bluuebunny/crossref_metadata_2025 huggingface dataset:
Plantlet formation from internode bases of carnation (Dianthus caryophyllus L.) in vivo - useful to mutation breeding or not?
Authors: Custers J.B.M.
Published: June 2020

After decapitation of the main shoot and subsequently the axillary shoots of carnation plants, annular zones extending between axils of opposite leaves produced numerous buds. Low temperatures (10-14 deg C) were essential for this bud formation, which was restricted to young internodes. The season affected the time till bud formation, and determined whether the buds were formed from the main axis or the laterals. Indications were found that these buds were adventitious. The possibility of using these buds in mutation breeding, and the possible risks if they are formed during clonal micropropagation in vitro, are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Hybrid tea-roses under controlled light conditions. 2. Flowering of seedlings as dependent on the level of irradiance.
Authors: Vries D.P. de , Smeets L.
Published: June 2020

Under the experimental conditions described in the preceding abstract, mortality increased with decreasing light intensities. The percentage of flowering seedlings increased and that of aborting ones decreased with irradiance. For the populations studied, no genotype-environment interactions for the percentages of flowering seedlings occurred. A selection procedure for roses with a low light requirement for flowering is considered. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of a soil compaction process on subsequent soil tillage processes. A new research method.
Authors: Koolen A.J.
Published: June 2020

The influence of a soil compaction process on subsequent tillage processes was studied by laboratory experiments on small soil samples. Suction curves as well as the relation between moisture content and strength properties depend on moisture content at precompaction. The described method allows the testing of many variables at relatively low costs. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A model of dry matter distribution in cassava (Manihot esculenta Crantz).
Authors: Boerboom B.W.J.
Published: June 2020

Results of an experiment in Trinidad were analysed and data obtained from literature were recalculated to determine which factors control the DM distribution in the cassava plant. Under given conditions for long periods, possibly for the storage life of cassava, the distribution of DM over tubers and shoot proved to be constant. Based on this finding, a model was developed and 2 parameters were introduced: ESRP, efficiency of the plant at producing tubers; ISS, initial plant wt. at which tuber production starts. The model was used to visualize genetic differences and the effect of environmental conditions on DM distribution. The relation between harvest index and ESRP was discussed. It is recommended that ESRP is used instead of harvest index as a selection trait. Selection material on ESRP can be screened rather early in the growth cycle as tuber wt. is linearly related to plant wt. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Fertilizer response of cold-tolerant sorghums under semi-arid high-altitude conditions.
Authors: Arkel H. van
Published: June 2020

5 fertilizer trials were carried out in 1974-5 at 3 different high-alt. locations in Kenya. In 3 of the 5 trials the yield response of a grain-type sorghum cv. was compared with the response of a forage-type cv. to N and P. In the other 2 trials the yield response of a grain-type sorghum to N, P, K and Mg + Zn, B and Cu was studied. Rainfall during the field period of the crop varied from 225 mm to 811 mm. There was no interaction with yr, but the responses varied greatly with trial site. Although DM yields obtained from the grain type in the driest trials were considered good (4.9 t DM/ha on 255 mm and 7.2 t DM/ha on 294 mm), no response to N or P was observed. Under wetter conditions it appeared that N increased the total DM yield of the forage-type cv. and the grain yield of the grain-type cv.; the type was accentuated. P increased the grain yield and total DM yield of the grain-type cv. Both N and P increased the CP content of the forage sorghum, but with the grain sorghum only N increased CP content whereas P decreased it. K and trace elements had a positive influence on yield in 2 experiments, but more work is needed to evaluate this effect in detail. Yield and forage quality differences resulting from different fertilizer applications were small. One possible reason for this is N-fixation in the soil, but more research is needed to substantiate this. In the trials with the lowest rainfall, the earlier maturing grain type outyielded the forage type, but if rainfall was less limited the forage type had a clear advantage over the grain type. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Patterns of tillering and grain production of winter wheat at a wide range of plant densities.
Authors: Darwinkel A.
Published: June 2020

