bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, yield performance and market quality of groundnut (Arachis hypogaea) as affected by cropping season in southern Sierra Leone
Authors: Sesay A. , Yarmah A.
Published: March 2009

Traditionally, only one groundnut (Arachis hypogaea) crop is grown in the uplands during the rainy season (May-October) in Sierra Leone, with sowing starting at the beginning of the rains. However, a recent trend among groundnut farmers is to sow a second crop in September after harvesting the first crop. Thus a system comprising a first (major) and a second (minor) cropping season is being adopted, with the second season crop having to depend largely on moisture stored in the soil. Experiments were conducted in 1993 at the Institute of Agricultural Research Experimental Farm, Njala, to assess the agronomic potential of growing two crops a year. Crop phenology, growth and productivity were strongly influenced by cropping season. Pod yield ranged from 1·63 to 2·58 and from 1·16 to 1·95 t ha-1 in the major season, declining to 0·72–1·29 and 0·57—1·07 t ha-1 in the minor season. Haulm yield, number of mature pods, crop growth rate and partitioning were lower in the minor season by 58, 57, 40 and 13%, respectively. However, kernel quality was higher in the minor season. The results suggest that the growing of two groundnut crops in the uplands is a potentially viable management option in Sierra Leone, and could represent a more efficient utilization of the growing period.
Simulation of digestion in cattle fed sugarcane: prediction of nutrient supply for milk production with locally available supplements
Authors: Dijkstra J. , France J. , Assis A. G. , Neal H. D. St. C. , Campos O. F. , Aroeira L. J. M.
Published: March 2009

A previously described model of digestion in cattle fed sugarcane diets was applied to predict nutrient supply to the host animal from dietary intake, to indicate pre-experimentally the suitability of various supplements to enhance the milk production of dairy cattle in the tropics fed sugarcane–based diets. Potential milk production was calculated according to simulated energy and lipogenic, glucogenic and aminogenic nutrient availability. The addition of small amounts of urea (10 g/kg sugarcane fresh weight) improved microbial efficiency and degradation of substrates in the rumen, but further increases could only be achieved by supplements containing rumen degradable protein. The simulated level of absorbed amino acids was low in comparison with the level of absorbed energy and glucogenic substrates. This low amino acid availability was the factor most limiting milk production on sugarcane diets and supplements which increase the amino acid availability in the gastrointestinal tract are recommended. At increasing supplementation or intake levels, and once amino acid requirements were met, an increased absorption of energy and long chain fatty acids could enhance milk production. These suggestions should be evaluated experimentally in order to improve the model and ultimately, to result in an improved system to evaluate feeds, based on the supply and utilization of individual substrates.
Effect of species composition and sward structure on the ingestive behaviour of cattle and sheep grazing South African sourveld
Authors: O'Reagain P. J. , Goetsch B. C. , Owen-Smith R. N.
Published: March 2009

The effects of species composition and sward structure on the ingestive behaviour of cattle and sheep grazing a mesic, low quality grassland in South Africa were investigated over the 1990–93 grazing seasons. Species composition had a significant (P < 0·05) effect on sheep bite size and on cattle and sheep bite rates but had no effect on dry matter intake rate (IR). Species composition could, however, affect IR over longer grazing periods than those used in the experiment.

Sward structure had a major effect on ingestive behaviour. Cattle and sheep bite rates and cattle grazing time, were negatively correlated (P < 0·05) with plant height but positively correlated (P < 0·05) with sward greenness. Bite size and hence IR in cattle and sheep were strongly correlated (P < 0·001) with plant height. Cattle IR increased from 6 to 20g/min over the range of heights encountered and appeared to reach an asymptote at a plant height of 20–25 cm. Sheep IR, expressed per unit of body mass, increased from 0·01 to an asymptote or maximum of 0·13 g/min/kg at plant heights of 10–15 cm. For sheep there was evidence of a non-asymptotic functional response at some sites with IR being maximized at certain sward heights but declining thereafter. This suggests the possible existence of a third, quality dimension to the functional response on these low-quality grasslands.
Differences between related grasses, times of year and plant parts in digestibility and chemical composition
Authors: Wilman D. , Gao Y. , Altimimi M. A. K.
Published: March 2009

True dry matter digestibility, proportion of cell content, digestibility of cell wall, N and water-soluble carbohydrate were determined in eight related grasses in February, June and September in each of three years. In a separate experiment, true dry matter digestibility, proportion of cell content and digestibility of cell wall were determined in five plant parts of vegetative tillers of two grasses in February, April, June, August, October and December in each of two years.

Perennial ryegrass (Lolium perenne) was the most digestible grass and tall fescue (Festuca arundinacea) and Westerwolds ryegrass (Lolium multiflorumvar.Westerwoldicum) were the least digestible. Italian ryegrass (Lolium multiflorum) was high in proportion of cell content, but not in digestibility of cell wall. Meadow fescue (Festuca pratensis) was high in digestibility of cell wall, but low in proportion of cell content. Perennial ryegrass and hybrid ryegrass were high, and tall fescue low, in both proportion of cell content and digestibility of cell wall. Ryegrasses were lower than fescues in concentration of N and higher than the fescues in water-soluble carbohydrate; ryegrass × meadow fescue hybrids were intermediate between the parent species in N and watersoluble carbohydrate.

