bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tillage and irrigation effects on root growth, soil water depletion and yield of wheat following rice
Authors: Chaudhary M. R. , Khera R. , Singh C. J. 
Published: March 2009

SUMMARYThe effects of deep tillage and no-tillage on soil physical properties and wheat yield following rice were compared with conventional tillage at three irrigation rates (irrigation water:open pan evaporation ratios of 0·6, 0·9 and 1·2) in 1982–85 at the experimental station of the Punjab Agricultural University, Ludhiana. Deep tillage decreased soil bulk density and penetrometer resistance, and increased depth of rooting, profile water use and wheat yield. No-tillage adversely affected all these variables. The tillage effects varied with amount and distribution of rain during the cropping season.
Use of successional sowing in evaluating cowpea (Vigna unguiculata) adaptation to drought in the Sudan savannah zone. 2. Response of reproductive traits
Authors: Muleba N. , Mwanke M. , Drabo I. 
Published: March 2009

SUMMARYTwo sets of experiments on cowpea sowing date were conducted in 1983–85 at Ouagadougou, Burkina Faso. One set tested six daylength-insensitive (DI) cultivars and the other compared four or five daylength-sensitive (DS) cultivars with one or two DI cultivars as controls. Sowing after inadequate rainfall, particularly when followed by drought stress, impeded seedling establishment and growth. Severe drought stress during the reproductive growth stages and prolonged drought stress throughout the crop season adversely affected flowering, flowering intensity and subsequent yield. Cultivar differences in ability to withstand drought damage were observed. The ability of cultivars to (i) branch profusely, to compensate for stands lost by drought during seedling growth and (ii) flower at such a time that pod set and fill coincide with favourable climatic conditions appears to be a prerequisite for satisfactory adaptation to the Sudan savannah zone of semi-arid West Africa. Daylength-sensitivity and early maturity per se were inadequate to prevent yield losses under drought conditions.
Seasonal changes in leaf water potential components in two almond cultivars
Authors: Ruíz-Sánchez M. C. , Sánchez-Blanco M. J. , Planes J. , Alarcón J. J. , Torrecillas A. 
Published: March 2009

SUMMARYAlmond trees (Amygdalus communisL. cvs Garrigues and Ramillete) were grown in the field under non-irrigated conditions in Murcia, Spain. Seasonal variations in leaf water potential components were studied in 1989. Predawn leaf water potential showed high values in both cultivars, due to the absence of soil water stress. Pressure-volume curve analysis indicated that the leaf osmotic potential at full saturation (Ψo(sat)) for cv. Garrigues remained fairly constant throughout the season. Bulk modulus of elasticity (E) showed, in both cultivars, a tendency to decrease as the season progressed. E values were higher in Ramillete than in Garrigues. The relative water content at the turgor loss point (RWCtlp) seemed to be controlled by E values. The larger relative apoplastic water content (RWCafound in Ramillete might have allowed it to retain more water at low leaf water potentials than Garrigues. These facts would support the suggestion that Ramillete is a more drought-resistant cultivar than Garrigues.
Effects of cutting height on the growth of leaves and stolons in perennial ryegrass–white clover swards
Authors: Wilman D. , Acuña G. H. p. 
Published: March 2009

SUMMARYAll combinations of five cutting heights (2, 4, 6, 8 and 10 cm) were compared, for 3 years (1986–88), on field plots sown with a mixture of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) in Wales. The plots were cut at 4-week intervals from April to October each year.A reduction in cutting height reduced the length, width and weight of clover leaflets, petiole length, stolon diameter, the length of stolon internodes and the height of stolons above ground level, but increased the length of clover stolon/m2, the number of stolon nodes/m2 and the proportion of stolon nodes which produced branches. The latter factors out-weighed the former, leading to the inverse relationship between cutting height and the proportion of clover in the sward previously reported (Acuñia & Wilman 1993).A reduction in cutting height reduced the following attributes of ryegrass: the height of the shoot apex, the length and width of leaf blades, sheath length, leaf extension rate, the death rate of leaves and the net gain in blade length.Cutting height had little effect on either the thickness of clover leaflets or the rates of leaf emergence in clover and ryegrass.
Nitrogen in the excreta of dairy cattle: changes during short-term storage
Authors: Whitehead D. C. , Raistrick N. 
Published: March 2009

