bluuebunny/crossref_metadata_2025 huggingface dataset:
The response of field beans (Vicia fabaL.) to irrigation and sowing date. 2. Growth and development in relation to yield
Authors: Husain M. M. , Hill G. D. , Gallagher J. N.
Published: March 2009

The growth and yield of four crops of field bean cv. Maris Bead in response to irrigation and sowing date were analysed in relation to leaf area expansion and senescence and their absorption and utilization of photosynthetically active radiation (PAR). Total dry matter (D.M.) production and seed yield were strongly correlated with total green area duration (GAD) and post-flowering GAD respectively.

Total D.M. production was also strongly related to radiation absorbed by the green surfaces of the crop although autumn sowing and drought both decreased the constant of proportionality, i.e. the growth efficiency (Eg). Autumn sowings yielded more than spring sowings because they grew for longer and received 22% more radiation. Their harvest index was also about 40% higher than in spring sowings. These more than compensated for their smallerEg. Drought decreased yield mainly by decreasing radiation received andEg. Growth duration was shorter and harvest index was smaller.

The rate of phenological development was strongly dependent upon temperature and to a lesser extent on photoperiod. The average thermal duration from emergence to flowering was 790 °Cd above a base of 0 °C. The time from sowing to the end of the pod growth was well represented by a simple multiplicative model in which development rate was a linear function of temperature above a base of 0 °C and photoperiod above a base of 6 h. The average photothermal duration required for 10 crops was 980 °Cd.

An attempt was also made to determine the crop physiological and environmental factors which govern the change in size of the yield components of field bean crops caused by irrigation and sowing date. The final number of pods per plant was closely correlated with the rate of supply of assimilates during pod filling. Irrigation increased assimilate flux by increasing leaf area, growth rate and total dry matter during pod growth. Both the rate and duration of pod growth were little affected by irrigation. Autumn sowings produced heavier pods and beans due to both a faster rate and a longer duration of growth which were associated with a greater production of assimilate during the seed growth period. Seed growth depends on both the current assimilate and stored reserves, the latter especially when plants were subjected to environmental stress.
Morphology of white clover (Trifolium repensL.) plants in pastures under intensive sheep grazing
Authors: Brock J. L. , Hay M. J. M. , Thomas V. J. , Sedcole J. R.
Published: March 2009

There has been little study on the growth and morphology of individual plants constituting the population of white clover in mixed swards under grazing. Such information is required if the mechanisms governing plant productivity and persistence are to be understood.

Intact white clover plants were sampled from intensively sheep-grazed pastures under set stocking, rotational grazing, and a combination of both systems, by taking turves (250 × 250 mm), and washing out the plants, every month for a year. Characters measured for every stolon of each plant were: presence of a growing point; numbers of leaves, roots and axillary buds; stolon length. Total plant leaf and stolon dry weight were also recorded. Plants were classified according to degree of branching, and the contribution of each branching order to the population determined.

There were strong seasonal variations in plant size (leaf and stolon dry weight, stolon length, and numbers of stolons and leaves per plant) which showed a significant decrease in spring with recovery over the following summer. This was paralleled by a rapid increase in the proportion of less branched plants (1st and 2nd branching order) in the population from 60 to 80% in spring, as higher-order plants broke up into smaller- and lower-ordered plants at this time. Numbers of roots per plant increased over winter to peak in early spring then declined in the following summer-autumn. While system of grazing management had no significant effect on branching structure of plants, it had a large effect on plant dry weight; rotationally grazed plants were 2·5 times larger than set stocked plants (0·182 cf. 0·073 g respectively).

Other general features of plant morphology were that each successive order of branch stolons was shorter and length before branching was less than that of their preceding parent stolon. The highest branching order observed was 6th order. There was no relationship between branching and numbers of roots; in branched plants only 55% of stolons were rooted regardless of plant order, but rooted stolons accounted for 85% of total stolon length and carried 62, 48 and 90% of the leaves, growing points and axillary buds per plant, respectively.

Comparison with other studies suggests that the processes outlined in this report may be common to white clover growth under grazing over a wide range of favourable environments.
Contributions of shoot categories to growth and yield of winter wheat
Authors: Thorne G. N. , Wood D. W.
Published: March 2009

Measurements were made at intervals during 1983–4 on the main stem and on tillers having defined morphological positions on plants of winter wheat cv. Avalon growing in a multifactorial experiment testing combinations of the following five factors: rotation, sowing date, amount of autumn N, amount of spring N, and timing of spring N. Some observations from similar experiments in the two previous seasons are also reported.

The tillers in the axils of the first three leaves (Tp, T2and T3) appeared on most plants. An average of 1·8 other tillers were produced on each plant, including 0·14 at the coleoptile node. When number of shoots was maximal, main stems (M), T1and T2together accounted for 64% of the total number of shoots, 76% of the total green area and 87% of the total above-ground dry weight. More than half of the T1s died before maturity, two thirds of the T2s and almost all of the other tillers. The final population of 566 ears/m2was made up as follows: M 56%, T126%, T216%. The differences between categories in dry weight per shoot at maturity were relatively less than earlier. Contributions to the mean grain yield of 9·9 t/ha were: M 60%, T1, 22%, T214%. M had more grains per ear than T1, or T2which had similar numbers. Dry weight per grain was similar in all three categories.