Grass sampled in June and August was lower in both proportion of cell content and digestibility of cell wall than grass sampled at cooler times of year. Grass sampled in February was high in proportion of cell content and N, intermediate to high in digestibility of cell wall and intermediate in water-soluble carbohydrate.

Expanding leaf blades of perennial and Italian ryegrass were higher than expanded blades and sheaths in digestibility of cell wall and similar to expanded blades and higher than sheaths in proportion of cell content. Cell wall was less digestible in the tip than in the middle and basal portions of expanded leaf blades.
Some properties of l-chloro-2,4-dinitrochlorobenzene linked glutathione S-transferase in dichlorvos resistant and susceptible strains of cotton aphid (Homoptera: Aphididae)
Authors: Owusu E. O. , Horiike M.
Published: March 2009

Effects of temperature, hydrogen ion and substrate concentrations on conjugation of l-chloro-2,4-dinitrochlorobenzene by glutathione S-transferase from susceptible and dichlorvos-resistant strains of cotton aphid (Aphis gossypiiGlover (Homoptera: Aphididae)) were evaluated. Enzymes from both strains had common optimum temperature and substrate concentration values of 30 °C and 10 mM respectively. Also, while enzyme activity of the susceptible strain peaked at pH 7·2, that of the resistant strain showed complete linear dependency up to pH 8·0. Of four subcellular fractions, the 100 000gsupernatant (soluble fraction) gave the highest enzyme activity in both phosphate and Tris/HCl buffers. There was no linear relationship between insecticide application frequency and production of enzyme activity in the susceptible strain but there was a very high positive correlation between these two parameters in the resistant strain.
An analysis of the agronomic, economic and environmental effects of applying N fertilizer to sugarbeet (Beta vulgaris)
Authors: Allison M. F. , Armstrong M. J. , Jaggard K. W. , Todd A. D. , Milford G. F. J.
Published: March 2009

The effects of different rates of N fertilizer (0–180 kg N/ha) were tested on the growth, yield and processing quality of sugarbeet in 34 field experiments in England between 1986 and 1988. The experiments were performed using soil types, locations and management systems that were representative of the commercial beet crop in the UK. The responses obtained showed that current recommendations for N fertilizer use are broadly correct, but large differences occurred on some soil types, in some years, between the recommended amounts and the experimentally determined optima for yield. The divergence was largest when organic manures had been applied in the autumn before the beet crop. Calculations using a simple nitrate-leaching model showed that much of the N in the manures was likely to be leached, the extent of leaching being much less if the manure application was delayed until spring. In these circumstances, spring measurement of inorganic mineral N in the soil could improve fertilizer recommendations. In situations where higher than optimum rates of fertilizer N were used, the extra N had little effect on yield. Increasing the rate from 0 to 180 kg N/ha increased the amount of nitrate left in the soil at harvest by only 8 kg N/ha. The amount of inorganic N released into the soil from crop residues at harvest increased by 50 kg N/ha with N application rate, and the fate of this N has not been established.
Intra-ruminal particle size reduction in deer fed fresh perennial ryegrass (Lolium perenne) or chicory (Cichorium intybus)
Authors: Kusmartono  , Shimada A. , Stafford K. J. , Barry T. N.
Published: March 2009

Pure swards of chicory (Cichorium intybus) and perennial ryegrass{Lolium perenne)were grown at Palmerston North, New Zealand. They were cut daily and fed fresh at 2 kg dry matter (DM)/day to ten hand-reared rumen fistulated castrated red deer stags kept in metabolism crates in April and October 1994. The efficiency of particle breakdown during the time allowed for rumination () to below the critical size required to leave the rumen (passage through a 1 mm sieve) and jaw activities (i.e. eating and ruminating) were measured. Total eating time and the number of eating bouts were similar for deer fed each forage, but deer fed chicory had a greater chewing rate during eating (97·4 v. 81·0 chews/min), and a higher number of chews/g DM eaten (36·2 v. 31·5). Deer fed chicory had lower total ruminating time (30 v. 257 min/22·5 h), lower number of boli ruminated (38 v. 440/22·5 h), lower number of rumination bouts (5·4 v. 16·2/22·5 h) and less chews per minute ruminating (16·5 v. 44·3) than those fed perennial ryegrass. Of the ten deer used to measure (), only four ruminated when fed chicory compared with nine when fed perennial ryegrass.

Deer fed chicory had a higher efficiency of particle breakdown (; 0-64 v. 0·42), higher fractional degradation of particles > 1 mm (9·2 v. 5·1 %/h) and faster fractional disappearance of total DM from the rumen (10·2 v. 5·3 %/h). All three measurements for chicory were similar in deer that did or did not ruminate, but with perennial ryegrass, all values were considerably reduced in the deer that did not ruminate.

