bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, yield and water use of lentils (Lens culinaris) in Canterbury, New Zealand
Authors: McKenzie B. A. , Hill G. D.
Published: March 2009

Lentils (Lens culinaris Medik.) were sown on eight sowing dates from April to November in two seasons in Canterbury, New Zealand. In 1984/85, six sowing dates were combined with two lentil cultivars (Olympic and Titore) and two irrigation treatments. In 1985/86, Titore was sown on two dates, with four irrigation treatments. An additional experiment grown under rain shelters examined the response of Titore to four irrigation regimes. The 1984/85 season was dry and rainfall was only 70% of the long-term mean. In this season, seed yield was high, 3·3 t/ha from the May sowing. The 1985/86 season was wetter than average and seed yields were lower, ranging from 0·6 to 1·5 t/ha. Under rain shelters, seed yield ranged from the equivalent of 0·32 to 2·5 t/ha.

Sowing date had the most marked effect on seed yield. In the 1984/85 season, all autumn and winter sowings yielded 2·4–3·3 t/ha, whereas the spring sowings yielded 0·5–1·5 t/ha. In 1985/86, unirrigated plots from the May sowing yielded 1·5 t/ha, whereas all other plots yielded c. 0·8 t/ha.

Generally, the small-seeded cultivar Titore outyielded Olympic. Dry matter (DM) accumulation followed similar trends to seed yield. Seasonal DM accumulation followed a sigmoidal curve. Functional growth analysis indicated that plants from autumn/winter sowings had a weighted mean absolute growth rate of 110–171 kg/ha per day, whereas spring-sown plants grew at 96–137 kg/ha per day. The maximum crop growth rate was 230 kg/ha per day in the July 1984 sowing.

There was little positive response to irrigation in both seasons. Under rain shelters, there was a linear increase in both dry matter and seed production with increased total water. Fully irrigated plants produced 1·27 g DM and 0·72 g seed/m2 per mm of water received.

In the field experiments there was no relationship between maximum potential soil moisture deficit (D) and yield. Under rain shelters, however, there was a linear relationship which indicated a limiting deficit of c. 130 mm. The relationship showed that, for each millimetre increase in D above D1, 0·39% of the maximum yield was lost.

Under the rain shelters, there was a strong relationship between yield and actual evapotranspiration (ET). Water-use efficiency (WUE) ranged from 2·81 g DM/m2 per mm ET in unirrigated plots to 0·69 g seed/m2 per mm ET.

The results showed that lentil growers in Canterbury, and presumably in similar environments, are unlikely to benefit from irrigating their crops. In such environments, lentils appear to be an ideal dryland crop.
Effect of water stress on potato growth, yield and water use in a hot and a cool tropical climate
Authors: Trebejo I. , Midmore D. J.
Published: March 2009

Irrigation experiments are described in which three cultivars were subjected to varying degrees of drought in the cool and hot seasons in Lima, Peru. The most severely draughted plots received, on average, 20% and 35% less water than the well-watered control plots, resulting in 20% and 52% yield reduction in the cool and hot seasons, respectively. Average fresh tuber yields ranged, according to cultivar, from 1370 to 2450 g/m2in the summer and from 2800 to 4450 g/m2in the winter, with tuber dry-matter percentages ofc. 17% and 20%, respectively. The production of total dry matter per unit intercepted solar radiation (the conversion coefficient, estimated from the slope of the regression, in g/MJ) was markedly less during the hot season but, regressed on a photo thermal quotient ∑((MJ/m2)/(°C > 4·5°C)), a common relationship across seasons was achieved. The conversion coefficient was less in draughted than in well-watered plots, more so in the hot season.

Crop transpirational and evapotranspirational water use efficiencies (WUE) were less in the hot season largely because of the greater saturation vapour-pressure deficit. However, because of greater harvest index (HI) and more-efficient interception of solar radiation per unit of applied water by draughted than by well-watered plots in the summer, and despite a lower conversion coefficient, draughted plots showed greater WUE. Based on total water applied and final fresh tuber yields, WUE was, on average, 3·9 and 12·4 kg/m3in the hot and cool seasons, respectively, values close to the extremes of the range of published values. Low HI in the summer was, to some extent, responsible for this seasonal difference.
Response of Egyptian cotton (Gossypium barbadense) yield to 1,1-dimethyl piperidinium chloride (Pix)
Authors: Sawan Z. M. , Sakr R. A.
Published: March 2009

Two field experiments were conducted in Egypt in 1985 and 1986 to examine the responses of yield and its components and fibre quality in the Egyptian cotton cultivar Giza 75 to the spray application of 0, 10, 20, 40, 60, 80, and 100 mg of 1,1-dimethyl piperidinium chloride (Pix)/litre at 90 days or at 90 and 110 days after sowing. Number of opened bolls/plant, boll weight, seed and lint index, seed cotton yield/plant, seed cotton and lint yield/ha and yield earliness increased, but lint percentage decreased after Pix application. The number of opened bolls/plant increased after one application, but there was no effect from a further application. There were no effects of concentration or number of applications of Pix on any fibre property.
Modelling the effects of sowing date and plant density on the yield and timing of development of Brussels sprouts (Brassica oleracea)
Authors: Hamer P. J. C.
Published: March 2009