Most of the effects of treatments on dry weight/m2, which have been described previously by Prewet al.(1986), were due to effects on all shoot categories. Several treatments increased the number of shoots/m2by increasing the average number per plant of tiller categories that were produced later. This was always the result of an increase in the proportion of plants having many tillers. Neither the maximum number of tillers found on a plant, nor the duration of tiller production, was affected.

Both within and between tiller categories, shoots that were produced last died first. Plants which started tillering late produced fewer, smaller, tillers than average and relatively few of these survived. The standard hierarchical order of tiller production and survival was disrupted when plants were damaged by stem-boring insects and when the period shortly before a tiller category was due to emerge was unusually dull and warm.
Modification of host–parasite interactions through mutagenesis in quantitative resistance of rice to bacterial leaf blight
Authors: Nakai H. , Katsumata K. , Gohda M. , Watanabe J. , Koike K.
Published: March 2009

A number of mutant lines showing different levels of improved quantitative resistance to bacterial leaf blight (BLB) were obtained through selection of plants or lines derived from seeds of the rice cultivar Harebare exposed to thermal neutrons and gamma-rays. The selections were made on M2–M4 materials under natural BLB-epidemic conditions and/or by artificial inoculation of one of the BLB isolates. Bacterial isolates predominating under the natural conditions were identified as belonging to the differential BLB isolate group I, and the isolates of this group were used in the artificial inoculation for selection of mutants. The selected M4 mutant lines were tested in M5 for BLB resistance by artificial inoculations of four differential bacterium isolates, groups I, II, III and IV. The M6 mutant lines showed quantitatively elevated resistances to the isolate of bacterium group I and also to the other three differential isolates. Analysis of variance of the data demonstrated that the observed elevated quantitative resistances of the mutants to the isolates I, II, III and IV were isolatespecific. Host-parasite interactions in quantitative resistance to BLB and their modification by induced mutations are discussed.
Relative accuracy of a neighbour method for field trials
Authors: Lill W. J. , Gleeson A. C. , Cullis B. R.
Published: March 2009

Two scries of simulation experiments were used to investigate the accuracy of treatment and variance estimation with a neighbour analysis of field trials proposed by Gleeson & Cullis (1987). The first series examined the accuracy of residual maximum likelihood (REML) estimation of seven theoretical error models applicable to field trials. REML estimation provided accurate estimates of the variance parameters, but the Ftest of treatments was slightly biased upward (to +2·4%) for first differences models and slightly biased downwards (to –1·4%) for second differences models. The second series of simulations, based on 19 uniformity data sets, illustrated that treatment effects were consistently estimated more accurately by the REML neighbour (RN) analysis of Gleeson & Cullis (1987) than by incomplete block (IB) analysis with recovery of interblock information. The relative gain in accuracy of RN over IB depends on the amount of systematic variation or ‘trend’ in the trial, and ranged from 6 to 18% with an average of 12% for a range of trend and error variances commonly encountered in field trials. The predicted average standard errors of pairwise treatment differences from the RN analysis were in close agreement with their empirical estimates, indicating that the predicted average S.E.D. is approximately valid.
Breaking of seed coat dormancy in a medicinal plant Tetrapleura tetraptera (Schum & Thonn)
Authors: Odoemena C. S.
Published: March 2009

Tetrapleura tetraptera (Schum & Thonn) is a member of the Family Mimosaceae. It is a perennial, wild West African tropical forest tree (Hutchinson & Dalziel, 1973) and is extensively used in many traditional medicines. The fruit is used in Nigeria as a spice added to soup for nursing mothers from the day of delivery to about 1 month postnatally, to prevent post-partum contractions.
The effect of reduced leaf shear strength on the nutritive value of perennial ryegrass
Authors: Mackinnon B. W. , Easton H. S. , Barry T. N. , Sedcole J. R.
Published: March 2009

Progeny of perennial ryegrass (PRG) plants selected for low and high leaf shear strength were sown in a spaced-plant field experiment and were shown to differ in leaf strength in the same direction, confirming this to be a heritable trait. Selection for low leaf shear strength also reduced weight per leaf length, but had no effect on dry-matter (D.M.) percentage, growth score, rust score or tendency towards aftermath heading.

Rates of D.M. consumption (g D.M./min) and ruminal degradation of D.M. using the polyester bag technique, were then determined with small quantities of the two PRG selection lines, and also white clover, using sheep fed a basal diet of fresh ryegrass/white clover pasture. Selecting PRG for low leaf shear strength slightly reduced concentrations of cellulose and hemicellulose, slightly increased total N concentration and increased rate of D.M. consumption by sheep (17%) but had no effect on rates of ruminal D.M. degradation. The selection thus moved the nutritional characteristics of PRG in the direction of white clover.