It was concluded that chicory can be broken down faster in the rumen, with less rumination being required than for perennial ryegrass, and that some deer (60%) could break down swallowed chicory to below the critical particle size without ruminating at all. The faster clearance of DM from the rumen explains the high voluntary feed intake (VFI) of deer grazing chicory. Future research needs to be done to partition rumen fractional disappearance rate into its components, rumen fractional degradation rate and rumen fractional outflow rate in deer fed chicory and perennial ryegrass.
Effect of thiourea on tuber yield of potatoes and uptake of phosphorus by tubers in the absence and presence of fertilizer phosphorus
Authors: Sud K. C. , Trehan S. P.
Published: March 2009

Field experiments were conducted at Fagu and Shimla in India in 1983 and 1984 to study the effect of thiourea (0 and 5 kg/ha) on tuber yield of potatoes and uptake of P with different rates of fertilizer P (0, 22, 33, 44 and 66 kg/ha). Application of phosphorus and thiourea, both alone and in combination, increased tuber yield and uptake of P significantly at both the locations in both years.
Interaction of molybdenum, phosphorus and potassium on yield in Vicia faba
Authors: Xia M. Z. , Xiong F. Q.
Published: March 2009

In pot and field experiments at Xichang, China, in 1984–85, (NH4)2MoO4 applied alone or with KH2PO4 to Vicia faba var. major increased total N, soluble sugar and chlorophyll contents and photosynthetic rate. The growth of root nodules and N fixation were stimulated, and more assimilate was distributed to seeds. Treatment with (NH4)2MoO4 combined with KH2PO4 gave the highest total N, soluble sugar and chlorophyll contents, the most root nodules, fruiting branches, fertile pods and seeds/plant and the highest 100-seed weight, and consequently produced the highest seed yield.
Straw and grain production in spring barley cultivars
Authors: White Ethel M.
Published: March 2009

Grain and straw yields of a range of spring barley cultivars were assessed in field experiments conducted from 1981 to 1983 in Northern Ireland. Mean straw yields varied between 2·75 t/ha in Inga and 1·94 t/ha in Golden Promise over the 3-year period. Both grain and straw yields varied from year to year, with straw production being more consistent for individual cultivars than grain yield. High grain yields were not associated with high straw yields, straw to grain ratios varying between 0·72 in Midas and 0·51 in Corgi. Neither grain yield nor straw length were good predictors of straw yield of cultivars. The role for and assessment of straw yield in cultivar evaluation is discussed.
Influence of growing various crops in five fixed cropping sequences on the changes in phosphorus and potassium content of soil
Authors: Sharma K. N. , Rana D. S. , Bhandari A. L.
Published: March 2009

The results on the influence of growing various crops in five fixed annual sequences on the changes in available and total phosphorus and potassium content of a Tolewal sandy loam (Typic Ustipsamment) are reported. The available phosphorus content showed an increase in each of the five crop rotations after completion of two cycles. The maximum increase was observed in groundnut-based cropping sequences whereas the increase under the other three rotations was more or less of the same order. A slight decrease in the available P content during the 3rd year was observed after the harvest of bajra in a bajra fodder–potato–wheat sequence which was replenished after the harvest of potato and wheat. Total P content of the soil also showed an increase in all five rotations after completion of two cycles. A decrease in total P content of the soil was also observed after the bajra harvest. Balance sheet of P indicated net gain of P in all five crop rotations and the maximum gain of 62 kg P/ha was observed in the maize–wheat–moong rotation. Theavailable K status of the soil showed an increase in each of the five cropping sequences after completion of two cycles. The available K status after harvest of various crops in the rotation could not fully explain the dynamics of K availability. The total soil K content indicated a negative K balance in each of the five crop rotations after completion of three cycles and the maximum negative balance occurred in a maize–wheat–moong sequence. The negative K balance was related to the amount of fertilizer K added and that removed by the crops. The results suggested the need for modifying the existing K fertilizer recommendations to compensate gradual loss of native K soil fertility.
Chemical properties of salt-affected soils in north Kent and their relationship to soil instability
Authors: Loveland P. J. , Hazelden J. , Sturdy R. G.
Published: March 2009

Soil instability, as measured by the dispersion ratios of the reclaimed salt-marsh soils of ca. 70 km2 of north Kent, was assessed on samples taken from 0–15, 35–50 and 70–85 cm depths from sites at the intersects of a 250 m square grid or along transects. The dispersion ratios were related to other soil properties including exchangeable sodium, potassium and magnesium percentages, organic carbon content, calcium carbonate content and electrical conductivity. The dispersion ratio correlates most closely with exchangeable sodium percentage and organic carbon content; weaker correlations exist with exchangeable potassium and calcium carbonate contents. Dispersion ratios rise sharply, i.e. reflect a marked increase in soil instability, when organic carbon content is less than 2·5% and calcium carbonate content is less than 2%. Magnesium has little effect on the dispersion ratio. The soil solution salt concentration (as expressed by electrical conductivity) is too low over much of the area to promote flocculation, and hence stability, of the soil clays.
Productivity of pigeonpea-wheat cropping systems
Authors: Singh K. A. , Pal Mahendra
Published: March 2009

