bluuebunny/crossref_metadata_2025 huggingface dataset:
The difference in development rate of rye in relation to the number of spikelets per ear.
Authors: Hoogland R.F.
Published: June 2020

Leaf development in winter rye cv. Petkuser and Zelder [see F.C.A. 17: 1341] was further studied in 1962-3, after sowing on 25 Sep. Average stalk length increased with final number of leaves (11-14). Plants attained the same final leaf number either by a rapid rate of leaf emergence before winter and a slow rate after winter, or the reverse; the former growth pattern produced earlier emergence and greater areas of the 2 uppermost leaves, longer upper leaf sheaths, longer upper (and shorter lower) internodes, and slightly more spikelets/ear.-W.M.S.R. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The determination of magnesium with titan yellow; masking interferences with phosphates.
Authors: Van Schouwenburg J.C.
Published: June 2020

Phosphate very effectively masked heavy-metal interference in Bradfield's method for determining Mg. (Abstract retrieved from CAB Abstracts by CABI’s permission)
On soil genesis in temperate humid climate. V. The formation of the "albic" and "spodic" horizon.
Authors: Van Schuylenborgh J. , Bruggenwert M.G.M.
Published: June 2020

With the aid of parahydroxybenzoic acid as a model substance, some suggestions are given on the formation of the albic and spodic horizons under well-aerated conditions in very poor and acid parent materials. The acid forms soluble complexes with Fe, while insoluble compounds are formed with Al. The stability constants of the Fe complexes and the solubility product of the Al complex were determined. Hydrolysis of the Fe complexes formed in the A horizon, and formation of an insoluble Al complex are the most important mechanisms in the formation of the B2ir and B2h horizons, respectively. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Influence of higher fatty acids on the availability of magnesium in milking cows.
Authors: Kemp A. , Deijs W.B. , Kluvers E.
Published: June 2020

The availability of dietary Mg for five lactating cows decreased in proportion to the amount of animal fat added to their winter ration. Previous workers have reported that increasing crude protein content of the herbage is associated with decreasing availability of Mg for the cow, and that the content of higher fatty acids in grass and hay increases with increasing crude protein content. It was suggested that nitrogen fertilizers increase the fat content of the herbage, thereby reducing the availability of Mg. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Contribution to the knowledge of a solonetsic, magnesium-rich alluvial silty clay in the Maro-Koembe plain.
Authors: Van Es F.W.J. , Van Schuylenborgh J.
Published: June 2020

Soil survey and analysis of several profiles showed that the alluvial sediment was in an early stage of soil formation. Chemical analysis showed that it would eventually become a natraqualf. Studies of cation-exchange characteristics and of the soil solution suggested that Ca2+was removed more intensively than Mg2+ from the surface layer. However, Mg2+ was released strongly by weathering of minerals, but before being released into solution it was adsorbed so that there was high Mg-saturation of the exchange complex. A distribution coefficient of 1.2 for the Ca/Mg exchange equilibrium would be expected but a higher coefficient (1.4) in the A horizons of the most strongly leached soils was probably due to organic matter; a lower coefficient (1.0) in the deeper horizons was due to the mechanism of Mg release described above. Distribution coefficients for Ca/Na and Mg/Na exchange equilibria were 1.8 (Gapon) and 1.3 (Vanselow or Heald et al). It seemed possible to forecast the changes in cation-exchange characteristics that would result from further leaching and to predict the group to which the soils would finally belong. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Copper metabolism in milch cows. IV. Proof of the method: the liver uptake in gravidity.
Authors: Binnersts W.T.
Published: June 2020

The external method of measuring liver copper [V.B. 35, abst. 1026] was used to determine the percentage liver uptake after i/v or i/m inj. of Cu-64. The liver uptake was decreased to 35% in the last six months of pregnancy compared with an uptake of 50% in early pregnancy and non-pregnancy. This confirms the hypothesis that the fetal liver derives its copper mainly from the maternal "inorganic" blood copper rather than from the caeruloplasmin. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Root growth in acid soils.
Authors: Wind G.P.
Published: June 2020

In pot and field trials with oats and spring wheat grown in acid soils, a sharp limit to root development was observed at about pH 3.5; below pH 3.4 hardly any root growth occurred and above pH 3.6 it was hardly affected by pH. High acidity decreased weight and increased diameter of the roots.-M.S.M. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Growth, flowering and fruit-set of the tomato at high temperature.
Authors: Abdalla A.A. , Verkerk K.
Published: June 2020

Fireball, Hot Set and Porter were compared at 35 degrees C. day and 25 degrees C. night temperatures and at 22 degrees C. day and 18 degrees C. night temperatures. In the high-temperature conditions, Porter gave the highest yield of fruit. At the lower, more normal temperature for tomato growing, Fireball had the highest fruit yield and Porter the lowest. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Growth of closed green crop surfaces in the Netherlands.
Authors: Sibma L.
Published: June 2020