The first nutritional response to the selection appears to be a faster rate of D.M. consumption, and it is considered that leaf shear strength has potential for selecting PRG with increased rates of voluntary intake by ruminants.
The factorial combination of treatments in rotation experiments
Authors: Patterson H. D.
Published: March 2009

The paper deals with points arising in the design of factorial schemes for incorporating fertilizer and other treatments in rotation experiments. These schemes make extensive use of fractional replication and confounding, including split-plot confounding. They are complicated by the need to apply some treatments cumulatively and others with levels changed between plots in successive cycles so as to minimize errors due to constant plot differences.

Design keys are used to identify the treatment main effects and rotation differences with particular plot contrasts. The keys exhibit the structure of a design more compactly and clearly than a complete enumeration of identities and confounded contrasts and enable treatment combinations to be generated systematically.
Striga hermonthica on sorghum in East Africa
Authors: Doggett H.
Published: March 2009

Two sorghum varieties, Dobbs and Bukura Mahemba, were grown in Tanganyika over a wide range of sites, seasons and naturally occurring levels of Striga infestation. Dobbs showed good Striga resistance relative to Bukura Mahemba: In Dobbs there were 9% of the number of witchweed plants above ground as against Bukura Mahemba. (3200 to 37,200 Striga plants per acre): The grain yield of Bukura Mahemba (845 lb./acre) was adversely affected by the Striga. That of Dobbs (1325 lb./acre) was not.
Factors affecting the yield of seed produced by different varieties of red clover
Authors: Hawkins R. P.
Published: March 2009

Yields of varieties of red clover were found to vary from year to year and relative to each other.

Apart from losses in harvesting the seed, which were not studied, yields of seed were found to be correlated with seed set, size of seed and numbers of heads in the crop. In 1958 the dominant factor affecting yields was Kabatiella.

Because of the value of seed set in indicating potential yield, its relation to other characters was studied. Data are given for length of corolla tube, numbers of positive pollinators and size of head as indicated by the number of florets, and their relationship to seed set and to one another.
Sterile boars with ‘knobbed’ spermatozoa
Authors: Buttle H. R. L. , Hancock J. L.
Published: March 2009

Investigations have been made of boars yielding spermatozoa with a specific morphological (‘knobbed’) defect of the acrosome.

Counts were made of the number of knobbed spermatozoa in pairs of nigrosin eosin smears made from the semen of normal boars, in the semen of two (‘affected’) full brothers with ejaculates known to contain a high proportion of knobbed spermatozoa, and in mixtures of normal and affected ejaculates. Few or no knobbed spermatozoa were recorded in the semen of normal boars. Virtually all spermatozoa from the affected boars were recorded as knobbed. Counts on mixed samples agreed well with expected values.
Relationship between growth stage and digestible organic matter in triticale
Authors: Brignall D. M. , Ward M. R. , Whittington W. J.
Published: March 2009

In two experiments the yield, digestibility, protein and cell wall contents of several autumn-sown triticale cultivars were compared with rye at defined growth stages. Yields at each growth stage were highest in the triticale cultivars. The content of leaf blade and sheath fell with increased maturity while stem and ear content increased. There were differences between cultivars in the contribution of individual stem internodes. Digestibility also declined with maturity for all plant parts, and differences were apparent between plant parts and between cultivars. Leaf blade showed a slow decline in digestibility whereas stem digestibility showed a rapid reduction so that, at growth stage 43, young stem internodes were of much higher quality than older ones. Spring-type triticales (A208 and A476) had the highest digestibility at stages from flag leaf emergence to anthesis. The relationships between digestibility, plant part contents and cell wall characteristics are discussed.
Effect of preceding fodder crops on the nitrogen requirement of tall wheat
Authors: Narwal S. S. , Malik D. S.
Published: March 2009

In a 2-year field study, leguminous fodder crops (cowpea (Vigna unguiculata) and cluster bean (Cyamopsis tetragonoloba)) responded more to P than did nonleguminous fodder crops (maize (Zea mays), sorghum (Sorghum bicolor) and pearl millet (Pennisetum americanum)). The local cultivar of tall wheat, C306, yielded more when sown after fallow or legumes than after nonlegumes. Wheat sown after fallow or legumes produced more ear-bearing tillers and more grains per ear than when sown after nonleǵumes. Wheat sown after fallow or legumes responded to N application of up to 20 kg/ha, while when sown after nonlegumes it responded linearly to the highest rate of 60 kg/ha. Thus, preceding fallow, cowpea and cluster bean reduced the N requirement of wheat by 20–40 kg/ha compared with preceding maize, sorghum and pearl millet. Nitrogen increased grain yields only at applications of up to 40 kg/ha because lodging occurred at the higher rates. A cluster bean-wheat cropping sequence proved the most profitable.
Root and shoot growth and water use of chickpea (Cicer arietinum) grown in dryland conditions: effects of sowing date and genotype
Authors: Brown S. C. , Gregory P. J. , Cooper P. J. M. , Keatinge J. D. H.
Published: March 2009

Growth and water use of kabuli-type chickpea was measured during the 1982/83 and 1983/84 growing seasons in northern Syria under rainfed conditions. Winter-sown (November) and springsown (March) crops of cv. ILC 482 were grown in 1982/83 while in 1983/84 spring-sown crops of contrasting genotypes (ILC 482, ILC 1929 and ILC 3279) were compared.