Studies on productivity of pigeonpea-wheat cropping systems at the Indian Agricultural Research Institute, New Delhi during 1984–6 revealed that wheat following summer pigeonpea and given 120 kg N/ha produced 4–93, as compared with 451 t grain/ha when it succeeded kharif pigeonpea. Intercropping of preceding pigeonpea with dhaincha for green manure, fodder cowpea and greengram (grain) gave higher yields of 4·35, 397 and 3·68 t/ha respectively than the wheat following pigeonpea alone (3·20 t/ha). Similar effects on wheat straw were also recorded. Summer-sown pigeonpea produced 2·38 t grain/ha without any adverse effect of intercrops. However, kharif pigeonpea produced grain yield half of that obtained in the summer-sown crop. Further, the reductions in grain yield of kharif pigeonpea due to dhaincha, cowpea and greengram were 0·60, 0·52 and 030 t/ha, respectively. Summer pigeonpea + dhaincha-wheat and summer pigeonpea+greengram-wheat proved their superiority over other cropping systems.
Alkali investigations in the Sudan
Authors: Joseph A. F.
Published: March 2009

(1) The cotton growing area in the Gezira consists of a heavy clay soil, the proportion of clay being about 50–60 per cent. in the upper layers with a maximum at about the 4th foot.

(2) The water soluble salts amount to about 0·2 per cent. The proportion is highest at about the 3rd to 5th foot. The alkalinity (pH) is highest at the 2nd foot.

(3) In the first 2 feet, the salts consist mainly of sodium carbonate and the third and fourth of sodium sulphate.

(4) The irrigation (Blue Nile) water is of excellent quality as judged by its natural chemical composition. The concentrated water, however, contains a very high proportion of alkali salts. It is estimated that a season of normal irrigation would cause an increase of 0·01 per cent. in the alkali content of the first 4 feet of soil.

(5) The sodium salts can readily act on the clay and the sodium clay so formed hydrolyses with the formation of sodium carbonate.

(6) Samples taken at the same time from good and bad plots in the same area show a strong correlation between salt content and cropyielding power. There is also a correlation between pH and fertility.

(7) In the same season and in the same area, virgin (i.e. unirrigated) plots give a higher yield than those which have been previously under the same system of cultivation.
Dephenolisation in soil. II
Authors: Sen-Gupta Nagendra Nath
Published: March 2009

1. A number of soils—treated with acid and washed free from it—have been found to possess in high degree the power of destroying phenol. Soils derived from certain geological formations seem to possess this property more than those derived from others.

2. This effect has been obtained from soils treated with sulphuric, hydrochloric, nitric, phosphoric, formic, and acetic acids.

3. The bulk of the loss of phenol is instantaneous; but the maximum loss is attained within about 20 hours.

4. An inverse relation seems to exist between the period of contact of acid with soil and the extent of the subsequent loss of phenol.

5. The loss of phenol is prevente d by several treatments—ignition of soil before or after acid-treatment; treatment with alkalis or sulphurous acid after acid-treatment; autoclaving the soil after acid-treatment and also in less degree before acid-treatment.
Specific gravity, carcass fat and prediction of fatness in quail carcasses
Authors: Tserveni A. S. , Yannakopoulos A. L.
Published: March 2009

Carcass measurements including chemical composition and specific gravity data from 40 male and 40 female quails killed at 42 days of age were evaluated for use as an indirect means of estimating carcass fat. The results indicated that carcass fat was highly negative correlated to water (r = —0·93 and —0·87 for males and females, respectively) and that the inclusion of carcass protein improved the accuracy of prediction a little (r = -0·93 and -0·88). Carcass fat was only moderately related to specific gravity (r = —0·55 and —0·42) and the reliability as estimator of carcass fat was less than water or protein. Also, body weight was positively related to carcass fat (r = 0·71 and 0·42).
Effect of oestradiol-17β on energy metabolism of steers fed roughage diets
Authors: Hunter R. A. , Vercoe J. E.
Published: March 2009

In many areas of the world grazing cattle lose weight for part of the year because the dry standing pasture on offer is of poor quality and animals are unable to eat enough to meet their maintenance energy requirements. In countries where growth promoting anabolic agents are used, a perod of liveweight loss may coincide with the functional life of an implanted agent. There is evidence to suggest that diethylstilboestrol, a xenobiotic with oestrogenic activity, may increase maintenance energy requirements (Rumsey, Tyrrell & Moe, 1980). This has the effect of increasing the rate of live-weight loss under restricted submaintenance feeding conditions (Oltjen et al. 1973). One of the most common anabolic agents currently in use is the naturally occurring oestrogen, oestradiol-17β. However, its effects on energy requirements of animals either gaining or losing weight are unknown.
Response of lactating goats to low phosphorus intake 1. Milk yield and faecal excretion of P and Ca
Authors: Müschen H. , Petri A. , Breves G. , Pfeffer E.
Published: March 2009

In weeks 1–6 of lactation, 11 goats were fed diets adequate in phosphorus content, supplying a basal intake of 2·8 g P/day plus 1·4 g P/kg milk produced. In group 1 (three goats), this scheme was continued until week 16. In group 2 (four goats), P supply was changed from an adequate one to a reduced amount by restricting the variable intake to 1·0 g P/kg milk during weeks 7–16 and the basal intake to 0·8 g P/day during weeks 12–16. In group 3 (four goats), P deficiency was caused during weeks 7–11 by a basal intake of 0·8 g P/day plus only 0·4 g P/kg milk. During weeks 12–16 these goats received the same supply of P provided in weeks 1–6.