Highest growth rates of 10 crops with a closed leaf canopy and non-limiting supplies of water and minerals ranged from 162 (grass) to 228 (potatoes) kg DM/ha per day. When root DM was taken into account, the growth rate of most crops was similar, about 250 kg DM/ha per day, the determining factor being the weather. Differences in DM yields between crops were determined mainly by the duration of the growing period.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Climate, nitrogen and grass. 2. The influence of light intensity, temperature and nitrogen on vivo digestibility of grass and the prediction of these effects from some chemical procedures.
Authors: Deinum B. , Van Es A.J.H. , Van Soest P.J.
Published: June 2020

For part 1, not numbered, see Abst. 4271, Vol. 37. 2. Digestibility of forages grown at different in-tensities of light, temperatures and amounts of N fertilizer was estimated with wethers. The different factors affected chemical composition more than digestibility. Greater intensity of light increased digestibility and higher temperature decreased it. N fertilizer increased it but not significantly. Digesti-bility was less during stem formation. For prediction of digestibility in vivo by different chemical procedures, true digestibility in vitro estimated from digestibility of cell walls was the most accurate.-T. W. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of soil steaming on some properties of the soil and on the growth and heading of winter glasshouse lettuce. I. Changes in chemical and physical properties.
Authors: Jager G. , Van der Boon J. , Rauw G.J.
Published: June 2020

Soil steaming caused an increase of 33 ppm mineral N. There was no significant effect on water-soluble P2O5. The influence of steaming on buffer-soluble Mg content varied with the treatment but there seemed to be a negative correlation with the P content. Steaming enhanced K solubility and increased buffer-soluble Mn content. Fe and Al soluble in buffer solution were slightly increased. 44 references. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of CCC on growth and gibberellin content of tomato plants.
Authors: Van Bragt J.
Published: June 2020

A single application of CCC to the roots of young tomato plants cv. Moneymaker reduced the growth rate for about 3 weeks. After this period the growth rate of treated plants was higher than that of the controls as a result of accelerated growth of the top internodes. Extracts from CCC-treated plants, obtained on day 5 and day 29 after CCC treatment, contained slightly more gibberellin-like substances than extracts from control plants. These findings suggest that CCC does not inhibit gibberellin synthesis in tomato plants.-Univ. Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Factors affecting adventitious root formation in isolated stem segments of Rhododendron.
Authors: Pierik R.L.M.
Published: June 2020

Stem expiants of the rhododendron cultivar Catawbiense Album rooted more easily in vitro than those of Pink Pearl, agreeing with the experience of nursery practice. Rooting occurred only on segments of young soft shoots and was strongly promoted when the expiants were placed inverted on the medium. Continuous light inhibited, whereas continuous darkness promoted rooting. Rooting occurred only in the presence of an auxin together with a sugar in the culture medium. There was no evidence that mineral nutrition and temperatures between 21 degrees and 29 degrees C. play an important role.-Univ. Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Changes in the gibberellin content of Bryophyllum daigremontianum in connection with floral induction.
Authors: Zeevaart J.A.D.
Published: June 2020

After transfer from long days (LD) to short days (SD) the GA content of B. daigremontianum increased to a maximum at 14 SD, which is the minimal duration of inductive treatment necessary for flowering. At the time flower primordia started to differentiate the GA level reached a second peak. Between the two maxima the GA content dropped to a low level at 20 SD. Under LD conditions it showed little variation. Plants shifted to SD at a night temperature of 23 degrees C. did not flower and the GA content diminished to that of plants grown in SD throughout. Variations in the GA level were due to changes in fraction II, which is probably identical with GA5. No significant changes in the level of fraction I were observed.-Mich. St. Univ., East Lansing. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of the mother tuber on growth and tuberization of potatoes.
Authors: Bodlaender K.B.A. , Marinus J.
Published: June 2020

Sprouts separated from mother tubers showed under certain conditions (e.g. in the late variety Alpha under long-day) good foliage growth comparable with that of plants with a mother tuber; under other conditions (e.g. in the early variety Eersteling under short-day) foliage growth produced by such sprouts was relatively weak. Root development of the sprouts determined to a large degree the foliage growth and tuber yield. Experiments with Alpha showed that no direct or indirect influence of a mother tuber or inducing conditions (short-day) are necessary for tuberization, indicating that tuberization is a normal phase in the development of potato plants. In these experiments. plants from sprouts, cuttings of the 1st generation taken from these sproutlings and cuttings of the 2nd generation taken from the cuttings of the 1st generation, produced tubers under non-inducing conditions (long-day).-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Calculation of production of potatoes.
Authors: Rijtema P.E. , Endrodi G.
Published: June 2020