In 1982/83, shoot dry matter and seed yields of the winter-sown crop were almost twice those of the spring-sown crop although the water use of both crops was almost the same. Root growth of both crops was most rapid before flowering but continued until maturity (early June) in the winter-sown and until mid to late pod filling (also early June) in the spring-sown crop. Root dry weight (c. 45 g/m2) and length (c. 45 cm/cm2) were similar in both crops during pod filling.

In 1983/84, shoot weight, root weight and root length were similar in all genotypes but the later maturity of ILC 3279 resulted in lower seed yield and hence harvest index, and greater water use.

The root length density decreased approximately logarithmically with depth in the soil profile although comparison between seasons and with other published results showed that the relations could not be used predictively. Water use efficiency was poorer in the second, drier season and was almost doubled by winter sowing.
Ammonia fluxes from grazed grassland: annual losses from cattle production systems and their relation to nitrogen inputs
Authors: Jarvis S. C. , Hatch D. J. , Lockyer D. R.
Published: March 2009

Losses of NH3 from a number of swards grazed by cattle were measured through 2 (1986–87) grazing years using a mass balance micrometeorological method. Comparisons were made of grass swards receiving 420 or 210 kg fertilizer N/ha per year and a grass-clover sward (GC) dependent upon fixation under rotational grazing managements. In one year a continuously grazed sward was also examined. Rates of NH3 loss were usually greatest whilst animals were present, especially during early and late season. This was not always the case, however, and losses sometimes continued into the next grazing period; there were also large day-to-day variations in fluxes. Seasonal trends were also not distinct, but losses tended to be lower during early and late grazings.

The annual losses from 420 and 210 kg N/ha and GC treatments were 25, 10 and 7 kg N/ha, respectively, and the differences between treatments were still marked when losses were expressed on a per animal basis. Total loss under continuous grazing was 61 % of that under the rotational system. Although the losses represent only 7·8, 5·6 and 3·7% of the inputs to420N, 2 ION and GC treatments, there was a good relationship between inputs and total losses, and also between the concentration of N in the herbage and losses per animal. The effects of the measured rates of loss on the input of NH3 from grazed grassland to the atmosphere are discussed.
Effects of irrigation, N fertilizer, cutting frequency and pesticides on ryegrass, ryegrass–clover mixtures, clover and lucerne grown on heavy and light land
Authors: McEwen J. , Day W. , Henderson I. F. , Johnston A. E. , Plumb R. T. , Poulton P. R. , Spaull A. M. , Stribley D. P. , Todd A. D. , Yeoman D. P.
Published: March 2009

The effects of irrigation, nitrogen fertilizer, cutting three or six times per year and a combined pesticide treatment that included aldicarb, phorate, benomyl and methiocarb on ryegrass (Lolium perenne) cv. S.23, either alone or in mixtures with white clover (Trifolium repens) cvs S.I00 or Blanca, and on lucerne (Medicago sativa) cv. Vertus grown on a silty clay–loam at Rothamsted and a sandy loam at Woburn were studied in 1977–81.

Benefits from irrigation were greater for six-cut than three-cut swards, with pesticides than without, for ryegrass with clover S. 100 than ryegrass with Blanca and at Woburnthan at Rothamsted. Lucerne did not benefit.

Responses of ryegrass to fertilizer N were best fitted by the model y = a + b/1+cx+dx2; and those of ryegrass–clover by the model y = a+bx (where y = yield, x = amount of N; a, b, c and d are constants). Without N, yields of ryegrass–Blanca clover mixtures considerably exceeded those of ryegrass–S.100. The former gave yields equivalent to those of ryegrass given 270 kg N/ha at Rothamsted and 330 kg N/ha at Woburn.

Lucerne without irrigation, N or pesticides gave yields in excess of all other unirrigated crops, even when these received pesticides and maximum N. Yields from three cuts of ryegrass greatly exceeded those from six cuts but yields of ryegrass–Blanca were greater from the six-cut regime.

Pesticides substantially improved the yields of ryegrass and clover, whether grown separately or mixed, but not those of lucerne. Pesticides not only controlled pests and diseases but also increased the incidence of vesicular–arbuscular mycorrhizas. The relative magnitude of yields of the different swards at the two sites differed, depending on treatment with irrigation, N fertilizer and pesticides. Differences between sites were removed or reversed by appropriate combinations of treatments.

Ryegrass–Blanca given no N fertilizer and cut six times removed 300 kg N/ha, an amount that was increased by irrigation and decreased by less frequent cutting; ryegrass–S.100 clover contained less N. Removals of P and K. often exceeded 35 and 300 kg/ha, respectively, each year. Herbage containing Blanca clover had much more Ca than that containing S.100 but at comparable yields all swards contained similar amounts of Mg.
The artificial rearing of lambs
Authors: Large R. V.
Published: March 2009

Artificial rearing involves the replacement of those contributions made by the ewe which are essential to the growth and development of the lamb. This not only includes the supply of food but also the warmth, shelter and ‘mothering’ normally provided by the ewe.