Milk yield was depressed in group 3, but not in group 2. Composition of milk was not affected by P intake in either group. Digestibility of organic matter was reduced from 0·73 to 0·64 by P deficiency treatment. Reduction of faecal P excretion in group 2 appeared to enable P homoeostasis even at the reduced level of P intake. The amounts of P and Ca secreted in milk during P deficiency in group 3 clearly exceeded the corresponding net absorptions. During this period, daily faecal P excretion was reduced to 17 mg/kg live weight. P concentrations in blood plasma, saliva and particle-free rumen fluid were also drastically reduced. Faecal excretion of P increased after the animals returned to the diet supplying adequate P. The increase occurred before the pre-depletion P status had been restored.
Brown, heart in swedes: a Cumbrian survey
Authors: Dermott W. , Trinder N.
Published: March 2009

1. A survey was made of swede fields in Cumberland and it was found that more than half the gross acreage was affected with Brown Heart to a greater or lesser extent.

2. The water-soluble boron content of soils from affected and non-affected fields was determined. In general the boron content of fields showing Brown Heart was less than 0·30 parts per million.

3. There is a close association between soil texture and the incidence of boron deficiency, a greater proportion of cases occurring on light soils.

4. Recent liming rather than the actual pH. level of the soil appears to be correlated with the occurrence of Brown Heart in the field.

5. It would appear that some prediction of the possibility of Brown Heart occurring might be made from a knowledge of the ‘available boron’ content of the soil taken in conjunction with such factors as the soil-texture and liming history of the field concerned.
Growth, yield and chemical composition of different oilseed crops as influenced by sodicity
Authors: Singh K. N. , Sharma D. K. , Chillar R. K.
Published: March 2009

An experiment was conducted during the rabi seasons of 1980–1 and 1981–2 to study the effect of exchangeable sodium percentage (ESP) of 87, 62, 44, 34 and 27 on growth, yield and chemical composition of toria (Brassica campestris var. Toria), raya (Brassica juncea L.) rapeseed (Brassica campestris var. Brown Sarson) and taramira (Eruca saliva). Number of branches per plant, number of siliquae per plant and seed yield of these crops were highest at 27 ESP. Increasing ESP decreased N, P, K, Ca, Mg, Fe, Zn, Cu and Mn concentrations and decreased that of Na in seed and stover. These crops can be grown successfully up to about 44 ESP without significant reduction in yield. Raya and rapeseed produced higher yields than the other oilseed crops on sodic soil.
Development of leaf spot caused by Ramularia carthami and reaction of safflower cultivars
Authors: Kumar A. , Joshif H. K.
Published: March 2009

Safflower (Carthamus tinctorius L.) is an important oilseed crop in India. A severe leaf spot disease caused by Ramularia carthami Zaprom. was observed in 1983 and investigations were carried out in order to analyse the role of environmental factors in disease development. High temperature and normal relative humidity, with dry rainless days, favoured disease development. Studies on the nature of in vivo resistance and susceptibility to R. carthami showed that growth of the fungal germ-tube was slower on resistant than on susceptible safflower cultivars, where the germ-tube extended with or without branching and penetrated infected leaves through the stomata. Of the four safflower cultivars evaluated, none were entirely free from the disease, but on the basis of lesion number and size, cultivar IGFRI-116 was rated as highly resistant.
Effect of short-term waterlogging on growth, yield and nutrient composition of wheat in alkaline soils
Authors: Sharma D. P. , Swarup A.
Published: March 2009

In a field study at exchangeable sodium percentage (ESP) values of 11 and 32, subjecting a wheat (Triticum aestivum L.) crop to waterlogging for 1, 2, 4 and 6 days at the time of first irrigation (25-day-old plants), significantly reduced tillering and plant height, delayed ear emergence and resulted in 8, 17, 27 and 39% reduction in grain yield, respectively. Waterlogging decreased oxygen diffusion rate (ODR), restricted root growth and reduced ion uptake, especially of N, P, K., Ca, Mg and Zn, and led to higher absorption of Na, Fe and Mn. However, the effects of waterlogging were more pronounced at higher alkalinity values. The results indicated that, to ensure optimum wheat yield in alkaline soils, waterlogging must be avoided.
Use of water by six grass species. 1. Dry-matter yields and response to irrigation
Authors: Garwood E. A. , Tyson K. C. , Sinclair J.
Published: March 2009

The yield and quality of herbage produced by six grasses (perennial ryegrass, cocksfoot, timothy, rough-stalked meadow grass, tall fescue and Italian ryegrass) were examined both without irrigation and under two irrigation regimes. Water was applied according to the potential soil water deficit (potential SWD): the soil was either partially returned to field capacity (FC) after each cut or fully returned to FC whenever the potential SWD reached 25 mm. The swards were cut either at 3 (C3) or 6 (C6) week intervals over a 2 year period.

Partial irrigation increased yields by 12–14% in the first year and by 36–58% in the second. Full irrigation produced little more growth than partial irrigation in the first year (maximum SWD, 188 mm) but increased yield by 78–93% in the second, very dry, year (maximum SWD, 311 mm). Under treatment C3 response per unit of water applied was similar with both partial and full irrigation, but under C6 the response was greater with partial (2·86 kg D.M./m3) than with full irrigation (1·79 kg D.M./m3).