The effect of plant density on the growth and productivity of the various ear-bearing stems of winter wheat was studied in detail to obtain information on the pattern of grain production of crops grown under field conditions. Strong compensation effects were measured: a 160-fold increase in plant density (5-800 plants/m2) finally resulted in a 3-fold increase in grain yield (282 to 850 g DM/m2). Max. grain yield was achieved at 100 plants/m2, which corresponded to 430 ears/m2 and to about 19 000 grains/m2. At higher plant densities more ears and more grains were produced, but grain yield remained constant. Tillering/plant was largely favoured by low plant densities because these allowed tiller formation to continue for a longer period and a greater proportion of tillers produced ears. However, at higher plant densities more tillers/unit area were formed and, despite a higher mortality, more ears were produced. The productivity of individual ears, from main stems as well as from tillers, decreased with increasing plant density and with later emergence of shoots. In the range from 5 to 800 plants/m2 grain yield/ear decreased from 2.40 to 1.14 g DM. At 800 plants/m2 nearly all ears originated from main stems, but with decreasing plant density tillers contributed increasingly to the number of ears. At 5 plants/m2, there were 23 ears/plant and grain yield/ear ranged from 4.20 (main stem) to 1.86 g DM (late-formed stems). Grain number/ear was reduced at higher densities and on younger stems, because there were fewer fertile spikelets and fewer grains in these spikelets. At the low density of 5 plants/m2, plants developed solitarily and grain yield/ear was determined by the number of grains/ear as well as by grain wt. Above 400 ears/m2, in this experiment reached at 100 plants/m2 and more, grain yield/ear depended solely on grain number, because the wt. of grains of the various stems were similar. The harvest index showed a max. of about 44% at a moderate plant density; at this density nearly max. grain yield was achieved. At low plant densities the harvest index decreased from 45% in main stems to about 36% in late-formed stems. However, no differences in harvest index existed between the various ear-bearing stems if the number of ears exceeded 400/m2. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A case study on the effect of soil compaction on potato growth in a loamy sand soil. 2. Potato plant responses.
Authors: Loon C.D. van , Bouma J.
Published: June 2020

Potato plant reactions to soil compaction were studied in the field in the dry yr 1976. Irrigation was applied in some of the treatments. Strong compaction of topsoil resulted in shallow rooting, low water availability and relatively slow foliage and root growth in the first 60 days after emergence, compared with the non-compacted treatment. Compaction of the subsoil (formation of a plough pan) initially resulted in relatively rapid foliage growth, which was partly due to a high capillary flux from the water table; however the rate slowed down as vertical root elongation became inhibited by the plough pan. Topsoil compaction resulted in depressed tuber yields and severe induction of second growth compared to the non-compacted or irrigated treatments. At maturity, differences in total yields among treatments were small except for the treatment with a plough pan where the yield was low; soil compaction decreased marketable tuber yield. The quantity of available water for the crop, defined as the measured water uptake from the rooted zone and a calculated capillary flux to the rooting front was compared with potential evapotranspiration and significant differences thus obtained among treatments were well reflected by observed differences in vegetative growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A study into the mobility of iron in podzolized Sarawak upland soils by means of selective iron extractions.
Authors: Andriesse J.P.
Published: June 2020

The presence of relatively large amounts of crystalline free iron oxides gradually increasing with depth, a virtual absence of new iron accumulations in the amorphous form and a great activity of organic acids in complexing iron in surface horizons were observed. Additional field information provides evidence of large accumulations of iron oxides at great depth in cracks and joints of sedimentary rocks. These characteristics suggest that there has been a relative accumulation of crystalline iron oxides through desilication during an early stage in soil formation. This was followed by a loss of iron in varying degree from the upper horizons, which can most likely be attributed to fossil argilluviation and weathering of iron-rich clay, or possibly to fossil reduction with transport in ferrous form. The latter would presuppose the existence of poorly drained conditions prior to strong dissection resulting in the present landscape. The strong and extensive accumulation of iron oxides at great depth in cracks and joints may be attributed to the oxidation and precipitation of ferrous and ferric iron mobilized upon initial oxidation of pyrites in the weathering front of the sedimentary rocks. Lateral movements of soil water may play a role in this. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Drainage criteria for soil workability.
Authors: Smedema L.K.
Published: June 2020

Drainage requirements for workability are formulated on the basis of the soil moisture content at the lower plastic limit, and the relationship of the latter value to field capacity is investigated. Current drainage design criteria are analysed with respect to soil workability requirements; it is concluded that there is little technical and even less economic scope for improving soil workability by adopting stricter criteria, leading to narrower drain spacings. However, a case can be made for increasing the drain depth in medium and heavy textured soils beyond the commonly applied depth of about 100 cm, in the Netherlands. The effects of soil management on soil workability are briefly discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of photoperiod on head formation in some Brachiaria species and Chloris gayana cv. Masaba.
Authors: Dirven J.G.P. , Soest L.J.M. van , Wind K.
Published: June 2020

The effect of the photoperiod on head formation was investigated in 5 Brachiaria spp. and selected ecotypes of C. gayana cv. Masaba. The experiments were conducted in the glasshouse with photoperiods of 10, 12 or 14 h in 1971 and 9, 10.25 or 12.5 h in 1973. The photoperiods comprised 9 h natural daylight in the summer, supplemented with 40 W incandescent lamps. It was concluded that B. mutica is a qualitative (obligate) short-day plant whereas B. ruziziensis and cv. Masaba are quantitative short-day plants. B. brizantha and B. decumbens were already flowering when exposed to 24-h photoperiods during the pre-experimental period in 1971. In Brachiaria introduction PI 299498, head formation in both experiments occurred a few days earlier under the short photoperiod treatment. In the later-formed heads of all grasses tested the number of racemes/head decreased, though the length of the racemes was not affected. During the 1971 experiment, culm branching was observed in most of the grasses. It was found that in Masaba "secondary" culms were mainly formed during photoperiods of 10 and 12 h but rarely in 14 h. "Tertiary" culms in B. ruziziensis were observed in photoperiods of 10 and 12 h. It is suggested that culm branching can be attributed to high RH. The low seed production of tropical grasses is mainly caused by the low number of heading tillers/unit area and the disynchronization of the flowering resulting from the long period of head production. It is suggested that more research on the photoperiodic response of these grasses would provide useful information on seed production. After selection of photosensitive cv. and seed production at lat. of approx. 15 deg N. and 15 deg S. the long period of heading would be reduced and the synchronization of the flowering would be improved. Some of the early heading types of Masaba are typical examples of photosensitive cv. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of soil moisture condition on the conversion rate of oxamyl.
Authors: Smelt J.H. , Dekker A. , Leistra M.
Published: June 2020