The effect of sowing date and plant density are modelled in relation to three variables: Ym, the maximum yield the crop can produce; τ, the interval from sowing to Yb/Ym = 0·5 where Yb is the yield of Brussels sprout buttons and Nb, the number of buttons on a plant stem. Ym is well related to the quantity of solar energy which the crop intercepts during the main period of growth. The fraction of radiation intercepted by the crop canopy is related to leaf area index (L) and sub-models relate L to sowing date and plant density. An empirically derived parameter relates the value of τ to thermal time and photoperiod time. The time course of Nb is modelled relative to the number of buttons at the end of the growing season. To overcome influence of site, variety and season, a generalized equation relates Nb, to plant density and a ‘known’ number of buttons at a specified planting density. The yield of buttons in specific size ranges (required for marketing) is described by a normal distribution with the standard deviation (σ) representing the spread of button diameter. There were no obvious effects of sowing date and plant density on σ. The model enables the effects of sowing date and plant density to be simulated using only simple and easily understood parameters. A sample simulation is presented.
An induced mutant with extended vegetative phase in stem nodulating Sesbania rostrata
Authors: Joshua D. C. , Ramani S.
Published: March 2009

The flowering response of a late-flowering mutant of Sesbania rostrata was compared with that of the parent plants by sowing it on ten different dates, from December 1990 to September 1991, in India. Flowering response was also studied following exposure to an 8-h photoperiod at four different stages of growth. The parent flowered at different times of the year depending on the time of sowing, while the mutant flowered only during October–November irrespective of sowing date. The parent was sensitive to a short-day photoperiod as early as 15 days after sowing, but the mutant became sensitive to the critical photoperiod only after 60 days of vegetative growth. The mutant, by virtue of its longer vegetative phase, had the potential to produce adequate phytomass irrespective of the time of sowing.
Use of prolonged-release bovine somatotropin for milk production in British Friesian dairy cows. 2. Effect on health and reproduction in two consecutive lactations of treatment
Authors: Weller R. F. , Phipps R. H. , Craven N. , Peel C. J.
Published: March 2009

There were 45 cows in each of the control and treated groups in the first lactation of the study and, of these, 30 cows in each group received the same treatment for a second lactation. The study was conducted during the winters of 1985/86 and 1986/87. Injections of either bovine somatotropin (BST) or a placebo were started at day 60±3 post partum and repeated at fortnightly intervals for the remainder of each lactation.

Body temperature and heart and respiration rates were unaffected by the administration of BST. Minor abnormalities were noted in individual animals in both groups, hygromata of the tarsus or carpus being most common. However, no health problems could be related to treatment. There was no evidence that the administration of BST increased the incidence of metabolic disorders. Ketosis was not observed in either lactation.
Effects of temperature and diet on the water and energy metabolism of growing rabbits
Authors: Jin L. M. , Thomson E. , Farrell D. J.
Published: March 2009

Water and energy metabolism were measured in six growing female New Zealand White rabbits placed individually in metabolism cages within chambers at 20 or 30 °C and offered a diet high (H) or low (L) in roughage. For water balance measurements, feed intake was higher at 20 °C than at 30 °C; mean water balance of rabbits on diet L was 7 g/day at 20 °C and 36 g/day at 30 °C. Total daily water consumption was 84–96 g/kg body weight (W), and the ratio of free water to feed intake was 1·6:1 at 20 °C and 2·3:1 at 30 °C.

Calorimetric measurements showed no differences in energy metabolism of rabbits due to diet or temperature. Metabolizable energy needed for maintenance was 357 kJ/kg W0·75 per day and was used with an efficiency of 0·44 for weight gain.
Differences in barley grain yields as a result of soil variability
Authors: Finke P. A. , Goense D.
Published: March 2009

Field scale variability in the grain yield of barley in 1989 was investigated in 62 field plots in a Dutch polder area, and compared to soil- and simulation-type characteristics. Total grain mass varied between 3409 and 6019 kg/ha, and grain moisture content between 131 and 14·7%. Soil profile descriptions and soil characteristics were used as basic input data for simulations. Soil water flow was simulated at 119 locations with the LEACHM model, for the purpose of quantifying spatial variability in transpiration deficits in the growing season. Both soil- and simulation-type characteristics were translated from point values to spatial averages for the harvested fields, using kriging. Kriged characteristics were correlated with yields, and used to construct transfer functions. Simulated transpiration deficits during sensitive crop development phases showed negative correlations with grain yield. Transfer functions explained at maximum 68·2% of the variance in the yields.
Influence of planting seed tubers with gangrene(Phoma foveata) and of neighbouring healthy, diseased and missing plants on the yield and size of potatoes
Authors: Hide G. A. , Welham S. J. , Read P. J. , Ainsley A. E.
Published: March 2009

