·7 h and back to 12·6 h. Mean time to 50% emergence was 111 days while mean time to 50% flowering was 47·5 days. The thermal time to first pod production varied with daylength, decreasing as daylength decreased, to an approximately constant value when daylength after flowering was less than about 12 h. Consequently, the plant size at which pods were produced also varied. The practical implications for date of sowing and plant spacing are discussed.
Factors influencing establishment inVicia faba
Authors: Villalobos M. J. Pascual , Jellis G. J.
Published: March 2009

Tannin-containing and tannin-free members of two pairs of near-isogenic lines ofVicia fabawere studied in glasshouse experiments at Plant Breeding International Cambridge in 1989 to determine the cause of poor establishment of tannin-free lines in the field. Tests in field soils demonstrated marked differences in disease severity and growth, the tannin-containing lines being the more resistant toFusarium culmorumandF. solani, the principal pathogens isolated. Susceptibility was not attributable to testa damage in tannin-free lines. In further tests on a range of varieties, some tanninfree and low-tannin, coloured-flowered varieties were as resistant as standard high-tannin lines. The results indicate that it should be possible to select for resistance to seedling infection and to subseque1t poor establishment among tannin-free lines and varieties.
Improvement of carrot crop establishment by combining seed treatments with increased seed-bed moisture availability
Authors: Finch-Savage W. E. , Pill W. G.
Published: March 2009

In studies of carrots sown on three dates at Wellesbourne in 1986, mean time to seedling emergence and spread of times to seedling emergence of untreated and fluid-drilled seeds increased as seed-bed moisture at sowing decreased. These differences were not observed with irrigation before sowing.

Osmotic priming increased the percentage of seeds with emerged radicles at the time of fluid drilling from 17% in the untreated control to 56%. Irrespective of seed-bed moisture, time to emergence was shorter from primed germinating seeds than from germinating seeds, both treatments giving earlier seedling emergence than untreated seeds. Seedling shoot weight was greater from treated than from untreated seeds.

Seed-bed characteristics on unirrigated plots had no effect on seedling emergence when soil moisture was adequate but, where soil moisture was limiting, rolling the seed bed to increase capillarity resulted in 79% emergence compared with the 67% average from seed beds that were not rolled. Application of a soil conditioner to stabilize the seed-bed surface structure generally improved emergence when rain fell soon after sowing. The results suggested that a combination of seed-bed and seed treatments can significantly improve the predictability of crop establishment of carrots on different dates.
Effects of nitrogen timing and frequency of fungicide applications on grain yields of winter barley in Ireland
Authors: Conry M. J. , Dunne B.
Published: March 2009

The effects of varying the timing of nitrogen application and the frequency of fungicide sprays on the incidence of foliar disease and on the grain yield of winter barley (cv. Panda) were investigated at two sites in Ireland over three years, 1986–88. Nitrogen application timing had little effect on the amount of foliar necrosis due to disease but delaying application of all the nitrogen until April significantly reduced grain yields in two of the three years when compared with standard split dressings in March and April. The reductions in yield reflected small differences in 1000-grain weight.

The number of fungicide sprays applied had significant effects on the amount of foliar necrosis and on grain yields. One-spray and two-spray programmes increased average yield by 16 and 32%, respectively. The yield increases were attributable to more ears/m2 and larger grains (greater 1000-grain weight). Fungicides also delayed the onset and significantly reduced the amount of brackling. Delaying nitrogen application in the spring did not decrease the number of fungicide sprays required to achieve maximum yield.
Progesterone, oestrogens and selected biochemical constituents in plasma and uterine flushings of normal and repeat-breeder buffalo cows
Authors: El-Belely M. S.
Published: March 2009

Sixty-four lactating buffalo cows (24 normal cycling, 8 pregnant and 32 repeat-breeder), selected from two buffalo farms near Cairo during 1987 and 1988, were studied during thefirst 26 days after oestrus (day 0). Plasma progesterone concentrations were significantly (P< 0·01) higher in pregnant than in cyclic (between days 3 and 5) and repeat-breeder (between days 0 and 8) animals. Concentrations of total unconjugated oestrogens were also highest (P< 0·01) in the pregnant group between days 6 and 16. Cyclic and pregnant cows had higher (P< 0·01) concentrations of plasma calcium between days 3 and 7, inorganic phosphorus at all times and glucose between days 2 and 8 than repeat-breeders. Plasma protein concentrations were greater at all times, except between days 6 and 8, in the first two groups. Analysis of the uterine fluid collected from cyclic and repeat-breeder buffalo cows revealed that concentrations of all biochemical components, except for calcium, were significantly (P< 0·01) higher in flushings from the uterus of cyclic animals than from repeat-breeders at alltimes for inorganic phosphorus, between days 6 and 12 for glucose and on day 2 as well as between days 8 and 12 for protein. Large differences were found in calcium levels, especially on day12 when flushings from repeat-breeder cows contained more than six times the concentrations of this metabolite in uterine flushings from cyclic animals. The results suggested that reduced luteal function, related to atypical profiles of plasma biochemical components, during the oestrous cycle in repeat-breeder buffalo cows might provide the basis for altered syntheses and secretions of uterine calcium, phosphorus, glucose and proteins which are needed for embryo development.
Influence of sowing date on the uptake of and responses to soil and fertilizer nitrogen by the spring wheat cultivar Tonic
Authors: Webb J. , Sylvester-Bradley R. , Wafford J. D.
Published: March 2009