The decomposition of oxamyl in four soils under moist conditions was measured in incubation experiments at 15 deg C. Half-lives of oxamyl in soils with moisture tensions of approx. -9.8 X 103 Pa were 13 days in a clay loam, 14 days in a loamy sand, 34 days in a peaty sand and 39 days in a humic loamy sand. The rate of oxamyl decomposition in the clay loam decreased with decreasing soil moisture content down to values for below wilting point. Oxamyl decomposition in the humic loamy sand decreased with decreasing soil moisture content, but increased sharply in the very dry range. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Remote sensing of surface roughness and top soil moisture of bare tilled soil with an X-band radar.
Authors: Koolen A.J. , Koenigs F.F.R. , Bouten W.
Published: June 2020

Using a ground-based radar with a single frequency in the X-band (3 cm wavelength), the feasibility of mapping soil surface roughness and top soil moisture content was investigated. In order to cover the broad range of bare-soil appearances which occur in agricultural practice, the field treatment included a number of tillage types, several degrees of soil structure change which normally occur after tillage, and different soil moisture content. Different angles between the ray beam and the irradiated land (grazing angles) were used. The shape of radar return ( gamma )-grazing angle curves were entirely determined by soil surface roughness, while their positions depended on moisture content. Although this type of radar had limited discrimination ability, mapping of roughness and moisture may be possible under certain conditions. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Root and crop growth of oats as affected by the length of periods of high water-table.
Authors: Schuurman J.J.
Published: June 2020

The influence of the duration of a high water-table on root and shoot growth of oats in an early growth stage was studied. Root wt., depth of rooting and number of nodal roots with a length of < 10 cm reacted favourably on a low water-table. In this experiment shoot growth, however, hardly reacted to better root growth. This meant that the plants with restricted root growth could absorb water and nutrients as well as those with larger root systems. The fertilization of the top 0-25 cm of soil could have been an important factor in this report. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The adaptation of cold-tolerant sorghum and maize to different environments in the highlands of Kenya.
Authors: Arkel H. van
Published: June 2020

2 new introductions of high alt. sorghum, one a grain type and the other a forage type and 2 maize cv. were tested in a number of trials during 1974-7 in the highlands of Kenya. Yield data were regressed on alt., rainfall and some data on temp. Alt. had no significant effect on either grain or forage yield of any crop over the range tested (1525-2593 m). Yields were positively correlated with rainfall and negatively with temp. The grain sorghum benefited less from increased rainfall and also suffered less from reduced rainfall than any other entry. There were indications that the same grain type sorghum was more sensitive to temp. than any other entry. The interaction between genotypes and environments was considered more important than the av. crop yield. For an accurate estimate of this interaction the yield stability analysis, whereby yields were regressed on the environmental index, proved essential. Although rainfall was the most important factor affecting yields, it only explained c. 50% of the yield differences, whereas the index accounted for more than or equal to 90% of the yield differences. The grain sorghum was the highest yielding grain crop at low and medium rainfall levels, but this was only partly due to its superior water-use efficiency and was mainly due to a more favourable DM distribution. The forage sorghum was the highest DM yielding entry under most conditions. The maize cv. outyielded the sorghums only if growing conditions were good. Where rainfall was high (>1000 mm) DM yields of all crops were lower than where rainfall was 800-1000 mm. Sorghum yields were especially reduced at high rainfall giving the maize a distinct advantage; it was not clear whether this effect was due to rainfall or temp. differences. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of soil pH on copper toxicity to forage maize grown under field conditions.
Authors: Lexmond T.M.
Published: June 2020

Cu toxicity to forage maize was studied in a factorial field experiment comprising 4 Cu rates (0, 100, 200 or 300 kg Cu/ha) and 4 pH levels. Results are presented for crop yield and mineral composition. Raising the soil pH reduced the toxic effect of Cu to a smaller extent than would be predicted from the reduction in the Cu2+ ion activity. Apparently an increase in pH increased the toxicity of Cu2+ ions in sol. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Nitrate poisoning in cattle. 6. Tungsten (wolfram) as a prophylactic against nitrate-nitrite intoxication in ruminants.
Authors: Korzeniowski A. , Geurink J.H. , Kemp A.
Published: June 2020