SUMMARYThe concentration of N in samples of urine from dairy cattle fed on grass herbage, or grass or maize silage, sometimes with additional concentrate feeds, ranged from 6·0 to 13·8 mg N/l with 67–91% of the total N being present as urea. The concentration of N in 11 samples of dung was 0·32–0·52% on a fresh weight basis (2·74–3·82% N in dry weight). About 18% of the dung N was contained in particulate material of > 0·2 mm diameter,c.72% in fine particulate plus colloidal material, andc.10% was soluble in the presence of A12(SO4)3.When urine was stored for 3 weeks, the urea component was hydrolysed with the formation of ammonium. The rate at which hydrolysis occurred was greatly influenced by temperature. Hydrolysis of urea was complete within 2 days at 35 °C, within 7 days at 20 °C and within 21 days at 10 °C, but was onlyc.90% complete after 21 days at 5 °C. The rate of hydrolysis of urinary urea-N at 20 °C was increased slightly by inoculation with slurry, dung or soil, and was also increased slightly by the greater aeration resulting from a continuous stream of bubbled air. No nitrification was detected, even in urine that was aerated for 6 weeks, probably because the process was inhibited under the conditions of high pH (9–10) and high concentrations of ammoniacal N.When dung was stored for 3 weeks at 5 or 10 °C, there was little change in the amount of organic matter or in the form of N. However, at higher temperatures, some mineralization occurred and the amount of organic matter declined by 8% at 20 °C and by 17% at 35 °C. About 10% of the organic N was converted to ammonium during 3 weeks at 20 °C, andc.18% at 35 °C.With a slurry prepared from approximately equal amounts of urine, dung and water, more of the dung material was mineralized than with the dung stored alone:c.15% of the organic matter was lost during 3 weeks at 5 °C and c. 34% at 35 °C. Despite this loss of organic matter, there was net immobilization of soluble N during the 3-week period by the solid fractions of the slurry, at all four temperatures.
Effects of intraruminal infusions of urea, sucrose or urea plus sucrose on plasma urea and glucose kinetics in sheep fed chopped lucerne hay
Authors: Obara Y. , Dellow D. W. 
Published: March 2009

SUMMARYThe effect of rumen fermentation on the relationship between urea and glucose kinetics was examined in sheep fed chopped lucerne hay with intraruminal infusions of water, urea, sucrose, or urea plus sucrose at Palmerston North, New Zealand in 1986. Sheep were fed hourly and infused intraruminally with water (1200 m1/day), or a similar volume containing either urea alone (13·7g/day), sucrose alone (178·2 g/day) or urea (14·6 g/day) plus sucrose (175·0 g/day). The added sucrose resulted in a lower rumen ammonia concentration (P< 0·05), lower plasma urea concentration (P< 0·05) and reduced urinary urea excretion (P< 0·05). Urea recycled to the gut tended to increase with the sucrose, urea or sucrose plus urea treatments compared with the water treatment. The fermentation of sucrose in the rumen resulted in decreases in ruminal pH (P< 0·05) and in the ratio of acetate to propionate (A:P) (P< 0·05). The infusion of sucrose also increased the concentration of propionate in rumen fluid (P< 0·05), tended to increase the plasma glucose level and increased plasma glucose irreversible loss (P< 0·05). The infusion of urea resulted in an increase in the plasma urea level (P< 0·05), urea pool size (P< 0·05) and urea irreversible loss (P< 0·01). However, urea infusion did not affect glucose metabolism or volatile fatty acid (VFA) fermentation. The effects of sucrose infusion on glucose and urea kinetics were broadly similar when given alone or with urea, apart from changes in the urea degradation rate. It was concluded that the additional fermentative activity resulting from sucrose increased propionate production which, in turn, was available for glucose production, thus ‘sparing’ amino acids for tissue protein utilization and reducing urea excretion.
Effects of cultural practices on reducing field infestation of potato tuber moth (Phthorimaea operculella) and greening of tubers in the Sudan
Authors: Ali M. A. 
Published: March 2009