Potato seed tubers infected or not infected with gangrene (Phoma foveata) were planted at Rothatnsted in 1987 to measure the effect of the disease and of neighbouring plants on yield. The experimental design was constructed so that the effect on growth of six adjacent plants (two nearest neighbours in each direction within rows and one nearest neighbour in each direction across rows) could be estimated for each plant. Total yield, ware (> 150 g) yield and tuber number from individual plants were affected most by the disease but also, in decreasing importance, by the two plants on either side within the same row (first neighbours), the two plants adjacent to the first neighbours (second neighbours) and the two adjacent plants in the rows on either side. Yield and tuber numbers increased as the different combinations of neighbouring plants contained increasing proportions of plants from diseased seed and missing plants; plants compensated for decreasing competition. Tuber size distributions showed that numbers of ware tubers decreased with increasing competition whereas numbers of small tubers were less affected. The fitted model was used to predict yields from crops planted with different proportions of diseased or missing seed tubers.
Effect of chronic cold exposure and underfeeding on hind-limb tissue metabolism in pregnant sheep
Authors: Symonds M. E. , Lomax M. A.
Published: March 2009

Muscle metabolism was studied in pregnant sheep over the final 4 weeks of pregnancy, between January and March 1985 and between December and March 1986, to investigate the effect of (i) chronic cold exposure, induced by shearing pregnant ewes 8 weeks before lambing and (ii) undernutrition in shorn and unshorn ewes. This was achieved by measuring hind-limb tissue metabolism using a combination of isotopic and arterio–venous difference techniques.

The rates of blood flow, oxygen uptake, carbon dioxide production and calculated heat production were all significantly higher across the hind-limb tissues in shorn than in unshorn ewes. The increase in hind-limb energy metabolism in the shorn group was such that 65% of the difference in wholebody heat production between shorn and unshorn groups could be attributed to muscle tissue. Following underfeeding, all of the difference in whole-body heat production between the two groups was completely attributable to muscle tissue.

Nonesterified fatty acid (NEFA) oxidation by muscle accounted for 46% of the difference in whole-body NEFA oxidation rate between fed shorn and unshorn groups. Underfeeding significantly increased the mean arterial plasma concentration of NEFA in shorn and unshorn ewes and the rate of NEFA oxidation across the hind-limb tissues in shorn ewes. The difference in whole-body NEFA oxidation between shorn and unshorn groups could, therefore, be completely accounted for by muscle. No significant differences in the arterial plasma concentrations of glucose, lactate or 3-hydroxybutyrate were recorded between shorn and unshorn ewes, although the rate of glucose uptake across the hind-limb tissued was significantly higher in the shorn group. Calculation of the maximum potential contribution of these substrates to hind-limb metabolism demonstrated that NEFA were the predominant energy source in all experimental conditions studied in all ewes. When data from fed and underfed shorn ewes were pooled, regression analysis revealed a significant negative correlation between the arterial plasma concentrations of glucose and 3-hydroxybutyrate, and significant positive relationships between the arterial concentrations of both glucose and 3-hydroxybutyrate and their rate of uptake across the hind-limb tissues. These relationsips were not observed in unshorn ewes.

It is concluded that the muscle mass plays a major role in the nonshivering thermogenic adaptation to chronic cold exposure in shorn pregnant sheep and that NEFA are the major substrate utilized for oxidative metabolism in this tissue.
Estimation of plant cell wall thickness and cell size by image skeletonization
Authors: Travis A. J. , Murison S. D. , Chesson A.
Published: March 2009

A system for automatically measuring the mean cell-wall thickness in a user-defined area of plant tissue has been developed using image analysis. The digitized grey-level image of a tissue section is first segmented using a histogram-partitioning algorithm. The resulting binary image is then repeatedly thinned until the minimum connected set of pixels, or ‘skeleton’, remains. A nearestneighbour length estimator is used to calculate the total length of the skeleton which approximates to the location of the middle lamella in the original section. The length of the skeleton and the number of nodes it contains are used to estimate the mean cell radius, and mean cell-wall thickness using the area of cell-wall material in the segmented binary image. The method has been used to estimate mean cell-wall thickness along a newly extendedZea maysinternode, and the results are compared to measurements obtained manually using a micrometer ‘line’. The techniques of rapidly assessing mean cell-wall thickness and cell dimensions using image analysis are needed to assess how much of the variation in nutritive value between forage cultivars can be ascribed to changes in cell-wall chemistry and how much to anatomical differences.
Cross resistance between water and oxidative stresses in wheat leaves
Authors: Pastori G. M. , Trippi V. S.
Published: March 2009

Seven-day-old leaves of two wheat cultivars, one resistant (Cruz Alta) and one sensitive (Leones) to water stress were subjected to 100% O2 and water stress in the light for 72 h. The aim of this work was to analyse the effects of both types of stress on the chloroplast antioxidant enzymes, glutathione reductase (GR) and ascorbate peroxidase (AP) and their relationship with stress resistance.

Both GR and AP increased following 100% O2 and water stress in the resistant cultivar Cruz Alta only. Sulphydryl (SH) groups increased in the resistant cultivar and decreased significantly in the sensitive one under both stress treatments. Measurement of stress parameters (chlorophylls, proteins, lipid peroxidation and conductivity) revealed that oxidations caused by stress treatments appeared to be higher in the sensitive cultivar Leones than in the resistant Cruz Alta.