The amount of nitrite formed in the rumen after supply of potassium nitrate was decreased considerably by tungsten, which was administered as sodium tungstate to cows orally and by rumen fistula in daily doses of up to 6.6 mg per kg body weight. This effect of tungsten depends on the molybdenum content of the fodder and can be overcome in the case of high molybdenum levels. The relationship between the nitrate intake of the animal, the dose of tungsten administered to the animal daily and the highest concentration of nitrite reached in the rumen is given as a mathematical equation as well as in the form of a triangular diagram. By means of this three-element relationship and as a result of kinetic studies on the action of tungsten, a dosage pattern of tungsten was elaborated. The effectiveness of tungsten as a protective against nitrate intoxication was proved on cows dosed repeatedly as well as with single doses of nitrate up to 500 mg NO3 per kg body weight. It is concluded finally that tungsten offers a high degree of protection against nitrate toxicity to ruminants. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of fat supplementation of concentrates on digestion and utilization of energy by productive dairy cows.
Authors: Honing Y. van der , Wieman B.J. , Steg A. , Donselaar B. van
Published: June 2020

Two energy balance experiments each used 6 high-yielding dairy cows. In the first, a 3 X 3 Latin square with one replicate, rations were of 7 kg hay and 11 to 14 kg of concentrates having crude protein 251 g and gross energy 17.9 MJ/kg, given alone or with 5% tallow or 5% soya bean oil. Three weeks of adaptation were followed by 10 to 12 days when excreta were collected and gas exchange estimated. Digestibility and metabolizable energy of concentrates and hay were also assessed using wethers fed to maintenance only. Intakes of DM and digestibility of nutrients other than lipid did not differ among treatments with either sheep or cows. There were no apparent differences in rumen fermentation in the one cannulated cow used, and energy loss in urine was also unaffected. Lipid supplement reduced methane loss. Milk yield and milk energy were increased with tallow, with a simultaneous reduction of milk fat and percentage of protein. Soya bean oil reduced the percentage of milk fat and milk energy produced. The second trial, using similar animals and with similar management had a change-over design in which the concentrate was given alone or with 7% tallow. Results confirmed those of trial 1. The effect of level of feeding on the efficiency of utilization of energy is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Lelydorp project-a pilot scheme for land development in Surinam.
Authors: De Haan J.H. , Hendriks J.A.H.
Published: June 2020

Agriculture, land utilization, land clearance and development in Surinam are discussed. The Lelydorp project is a pilot scheme in an infertile area on the old coastal plain of Surinam that runs parallel with the present coastline. In the north of the plain the land is sandy and undulating; in the south the soils are silty loams and clays of the old tidal flats. Five soil types are described. All are low in P and K. The organic-matter content of the valley soils and swamp soils is fairly high. It is hoped that the project will provide the basis for developing small independent farms by mixed farming and cultivation of perennial export crops. The farms will be mechanized as far as possible. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of a switch in photoperiod on the reproductive development of temperate hybrids of maize.
Authors: Struik P.C.
Published: June 2020

The reaction of maize to a switch in light phase was investigated in 3 phytotron experiments. Number of leaves was increased by a long-day phase (20 h) before tassel initiation but was not affected thereafter. Reproductive development was delayed by long days before tassel initiation and slowed down by long days after tassel initiation but ear development was affected more than tassel development. The time lag between anthesis and silking increased when short days (12 h) were followed by long days and the opposite was true when long days were followed by short days. Direct responses to photoperiod such as number of leaves and tassel branches occurred over a rather short time. Indirect effects such as area of leaves, ht. of plant and length of the ear shoot were max. when daylength no longer affected the number of leaves. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Nitrate poisoning in cattle. 7. Prevention.
Authors: Geurink J.H. , Malestein A. , Kemp A. , Korzeniowski A. , Klooster A.T. van't
Published: June 2020

Results are summarized from 44 feeding trials with dry or lactating cows fed hay, pre-wilted grass silage or freshly mown grass with or without concentrates. As nitrate content of the forage increased, the moment at which the highest methaemoglobin (MHb) concentration occurred was delayed. As the MHb peak increased, more time was required to reduce MHb to normal values of 2-3%. Dry matter (DM) intake varied with type of forage. Consumption of 1.1 kg DM/100 kg bodyweight required 2 hours with hay or silage and 3.5 h with fresh grass. The relationship between nitrate intake and the formation of MHb in the blood was used to calculate the amount of forage that may be consumed per meal without causing symptoms of nitrate poisoning. Hay and pre-wilted silage with a nitrate content of up to 0.75% in the DM may be given ad lib. Indoor feeding of freshly mown grass with a nitrate content of up to 1.5% may also be given with restriction. Under grazing conditions, grass with a nitrate content of 2% in DM was safe without restriction. Nitrate poisoning may also be prevented by inhibiting nitrate reduction in the rumen by a daily dose of tungsten (wolfram). However, all potential hazards of this prophylactic treatment need to be examined before its use under practical conditions can be recommended. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of length of growing period, nitrogen fertilization and shading on tillering of perennial ryegrass (Lolium perenne L.).
Authors: Alberda Th. , Sibma L.
Published: June 2020