There were marked differences between the species in their ability to grow under drought conditions in the second year of the experiment. Without irrigation, roughstalked meadow grass and Italian ryegrass did not survive the drought. The performance of tall fescue was markedly superior to both perennial ryegrass and cocksfoot in these conditions. Of the surviving grasses timothy made least growth.
Effects of season, sowing date, nitrogenous fertilizer and insecticide spraying on the incidence of insect pests on cotton in the Sudan Gezira
Authors: Jackson J. E. , Burhan H. O. , Hassan H. M.
Published: March 2009

The effects of the sowing date of cotton and application of nitrogenous fertilizer to it on the incidence of insect pests were investigated over a 5-year period. Response to frequent insecticide spraying was also determined and the results were related to previously reported interactions between nitrogen, sowing date and insecticide application in their effects on yield and its year-to-year variation. Numbers of jassids (Empoasca lybica de Berg) and whiteflies (Bemisia tabaci Genn) were considerably greater on the fertilized plots. The pattern of pest population change over the season varied with sowing date and also from year to year as did the relative numbers of jassids and whiteflies. Effects of spraying on the yield obtained under different agronomic treatments and in different years were clearly related to effects on numbers of insect pests.
Root biomass in timothy and red clover leys estimated by soil coring and mesh bags
Authors: Steen E.
Published: March 2009

Root biomass of timothy grass (Phleum pratense L.), at low and high N fertilization rates, and of red clover (Trifolium pratense L.) were estimated with soil cores and in mesh bags in a field trial on a sandy loam in central Sweden. First and second full-harvest year leys were sampled three times each year from May to October. Mesh bags were inserted in the soil in autumn shortly after sowing (longterm bags); in spring and autumn of the first year and in spring of the second year (medium-term bags); and every third month during both years (short-term bags). Mesh bags of each type were sampled when the soil cores were taken.

Root biomass in the long-term bags was generally about the same as that in the soil cores, but taproot biomass in the clover crop was underestimated in the bags. In the grass plots, differences between soil cores and mesh bags were probably caused by ingrowth of weed roots in bags and by larger root biomass in plant rows than between rows. If soil cores and long-term mesh bags are sampled in exactly the same way identical estimates of biomass should be obtained.

Root biomass in short-term and medium-term bags was about the same as that in the soil cores and long-term bags on many of the sampling occasions. Thus a stable level of biomass was reached in a rather short time, i.e. after 3 months or less. Then root production, root mortality and root decomposition occurred simultaneously at a fairly constant level.

The bags did not contain residues from earlier crops, which reduced the amount of separation work necessary. The absence of crop residues in the bags did not seem to affect root biomass.

The mesh bag method is a useful alternative to soil core sampling for studying root biomass and root dynamics in perennial and annual crops. However, the bags must be inserted into the soil just after sowing and they must be placed in, as well as between, plant rows.
The prediction of body composition in live ewes in early lactation from live weight and estimates of gut contents and total body water
Authors: Cowan R. T. , Robinson J. J. , McHattie I. , Fraser C.
Published: March 2009

The efficacy of estimates of gut contents and total body water in increasing the precision with which the chemical composition of the body could be estimated in early lactation was evaluated in 36 Finnish Landrace × Dorset Horn ewes. The ewes were fed at two levels in pregnancy, and, in lactation, given diets of two metabolizable energy concentrations.

The allometric relationships relating weight of chemical fat and protein to emptybody weight were not affected by treatment or stage of lactation. Inclusion of an index of gut contents, based on dry-matter intake, indigestibility and retention time of food residues, together with live weight in a regression equation predicting weight of body fat, only slightly increased the precision of estimate compared with equations using live weight alone.

There was a close negative relationship between the proportions of water and fat in live weight. Inclusion of weight of body water with live weight in a regression equation predicting weight of body fat markedly increased the precision of estimate and the residual error (0·81 kg) was similar at different stages of lactation. However, when deuterium oxide space was used instead of body water there was only a small increase in precision of estimate and the residual error varied from 5·3 kg in early lactation to 2·1 kg in mid-lactation. The relationship between deuterium oxide space and body water was shown to be variable and altered by stage of lactation, and these differences were associated with differences in rate of water turnover in the animal's body.

It is concluded that estimates of body water are unsuitable for estimating weight of body fat in early lactation.
A labour-saving system of yam (Dioscorea spp.) production through weed control with herbicides, the elimination of staking, and cropping at high density
Authors: Onwueme I. C. , Fadayomi O.
Published: March 2009

Experiments were made over a 3-year period in order to evolve a production package for yam that would eliminate the laborious operations of hand weeding and staking. First, nine herbicides were applied to yam plots before or after yam emergence. On the basis of weed control effectiveness and low phytotoxicity to yam plants, ametryne (2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-S-triazine) was chosen for subsequent experimentation. Next, ametryne at 2, 4 or 6 kg/ha was applied to yam plots either immediately after planting, or with 1 kg/ha paraqviat (l, 1'-dimethyl-4,4'- bipyridinium ion) 3 weeks after planting. The delayed applications gave more effective weed control and higher yields than the early applications. For the delayed application, 4 and 6 kg ametryne/ha did not give significantly different yields, but yielded significantly more than 2 kg/ha. When a combination of ametryne at 4 kg/ha and paraquat at 1 kg/ha was applied 3, 6 or 9 weeks after planting, the weed control effectiveness was greatest at 6 weeks after planting while the 3- and 6-week applications did not give significantly different yields. Herbicide applied 9 weeks after planting gave the poorest weed control and the lowest yields.