It is suggested that there may be a link between GR, AP and oxidative protection. Some cross resistance between water and oxidative stresses in wheat leaves is also indicated.
Digestion by sheep of silages prepared from mixtures of tropical grasses and legumes
Authors: Tjandraatmadja M. , MacRae I. C. , Norton B. W.
Published: March 2009

Four silage diets were prepared from tropical grass and legume mixtures and fed to intestinally fistulated sheep to determine the sites and extent of digestion of the different silage components in the digestive tract. Pangola grass (Digitaria decumbens) was ensiled either alone or with the addition, 33% (w/w), of leucaena (Leucaena leucocephala cv. Cunningham), gliricidia (Gliricidia sepium) or cowpea (Vigna unguiculata cv. Caloona). All forages were grown at the University of Queensland farm in 1985. All silages were well preserved as indicated by low pH (< 4·1), ammonia N (< 9% total N), acetic acid (< 13 g/kg dry matter (DM)) and ethanol (< 19 g/kg DM) contents, and high DM (> 290 g/kg) and lactic acid (> 41 g/kg DM) contents. The inclusion of leucaena and gliricidia significantly increased the total N content of the silages. The addition of legumes at ensiling significantly increased rumen ammonia N (pangola 59 mg N/l, legume diets 110–115 mg N/l) and the proportion of propionic acid in rumen fluid. Sheep given pangola + leucaena silages had significantly higher DM intakes (66·3 g/kg W0·75 per day) than sheep given pangola and pangola + cowpea silages (52·4 and 53·2 g/kg W0·75 per day respectively). The inclusion of gliricidia significantly depressed silage intake (43·1 g/kg W0·75 per day). There were no significant effects of diet on DM (551–609 g/kg) and organic matter (550–612 g/rkg) digestibility. Sheep given pangola + leucaena silages had higher N intakes, N balances, rates and efficiencies of microbial N synthesis and total non-ammonia N (NAN) flows to the small intestine than did sheep given the other silages. Apparent degradabilities of silage N in the rumen were similar for all diets (0·491–0·559 g N/kg N intake), but sheep given pangola + leucaena silages had lower true (corrected for endogenous N) N degradabilities (0·648 g N/kg N intake) than those given the other diets (0·751–0·775 g N/kg N intake). The values obtained in this experiment were compared with those reported for temperate grass silages, and it was concluded that whilst the digestibility of tropical grass/legume silages was low, intakes and rumen fermentation characteristics were similar to those found for temperate grass silages.
Grass yield in relation to potassium supply and the concentration of cations in tissue water
Authors: Barraclough P. B. , Leigh R. A.
Published: March 2009

A long-term field experiment on permanent grass at Rothamsted (UK) was studied between 1988 and 1991 to determine the relationship between soil and plant K and to identify critical soil and plant concentrations for grass yield. Maximum dry matter yield was obtained at a soil exchangeable K concentration (Kex) of 114 mg/kg dry soil (45 μм-K in the soil solution). Grass well-supplied with K maintained an average concentration ofc.200 m м-K in the tissue water of whole shoots in spring, although individual measurements varied in the range 140–320 mм, depending largely on the soil water availability. These tissue concentrations were not exceeded in soils with Kexvalues up to 800 mg/kg. Yield was reduced by 60% on plots low in K (Kexin the range 60–90 mg/kg). The yield reductions were probably due to low turgor because tissue osmotic pressures were low and potassium concentrations in tissue water (which averaged 64 mм) were probably too high to disrupt the biochemical functions of K. The results suggest that there is no universal critical tissue water concentration for K in the biophysical role of turgor maintenance, as other cations and solutes are able to substitute for it. The ultimate determinant of turgor-dependent yield loss is tissue osmotic pressure. The critical tissue osmotic pressure in grass shoots in a typical season at Rothamsted wasc.400 mosm/kg. No universal critical osmotic pressure can be expected however, as this will depend on the availability of water and therefore on growing conditions.
Internodal invertases and stalk maturity in sugarcane
Authors: Sehtiya H. L. , Dendsay J. P. S. , Dhawan A. K.
Published: March 2009

Acid and neutral invertase activities in the stem of an early (CoJ 64) and a late cultivar (Col 148) of sugarcane were estimated by incubating stem slices in buffered sucrose solution and measuring the production of reducing sugars. High enzyme activity occurred in young tissue but the activity of both enzymes was considerably lower in the mature internodes. Acid and neutral invertase activity was highest in the midinternode position, corresponding to the region of cell expansion.
Effects of subsoiling and associated incorporation of fertilizer on soil rehabilitation after opencast mining for coal
Authors: Scullion J. , Mohammed A. R. A.
Published: March 2009

A trial was set up in South Wales in 1980 on land replaced in 1972 after opencast coal mining, to assess the effects on soil rehabilitation of regular subsoiling, through an established sward, with and without incorporation of a ‘semi-organic’ fertilizer into subsoiling slots. Treatments were assessed on the basis of yield, soil structure indices, root and organic contents and earthworm population densities. Apart from yields, data are for the eighth year of the experiment (1987), 18 months after the fourth programme of treatments.

Treatments did not markedly affect productivity, although it tended to be higher with subsoiling and fertilizer incorporation. Subsoiling had little effect on root and organic content, but fertilizer incorporation increased the latter, particularly at depth. Earthworm population densities were markedly higher on subsoiled areas, the increase in the deeper burrowing speciesAporrectodea caliginosabeing largest. Fertilizer incorporation increased abundance ofLumbricus rubellus, but had little effect on other species. Subsoiling reduced surface wetness, but did not result in any significant improvement in structure. Fertilizer incorporation reduced clay dispersion at depth and, with subsoiling, also increased pore space.