SUMMARYThe population dynamics of the potato tuber moth (PTM) Phthorimaea operculella (Zeller) and the influence of potato cultivar, planting date, planting depth, hilling-up, irrigation intervals and mulching on insect infestation and on the greening of tubers in the field were studied at Shambat, Khartoum North, Sudan in the 1987/88 and 1988/89 winter seasons.The insect population initially increased slowly, then more rapidly after crop establishment and throughout the harvest period, after which it declined sharply. Tuber shape and skin characteristics had no effect on the degree of PTM infestation. Planting in the second week of November resulted in less insect damage and a significantly greater total yield compared with crops planted 3 weeks later. Greater depth of planting and more frequent hilling-up significantly lowered infestation levels and reduced the greening of tubers; for example, insect damage in early planted crops ranged from 3·3% (planting 10 cm deep and hilling-up thrice) to 16% (planting at 5 cm depth and hilling-up once).Irrigation and mulching both significantly reduced PTM damage and the greening of tubers.Light irrigation every 4 days and mulching with neem (Azadirachta indica) leaves during the last 4 weeks before harvest were the most effective treatments.Significant reductions in losses inflicted by PTM and by the greening of tubers were therefore achieved by the manipulation of crop husbandry practices.
Screening of groundnut germplasm collection and selection of genotypes tolerant of lime-induced iron chlorosis
Authors: Singh A. L. , Chaudhari V. 
Published: March 2009

SUMMARYErect type groundnut germplasm belonging to the Valencia and Spanish botanical groups was examined in the field for five consecutive cropping seasons (wet 1988, 1989 and 1990 and dry 1989 and 1990) at Junagadh, India, in order to identify groundnut genotypes with the ability to grow in calcareous soil and tolerate iron deficiency (lime-induced iron chlorosis). On the basis of the visual chlorotic rating scores of their leaves, 17 and 19 genotypes of the Valencia and Spanish groups, respectively, which showed the least or no chlorosis were classified as tolerant (iron-efficient) to iron chlorosis. These genotypes may now be used as donor parents in groundnut breeding programmes for the development of iron chlorosis-tolerant varieties.Almost all the iron-efficient groundnut genotypes had higher pod and seed (kernel) yields and Harvest Index (HI) than the susceptible types. The seed yield of 12 iron-efficient groundnut genotypes was either equal to or higher than a commercial cultivar which showed tolerance to iron chlorosis and, hence, these genotypes could profitably be grown in those areas where chlorosis due to iron deficiency is a major problem.
Use of a long-term rumen simulation technique (Rusitec) to provide micro-organisms forin vitrodigestibility assays
Authors: Owen E. , Jayasuriya M. C. N. , Hamilton R. , Lalenta M. 
Published: March 2009

SUMMARYFour experiments involving the two-stagein vitrodigestibility technique of Tilley & Terry (1963) were undertaken to investigate whether cow rumen liquor could be replaced with effluent or extract from feed residue containing micro-organisms derived from the long-term rumen simulation technique (Rusitec) of Czerkawski & Breckenridge (1977).In Expts 1 and 2, the dry matter digestibility (DMD) of hay was determined using either cow rumen liquor or Rusitec liquid effluent or extract from feed after 48 h of digestion in a Rusitec apparatus using various volumes of liquor and artificial saliva. Digestibilities determined with rumen liquor werec.70% (c.v. 1·2%) while those determined with Rusitec effluent or extract werec.62% (c.v. 1·8%). In treatments common to Expts 1 and 2, Rusitec effluent digestibilities were more repeatable than extract or rumen liquor digestibilities.In Expts 3 and 4, Rusitec effluent was compared with cow rumen liquor for determining DMD of seven forages with DMD ranging from 33 to 70%. For a given feed there was good agreement between experiments in DMD values determined with Rusitec effluent, and for ten paired values there was a high correlation (r2= 0·976) between DMD determined by the two methods. DMD determined using rumen liquor (y) was accurately predicted by Rusitec liquid effluent digestibility (x) from the equationy= 2·663 + 1·06477.x; R.S.D. 2·433.The results show that Rusitec liquid effluent can be used instead of rumen liquor as a source of micro-organisms for the two-stagein vitrodigestibility method. Routine use of Rusitec would obviate the need for using fistulated animals.
Micrometeorological studies of ammonia emission from sheep grazed swards
Authors: Jarvis S. C. , Hatch D. J. , Orr R. J. , Reynolds S. E. 
Published: March 2009