The formation and death of tillers was studied in swards of perennial ryegrass. These swards differed in the length of the growing period and in the amount of N applied after each cut. Tillers died faster after a 6-weekly growing period than after a 4-weekly period. Some plants were far more affected than others, often resulting in the complete death of plants and thus in open spaces in the sward. Shading experiments suggested that plant deaths resulted from mutual shading. Small plants are shaded by taller ones and have a lower reserve content and a therefore higher death rate. High cutting frequencies or low N application rates could prevent open spaces from appearing or could be used to rehabilitate an open sward provided it was not yet infested with unwanted species. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Night temperature and fruiting of glasshouse cucumber (Cucumis sativus L.).
Authors: Heij G. , Lint P.J.A.L. de
Published: June 2020

Cucumber seedlings, cv. Farbio, planted in the greenhouse on 13 or 27 December or 10 or 24 January, were grown at 21-27 deg C day temperature and 12, 16 or 20 deg night temperatures until 1 April. Later planting produced more fruit than early planting. Night temperature had only a slight effect on fruit numbers/stem, but there was an optimum near 16 deg . The rate of fruit production between 12 and 20 deg was similar, but increased slightly with later planting. Production started earlier with higher night temperature and later planting. Fruit growth was not affected markedly by night temperature and fruit weight at harvest increased with season but was not dependent on the treatments. Fruit length was also independent of night temperature or planting date. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A smoke treatment inducing flower formation in iris bulbs.
Authors: Schipper J.A.
Published: June 2020

Bulbs of the iris cvs Ideal (8-9 or 10 cm circumference) and Prof. Blaauw (9-10 or 11 cm circumference) for early forcing were exposed to smoke from burning damp wheat straw during the first or second week of storage at 35 deg C after lifting. Smoke treatment was applied for 1, 3 or 5 days; gas analyses for ethylene, CO and O2 showed considerable variations in composition. With Ideal, treatment reduced the % non-flowering plants (in terms of bud blast for the 10-cm bulbs and three-leaved plants for the 8-9 cm bulbs) compared with controls; the larger bulbs also flowered earlier than those of controls. Fewer leaves than normal were produced. Flowering % in Prof. Blaauw was improved slightly by treatment, but earliness was not increased. No difference in effect was observed between the 2 treatment dates or the 3 durations. [For earlier work see HcA 51, 480.] (Abstract retrieved from CAB Abstracts by CABI’s permission)
An integrated chemical and micromorphological investigation of humic substances in three podzolized soils of the Netherlands.
Authors: Drozd J. , Jongerius A. , Kowalinski S.
Published: June 2020

The humic substances in a 'Holt' leptic podzol, a 'Haar' humic podzol and a 'Veld' gleyic podzol from the Netherlands were analysed chemically and micromorphologically. The absorption spectra of Na-humates in visible light and infrared spectra were determined for the humic acids. The translocation and distribution of the principal humus compounds occurred by mechanical illuviation in the 'Holt' podzol, and by translocation in solution in the 'Haar' podzol and the 'Veld' podzol. The micromorphological images were closely correlated with the chemical composition of the humic substances. Illuviation cutans occurring in the B horizons of the 'Haar' podzol and the 'Veld' podzol appeared to consist mainly of fulvic acids. The dark humus micro-aggregates characteristic of the 'Haar' podzol and the Ap horizon of the 'Veld' podzol were composed mainly of bitumens, humins and humic acids of high molecular weight, while the brown micro-aggregates of the 'Holt' podzol and the lower horizons of the 'Veld' podzol consisted mainly of fulvic acids and humic acids of low molecular weight. The stability of micro-aggregates was correlated with their composition. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Concentrate feeding and ruminal fermentation. 2. Influence of concentrate ingredients on pH and on L-lactate concentration in incubations in vitro with rumen fluid.
Authors: Malestein A. , Klooster A.T. van 't , Counotte G.H.M. , Prins R.A.
Published: June 2020

2. Rumen fluid was sampled before feeding from cows given hay, diluted with an anaerobic salt solution and added (20 ml) to different amounts (mostly 1 g) of maize gluten meal, maize, citrus pulp, tapioca, beet pulp, coconut expeller or soya bean oilmeal for incubation at 39 deg C. After at least 4 h of incubation there were large differences in pH and lactic acid concentration. The acidotic index of the feeds was influenced by increasing concentration of the substrate. Except with maize meal, there was little effect of particle size on pH and lactic acid concentration. There were differences in effect on pH and lactic acid concentration between different batches of the same feeds, especially with maize meal. Incubations with mixtures of concentrate ingredients showed different pH and lactic acid concentrations from values expected from results with the single ingredients. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of light intensity after flowering on the productivity and quality of silage maize.
Authors: Struik P.C. , Deinum B.
Published: June 2020