Treatment responses in term of soil structure were not large, but the incorporation of fertilizer did markedly accelerate structure rehabilitation at depth. Subsoiling alone contributed to land rehabilitation by controlling surface wetness and encouraging an increase in earthworm populations.
Use of n-alkanes for the estimation of herbage intake in sheep: accuracy and precision of the estimates
Authors: Vulich S. A. , O'Riordan E. G. , Hanrahan J. P.
Published: March 2009

Two experiments at Belclare, Co. Galway, in late autumn 1988, evaluated the use of herbage and dosed n-alkanes for estimating herbage intake by sheep. The first experiment examined faecal recoveries of dosed and herbage n-alkanes. The second experiment assessed the accuracy and precision of herbage intake estimates obtained using the n-alkane technique, and tested the effect of supplying n-alkanes to animals either in gelatine. capsules (containing different ratios of n-alkane: cellulose fibre) or in pellets prepared from shredded paper onto which the n-alkanes had been adsorbed. Individually penned wether lambs were offered freshly cut herbage ad libitum (+ 10%) and actual dry matter intake was recorded daily. Intake was estimated using the C31:C32 and C33:C32 (natural:dosed) n-alkane ratios.

There was no significant effect of n-alkane chain length on faecal recovery rate for either the dosed n-alkanes (C32 and C36), the herbage odd-chained n-alkanes (C29, C31, C33 and C36) or those used for the estimation of herbage intake (C31, C32 and C33). The accuracy and precision of the n-alkane technique for estimating herbage intake were unaffected by whether the dosed n-alkane was supplied in capsules or pellets or by the n-alkane:cellulose fibre ratio in the capsules. The bias in the estimated intake was – 8% (± 1·1%) and + 3% (± 1·2%) for estimates based on C31:C32 and C33:C32 ratios, respectively. The estimates based on C31:C32 and C33:C32 exhibited similar precision in the estimation of herbage intake, with a R.S.D. of 6% in actual intake when adjusted for variation in estimated intake and a correlation of +0·92 between actual and estimated herbage intake. The C.V. for actual herbage intake was 17%. The repeatability of actual dry matter intake over three consecutive 6-day periods was 0·54 while those of estimated intake were 0·57 and 0·60 for estimates based on C31:C32 and C33:C32, respectively. The results show that the n-alkane technique can provide an accurate and precise estimate of herbage intake.
Controlling manganese deficiency in sugarbeet with foliar sprays
Authors: Last P. J. , Bean K. M. R.
Published: March 2009

Field experiments in 1987 and 1988 on peaty-loam, Mn-deficient soils of the Adventurers series in Cambridgeshire, UK, tested the response of sugarbeet to three forms of manganese fertilizer supplied as foliar sprays. The influence of a wetter and an adjuvant on manganese absorption and growth was also investigated.

Cutonic and chelated forms of Mn, when applied at standard rates, were inefficient at increasing Mn concentrations in plants and alleviating deficiency symptoms during early summer. Mn concentrations in foliage increased rapidly after spraying with manganese sulphate, and most of the deficiency symptoms disappeared. These benefits were usually enhanced when manganese sulphate sprays were used with an adjuvant.

Averaged over both years, yield without Mn was 8·83 t sugar/ha; the largest yield, 9·56 t/ha, was obtained with manganese sulphate plus adjuvant. Smaller benefits were obtained with the other forms of Mn. The adjuvant, when used with chelated Mn, appeared to depress sugar yields in both years. The likelihood of reducing the number of sprays required to control Mn deficiency on Fen soils was improved by using an adjuvant with manganous sulphate sprays.
In saccodegradation of organic matter and crude protein of fresh grass (Lolium perenne) in the rumen of grazing dairy cows
Authors: van Vuuren A. M. , Tamminga S. , Ketelaar R. S.
Published: March 2009

In three experiments, carried out in 1985 and 1986 in the Netherlands, the effects of herbage maturation and rate of nitrogen fertilization on rumen degradability of organic matter (OM) and crude protein (CP) in fresh herbage (Lolium perenne) were studied using the nylon bag technique. Experimental farms at Lelystad and Swifterbant (clay soil) and Achterberg (sandy soil) provided the herbage samples. From the results, the content of digestible CP entering the small intestine (DPI) was estimated.

Crude protein content andin saccodegradability of OM and CP decreased with increasing grass maturity and with decreasing rate of N application. With every 100 g/kg DM decrease in CP content, the estimated content of DPI decreased by 19 g/kg DM, no matter how the CP content was manipulated.
Leaf and flower initiation in potato (Solanum tuberosum) sprouts and stems in relation to number of nodes and tuber initiation
Authors: Firman D. M. , O'Brien P. J. , Allen E. J.
Published: March 2009

Experiments were conducted in controlled environment cabinets and in the field at Cambridge, UK, in 1987–90 and in Valencia, Spain 1989–90 with several varieties of potato. The initiation of leaf primordia and flowers was recorded in sprouts stored for long periods at 13°C with constant illumination and in sprouts exposed to different photoperiods and periods of cold storage. In field experiments, the effects of a wide range of planting dates, differences in physiological age, the time at which seed tubers were sprouted and of imposing an 8 h photoperiod were investigated.