Relatively little information is available on the artificial rearing of lambs. The earliest report, perhaps, is that of Mumford (1901) who bottle-fed the milk produced by eight ewes to four lambs. The more practical aspects of rearing orphan lambs have been described by Preston (1958) and Caldwell (1957). More recent reports on the artificial rearing of lambs have been made by the Grassland Research Institute (1959–60, 1960–61), Cunningham, Edwards & Simpson (1961) and Large (1962).
The response of grass-clover and pure-grass leys to irrigation and fertilizer nitrogen treatment. II. Clover and fertilizer nitrogen effects
Authors: Reid D. , Castle M. E.
Published: March 2009

1. The effects of irrigation and fertilizer nitrogen treatments on four swards were studied for 3 years in an experiment at the Hannah Institute. This paper describes only the effects of the fertilizer nitrogen treatments and their interactions with the presence or absence of clover in the sward, since those of the irrigation treatments have been reported previously.

2. Annual applications of 0, 104, 208 or 312 lb. of fertilizer nitrogen per acre were made on swards of S 23 rye-grass or S 37 cocksfoot with or without S100 white clover.

3. The yields of the grass + clover swards exceeded those of the pure-grass swards at all fertilizer nitrogen application rates in the first 2 years and at the 0 and 104 lb./acre rates in the third year.
Irrigation of groundnut (Arachis hypogaea) grown in a Mediterranean environment
Authors: Metochis C.
Published: March 2009

The response of groundnut to different amounts of irrigation water and the effect of irrigation on the occurrence of chlorosis during the establishment period of the crop were studied in south-west Cyprus in 1984–88. The irrigation requirement of groundnut for the entire growing season was found to be 480 mm. Under-irrigation resulted in a soil water deficit and reduced production. Application of water in excess of requirement also reduced yield. Daily evapotranspiration under optimum soil moisture conditions increased from 1·5–2·0 mm at the beginning of the growing season to 7·0–7·5 mm at full crop development; it then decreased to 2·0–3·0 mm by the end of the season. In soils of low CaCO3 content, neither frequent water application nor over-irrigation during the crop establishment period caused any chlorotic symptoms or affected yield.
Rainfall and temperature effects on lentil (Lens culinaris) seed yield in Mediterranean environments
Authors: Erskine W. , El Ashkar F.
Published: March 2009

Lentil (Lens culinaris Medikus) is a rain-fed crop in North Africa and West Asia whose yields are limited by the amount and distribution of rainfall and winter cold. This study aimed to quantify the effects of climatic variables on lentil seed yields through the fitting of simple empirical models to trial data of two cultivars sown at six sites, 1983–89, representing 31 environments in Syria. The ranges over environments were 152–527 mm for total season rainfall and 1–52 for the number of frost nights. Overall, the total seasonal rainfall accounted for 40·8% of the variance in mean seed yield (1·27 t//ha, S.D. 0·82) with a response of 5·68 kg/ha/mm. A multiple regression model with monthly rainfall from November to May explained 67·6;0% of the variance in mean seed yield. From November to February the response of seed yield to rain was < 10 kg/ha/mm; rain in March, the period of late vegetative growth, made the most important contribution to seed yield. The response to April rain was negative. At Tel Hadya (the most frequently used site), the total seasonal rainfall accounted for 79·8% of the variance in mean seed yield, and the addition of the number of frost nights to the model improved the fit to 92·7%. Winter cold had a smaller effect on yield than rainfall, with no consistent overall effect, but differences over regions. The cultivars contrasted in their responses to drought (78S26002 was superior to ILL4400 at seasonal rainfall levels down to 134 mm) and the number of frost nights at Breda and Tel Hadya (78S26002 was more susceptible to cold than ILL4400). Thus, despite the predominant influence of rainfall on yield, the genetic variability in response to moisture and cold shows the scope for selection under rainfed Mediterranean environments.
Effects of feed intake and environmental temperature on chick growth and development
Authors: Smith M. O. , Teeter R. G.
Published: March 2009

Broiler chicks reared under three environmental temperatures (7·2, 23·9 and 35 °C) in the Southeastern United States of America in 1988/89 were precision-fed to levels which were c. 70, 90, 110 and 130% of the consumption observed in ad libitum-fed controls at 23·9°C, in order to examine the limitations imposed by feed intake upon growth rate, feed efficiency and survival. Ad libitum-fed birds that were housed at 7·2, 23·9 and 35 °C consumed feed at 12·1, 9·4 and 8·5% of body weight, respectively. Liveweight gain of birds consuming feed ad libitum was depressed by 26 and 46% in the 7·2 and 35 °C environments respectively. Increasing feed intake by precision feeding exceeded ad libitum consumption in the 23·9 and 35 °C environments, but not at 7·2 °C. Consumption of feed above thermoneutral ad libitum levels failed to increase (p <0·l) liveweight of carcass gain. Ration digestibility and dressing out percentage declined (P < 0·05) at the higher feed intake levels in the 7·2 °C environment.
Influence of faba bean tannins on male broiler chicks: evaluation of hulls from white- and coloured-flowered cultivars and of near-isogenic lines
Authors: Wareham C. N. , Wiseman J. , Cole D. J. A.
Published: March 2009

The hulls (seed coat) of tannin-free, white-flowered and tannin-containing, coloured-flowered faba beans (ViciafabaL.) were used in three experiments (1989–90) to investigate the effect of tannins on the apparent metabolizable energy corrected to zero nitrogen retention (AMEN) and apparent metabolizable nitrogen (AMN) of broiler chick diets.