In field trials during 1977-9, maize was grown under shade conditions at various stages of development. Grain yield was correlated with irradiance received during grain filling and was increased by 10 kg/ha for every MJ/m2 at full light intensity when density was not limiting. In vitro OM digestibility and cell wall content decreased with shading during the latter part of the growing season. Shading also altered ensiling qualities. A hypothesis is formulated to account for the effect of shading on ear size, ear growth and leaf longevity in terms of the prompt effects of shading on root activity. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Plant growth in response to CO² enrichment, at two levels of nitrogen and phosphorus supply. 1. Dry matter, leaf area and development.
Authors: Goudriaan J. , Ruiter H.E. de
Published: June 2020

The effect on plant growth of doubling the normal aerial CO2 content was studied in lucerne, faba bean, perennial ryegrass, wheat, maize, poplar and potato. Because nutrients often limit growth, the effect of CO2 under N or P shortage was also studied. Doubling CO2 had the largest effect on DM yield with a good nutrient supply, but with N shortage part of the CO2 effect was retained even in non-leguminous spp. Except for faba bean, no CO2 effect existed with P shortage. Maize showed a small positive CO2 reaction under good nutrient supply but a negative one with nutrient shortage. Potato showed a small negative reaction to CO2 enrichment. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Notes on determinations of nitrate in plant material.
Authors: Novozamsky I. , Houba V.J.G. , Eijk D. van der , Eck R. van
Published: June 2020

The determination of nitrate in extracts of plants including grass, maize, sugarbeet leaves, lucerne, peas, cucumber, radish and lettuce by 3 different methods was tested. The methods based on nitration of O'-xylenol and dialysis of plant extracts and reduction of nitrate to nitrite ions by a Cu-Cd reductor were equally satisfactory. No influence of the extraction ratio was found. Extraction of plant material with water or electrolyte solution gave comparable results. Direct potentiometry gave too high results at lower nitrate ion levels. This phenomenon depends on the nature of plant material analysed and is apparently caused by organic anions. For spinach, the electrode can be used when the nitrate content is about 300 mmol nitrate/kg DM or higher. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Root-shoot interactions and plant life forms.
Authors: Schulze E.-D.
Published: June 2020

Interactions of water and nutrient flows on C relations are explained and typical features of root:shoot ratios in perennial plants including grasses and woody spp. are discussed. In a hydrostable annual crop plant (cowpea) partitioning was controlled by transpiration rate/leaf area and by the capacity of the root for water uptake. For perennial woody spp. the significance of plant architecture and morphology is demonstrated for a situation of competitive growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Variation in the root mass of ryegrass types and its ecological consequences.
Authors: Ennik G.C. , Hofman T.B.
Published: June 2020

The shoot:root ratio of Italian ryegrass and perennial ryegrass cv. in the vegetative phase was constant under constant conditions. With intermittent N supply, root mass and shoot:root ratio of ryegrass in monoculture varied widely. Both relatively and absolutely, root mass was larger than with constant N supply. Short periods of low N were sufficient for a marked increase in root growth. Under constant environmental conditions root mass was closely related to defoliation frequency. Considerable genetic variation in root mass existed between perennial ryegrass clones. Differences were largest under conditions of max. root growth. Root mass was positively related to competitive ability. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Concentrate feeding and ruminal fermentation. 3. Influence of concentrate ingredients on pH, on DL-lactic acid concentration in rumen fluid of dairy cows and on dry matter intake.
Authors: Malestein A. , Klooster A.T. van't , Prins R.A. , Counotte G.H.M.
Published: June 2020

Concentrate ingredients (maize meal, coconut oilmeal, maize gluten feed, citrus pulp, tapioca and soya bean oilmeal) were given daily at 0900 h into the rumen of 4 cows for 5 successive days. Hay was given freely at 1300 h. Between experimental periods there were intervals of at least 17 days when hay was given at 0800 and 1700 h. In a second experiment 6-kg amounts of 1:1 mixtures of 2 ingredients were given. Lowest pH and highest concentrations of D- and L-lactate in rumen fluid were reached 2 to 3 h after ingredients were given. Lowest pH and highest D- and L-lactate concentration in rumen fluid relative to the situation after citrus pulp was given, taken together as the potential risk of lactic acid acidosis (RLA), was best correlated with the content of glucose plus fructose (GF) and soluble protein (SPROT); RLA = 1.47GF + 0.49SPROT + 22.50 (r = 0.89). When combined ingredients were given, pH and D- plus L-lactate concentrations differed from values calculated from results after the same ingredients had been given separately. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effects of a localized supply of H₂PO₄, NO₃, Ca and K on the concentration of that nutrient in the plant and the rate of uptake by roots in young maize plants in solution culture.
Authors: Jager A. de
Published: June 2020