More than 40 leaf primordia were initiated in the sprouts of Home Guard and Arran Comet stored at 13 °C, but, in other varieties, fewer leaves were initiated. Flowers were initiated in the sprouts of some varieties. In field-grown plants, the number of nodes to the first flower differed between varieties and was increased by ageing sprouts before planting. Stems from physiologically old seed of all varieties had more nodes below ground than young seed but the number of aerial leaves to the first flower increased only slightly with increasing physiological age. The number of aerial leaves to the first flower was lower and less variable in Estima than in Maris Piper.

Initiation of flowers usually occurred before tuber initiation and within two weeks of emergence but was earlier in some varieties than others. There was little influence of photoperiod on the time to initiation of flowers and tubers in most experiments but, with low levels of radiation, flowering was completely inhibited in the variety Maris Piper.
Effect of nitrogen on nodulation and yield of soya beans under two systems of production in Sudan
Authors: Khalifa F. M.
Published: March 2009

Two experiments were run over a 3-year period in the central rainlands of Sudan under two systems of production, rainfed and irrigated, to assess the effects of system of production, inoculation and nitrogen fertilizers on plant and nodule development and grain yield of soya beans. Nodulated plants could fix more than 80 kg N/ha under irrigation whereas under rainfed conditions nodulation was neither effective nor efficient. Soya bean was responsive to nitrogen fertilizers under both systems of production giving significant increments in grain yields. Non-nodulating plants with added nitrogen fertilizers produced more total dry matter than nodulating plants during the vegetative phase until flowering time. At 2 weeks after flowering total dry-matter production for both types was equal and from then on to maturity nodulating plants outyielded non-nodulating ones in total dry-matter production. In 1979 and 1980 yield of irrigated nodulating soya-bean grain was 0·53 and 1·54 t/ha higher than rainfed yields whereas the difference in grain yields of the non-nodulating soya beans was 0·21 t/ha and zero during the same two seasons, respectively. There was a contrasting inverse relation between the number of nodules and dry weights under the two systems of production. Fewer and heavier nodules were produced under irrigation whereas under rainfed conditions nodulation was profuse and nodules were light. On the evidence available 1–4 g/m length of the granular form of soil implant inoculant (Nitragin), i.e. 16·6·66.4 kg/ha, is to be recommended for irrigated soya-bean production in Sudan.
Decline in plant and animal production from ageing pastures of green panic (Panicum maximum var. trichoglume)
Authors: Robbins G. B. , Bushell J. J. , Butler K. L.
Published: March 2009

The impact of age on the productivity of sown pastures of green panic (Panicum maximum var. trichoglume cv. Petrie) growing on black earth soil in south-east Queensland was measured from 1976 to 1981. During winter and spring, weaner steers grazed at 2·4 animals/ha on summer-spelled pastures which, in each year, were 1, 2, 3, 4 and 5 years old. Pastures were given 58 kg N/ha as urea each year. Live-weight gain averaged 74 kg/head on 1-year-old pasture but only 35 kg/head on 5-year-old pasture, with most of the reduction in weight gain in winter (June to August) occurring up to age 3 years, and with most of the reduction in spring (September to November) occurring for pastures older than 3 years.

The decline in animal production was not caused by changes in species composition of the pasture. Rather, weight gain on older pastures was restricted by pasture quality in winter and by reduced pasture growth in spring, but not by presentation dry-matter yield. The decrease in pasture productivity seemed to be primarily due to reductions in available soil mineral N with age, since the N concentration of plant shoots decreased as a pasture aged. Tt is postulated that the immobilization of N in decomposing grass litter is a primary cause of productivity decline in ageing pastures.
Desodification of a salt-affected soil in plots of various sizes under two modes of water application
Authors: Dahiya I. S. , Grewal K. S. , Dahiya D. J.
Published: March 2009

Desodification of a highly saline-sodic, permeable, sandy loam soil was accomplished in 2 × 2 m (S1), 4 × 4 m (S2) and 6 × 6 m (S3) plots under continuous and intermittent ponding. The soil contained large amounts of soluble salts and exchangeable sodium throughout the profile to the water table. The chief salts were chlorides and sulphates of sodium, calcium, and magnesium. The leaching curves with respect to desodification did not differ significantly between the S1, S2 and S3 plots under continuous ponding but did under intermittent ponding. With intermittent ponding, the efficiency of leaching exchangeable sodium in the S1 plots was very significantly higher than that in the S2 and S3 plots, i.e. the leaching efficiency decreased sharply with increased plot size. The leaching efficiency in the S1 plots was significantly greater with intermittent than with continuous ponding, but the reverse was true in the S2 and S3 plots. The results further indicated that there is no need to apply an amendment such as gypsum, mainly because calcium and magnesium present in such soils are adequate to replace the initially high exchangeable sodium during leaching. The displacement of exchangeable sodium in the S1 plots under intermittent ponding was nearly piston-like. With increased plot size, it tended to deviate from this behaviour. It is concluded that under practical situations in which reclamation is accomplished in large plots, the practice of leaching the saline constituents with intermittent ponding would be less effective. Thus, leaching of salts down into the soil with a single heavy irrigation would be more desirable.
Fractional rate of protein synthesis in liver and in individual muscles of lambs: effect of time of sampling following the use of the continuous infusion technique
Authors: Hunter R. A. , Davey Jane B. , Buttery P. J.
Published: March 2009