At 14 sites in the UK, spring wheat (Triticum aestivum) cv. Tonic, was sown on three or four dates at each site between October and March in the 1988/89, 1989/90 and 1990/91 seasons. Responses to spring-applied fertilizer N over the range 0–320 kg/ha were determined. Earlier sowing did not increase uptake of soil N by the crop. Fertilizer N increased grain N offtake by between 25 and 140 kg/ha and yield by between 0·3 and 5·5 t/ha, although grain yield was less responsive to fertilizer N at later sowing dates. Apparent recovery of fertilizer N (AFR) also decreased as sowing was delayed but there was no effect of delayed sowing on the amount of grain produced from each kg of fertilizer N recovered. Because fertilizer N recovery decreased with later sowing, the amount of fertilizer N needed to produce the optimum economic grain yield was not reduced. Neither AFR nor optimum fertilizer (Nopt) was related to optimum yield. Regression of Nopt on the difference between optimum yield and yield without fertilizer N (△y) explained 77% of the variance in Nopt. There was an inverse relationship between △y and soil mineral N (SMN) in spring; regression of △y, on SMN in spring accounted for 29% of the variance in △y Current advisory systems which adjust economic fertilizer N recommendations according to anticipated yield are not justified by these results. Moreover the adjustments made, based on yield expectation, appear about three times as large as those needed to minimize residues of fertilizer N left unrecovered by the crop and to reduce the risk of nitrate leaching in the following winter.
The genetic control of maturity and seed characters in sunflower crosses
Authors: Holtom M. J. , Pooni H. S. , Rawlinson C. J. , Barnes B. W. , Hussain T. , Marshall D. F.
Published: March 2009

Data from the F1, F2 and F3 generations derived from four F1 hybrids of sunflower were analysed to determine the genetical control of eleven agronomically important traits namely, flowering time (FT), final height (FH), seed set (SS), fresh seed weight (FSW), dry seed weight (DSW), 25-seed weight (SSW), head diameter (HD), head angle (HA), neck width (NW), Botrylis infection (BI) and percentage oil content (PO), with the objective of assessing their potential for producing superior recombinant lines. Comparisons of means revealed significant differences between the F: generations of crosses for all the characters except FT. Model fitting indicated that these differences were attributed either to variation in the magnitude of the dominance component [h], or the projected mean of the Finfin; generation, m. Further, all the variation in the generation means was accounted for by the m and [h] parameters and epistasis was shown to be non-existent for almost all the traits. Analysis of the second degree statistics revealed the presence of additive genetic effects and most of the characters showed moderate heritability except for HD, which was highly heritable. All the crosses were predicted to produce significant numbers of transgressive segregants and consequently were expected to yield superior inbred lines and second cycle hybrids either to be released as varieties as such or to be utilized in future breeding work. The overall differences between the crosses, however, were not highly pronounced and therefore it was not possible to identify a cross which would yield markedly superior recombinant lines and F1 crosses compared to the others.
Effect of dietary copper sulphate on the performance of growing Japanese quail
Authors: Yannakopoulos A. L. , Tserveni-Gousi A. S. , Zervas G.
Published: March 2009

The effect of 200, 400 and 600 mg dietary copper sulphate/kg was studied in 64 Japanese quail (Coturnix coturnix japonica) in 1987. The results indicated that addition of 200 or 400 mg/kg to conventional diets of quail 7–42 days old significantly increased (P < 0·05) body weight gain and significantly decreased (P < 0·05) feed intake. There were significant (P < 0·05) increases in carcass, breast and leg weights in some cases; the first two characters had the highest values in the quail fed the diet containing 200 mg Cu/kg. The addition of 600 mg Cu/kg to the diet had an adverse effect on liver weight compared with the addition of 200 and 400 mg/kg. Copper concentration in the liver was not influenced by any rate of copper supplementation.
Evaluation of groundnut (Arachis hypogaea) genotypes for intercropping with two types of pigeon pea (Cajanus cajan)
Authors: Rao L. J. , Mittra B. N.
Published: March 2009

Eight genotypes of groundnut and two of pigeon pea were evaluated in intercropping at the Indian Institute of Technology, Kharagpur, during the monsoon and winter seasons in 1985 and 1986, to identify plant characters associated with high yield in intercropping. The pod yield of groundnut decreased when intercropped with pigeon pea, the extent of the decline differing with groundnut and pigeon pea genotypes. The reduction in groundnut pod yield and the degree and duration of shading was less when grown with pigeon pea type ICPL87 than with LRG30. During the monsoon, pod yield among intercropped groundnut genotypes ranged between 47% and 88% of their yields under monocropping because of differences in growth pattern and duration (90–125 days). The groundnut type most suitable for intercropping had early vigour, early maturity and high partitioning and pod growth rate. However, variation in pod yield among groundnut genotypes was not observed during the winter season because they showed less variation in duration and growth and there was less shading by the associated pigeon pea.
A comparison of the effects of single or multiple spring applications of prilled urea or ‘Nitro-chalk’ to winter oilseed rape (Brassica napus)
Authors: Darby R. J. , Hewitt M. V.
Published: March 2009