SUMMARYLosses of ammonia (NH3) through volatilization from the excretal returns from sheep grazing a range of swards in S.E. England were determined over two seasons. Four swards were examined: grass + 420 or 0 kg N/ha per year, grass/white clover and clover monoculture. These were grazed continuously to sustain a constant sward height of 6 cm. The patterns of NH3-N concentration above the sward changed with treatment and throughout the season: there were, on occasion, irregularities in the concentration profiles which may have been due to differential behaviour of paniculate and gaseous forms. Significant losses of NH3 occurred on all treatments, although on some occasions the low input systems appeared to be acting as sinks rather than sources of NH3. There were trends for the losses to be greater during the middle of the grazing season. In contrast to previous studies there was little relationship between seasonal N losses and changes/differences in dietary N content. The overall losses, whether on a per unit area or per animal basis, were generally in the order, clover > grass + 420 kg N > grass+ 0 N > grass/clover. Mean annual losses from grass + 420kg N and grass/clover were 94 and 1·2 kg N/ha, respectively. For a comparable fertilizer N treatment, losses were lower than previously found with swards which were rotationally grazed by cattle. The present losses, although dependent upon level of N input, whether from fertilizer or from biological fixation, were relatively small, ranging from 05 to 11·2 kg N/ha per year, and represented small proportions of either the N input to the system or the excretal returns from the animals.
The relationship between total yield, number of tubers and yield of large tubers in potato crops
Authors: Burstall Lindsay , Thomas M. N. , Allen E. J. 
Published: March 2009

SummaryExperiments were made over 2 years at two sites using three varieties to investigate the relationship between total yield, number of tubers > 1 cm and the yield of tubers in the 60–80 mmsize range. Regressionanalysisrevealed that yield of tubers in the 60–80 mm size range was a linear function of total yield and number of tubers > 1 cm. The effect of changes in tuber shape on this relationship is discussed.
Growth and chemical composition of carrots as influenced by the time of sowing and harvest
Authors: Nilsson T. 
Published: March 2009

SummaryThe effects of the time of sowing on growth and chemical composition of carrots grown from May to November were studied during 3 years.Delaying sowing for 1 or 2 months after the beginning of May resulted in a reduction in the growth of both roots and foliage and gave roots with lower dry-matter content and glucose/fructose ratio but higher amounts of hexoses, total nitrogen and amino nitrogen in root dry matter. Sowing date had no influence on the concentration of sucrose, phosphorus, potassium, calcium and magnesium in root dry matter up to 137 days from sowing. Carotene decreased only after the last sowing. Sucrose concentration of the roots increased throughout the periods studied irrespective of the time of sowing. The longer the growing period the higher was the sucrose concentration. The concentration of hexoses decreased from the first harvest at 70 days to reach a constant level at about 130 days from sowing.The results did not indicate the presence of a well-defined stage of biochemical maturity in the autumn when carrot roots are expected as most suitable for harvest and subsequent long-term storage.
Effect of nitrogen fertilizer on yield and nitrogen concentration in grain and straw of rice under semi-deepwater conditions (51–100 cm)
Authors: Reddy M. D. , Panda M. M. , Ghosh B. C. , Reddy B. B. 
Published: March 2009

SummaryUnder conditions of semi-deep water (51–100 cm) rice varieties with greater plant height produced more dry matter and grain yield as N fertilizer was increased from 0 to 20 and 40 kg/ha. The varieties which performed better in a situation of slow rise in water level to a depth of 120 cm could not survive a quick rise in water level owing to their lesser plant height and elongation ability. The loss of dry matter (dead and dried leaves) was also greater in varieties susceptible to deep water than varieties tolerant of deep water.With the increase in N fertilizer, there was increase in plant height, number of tillers, dry-matter production and grain yield. The loss of dry matter was less in crops given N fertilizer than in those not given N fertilizer. The varieties capable of producing higher grain yield in response to N fertilizer under semi-deep water did not improve their grain yield under intermediate deep water (15–50 cm). With increase in application of N fertilizer from 0 to 40 kg/ha the N concentration in grain increased. N concentration did not vary in straw under intermediate deep water, there was no definite trend in semi-deep water, and it was higher under conditions of semi-deep than intermediate deep water.
Performance of carrot seeds possessing different germination rates within a seed lot
Authors: Finch-Savage W. E. , McQuistan C. I. 
Published: March 2009