Restricting the supply of a single nutrient to 1 of 4 maize roots resulted in a shoot conc. of that nutrient between that in the supplied and that in the non-supplied control plant. The calculated rate of root uptake (mmol/g day) of the locally supplied nutrient was higher in the supplied root of the treatment than in those of the supplied control plant. The negative relationship between shoot nutrient conc. (and sometimes root nutrient conc.) and the rate of root nutrient uptake indicates the existence of a negative feedback control by the shoot conc. on the rate of root uptake directed to a desired level in the shoot. The possible nature of the controlling signal is discussed. Increase in content of locally supplied nutrient in non-supplied roots indicates a net flux of nutrients from shoot to root. This flux concurs in non-supplied plants with decreasing shoot:root ratio and in treated plants with restored growth rate of the non-supplied roots. Total cation conc. (K + Na + Ca + Mg) was independent of treatment and type of tissue, but at K deficiency Na and Mg contributed more in the root and Mg more in the shoot. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of muscle temperature soon after slaughter on pork quality: a pilot study.
Authors: Wal P.G. van der , Eikelenboom G.
Published: June 2020

The effect of various environmental temperatures, ranging between 42.5 and 25 degrees C during the first 2 h after slaughter, on pork quality was studied in longissimus dorsi samples. Higher environmental temperatures resulted in higher lactate and lower pH 2 h after slaughter. Samples kept at higher environmental temperatures (42.5 and 40 degrees C) showed characteristics typical for pale soft exudative pork. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Quantified 'Land-use policy options' in forest land evaluation for watershed management.
Authors: Thalen D.C.P. , Smiet A.C.
Published: June 2020

A forest land evaluation was made in the upper Kali Konto watershed in E. Java (Indonesia). The suitability of 155 Land Mapping Units for each of 13 Land Utilization Types was rated by standard procedures developed for rural land evaluation. A new concept of quantified 'land-use policy option' was introduced, being a theoretical combination of LUTs showing quantitatively, for the area as a whole, the consequences of a particular policy. The options are quantified by further specification of the LUTs in terms of one or more forest management models. The policies themselves comprise not only extremes such as 'conservation', 'population [needs]' or 'financial return' but also 'integrated' policies. In this case it is shown that an integrated land-use pattern could be developed to guarantee conservation of resources while largely meeting the demands of the local population for fuelwood and light timber and also yielding direct monetary benefits. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The use of and alternatives for tropical hardwood in the Netherlands.
Authors: Meijenfeldt C.F.W.M. von
Published: June 2020

The imports and end-uses of tropical hardwoods are analysed. Since 1972 annual imports have been around 1 million msuperscript 3 EQ (roundwood equiv.) of which 75% were used in the building industry, mainly in windows and window frames. Another important use is for pile plankings on canal banks, for which ekki [Lophira alata] is preferred. Possible substitutes for some end-uses are discussed: softwood (especially if preserved) is the most likely; reprocessed waste materials may also be used. A policy is proposed for conservation of the tropical rain forests, partly through their sustained yield management. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The accuracy and relative efficiency of Landsat data and orthophotos for determining area and volume of spruce.
Authors: Stellingwerf D.A. , Lwin S.
Published: June 2020

Comparative estimates were made for a 12 841-ha area of Upper Austria comprising areas of pure or mixed Norway spruce and beech, young stands and non-forest. The Landsat data, classified by principal components analysis, gave very inaccurate differentiation of species, age classes and smaller non-forest areas, although the total forest area was reasonably accurate. Stand vol. of spruce was estimated by 2-stage sampling of both data sets followed by field work on sample plots. The Landsat method required 53% more primary (first-stage sampling) units, 23% more man-days and higher extra costs than the orthophoto method for the same accuracy. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Priority listing for resource allocation: a method based on competitive influences between population centres.
Authors: Gier A. de
Published: June 2020

A method is described for quantitatively estimating the levels (intensities) of competition between adjacent population centres where the inhabitants collect a scarce resource, such as fuelwood, in the area around their population centre. A ranking of these levels indicates where competition is most severe and where action, e.g. fuelwood planting, is most needed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Some aspects of adaptation and adaptability of barley in European conditions.
Authors: Jestin L.
Published: June 2020

After a review of different approaches found in the literature to problems of adaptation and adaptability of barley, attention is paid to the ecophysiological reasons which may explain the recent extension of winter barley cultivation in NW Europe. A brief account is given of cooperative trials carried out in Europe to define spring barley varietal adaptability ("ESBAN" and "JESBT" trials). A general view of current statistical procedures to analyse adaptability and genotype environment interaction patterns is presented. Some indications are given of the use that the breeder can make of ecophysiological methodology and statistical models in breeding barley for wider adaptation. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Developments in breeding winter wheat for bread-baking quality in some north-western European countries.
Authors: Mesdag J.
Published: June 2020