Finally comparisons were made between the conventional staked, hand-weeded yam production, and a new production package in which the yams were not staked and weeds were controlled with ametryne (4 kg/ha) + paraquat (1kg/ha) applied at or just before emergence. When small (150g) setts were used, yields from the new package were not significantly lower than those from the conventional system, even though the new package was considerably less laborious. Cultivation with large setts, however, resulted in a decrease in yield when the plants were not staked. Strategies that could further enhance the attractiveness of the new production
Growth and water relations of diverse populations of Lolium perenne exposed to drought in field, glasshouse and controlled environment
Authors: Amin Md R. , Thomas H.
Published: March 2009

Nineteen populations of Lolium perenne were grown near Aberystwyth as small plots (sown in 1988) in the field, and as pot plants (sown in 1989) in the glasshouse and controlled environment (CE). In the summer of 1989 they were subjected to drought, and then rewatered. Herbage growth and water relations characters were measured. There was significant diversity between populations (narrowsense heritability) for: herbage production and yield stability before, during and after drought; tillering; osmotic potential and adjustment; tissue water content; and membrane stability (MS) following heat shock. There were no such differences in leaf water conductance, MS following desiccation shock, or chlorophyll stability under osmotic stress. The range of expression of characters was very different in the three environments, as was the ranking of populations, emphasising the danger of working in unnatural environments. Correlation analysis revealed no relationships between growth and physiological characters that were consistent across environments. Nevertheless, hierarchical cluster analysis indicated that some populations having a ‘hay-type’ morphology performed well over all three environments, and merit further study.
Rethinking child difficulty: The effect of NP type on children's processing of relative clauses in Hebrew
Authors: ARNON INBAL
Published: March 2009

Children find object relative clauses difficult. They show poor comprehension that lags behind production into their fifth year. This finding has shaped models of relative clause acquisition, with appeals to processing heuristics or syntactic preferences to explain why object relatives are more difficult than subject relatives. Two studies here suggest that children (age 4 ; 6) do not find all object relatives difficult: a corpus study shows that children most often hear and produce object relatives with pronominal subjects. But they are most often tested on ones with lexical-NP subjects (e.g.The nurse thatthe girlis drawing). When tested on object relatives with pronominal subjects (e.g.The nurse thatIam drawing), similar to those they actually hear and produce, Hebrew speakers aged 4 ; 6 show good comprehension (85% accuracy) that matches their production ability. This suggests a different path of relative clause acquisition, one that is sensitive to fine-grained distributional information.
Civic Solidarity in Hong Kong and Taiwan
Authors: Lo Ming-Cheng Miriam , Bettinger Christopher P.
Published: March 2009

This study examines civic solidarity in Hong Kong and Taiwan at key democratic moments. Using political cartoons published during the 1995 LegCo election campaign in Hong Kong and the 2000 presidential election campaign in Taiwan, our findings indicate that the cultural codes of liberty, though not typically considered part of traditional Chinese values, have become the dominant cultural source for discourse in civil society. Values of caring and state paternalism, which resemble subsets of Confucian values, exist as competing, alternate cultural codes. In Taiwan, politically-divided members of civil society appear to share the same cultural language, thereby fostering a basis for mutual engagement. Nevertheless, little mutual engagement is actually found among politically divergent discourses. In Hong Kong, even a shared cultural language cannot be documented. The conclusion discusses the broader implications of these findings for the inclusive potential of civic discourses, amidst competing identity claims, in Hong Kong and Taiwan.
Theory and Practice: A Jewish Physician in Paris and Avignon
Authors: Einbinder Susan
Published: March 2009

Not otherwise known as a bright era for the Jews of Christian Europe, the late fourteenth century nonetheless counted a number of thriving Jewish medical careers. One physician who surfaced in this period was Jacob b. Solomon of Avignon (sometimes called Jacob b. Solomon haTzarfati), whose career has been documented in two cities. In northern France, the land of his ancestors, we find him in the 1370s in the orbit of the University of Paris and its prestigious medical faculty. By the early 1380s, however, Jacob was at the papal court in Avignon, where or near where he was raised. There, in his own day at least, he achieved some renown while serving as physician to Pope Clement VII's brother, Count Pierre of Geneva.
A simple model for simulating immunity rate dynamics in a tropical free-range poultry population after avian influenza vaccination
Authors: LESNOFF M. , PEYRE M. , DUARTE P. C. , RENARD J.-F. , MARINER J. C.
Published: March 2009