An earlier report of leaf scorch and diminished yield when using large amounts of urea on winter oilseed rape (Brassica napus) was investigated by applying 200 kg N/ha as calcium ammonium nitrate (‘Nitro-chalk’) or urea as a single dressing or divided in six ways. The ‘single-low’ variety Mikado (low in erucic acid) was grown in 1986 and was compared with the ‘double-low’ variety Ariana (low in erucic acid and glucosinolates) in 1987 and 1988. No scorch was seen in these experiments. Yield from rape fertilized with prilled urea was, on average, 98% of that from rape fertilized with ammonium nitrate. The timing and distribution of the fertilizer also had little effect on yield, though yield slightly decreased when part of the dressing was withheld during March. The earlier-maturing variety Mikado always outyielded Ariana except when harvest was delayed by bad weather.

When plots were fertilized with urea, the oil content of the seed was a little larger than when fertilized with Nitro-chalk, which compensated for the smaller seed yield, resulting in almost equal oil yield from both forms of N fertilizer. Crude protein content was lower after a large single dose of urea fertilizer but parity with ammonium nitrate was restored by smaller amounts applied on a number of occasions. Neither form nor timing of N fertilizer had any consistent effect on the total glucosinolate content.

The incidence of disease was significantly greater in rape given either form of N fertilizer than where none was given, but when downy mildew (Peronospora parasitica) was prevalent on pods there was significantly less infection in plots fertilized with urea than with ammonium nitrate.
Effects of dehydration on the heat tolerance of male and female New Zealand White rabbits
Authors: Thwaites C. J. , Baillie N. B. , Kasa W.
Published: March 2009

Male and female New Zealand White rabbits were exposed for 3h to 34 °C and 36 °C (both at 40% r.h.) when hydrated and dehydrated. Females had lower rectal and skin temperatures and respiratory rates than males (P <0·001). Differences between the sexes in rectal temperature were greater at 36 °C than at 34 °C. Withholding water for 24h significantly increased the responses in rectal temperature; the differentials between hydrated and dehydrated males and females being 0·3 °C and 0·2 °C, respectively. In contrast, respiratory rates were lower in dehydrated than in hydrated rabbits, suggesting that the former were attempting water homeostatis at the expense of thermoregulation.

The results suggest that the performance of rabbits in the tropics is likely to be maximized when drinking water is available at all times, and that of males, particularly breeding bucks, might be improved simply by housing them in the coolest available location. Significant individual differences in observed responses point to the need for genetic studies of heat tolerance and the possibility of developing better adapted genotypes.
Prediction of intake and digestion in ruminants by a model of rumen kinetics integrating animal size and plant characteristics
Authors: Illius A. W. , Gordon I. J.
Published: March 2009

Simulation modelling was used to investigate interactions between forage degradation characteristics, rumen processes and body weight, and to predict the voluntary food intake and digestion of a range of forages. Predicted voluntary intake and digestion agreed well with empirical data, explaining 61 and 70%, respectively, of variance in observed values. Since the data covered a wide range of animal weights and forage qualities, these results suggest that the model is a useful means of integrating the effects of animal and forage variables. Interactions were examined between animal weight and diet quality, as defined by the proportion of potentially digestible cell contents and cell walls and their rates of digestion. Retention time of food in the digestive tract was shown by regression to scale with W0·27. The time taken to comminute large fibre particles also scaled with W0·27. Longer retention of digesta by large ruminants increases digestive efficiency compared with small animals and would permit them to survive on lower-quality foods. The model showed that maximum intake of metabolizable energy scales with c. W0·87, greater than the scaling of maintenance with W0·73.
Relationship between air conditions and the drying rate of thin-layers of grass
Authors: Lamond W. J. , Graham R.
Published: March 2009

A series of 240 thin-layer drying runs carried out in 1988 and 1989 at the Scottish Centre of Agricultural Engineering were analysed to find out which factors influenced the rate of drying of grass mixtures. The grass used in the experiments was cut by hand, by a mower without conditioner or by a mower with conditioner. The experiments covered a range of air conditions from 16·0 to 40·4 °C temperature and 24·4 to 82·8% relative humidity. By fitting curves to the experimental data it was shown that the drying curves could be simulated by a two-parameter, exponential equation. Analysis of the data showed that the experimental results could be adequately represented by holding one of the parameters fixed and fitting the curves with only one parameter varying. The variable parameter, called the drying coefficient, was dependent on harvesting method and related to drying air temperature, initial moisture content and ratio of leaf area to stem area. A regression equation relating the drying coefficient to these variables for conditioned and unconditioned grass is presented.