There is little information on rates of protein synthesis in individual muscles in ruminant animals. Skeletal muscle is the largest single tissue and, as such, has a considerable effect on nitrogen transactions in the body. Arnal (1977) found a substantial decline in synthetic rate between 1 and 16 weeks of age in lambs and also observed differences between red and white muscles. Bryant & Smith (1982a) measured synthesis in several muscles of mature sheep and they observed lower rates than Arnal (1977) with little difference between most muscles. Vastus intermedius muscle in the hind leg, however, had higher rates of synthesis than other muscles. Here we report rates of protein synthesis in individual muscles in rapidly growing lambs approximately 12 weeks of age. The major back muscle, the longissimus dorsi, and two hind leg muscles, the vastus lateralis and the vastus intermedius, were chosen for study.
Comparative efficiency of different planting methods in intermediate deepwater (15–50 cm) rice
Authors: Reddy M. D. , Ghosh B. C.
Published: March 2009

In rainfed lowland rice areas of intermediate deepwater (15–50 cm), transplanting in greater depths of water (50–60 cm) with clonal tillers (double transplanting) from 20 or 40- to 50-day-old-transplanted crops of similar environment increased grain yield significantly compared with seedlings of the same age (60 or 80- to 90-day-old) from a nursery. The grain yield did not decrease significantly when the clonal tillers were removed at 20 or 40 days after transplanting compared with that of the undisturbed crop. The practice of double transplanting (clonal propagation) increased tiller production and the number of panicles, and the crop could tolerate better the greater depths of water and thereby give greater grain yield.
Effect of preceding legume or cereal on barley grain and nitrogen yield
Authors: Papastylianou I.
Published: March 2009

Two separate short-term rotation experiments were conducted during 1982–5 in order to study the production and effect on subsequent barley of legumes grown in Cyprus. The treatment crops, seven legumes and three cereals, were grown in 1982–3 and in 1983–4 growing seasons and barley was grown in the subsequent growing seasons (1983–4 and 1984–5).

Among the treatment crops, cereals gave equal or higher dry-matter yields, but equal or lower nitrogen yields compared with legumes. Barley, the test crop, which followed the treatment crops, gave lower grain and nitrogen yields when following cereals than after legumes. There were differences among legumes in their residual effect on the subsequent crop.
Effect of rates and methods of phosphorus application on herb and oil yields and nutrient concentrations in Japanese mint (Mentha arvensis L.)
Authors: Kothari S. K. , Singh Virendra , Singh Kamla
Published: March 2009

Japanese mint (Mentha arvensis L.), one of the important essential-oil-bearing crops of India, is a potential source of natural menthol which is widely used in various pharmaceutical and cosmetic preparations. Generally under intensive cultivation, the application (broadcast with incorporation) of phosphorus leads to enhanced herb and oil yields of different mint species (Rao, Rao & Singh, 1983; Singh et al. 1983; Vadivel & Sampath, 1981), but the knowledge that P-adsorption to soil surface reduces plant availability suggests that a P application method limiting soil-P contact may improve P availability and use efficiency (Phillips & Webb, 1971). Therefore, the placement depth and method may be an important factor in the proper use of applied phosphorus. Since uptake of P is reduced in dry soils (Reichman & Grunes, 1966; Simpson, 1960), P placed deeper in the soil would remain more available because of increased soil moisture. Another factor involved is the positional availability of the P source (Cooke, 1954). If placed too close to the surface, the roots may not come in contact with the fertilizer or too few would contact the band to maximize uptake.
The digestion by cattle of silage and barley diets containing increasing quantities of fishmeal
Authors: Rooke J. A. , Armstrong D. G.
Published: March 2009

A 4 × 4 latin-square design experiment was carried out to determine the effects of increasing nitrogen (N) intake by feeding diets containing increasing amounts of fishmeal upon the digestion of organic matter (OM) and N by cattle equipped with rumen and duodenal cannulae. A basal diet (B) containing 600 g silage and 400 g ground barley/kg diet and three diets (BF1, BF2 and BF3) in which increasing amounts of the silage and barley basal diet were proportionately replaced by fishmeal were fed. The mean daily intakes of OM and N when each diet was fed were 4·29, 4·28, 4·22 and 4·20 kg OM and 90, 108, 125 and 143 g N for diets B, BF1, BF2 and BF3 respectively.

Neither the amounts of OM entering the small intestine nor those voided in the faeces were altered by the diets fed. Thus mean apparent OM digestibility for all the diets fed was 0·74 ± 0·007 and the proportion of digestible OM intake apparently digested in the rumen was 0·83±0·011.

Mean daily concentrations of ammonia N in the rumen were significantly(P <0·01) increased from 85 mg N/l (diet B) to 129 mg N/1 (diet BF3) as fishmeal intake increased.

The quantities of non-ammonia N (P<0·05) and of amino acid N (P<0·001) entering the small intestine were significantly increased as more fishmeal was added to the diets fed. As fishmeal intake increased apparent N digestibility was significantly (P<0·001) increased.