In Experiment 1, the effects of four rates of hull inclusion from one white- and one colouredflowered cultivar (0, 28, 56 and 84 g/kg) on dietary AMENand AMN were studied. There was a significant response of AMENto hull inclusion rate (P <0·001) but no inclusion rate × cultivar interaction. For dietary AMN there was a significant effect of hull inclusion rate (P <0· 001) but no inclusion rate x cultivar interaction.

Experiment 2 consisted of two parts. In both, the total concentration of hulls was 227 g/kg but the ratio of white- to coloured-flowered hulls was varied in five increments; initially over the range 0·42–16·58 g/kg dry matter (DM) and subsequently, with another cultivar, 0·44–7·85 g/kg DM. Synthetic lysine and methionine were added to ensure that the basal diet was not limiting in these amino acids. A significant effect of tannin intake on dietary AMENand AMN was detected across the greater range of tannin concentrations (P <0·001) but not across the smaller one.

Experiment 3 evaluated three pairs of near-isogenic faba bean lines differing only in the gene governing tannin content and flower colour. Diets were formulated using three bean inclusion rates; 200, 400 and 600 g/kg. At each rate the white- and coloured-flowered lines were mixed in the ratios 100:0, 75:25, 50:50, 25:75 and 0:100. The response in carcass nitrogen retention (CNR) to tannin intake was assessed at each bean inclusion rate and for each pair of lines.

There was a significant effect of tannin intake on CNR in only one of the nine comparisons and in that case CNRincreasedas dietary content increased.

It was concluded that faba bean tannins can have a negative effect on the dietary AMENand AMN for chicks when present at a sufficiently high dietary concentration. However, the highest dietary concentration of faba bean tannins in Expt 3 was 10·52 g/kg DM, giving a maximum daily intake of 1·03 g tannins for the two-bird experimental unit. At concentrations and intakes up to this there was no evidence to suggest that faba bean tannins had a significant adverse effect.
Genetic improvement in the yield of winter wheat: a further evaluation
Authors: Austin R. B. , Ford Margaret A. , Morgan C. L.
Published: March 2009

Field experiments comparing 13 winter wheat varieties representing very old, old, intermediate and modern groups were carried out over three seasons. The experimental sites were on soils of high fertility and weeds, diseases and pests were controlled by applications of proprietary agrochemicals. Lodging was prevented by supporting the plants with coarse-mesh netting.

The average yield of all varieties over the three harvest years 1984, 1985 and 1986 was 7·7 t/ha (at 15% moisture content). Compared with the very old varieties which were grown by farmers during the 19th century, the modern varieties gave 59% more grain, had 14% more ears/m2 and 30% more grains per ear, but a similar mean grain mass. The modern varieties yielded slightly more biomass (total above-ground dry matter at harvest), were much shorter and reached anthesis about 6 days earlier than the older ones. In 1984, when the yields were greater than in 1985 and 1986, the yield advantage of the modern varieties was more in percentage and absolute terms than in the other years. Also, in 1984, the differences between the very old and the modern varieties in biomass was the greatest.

The genetic gain in yield measured in these experiments is compared with those estimated for other countries and reasons for the variation are discussed.
Influence of dietary phosphorus on the performance of lactating dairy cattle
Authors: Brodison Jane A. , Goodall E. A. , Armstrong J. D. , Givens D. I. , Gordonh F. J. , McCaughey W. J. , Todd J. R.
Published: March 2009

In an experiment, carried out over 3 years, two groups of dairy cows offeredad libitumaccess to grass silage received 8 kg/day concentrate differing only in phosphorus content (low P concentrate: 4·0–4·5 g/kg dry matter (D.M.); high P concentrate: 6·0–6·5 g/kg D.M.) during the winter feeding period of approximately 6 months. During the summer period all animals were grazed together on perennial ryegrass pastures. There were no consistent significant effects of P content on any of the variables measured. The mean calving indices were 371 (S.E. = 3·71,n= 122) and 379 (S.E. = 4·28,n= 95) days and overall conception rates were 0·70 and 0·68 for the low and high P treatments, respectively. Mean plasma P concentrations during the winter period were significantly reduced (P > 0·01 or greater) in years 2 and 3 of the study on the low P treatment. In 1 year milk yield was significantly higher (P > 0·01) on the low P treatment although the fat content was significantly reduced (P > 0·05) but these effects were not recorded in the other 2 years.
Photosynthesis, chlorophyll content and ribulose diphosphate carboxylase activity in relation to yield in wheat genotypes
Authors: Murthy K. K. , Singh M.
Published: March 2009

Photosynthetic rates, chlorophyll content and activity of ribulose 1,5-diphosphate carboxylase (RuDPC) were determined for 18 genotypes of wheat (Triticum aestivum L.) in pot culture. Measurements were made at various growth stages. Correlation studies between physiological characteristics and seed yield were made at each stage separately.