Predictions from the regression equations indicated that the temperature of the drying air had a major effect on the drying coefficient. Both the initial moisture content of the samples and ratio of leaf to stem had a smaller influence on the coefficient over their likely range.
Computer simulation of bovine copper metabolism
Authors: Blincoe C.
Published: March 2009

Copper deficiency in cattle is a world-wide problem. A deterministic digital computer simulation of copper metabolism was applied to cattle and especially to their response to dietary copper. This simulation was verified by comparison with published data on copper metabolism of cattle. Copper loss under conditions of dietary deficiency was governed largely by the rate of hepatic loss of copper. Copper stores were replenished gradually when the animal was returned to a normal diet. The increased copper consumption associated with increased total digestible nutrients (TDN) during lactation compensated for loss of copper in milk. Cattle have a very efficient mechanism for extrahepatic copper homeostasis by storage of excess copper in the liver, which can then be withdrawn in future deficiencies.
Response of winter barley cultivars to nitrogen and a plant growth regulator in relation to lodging
Authors: White E. M.
Published: March 2009

Applications of nitrogen and a plant growth regulator (mepiquat chloride and ethephon) were used to manipulate stem structure and induce differing degrees of damage due to leaning and lodging in six cultivars of winter barley grown in Belfast, UK, in 1986/87. Weighted incidences of leaning and lodging were combined to give an index indicating damage susceptibility of the cultivars. The index was very high (70) in Pipkin and ranged between 1 and 18 in the other cultivars. Differences between cultivars in number of internodes, plant height and stem weight did not explain their differences in resistance to damage. However, dry weight per unit length ranged from 2·35 and 2·34 mg/mm in the strongest cultivars, Panda and Jennifer, respectively, to 1·75 mg/mm in the weakest cultivar, Pipkin.

Nitrogen application increased plant height but did not affect dry weight/main stem, so that dry weight/unit length of stem decreased. The growth regulator treatments reduced plant height and although dry weight/stem did not decrease significantly, dry weight/unit length of stem was similar in treated and untreated plots.

Dry weight/unit length has potential as an objective indicator of straw strength in winter barley cultivars and could be used in cultivar evaluation in the absence of damage in field trials.
Evaluation of wild sunflower (Helianthus) species for high content and stability of linoleic acid in the seed oil
Authors: De Haro A. , Fernandez-Martinez J.
Published: March 2009

A collection of 168 accessions belonging to 62 species and subspecies was evaluated in Cordoba, Spain, in 1985 for fatty acid composition of the seed oil. Linoleic acid content of seed produced in Cordoba (mean temperature during seed formation 27·9 °C) was compared with that of seed obtained under much cooler environmental conditions in Montpellier, France, (mean temperature 19·5 °C). Linoleic acid content ranged from 27·3 to 83·7% in the warm environment and from 45·9 to 88·7% in the cool environment with average values of 64·3% and 75·0%, respectively. Twenty-three species with linoleic acid values of > 70% in both environments were evaluated again, in 1989 in Cordoba (mean temperature 31 °C). Twelve wild species showed consistently high and more stable linoleic acid contents than the cultivated control and could be readily used in breeding programmes to improve oil quality.
Effects of inflorescence removal on interactions between reproductive storage sites of field beans (Vicia faba) under different shading treatments
Authors: Aufhammer W. , Götz-Lee I.
Published: March 2009

In studies of two indeterminate cultivars in field experiments in 1985 and 1986 at Hohenheim University, the hierarchy within the reproductive storage system of field bean plants was manipulated by removal of inflorescences at various growth stages and nodes. Shading reduced pod set and seed weight mainly at basal nodes. Increasing plant population density reduced seed yield traits at all nodes. Removal of basal inflorescences increased pod set and seed weight at the remaining nodes, especially the lower ones. The favourable effects were greater under high light intensities and in sparse stands. The growth stages at which the basal inflorescences were removed and the removal of apical inflorescences were of minor importance.
Interaction of lipid supply and carbohydrates in the diet of sheep with digestibility and ruminal digestion
Authors: Elmeddah Y. , Doreau M. , Michalet-Doreau B.
Published: March 2009

Two groups of nine wethers, three of which were fitted with rumen cannulas, were used in a digestion trial at the INRA centre in Theix, France, in 1988. Group 1 received 65% maize silage and 35% concentrates; group 2 received 65% hay and 35% concentrates. Concentrates were based on either cereals rich in starch, or by-products rich in fibre and were given either alone or supplemented with lipids as calcium soaps. The fatty acid content of lipid-supplemented diets wasc.9·5 and 8·5% of dry matter, of which 85 and 89% was provided by calcium soaps, for maize silage and hay diets, respectively. For each group, the four diets were tested in four successive periods from January to June 1988.

Total digestibility of dry and organic matter, acid detergent fibre (ADF) and neutral detergent fibre (NDF) was measured in six wethers of each group by total faeces collection. On cannulated wethers, volatile fatty acid content and composition, pH and NH3-N in rumen liquor were determined four times a day;in saccodegradability of dry matter, ADF and NDF of the forage eaten by the wethers was estimated by the kinetics of incubation in the rumen.