SummaryThe relationship between germination rate within a carrot seed lot and subsequent seedling performance was studied in four seed lots of different viability. Seedling performance was assessed using slope tests conducted under controlled conditions and in the field following fluid drilling under a range of environmental conditions. Germination rate within a seed lot was positively related to vigour measured by slope tests, percentage emergence and seedling weight, and was negatively related to the spread of emergence times (In variance days) and the coefficient of variation (c.v.) of seedling weights. Sowing seeds selected as fast germinating resulted in greater seedling emergence percentages over a range of environmental conditions than when sowing seeds selected as slowly germinating.
The chromosomal locations in wheat of genes conferring differential response to the wild oat herbicide, difenzoquat
Authors: Snape J. W. , Angus W. J. , Parker Beryl , Leckie Debra 
Published: March 2009

SummaryF2, monosomic analysis involving crosses between the monosomic series of a resistant wheat variety, Chinese Spring, and a susceptible variety, Sicco, has located a major gene locus, designated Dfql, on chromosome 2B of wheat which determines the differential response of these varieties to treatment with the wild oat herbicide, difenzoquat. The allele from Chinese Spring conferring resistance is dominant and studies of the responses of Chinese Spring single chromosome substitution lines and nullisomic–tetrasomic lines for chromosome 2B indicate that this allele actively promotes resistance to the herbicide. It is suggested that this gene may prevent inhibition of DNA synthesis in the apical meristem, which is the site of action of the herbicide (Pallett & Caseley, 1980).Other chromosomes were also implicated as carrying ‘modifier genes’ which affect the ratio of resistant: susceptible plants in F2 monosomic families, namely 1D, 2D, 3A, 3B, 5B and 5D. These chromosomes may affect the retention and translocation of the herbicide to the target site and hence the threshold of response.The simple inheritance of difenzoquat resistance indicates that it should be easy by conventional breeding techniques to transfer the resistance into susceptible varieties.
Potassium requirement of groundnut (Arachis hypogeae) in the lowland tropics
Authors: Kayode G. O. 
Published: March 2009

SummaryA 2-year field study to investigate the potassium nutrition of groundnut in the lowland tropics showed that a low rate of K is beneficial to the crop. Applied K significantly increased leaf N, seed S, seed P, seed Fe, seed oil and protein content of groundnut. Leaf Ca significantly decreased with increased K application but K treatments significantly increased the seed and shell Ca. Potassium and Ca concentrations were highest in the leaf and lowest in the shell and seed respectively. The significant increases in shell P, shell Ca and shell Fe with increased K application would greatly improve the groundnut shell quality as an animal feed component. The relationship between seed oil and protein content was positive and significant.
Linkage between brown planthopper resistance and morphological characters in rice
Authors: Prasad G. S. V. , Sastry M. V. S. , Srinivasan T. E. , Kalode M. B. 
Published: March 2009

SummaryLinkage was detected between brown planthopper resistance and anthocyanin or nonanthocyanin pigmentation in rice cultivars. The crossover values were: 21·9–37% for leaf sheath, 31% for junctura, 41% for auricle, 12·5–40% for ligule, 14·32–1% for leaf tip and margin, 19·7–37% for stigma, 19·7–36% for apiculus and 46·7% for pericarp colour. Genes governing resistance and black hull colour or glabrousness of leaf blade assorted independently. The genes identified and designated for brown planthopper resistance and pigmentation have been tentatively proposed to linkage groups II, IV and V.
Growth, yield and crop quality performance of sugarcane cultivar Co 957 under different rates of application of nitrogen and potassium fertilizers
Authors: Abayomi A. Y. 
Published: March 2009

SummaryScreen house and field experiments at the Sugar Research Institute, University of Ilorin, Nigeria were carried out to evaluate the effects of various amounts of nitrogen and potassium fertilizers singly and in combinations on growth, yield and crop quality of sugarcane cultivar Co 957. Growth rate, number of green leaves per mother shoot, leaf area, plant height, stalk length and tiller density were significantly affected by nitrogen application but were not significantly affected by potassium. Similarly, cane tonnage was significantly affected by nitrogen but not by potassium. In the screen house trial, responses to N were linear from 0 to 160 kg N/ha. However, in the field, while the measured variables also increased linearly with N application from 0 to 160 kg N/ha, they decreased at 200 kg N/ha.Cane quality decreased with increased nitrogen and potassium. However, these reductions were significant only at the highest level of nitrogen and potassium. There were no significant nitrogen and potassium interactions on any of the variables studied.