Neither the quantities of microbial N entering the small intestine daily nor the apparent efficiency of microbial N synthesis within the rumen were increased by the diets fed. The quantities of feed N entering the small intestine daily were significantly (P<0·01) increased as fishmeal intake increased; thus apparent feed N degradability in the rumen was significantly (P<0·05) decreased from 0·84 (diet B) to 0·73 (diet BF3) as fishmeal intake increased. Similarly, the rates of disappearance of N from each of the four barley or barley and fishmeal concentrates when incubated in the rumens of the cattle in porous synthetic fibre bags were decreased as the proportion of fishmeal in the concentrates increased. Thus, the rumen N degradability of the diets fed, when calculated from the rates of disappearance of N from porous synthetic fibre bags placed in the rumen, decreased as fishmeal intake increased.

As fishmeal intake increased the amino acid composition of duodenal digesta (expressed as g/kg determined amino acids) changed such that the content of arginine increased (P<0·01) and the content of isoleucine decreased (P<0·01). The concentrations of arginine (P<0·01), leucine and lysine (P<0·05) in blood plasma increased as fishmeal intake increased.
The effect of a light pulse and melatonin, alone or in combination, on the reproductive performance of Finn-cross ewes in spring in Israel
Authors: Amir D. , Thimonier J. , Gacitua H.
Published: March 2009

Adult Finn-cross ewes, pregnant from September matings, were kept under natural photoperiod (control, 30 animals) or with an additional exposure to a 1 h long. 300 lux light pulse, 16–17 h after an artificial dawn (light-pulse treatment, 32 ewes) for 2·5 months. After lambing, the supplementary light was discontinued and half of the ewes from each group were injected daily with 2 mg melatonin for an additional 2·5 months.

The light-pulse ewes produced heavier lambs and more milk, as can be deduced from the higher rate of growth of their lambs during the first 10 days of life, than the control animals. The light-pulse and/or melatonin treatments delayed the occurrence of the first post-partum ovulation and oestrus (which occurred in the untreated animals about 4 and 6 weeks, respectively, after lambing), by 1–3 weeks. However, more ewes exhibited oestrus and cyclic activity in the light-treated than in the other groups. The fertility in the light-treated group was, consequently, superior to that in the group kept under natural photoperiod, in spite of the similar lambing rate of the mated ewes of the different groups.

It is concluded that the light-pulse, but not the melatonin treatment, had a beneficial effect on the reproductive performance of the ewes, as measured by the weight of the newborn lambs, the milk production of the dams during the first 10 days post-partum, and the cyclic activity of the ewes after February lambing in Israel.
The effect of dietary molybdenum and iron on copper status, puberty, fertility and oestrous cycles in cattle
Authors: Phillippo M. , Humphries W. R. , Atkinson T. , Henderson G. D. , Garthwaite P. H.
Published: March 2009

Two experiments were conducted to examine the effects of supplementation of a control diet of barley grain and barley straw containing 4 mg copper (Cu)/kg dry matter (D.M.) either with 5 mg molybdenum (Mo)/kg D.M. or with 500 or 800 mg iron (Fe)/kg D.M. on puberty, fertility and oestrous cycles of cattle. Puberty occurred normally in control, Fesupplemented and control animals on a restricted intake whereas it was delayed by 12 and 8 weeks respectively by Mo supplementation. This effect of Mo was not due to the low Cu status since this was equally low in the Fe-supplemented animals, nor was it due to the reduced growth rate since puberty occurred normally in control animals that had a similar live-weight gain. A significant reduction in the pulsatile release of luteinizing hormone was observed within 11 weeks of the Mo supplementation and before any of the other clinical signs were evident, suggesting that Mo may be affecting puberty by altering the release of luteinizing hormone either directly or indirectly.

Mo supplementation significantly reduced the percentage conception rate to 12–33% compared with 57–80% in control and Fe-supplemented animals. This effect was not dependent on the rate of live-weight gain which was standardized across the different treatments at approximately 0·6 kg/day. Within 12 weeks of the replacement of dietary Fe by Mo a lower conception rate occurred; replacing dietary Mo by Fe led to a normal conception rate within 12 weeks without any accompanying changes in Cu status or in the rate of live-weight gain. The plasma Mo concentrations, however, changed significantly during these alterations in dietary supplementation. The pre-ovulatory peak height of luteinizing hormone was significantly lower in animals on the Mo-supplemented diet compared with control and Fe-supplemented animals, but the administration of LHRH did not alter the conception rate.

More Mo-supplemented animals failed to ovulate following prostaglandin induced synchronization in comparison with the other treatments, and by the 84th week a significantly greater number of Mo-supplemented animals (12/18) had become anoestrous compared with the other groups (2/30). Cu repletion of these anoestrous Mo animals for a period of 20 weeks did not result in resumption of normal oestrous cycles, but ovulation and oestrus were induced by progesterone and LHRH treatment. Results in the latter part of the study indicated that Mo caused superovulation.

These data show that Mo supplementation delayed the onset of puberty, decreased the conception rate and caused anovulation and anoestrus in cattle without accompanying changes in Cu status or in live-weight gain. It is suggested that these effects of Mo are associated with a decreased release of luteinizing hormone that might be due to an altered ovarian steroid secretion.