In vivoandin saccoresults showed that dry matter and organic matter digestibilities were not modified by the nature of concentrates. Cell wall digestibility was higher for fibre concentrates than for starchy concentrates, by 4·1 and 6·2 percentage units for NDF in maize silage and hay groups, respectively. Volatile fatty acids (VFA) and ammonia concentrations were higher and pH was lower with the maize silage than with the hay diet.

Lipid supply slightly increased cell wall digestibility in the group fed maize silage by 7·5 and 2·0 percentage units for starch and fibre concentrates, respectively. This surprising increase was related to an improvement inin saccodegradability. In all diets, lipid supply increased pH, but variations in VFA concentration and pattern were low. Interactions between the nature of concentrate and lipid supply were moderate, but were higher in the group fed maize silage than in the group fed hay, especially for total digestibility.
The effect of irrigation on the growth and yield components of poppies (Papaver somniferumL.)
Authors: Chung B.
Published: March 2009

The effects of four irrigation treatments on the growth and yield of poppies were studied in two ‘drought’ seasons in Tasmania. Irrigation increased total dry-matter production, leaf area index and delayed leaf senescence in both seasons. Irrigation, which continued until leaf senescence, increased total morphine yield by 5–20 kg/ha compared with no irrigation. This yield increase was attributed to the increase in the number and yield of lateral heads, the yield of terminal heads and capsule morphine concentration.

As the effects of irrigation on head yield reflect the effects on total dry-matter production, irrigation guidelines for poppies were developed from an analysis of plant growth during theseason. For maximum yield, one irrigation of 50 mm should be applied at the 50% hook stage, at 50% flowering, at the end of flowering and 2 weeks after the end of flowering. Growers who currently cease irrigation at 50% flowering can expect yield increases of 4–13 kg/ha ifthey apply two further irrigations thereafter.
Effects of plant type and population density on growth and yield of chickpea
Authors: Singh A. , Prasad R. , Sharma R. K.
Published: March 2009

A field experiment was made with chickpea (Cicer arietinum L.) at the Indian Agricultural Research Institute, New Delhi during the winters of 1984–5 and 1985–6 to study the effects of plant type and population density on growth and yield of chickpea. Cultivars BG 257, BG 261, BG 268 and BG 274 produced signficantly more grain with 1000 × 103 and 660 × 103 plants/ha, whereas the cultivar BG 209 produced the most at 500 × 103 plants/ha. Among the cultivars, BG 257 and BG 268 gave highest grain yield with 660 × 103 plants/ha.
Moisture use characteristics of sugarcane genotypes under different available soil moisture regimes in alluvial entisols
Authors: Yadav R. L. , Prasad S. R.
Published: March 2009

To study the response of three sugarcane genotypes (CO 1148, COJ 64 and CO 1158) to variations in moisture availability in sandy loam soil (entisol), field trials were conductedat Lucknow (26·5° N, 80·5° E, 120 m altitude) during 1984–5 and 1985–6. Three moisture regimes, i.e. wet (irrigation at 75% available soil moisture (ASM)), moist (irrigation at 50% ASM) and dry (irrigation at 25% ASM) were maintained during the pre-monsoon (before June) period in spring-planted (February-March) sugarcane. During the summer months (until June)the variety CO 1148 had a significantly greater sheath moisture percentage than COJ 64 and CO 1158. Under stress conditions, leaf area index was reduced most in COJ 64 and least in CO 1148.Underground shoots and roots grew faster in CO 1148, and the growth of above-ground parts was quicker in COJ 64. Compared with the 75% ASM regime the reduction in cane yield in the 25% regime was more in COJ 64 and CO 1158 (31 t/ha) than in CO 1148 (12 t/ha). The water requirement of COJ 64 was greater than that of the other varieties. Therefore, for higheryields COJ 64 needed frequent irrigation whereas CO 1148 performed well even under moderate irrigation (50% ASM).
Use of soluble glass boluses containing Cu, Co and Se in the prevention of trace-element deficiencies in goats
Authors: Zervas G. P.
Published: March 2009

Two experiments were carried out to examine the value of copper, cobalt and selenium contained in soluble glass boluses as a means of providing supplementary trace elements to goats.

In the first experiment 36 purebred Toggenburg goats were used and divided into two groups. One group was treated with soluble glass boluses while the other was left as control.

In the second experiment 46 Saanen half-bred goats were used, divided into three groups. The first group was treated with soluble glass boluses, the second was treated with selenium injectable compound and the third was left as control.

Blood samples were collected on four occasions, during an experimental period of almost 12 months and plasma copper, serum vitamin B12 and blood selenium concentrations were determined. All those measurements showed significant increases for about a year, and were due to treatment. The advantages of glass boluses were not shared by the selenium injectable compound.
Phenotypic and genetic characteristics of growth of Peking ducklings under Egyptian conditions
Authors: El-Sayiad Gh. A. , Marai I. F. M. , Afifi E. A.
Published: March 2009

Peking ducklings were classified at 6 weeks of age according to their body weights in two categories: R, below the overall mean of the flock which were considered as retarded growth; and L, those of body weight equal to the overall mean and above which were considered as large. From each group, males and females were chosen to be parents of the next generation in a ratio 1:5 at 6 months of age and four systems of matings were conducted: RR, LL, RL and LR.