Genotypic variations were observed at different growth and developmental stages in photosynthetic rates (1·8–2·7-fold), chlorophyll contents (1·2-fold) and enzyme activities (2-fold). Chlorophyll content and enzymic activity increased in plant leaves with advancing age while apparent rates of photosynthesis decreased.

RuDPC activity in flag leaf at anthesis showed significant positive correlation with grain yield (r = 0·55). Other attributes did not show significant association with grain yield.
Graphical assessment of intercropping methods
Authors: Pearce S. C. , Gilliver B.
Published: March 2009

When experiments are conducted on two crops in association significance tests are available for judging whether treatments are having different effects or not. If, however, differences are established, it becomes necessary to assess the various treatments in agronomic, dietetic or economic terms. Graphical methods are here advanced to aid such assessment, special attention being given to (a) the stability of recommendations when the monetary or other values of the two crops change from season to season, (b) the measurement of yield advantage of mixtures over pure stands, and (c) the maximization of yield when it is desired to produce the two crops in specified proportions. The relationship to competition experiments is discussed.
The effect on earthworms of ploughing, tined cultivation, direct drilling and nitrogen in a barley monoculture system
Authors: Gerard B. M. , Hay R. K. M.
Published: March 2009

Dilute formalin was used to sample earthworm populations after the second (1969) and sixth (1973) harvests from a continuous barley experiment in which the cultivation treatments include deep (30 cm), normal ploughing (20 cm) and tined (three passes to 20 cm) cultivations and no tillage (direct drilling), at four nitrogen rates: 0, 50, 100 and 150 kgN/ha. Eight species of Lumbricidae were found, withAllolobophora chloroticaandA. longaco-dominant in both years, joined byA. caliginosain 1973.

In 1969,Lumbricusspp., particularly largeLumbricus terreslris, tended to be more numerous in the untilled plots.

In 1973, the total populations had increased by 170%, with 50–100% more earthworms in untilled than ploughed plots, one third more with 50 and 100 kg N/ha fertilizer than with no nitrogen, and one-third more in the slightly heavier sandy clay loam soil than the lighter loam.

Most earthworm species reacted in the same way, and the reasons for any unusual reactions are discussed.
The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumen liquor in vitro
Authors: Menke K. H. , Raab L. , Salewski A. , Steingass H. , Fritz D. , Schneider W.
Published: March 2009

A rapid method for measuring gas production during incubation of feedingstuffs with rumen liquor in vitro is described. Gas production in 24 h from 200 mg feed dry matter was well correlated with digestibility of organic matter, determined in vivo with sheep. Multiple regression analysis, when it included data from proximate analysis, resulted in an equation (R = 0·98) for prediction of metabolizable energy content, based on 30 experiments with rations varying in protein and crude fibre content, and 59 other experiments with concentrates. Energy content was in the range of 7·7–13·2 MJ ME/kg D.M. (± S.D. = 11·17 ± 1·08). The residual standard deviation of the equation was 0·25 MJ. Gas production was measured in calibrated syringes. The only chemical determinations needed are dry matter, protein and fat. Differences in activity between batches of rumen liquor are corrected by reference to gas production with standard feedingstuffs (hay meal and maize starch).
The effects of fluid sowing pre-germinated seeds and transplanting on emergence, growth and yield of outdoor bush tomatoes
Authors: Gray D. , Steckel Joyce R. A. , Ward J. A.
Published: March 2009

Experiments on outdoor bush tomatoes cv. Sleaford Abundance were conducted during 3 years to compare seedling establishment from fluid-sown pre-germinated seeds with that from conventionally sown dry seeds and to compare the effects on ripening and yields of these establishment methods with transplanting. Fluid-sown pre-germinated seeds emerged about 15 days earlier than conventionally sown dry seeds from sowings made in late April (mean soil temperature at seed depth from sowing to emergence ranged from 9 to 11.5 °C) and about 6 days earlier from sowings made in mid-May (mean soil temperature ranged from 12 to 15 °C). The percentage seedling emergence from pregerminated fluid-sown seeds was, on average, 57% from the earlier sowings and 65% from the later sowings, 34 and 24% higher, respectively, than from dry seeds sown conventionally. Plants from fluid-sown pre-germinated seeds were about 50% heavier than those from dry seeds at all stages of growth up to flowering. Crops established by fluidsowing started to ripen 7 days earlier than those established from dry seeds, when averaged over sowing dates and years. Yields of ripe marketable fruit > 35 mm in. size from crops established from pre-germinated seeds were 35·2 t/ha, averaged over sowing and planting dates, 37% higher than from dry seeds though 51% lower than from transplants. In the two years with good growing seasons crops fluid sown in late April gave as good yields as those transplanted in late May and early June, after the last frosts, though in the cool wet year yields from fluid-sown crops were considerably lower than those from transplanted crops. Yields of ripe, marketable fruit from ‘bare-root’ plants raised from pre-germinated seeds in unheated Dutch-light structures were, on average, 48·5 t/ha, 25% higher than from plants raised in soil blocks in a heated glasshouse.
An analysis of the effect of weed competition on growth and yield attributes in sorghum (Sorghum vulgare), cowpeas (Vigna unguiculata) and green gram (Vigna aureus)
Authors: Enyi B. A. C.
Published: March 2009