In developing countries, vaccination against highly pathogenic avian influenza subtype H5N1 (HPAI) in free-range poultry flocks is usually implemented as periodic campaigns and newborn chicks are generally not vaccinated by farmers between vaccination passes. The demographic population turnover leads to a continuous decrease in the population immunity rate (PIR) over time. We present a simple Leslie matrix model for estimating population turnover and PIR dynamics in a hypothetical small-size vaccinated free-range poultry population. Four different vaccination scenarios were identified assuming necessary procedures to achieve immunity. The results indicate that high levels of population immunity are difficult to sustain. Assuming an animal immunity response of 80% after vaccination and a constant population size, PIR 4 months after vaccination was ⩽30% in all the scenarios. Predictions averaged over time showed mean PIR between 36% and 48%, which is below the population immunity thresholds for eradication approximated fromR0estimates.
Elective affinities? Human rights and humanitarian law
Authors: Droege Cordula
Published: March 2009

Complementarity and mutual influence inform the interaction between international humanitarian law and international human rights law in most cases. In some cases when there is contradiction between the two bodies of law, the more specific norm takes precedence (lex specialis). The author analyses the question of in which situations either body of law is more specific. She also considers the procedural dimension of this interplay, in particular concerning the rules governing investigations into alleged violations, court access for alleged victims and reparations for wrongdoing.
There's no place like home: states' obligations in relation to transfers of persons
Authors: Gillard Emanuela-Chiara
Published: March 2009

The article sets out states' obligations in relation to transfers of persons under international law, and revisits the key elements of the principled non-refoulement, including its application where persons are transferred from one state to another within the territory of a single state; the range of risks that give rise to application of the principle; important procedural elements; and the impact on the principle of so called diplomatic assurances.

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Impact of submesoscale variability in estimating the air‐sea CO2 exchange: Results from a model study of the POMME experiment
Authors: Resplandy L. , Lévy M. , d'Ovidio F. , Merlivat L.
Published: March 2009

A high‐resolution ocean biogeochemical model is used to estimate oceanic pCO2 and air‐sea CO2 flux in the NE Atlantic. The model is validated against shipboard and Carioca drifting float data acquired during the POMME experiment. Between winter and spring, the seasonal variability is characterized by a rapid drawdown of pCO2 of ∼20 μatm associated with the phytoplankton bloom driving CO2 uptake by the ocean. The model reveals that this uptake propagates northward in response to the northward propagation of the bloom. More remarkably, this study demonstrates intense variability of the carbon system at the submesoscale. Our model predicts filamentary structures of pCO2 that show gradients of 25 μatm over 20 km, consistent with observations from Carioca drifting floats. This submesoscale variability is similar in magnitude to the mean seasonal drawdown. Lagrangian diagnostics suggest that pCO2 small‐scale structures are shaped by horizontal stirring of large‐scale gradients created by the bloom northward propagation. We compared air‐sea flux derived from model pCO2 and from observed pCO2 and estimated the error due to data undersampling to ∼15 to 30%. Results from a simulation at coarser resolution showed that the impact of model resolution on air‐sea CO2 flux is only ∼5%. This suggests that the submesoscale variability of pCO2, although large in amplitude, accounts for small modulation of the net air‐sea CO2 flux in this region.
Transionospheric attenuation of 100 kHz radio waves inferred from satellite and ground based observations
Authors: Fullekrug Martin , Parrot Michel , Ash Matthew , Astin Ivan , Williams Paul , Talhi R.
Published: March 2009

Around fifty LORAN (LOng RAnge Navigation) transmitters in the northern hemisphere currently launch continuously pulsed 100 kHz radio waves into the Earth's atmosphere for marine navigation. It is discovered that the 100 kHz radio waves from the LORAN transmissions can be detected by the DEMETER satellite at an altitude of ∼660 km above the transmitters. These novel electric field measurements in space enable the determination of the nocturnal transionospheric attenuation by comparison with ground based electric field measurements. The electric field measurements on the satellite indicate that the nocturnal transionospheric attenuation of 100 kHz radio waves from LORAN transmissions is equivalent to a nocturnal subionospheric attenuation of the 100 kHz radio waves at a distance of ∼7–9 Mm. The radio waves exhibit an average subionospheric attenuation of ∼5 dB/Mm and it is concluded that the nocturnal transionospheric attenuation of 100 kHz radio waves is ∼35–45 dB. This result enables future space missions to quantify the intensity of lightning discharges associated with transient luminous events and terrestrial γ‐ray flashes.
Phase relations of Fe‐Si alloy in Earth's core
Authors: Lin Jung‐Fu , Scott Henry P. , Fischer Rebecca A. , Chang Yun‐Yuan , Kantor Innokenty , Prakapenka Vitali B.
Published: March 2009

Phase relations of an Fe0.85Si0.15 alloy were investigated up to 240 GPa and 3000 K using in situ X‐ray diffraction in a laser‐heated diamond anvil cell. An alloy of this composition as starting material is found to result in a stabilized mixture of Si‐rich bcc and Si‐poor hcp Fe‐Si phases up to at least 150 GPa and 3000 K, whereas only hcp‐Fe0.85Si0.15 is found to be stable between approximately 170 GPa and 240 GPa at high temperatures. Our extended results indicate that Fe0.85Si0.15 alloy is likely to have the hcp structure in the inner core, instead of the previously proposed mixture of hcp and bcc phases. Due to the volumetric dominance of the hcp phase in the hcp + bcc coexistence region close to the outer‐core conditions, the dense closest‐packed Fe‐Si liquid is more relevant to understanding the properties of the outer core.