At all ages studied the large ducklings were significantly heavier than retarded growth ones and had significantly greater body gain, during the two successive generations.

The RL and LR matings were heavier than the RR and LL groups at the different ages studied, indicating an effect of heterosis and that the retarded growth character is controlled by few pairs of genes. The differences due to mating systems were not significant either in body weight or body gain, except in body weight at 18 and 24 weeks and relative gain at 6 weeks of age in which the differences were significant (P<0·05) in the second generation.

The other environmental factors studied were sex, month of hatch and 6-week body weight.

Heritability estimates were 0·489, 0·509, 0·576, 0·346, 0·713, 0·809, 0·651 and 0·386 for body weight at hatch 4, 6, 8, 12, 16, 18 and 24 weeks of age, respectively, using the data which were adjusted for the effects of sex, month of hatch, 6-week body weight and mating system. The same estimates were 0·482, 0·554, 0·578, 0·352, 0·713, 0·808, 0·650 and 0·386, respectively, using the same data but adjusted for month of hatch and sex only.

Phenotypic and genetic correlations between body weights at different ages for the two sets of data were estimated. The phenotypic correlations were negative between body weight at hatch and each of the body weights at 16 and 18 weeks of age for the two corrected sets of data. The genetic correlations were negative between hatch weight and each of the other body weights for the two adjusted sets of data and between body weight at 4 weeks of age and each of the body weights at 16, 18 and 24 weeks only for the first set of data. Phenotypic and genetic correlations between the body weights in older birds were highly positive.
Telemetered body temperatures in a group of cattle during gestation and lactation
Authors: Bennett I. L. , Holmes C. R.
Published: March 2009

In tropical and subtropical areas many cattle suffer from heat stress for more than half of each year. Added to the environmental heat stress is the heat production associated with lactation (Berman et al. 1985) and the resultant increased storage of heat (Araki et al. 1984). While the net effect of lactation on body temperature has been evaluated in dairy cattle (Collier et al. 1982) its effect on beef breeds in tropical and subtropical areas has not been defined. This is now possible with improved telemetry equipment, which allows body temperatures of free-ranging cattle to be monitored up to distance of 400 m.
The effect of sympathectomy on wool growth and catecholamine innervation of the skin in Wiltshire Horn sheep
Authors: Williams A. H. , Willis G. L.
Published: March 2009

Seven Wiltshire Horn rams were subjected to unilateral thoracic sympathectomy. Wool shedding was observed during the following 9 months. Fleece samples were collected on two occasions during winter from tattooed areas of skin on both the sympathectomized and unoperated sides. Skin samples were also taken from the sympathectomized and unoperated sides of the sheep during August and examined for catecholamine fluorescence using a fluorescence histochemical technique. While there was no difference in fleece casting between the sympathectomized and unoperated sides, there were increases in both wool growth and the number of brush end fibres on the sympathectomized side. Fluorescent histochemical evaluation of the skin samples revealed that the increases in shed fibres and wool growth were accompanied by a decrease in amine fluorescence in nonvascular tissue adjacent to the wool follicles.
The effect of dietary molybdenum and iron on copper status and growth in cattle
Authors: Phillippo M. , Humphries W. R. , Garthwaite P. H.
Published: March 2009

The effects of supplementation of a barley-barley straw diet containing 4 mg copper (Cu)/kg dry matter (D.M.) either with 5 mg molybdenum (Mo)/kg D.M. or with 500 mg iron (Fe)/kg D.M. on the Cu status, growth and clinical condition of calves are described. Liver and plasma Cu concentrations declined rapidly within 12–16 weeks to levels indicating severe Cu deficiency in both the Mo- and Fe-supplemented groups. The changes in Cu status were similar for both supplements and did not differ significantly from each other. Clinical signs of Cu deficiency, as indicated by reduced growth rate and changes in hair texture and colour, were evident after 16–20 weeks only in animals on the Mosupplemented diet. The reduced growth rate was accompanied by a decreased food intake and reduced efficiency of food utilization. The Mo-supplemented animals also exhibited an altered Fe metabolism, particularly when the growth rate was affected. The results confirm earlier reports that the effects of Mo on growth and clinical condition are independent of its effect on Cu status and suggest that the altered production might be due to effects on the control of food intake, food utilization, or Fe metabolism.
Relationships between time, temperature, daylength and development in spring barley
Authors: Wright D. , Hughes Ll. G.
Published: March 2009