The subject is surveyed under the following headings: baking quality in France; development of kernel yield and baking quality during the past 35 years in France; breeding wheat with improved baking quality in Great Britain in the 20th century; improvement of kernel yield and baking quality of winter wheat varieties during the past 30 years in England and Wales; development of wheat quality during the past 100 years in pre-war Germany and the German Federal Republic; the combination of higher yield and better baking quality in winter wheat varieties during the past 50 years in pre-war Germany and the German Federal Republic; and breeding research on baking quality in the Netherlands in the present century. It is shown that, within periods of time, varieties with a high score for baking quality generally tend to have a low grain yield. However, from the data presented, it is concluded that high yield potential and good baking quality can be combined in one variety, although the result may be attained less rapidly than with breeding for yield alone. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Digestion of proteins of varying degradability in sheep. 2. Amount and composition of the protein entering the small intestine.
Authors: Bruchem J. van , Rouwers S.M.G. , Bangma G.A. , Lammers-Weinhoven S.C.W. , Adrichem P.W.M. van
Published: June 2020

Sugarbeet pulp, citrus pulp, sugarbeet molasses and minerals and vitamins were mixed with different amounts of groundnut expeller, potato protein, peas or dried brewers' grains to give 6 concentrates with protein solubility from 7 to 51%. The concentrates (600 g daily) were given with rye grass (300 g daily) to 2 mature Texel wethers with an infusion tube into the abomasum and cannulae in the cranial duodenum and terminal ileum. Degradation of dietary protein in the rumen and synthesis of microbial protein were estimated from diaminopimelic acid and amino acid profiles. The extent of protein degradation in the rumen was almost independent of dietary protein content but varied with the nature of the diet. Degradability decreased in the order, groundnut expeller and peas, brewers' grains, potato protein. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of the ground-water regime and nitrogen fertilizer on the yield and quality of apples.
Authors: Visser J.
Published: June 2020

Results are summarized of a 12-year experiment with Cox's Orange Pippin and Golden Delicious on M9 rootstock. A 5-ha field of calcareous clay soil recently reclaimed from the sea was laid out to give 2 replicates of each of 11 drainage/subirrigation regimes. Three levels of N application were superimposed. The results are discussed in terms of changes in soil physical properties (structure, subsidence and compaction), root and shoot growth, and fruit yields and quality. Maximum vegetative growth occurred at groundwater levels of 70 to 130 cm in combination with adequate N application (75-150 kg N ha-1 year-1). The adverse effects of high groundwater levels on vegetative growth increased at higher N levels. Differences in fruit yields due to groundwater level were
Amino acid content and protein solubility of feather meal as affected by different processing conditions.
Authors: Papadopoulos M.C.
Published: June 2020

Feathers of broiler chickens were autoclaved for 30 to 70 min and feather moisture content was varied from 50 to 70% with no addition, addition of 0.2 to 0.6% sodium hydroxide or addition of 0.2 to 0.6% proteolytic enzyme. During processing there was marked degradation of cystine and smaller losses of the limiting amino acids lysine, methionine and histidine. Most of the lost cystine seemed to be converted to lanthionine. Digestibility (in pepsin-HCl solution) and solubility (in alkali or acid solvents) of feather meal protein were increased as a result of processing. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The in sacco degradation of crude protein and cell wall constituents in grass, alfalfa and maize silages.
Authors: Kwakkel R.P. , Bruchem J. van , Hof G. , Boer H.
Published: June 2020

Degradation of crude protein (CP) and cell wall constituents (CWC) in grass, lucerne and maize silages were estimated after incubation for 48 h in nylon bags in the rumen of 2 Dutch Friesian cows fed daily on hay 10 kg and concentrates 1 kg. Estimation of fractional rates of degradation was based on a single exponential degradation model. Fractional degradation rates of CP in grass, lucerne and maize silages were 5.2, 5.0 and 6.3% per h respectively. Corresponding values for CWC were 4.3, 4.0 and 2.8% per h. The non-degradable CWC fraction was higher in lucerne silage (52.1%) than in grass and miaze silages (20.4 and 24.6%, respectively). Extent of degradation of lucerne CWC was lower than that of maize and grass silages but voluntary intake of lucerne silage by steers was higher. Voluntary intake of silages cannot be explained by content, composition and degradation of CWC only; the physical structure may also be involved. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of slowly and rapidly degradable concentrate protein on a number of rumen parameters in dairy cattle.
Authors: Veen W.A.G.
Published: June 2020

In 5 trials with Dutch Black Pied or Dutch Black Pied X Holstein-Friesian cows the effects of feeding concentrates with rapidly and slowly degradable protein on rumen values were investigated. Samples of rumen fluid were taken before and 45, 90, 135 and 180 min after the morning concentrate feed. Rumen pH was not affected by protein degradability. Rumen ammonia content was higher when easily degradable protein was given than when slowly degradable protein was given; peak concentration varied from 10 to 12.5 and from 4 to 8 mmol/litre, respectively. Maximum concentration of lactate was not influenced by protein degradability. Rumen content of volatile fatty acids increased more rapidly when the slowly degradable protein rather than when the rapidly degradable protein was given. At all sampling times the molar acetate:propionate ratio was higher after feeding on slowly degradable protein than after rapidly degradable protein. (Abstract retrieved from CAB Abstracts by CABI’s permission)