In each of the crops studied, weeding increased grain yield, weeding 2 weeks after sowing being better than weeding either four or eight weeks after sowing and weeding two and four weeks after sowing being better than weeding either two and eight weeks or four and eight weeks aftersowing. Weeding thrice (two, four and eight weeks after sowing) was significantly superior to all the other weeding treatments. Weeding increased leaf area index, dry weight of side and mainstem and number of mature pods at harvest in green gram and cowpeas. In sorghum, apart from increasing leaf area index, it also increased the length of ears and grain weight per unit lengthof ear. The weeding treatments affected grain yield in cowpeas and green gram due totheir influence on leaf area development, development of the main and side stems and on the number of mature pods produced at harvest. The effect of the weeding treatments on grain yield of sorghum was due to their influence on leaf area development, length of ear and grain weight perunit length of ear.
Intake, digestion and gastro-intestinal mean retention time in Asiatic buffaloes and Ayrshire cattle given two contrasting diets and housed at 20° and 33 °C
Authors: Mathers J. C. , Baber R. P. , Archibald R. F.
Published: March 2009

Four adult (4·5–7 years old) swamp buffaloes (Bubalus bubalis)and four adult (4–5 years old) Ayrshire cattle (Bos taurus) were housed in climate chambers maintained at 20° or 33 °C and given ad libitum access to a medium-quality, complete pelleted diet (AA6) or a lower-quality pelleted diet of alkali-treated barley straw supplemented with urea, sulphur, minerals and vitamins (ATS). Using a balanced double cross-over design, each animal was studied at each temperature and whilst consuming each of the two diets in experimental periods lasting 20 days. On day 13 of each period, animals were given single doses of two nonabsorbable markers, and food intake and complete collections of faeces were measured for the remainder of the period. Blood samples were taken at the end of each period.

Voluntary food intakes on a per kg body weight (W) or per kg W0·75 basis were significantly higher for the cattle than for the buffaloes, although this difference was reduced with the lower-quality diet and at the higher temperature. Cattle appeared to be more heat stressed at 33 °C than the buffaloes, but species had little effect on digestion or gastro-intestinal mean retention time. Calculations suggested that a greater proportion of digestion of ATS than of AA6 occurred postruminally.
Efficiency of neighbour analysis for replicated variety trials in Australia
Authors: Cullis B. R. , Gleeson A. C.
Published: March 2009

Use of a one-dimensional neighbour method of analysis in 1019 variety trials of a range of crops conducted by plant breeders in four states of Australia in 1985–87 resulted in an average reduction of 42% in variances of varietal yield differences compared with conventional randomized complete block analysis. Of these trials, 219 were designed as square, rectangular or generalized lattices and the average reduction in variances of varietal yields with incomplete block analysis and recovery of interblock information was 33%. The results emphasized that plots should be wide enough to avoid interplot competition, and that neighbour analysis is of most benefit in trials with short plots or when the field layout has many plots in a row.
Effect of irrigation and nitrogen on herbage and oil yields of Japanese mint (Mentha arvensis)
Authors: Singh V. P. , Kothari S. K. , Singh K. , Singh D. V.
Published: March 2009

Japanese mint (Mentha arvensis Linn.), a succulent and multicut annual, has a very high water requirement because its active growth period coincides with premonsoon hot summer months, when soil moisture is inadequate and soil temperature is high. Maintenance of soil moisture and optimum N nutrition are important for realizing maximum yield potential. The effects of irrigation (Krupper et al. 1968; Duhan et al.1977; Clark & Menary 1980; Khera et al. 1986) and N fertilization (Singh 1986; Kothari et al.1987) in enhancing herbage and oil yields of mint have been well documented in the literature. There is, however, little information on the interactions of irrigation and N with growth and yield.
Effects of irrigation, plant density and genotype on pollination, fertilization and seed development in spring field beans (Vicia faba L.)
Authors: Stoddard F. L.
Published: March 2009

Incidences of pollination and fertilization were determined and the development of seeds was monitored in spring beans over 2 years. Plant density was varied in the 1st year and irrigation in the 2nd. The incidences of pollination, fertilization and seed development were all independent of plant density. The proportion of ovules that developed as seeds was slightly enhanced in irrigated plots as losses from abortion and from lack of fertilization within fertilized ovaries were both reduced. Autofertility, or spontaneous self-pollination leading to fertilization, led to an increase in the overall incidence of fertilization. Three autofertile stocks were up to 11% more pollinated and fertilized than two partly autofertile ones which, in turn, were up to 20% more than two non-autofertile, long-podded stocks. A closed-flower population was 30% less fertilized than the long pods and was insufficiently autofertile to allow an adequate number of pods to set on the lower flowering nodes. Three stocks, one autofertile, one with terminal inflorescences (ti) and the third with both characters, were subject to particularly high losses of fertilized ovules from abortion, 27–35%, while few ovules, 12% or less, aborted in closed flowers and long pods. Failure of seeds to mature in long pods was associated primarily with the low proportion of ovules fertilized within fertilized flowers, rather than with abortion of the fertilized ovules.