The effects of sowing date on leaf appearance, spikelet initiation and mainstem apical development in spring barley cv. Triumph were investigated in field experiments involving 13 sowings made during the period 22 February to 1 July over the years 1982–1985. Delaying sowing was associated with faster rates and shorter durations of leaf appearance and spikelet initiation and earlier attainment of all stages of apex development. The rates of leaf appearance and spikelet initiation were correlated with daylength at crop emergence although there was evidence that the latter process was also influenced by temperature. The derivation of three models relating the duration of developmental phases to temperature and/or daylength is described. In these models the attainment of successive stages of apical development was assumed to require the perception by the crop of a ‘threshold amount’ (THR) of accumulated temperature (THR(ΣT)) and/or daylength (THR(ΣPT), THR(ΣP)) above certain base values (TbPb). The base values of temperature and/or daylength for each phase were derived as those values which minimized the coefficient of variation of the amounts of accumulated temperature and/or daylength experienced by all 13 sowings. For various developmental phases the model based on temperature gave base values between 0 and 3 °C. The model based on daylength gave base values between 11 and 13 h. In both these models there was a highly significant correlation between observed and expected dates of attainment of various stages of apex development. It is suggested that the derived relationships between temperature, daylength and apical development could be used as an aid in the forward planning of crop management. The model based on temperature and daylength (photothermal time) gave no useful base values and it is concluded that more precise methods of relating development to these factors must be sought.
Interacting effects of magnesium with nitrogen on the growth and yield of wheat
Authors: Singh Harsharn , Gill H. S.
Published: March 2009

A field trial was conducted during 1982–3 and 1983–4 on a loamy sand soil to study the effect of magnesium application to the soil and in foliar spray in relation to various levels of nitrogen on the growth and yield of wheat. Results indicate that wheat responde significantly to magnesium application only at the higher level of nitrogen. At the higher level of N (120 kg/ha), the response of wheat to magnesium application (10 kg/ha) to the soil and in foliar spray was 56 and 68 kg grain/kg Mg, respectively. However, the corresponding values at a low level of N (60 kg/ha) were only 14 and 15 kg grain/kg Mg. Magnesium at the higher level of N increased the chlorophyll content of leaves, leaf area index, interception of photosynthetically active radiation, number of ear-bearing tillers and number of grains per ear. The higher level of magnesium (20 kg/ha) did not result in extra beneficial effect compared with the lower level of Mg (10 kg/ha). Maximum interception of photosynthetically active radiation by the wheat canopy coincided with the attainment of maximum leaf area index and chlorophyll content of leaves at 90 days after sowing.
Response of fluid-drilled ‘Grand Rapids’ lettuce seeds to high temperature and low moisture
Authors: Pill W. G. , Rojas J. E.
Published: March 2009

It is estimated that only 35–50% of the potential yield of field lettuce crops is harvested (Gray, 1978c). A major contributory factor is the failure to establish full, uniform plant stands. Erratic lettuce emergence has been attributed to inadequate soil moisture, soil crusting, and high (> 25 °C) soil temperature (Hemphill, 1982).
Relative efficacy of some new urea-based nitrogen fertilizers for growing wetland rice on a permeable alluvial soil
Authors: Bijay-Singh  , Katyal J. C.
Published: March 2009

Efficiency of N contained in some modified urea fertilizers was studied for wetland rice grown in an alkaline, low organic matter Fatehpur loamy sand (Typic Ustipsamment) soil having an average percolation rate of 109 mm/day. In the four field experiments, sulphurcoated urea (SCU) produced significantly more rice grain than urea supergranules (USG) or divided applications of urea or ammonium sulphate. Application of SCU at 58 kg N/ha yielded as much rice grain as was produced by divided application of urea at 116 kg N/ha. The N uptake data suggested that SCU-N was more efficiently translated into grain yield than urea N. Granular (7-day release rate 19%) and forestry (7-day release rate 29%) grades of SCU were equally effective. However, application of half the N basally through SCU and the remaining half top dressed as urea failed to outyield all urea divided in three applications. The indigenous coated materials, rock-phosphate-coated urea and urea gypsum, also did not perform better than divided urea applications as these did not possess a 7-day release rate less than 95%. Urea supergranules placed in the reduced zone of the soil could not come to the level of divided application of urea or ammonium sulphate. The N uptake data indicated that USG-N was correspondingly inefficiently utilized by rice. When the deep placement aspect of USG was combined with slow-release properties of SCU in the form of sulphur-coated urea supergranules (SCUSG), the performance of this product was inferior even to the divided application of urea. Undissolved or partially dissolved granules of SCUSG could be recovered even after the harvest of the crop.
Phosphorus sorption by acid soils: comparative study of some parameters
Authors: Arines J. , Sainz Maria
Published: March 2009

A comparative study of sorption maxima (simple and double Langmuir equations) and buffer capacity of acid soils was made in order to select the most useful P-sorption parameter. Data were obtained from 20 acid soils from Galicia (north-west Spain) and selection was made by linear and multiple regressions among sorption parameters, and between these and some soil characteristics related to phosphate sorption (clay and organicmatter content, pH in NaF, and 0·5 M-CuCl2-extracted Al).

The phosphate buffer capacity, determined by the slope of the regression ‘sorbed-P v. logc’, was the best parameter to represent soil phosphate sorption behaviour. 0·5 M-CuCl2- extracted Al was the edaphic characteristic which best related to sorption properties.
Effects of seed row and foliar applied pesticides on the yield of lucerne in clay soil, in the presence or absence of lucerne stem nematode, Ditylenchus dipsaci
Authors: Whitehead A. G. , Tite D. J.
Published: March 2009

Carbofuran at 1·5 kg a.i./ha applied around the seeds during sowing in spring controlled lucerne stem nematode and Sitona damage to lucerne and increased herbage yields in the susceptible cv. Europe. Such treatment was also beneficial to Europe in soil not infested with lucerne stem nematode and to the ‘resistant’ cv. Euver sown in infested soil. Subsequent treatment of the soil in spring each year with thiabendazole did not enhance lucerne yield but aldicarb at 1·5 kg a.i./ha watered onto the stubble and hydraulic or electrostatic sprays of carbendazim, thiabendazole hypophosphite, thiodicarb, dimethoate or pirimiphos methyl applied to new foliage after each herbage harvest lessened stem nematode injury and increased herbage yields in one experiment but had less or no effect in another.
Comparison of the site and extent of digestion of nutrients of a forage in kids and lambs
Authors: Alam M. R. , Lawson G. D. , Poppi D. P. , Sykes A. R.
Published: March 2009

The quantitative partitioning of digestion between the stomachs, small intestine and large intestine was compared in kids and lambs offered a high quality meadow hay (organic-matter digestibility, 0·74; N, 23·9 g/kg D.M.) in amounts between maintenance and ad libitum.

Nutrient flow past the abomasum and terminal ileum and in the faeces was measured by reference to 51Cr-EDTA and 103Ru-phenanthroline. Digestion of D.M., neutral detergent fibre (NDF) and non-ammonia N (NAN) in the rumen (R), small intestine (SI) and large intestine (LI) was estimated from the regression of nutrient flow on nutrient intake.

No difference was observed between the species in digestion of D.M., NDF and NAN at any site. Approximately 0·60, 0·29 and 0·13 of the total in vivo D.M. digestion (0·74) occurredin the R, SI and LI, respectively, and approximately 0·94 of the total in vivo NDF digestion (0·79) occurred in the rumen of both species.

There was a gain of total N and NAN of 22 and 15%, respectively, in the rumen of both species whilst net disappearance of NAN in the small intestine and of N in the large intestine was approximately 0·62 and 0·27, respectively. All these characteristics varied slightly with level of feeding.

It is concluded that there may be little difference in the partitioning of digestion of D.M., NDF and NAN in the digestive tract of kids and lambs when consuming high quality forages.
Genotype studies in a groundnut-pigeonpea intercropping system
Authors: Rao L. J. , Mittra B. N.
Published: March 2009

Intercropping has been recognized as an important farming practice, particularly under rainfed conditions, for its greater stability in production, equal distribution of labour throughout the growing season and greater diversity of food and income sources. Evidence for higher productivity from intercropping through more efficient use of resources has been demonstrated (Andrews, 1972; De & Singh, 1979; Willey & Natarajan, 1978). Groundnutpigeonpea intercropping, which is prevalent in semiarid conditions of India on alfisols, does not produce good yields because of the traditional practice of having low pigeonpea density. Also, unsuitable genotype and poor arrangement of the crops often prove to be disadvantageous.
Seed production and seed survival under grazing of annual medics (Medicago spp.) in north Syria
Authors: Cocks P. S.
Published: March 2009

Three experiments which measured seed production and seed survival of annual medics (Medicago spp.) were conducted at Tel Hadya in north Syria. In Expts 1 and 2, conducted in consecutive years, the effects of rate and date of sowing on seed yield and its components were measured, while in Expt 3, the residual seed under summer grazing was monitored. In all three experiments seed permeability was observed at frequent intervals in summer and autumn. Selected ecotypes of three native medics (Medicago rigidula (L.) All., M. rotata Boiss. and M. noeana Boiss.) were compared with cultivars of M. truncatula Gaertn. and M. polymorpha (L.).

Seed production was greatest at sowing rates of 20–40 kg/ha. The native species produced more seed (up to 1000 kg/ha) than the cultivars (less than 500 kg/ha), although not significantly so in the case of the late-flowering ecotype of M. noeana. Seed yields of 500–1000 kg/ha were considered to be sufficient to perpetuate the pastures, but even higher seed yields are desirable.

Seed yield was closely related to number of pods in all ecotypes and, in Expt 2, up to 95% of flowers failed to produce mature pods. Flowers were more likely to mature at high sowing rate (256 kg/ha), in striking contrast to flower production itself which was greatest at sowing rates of less than 30 kg/ha. Flowers produced early in the season (before mid-April) were far more likely to give mature pods than late-produced flowers.

In late October, seeds of the native species were less permeable (10%) than those of the cultivars (30%), although their permeability was similar to that of the cultivars in Australia. In the three experiments the seasonal pattern of permeability varied, although there was a tendency for seeds to gain permeability in autumn. In Expt 1 there was a strong suggestion that the change from impermeability to permeability was reversible.

Ewes grazing mature pods gained weight, apparently as long as pod availability exceeded 10 kg/ha. It was clear that the condition of ewes was not a good guide to appropriate stocking rate for persistence of pastures, and that farmers will have to use other methods to assist them in grazing management.