Net photosynthesis in potato crops is discussed. It was possible to calculate DM production even when water supply limited growth, using a modification of the procedure proposed by de Wit (see F.C.A. 19: 515). The relation between transpiration and total DM production was dependent on meteorological conditions during growth and not on specific differences between cv. DM distribution in potato plants is discussed.-F.A.S. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Spacing experiments with brussels sprouts grown for single-pick harvests.
Authors: Verheij E.W.M.
Published: June 2020

Two-year trials are discussed on the effects of different spacings, planting pattern and row orientation, stopping the plants, and time of harvest on the cropping, habit and root growth of the hybrid brussels sprouts variety Thor. Yields of dry matter per sq.m. rose sharply with increasing plant density up to about 4 plants per sq.m., above which there was little further increase. The average weight per plant, however, showed the reverse trend, and declined with closer spacing. The total yields of sprouts from unstopped plants attained a maximum at a density of about 1 plant per sq.m., but the maximum yields and numbers of marketable sprouts were obtained with densities of about 2 and 2 plants per sq.m., respectively. Plants grown at high densities were taller and more slender than low-density plants, a habit well suited to mechanical stripping. Moreover, the sprouts from high-density plants were more uniform, which facilitated grading. There was little difference between the number and distribution of the roots, including depth of rooting, over a wide range of plant densities. However, high-density plants had fewer thick roots, and at the widest spacings the total number of roots per sq.m. declined. The pattern of planting had a slight influence on the height of the low-density plants, but differential effects of various row orientations were negligible. Stopping the plants greatly increased the total yields of sprouts at all densities; the numbers of marketable sprouts from the stopped plants were also greater, especially at densities of 3 plants per sq.m. and above. Harvesting stopped plants in late October instead of late September resulted in much higher yields of sprouts at all densities except the lowest, despite a decline in the fresh weights of the plants during this period.-I.T.T., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Relation between total radiation and yield of some field crops in the Netherlands.
Authors: Sibma L.
Published: June 2020

Statistical treatment of yield data from potatoes, sugar-beet, peas, wheat, barley, flax and maize grown in short- and long-term experiments where water and mineral supplies were optimum showed that variations in yields, especially those of potatoes, were positively correlated with the total global radiation received during the growing period. Partial correlation coefficients showed that the length of the growing period and the annual yield increase might explain much of the yield variation.-G.M.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The developmental pattern of roots and shoots of oats under favourable conditions.
Authors: Schuurman J.J. , De Boer J.J.H.
Published: June 2020

Oats were sown on 24 Mar. in asbestos tubes 75 cm long and 15 cm in diameter filled with humus sand and placed in the open. The water level in the soil profile was maintained at about 70 cm below the soil surface by natural rainfall and by a controlled water supply from shallow dishes in which the tubes stood. Plants were sampled in duplicate at weekly intervals between 13 May and 15 July and the developmental growth pattern of shoots and seminal and nodal roots was examined. The total weight of nodal roots increased until the plant had attained its maximum shoot length, and until about 5 weeks after the last leaf appeared on 26 May. Weights and DM content of the shoots increased over the whole of the experimental period. The greatest number of nodal roots was initiated during 3-10 June, between the end of tillering and the beginning of panicle emergence; after that the numbers initiated per week decreased gradually. The number of seminal roots varied between 4 and 5 per plant and reached their maximum weight just after the end of tillering and before the panicles became visible. After 10 June the weight and growth rate of seminal roots decreased rapidly. Seminal roots and the early initiated nodal roots were the most important part of the root system. In the week before the panicles became visible, root and shoot growth was interrupted; this was thought to be related to the transition from the vegetative to the generative stage. CMC. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Studies on pod and bean values of Theobroma cacao L. in Nigeria. II. Number of beans per pod, with special reference to the natural pollination process.
Authors: Toxopeus H. , Jacob V.J.
Published: June 2020

Studies on open pollinated pods harvested from monoclonal, biclonal and polyclonal plots and 4 Amazon seedling trees over various periods showed that season, genotype and their interaction all have a significant effect on number of beans per pod. The character shows a high variability as a result of natural pollina-tion. The excessive variation observed in the number of beans of pods from the clone Na32 in a biclonal plot could be attributed to its self-incompatibility, location and flowering pattern. [For part I see the previous abstract.]-Cocoa Res. Inst. Nigeria, Ibadan. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The energy requirement for maintenance and production of laying hens.
Authors: Grimbergen A.H.M.
Published: June 2020

Heat production was recorded by open-circuit respiration calorimetry. In the first 3 experiments heat production after 24 h without feed by birds laying at about 80% production was measured. Mean daily fasting heat production of 12 White Leghorn hens of 1.68 kg bodyweight caged individually, 12 White Leghorn hens of 1.68 kg caged in pairs and 10 Australorp x Rhode Island Red hens of 2.4 kg caged in pairs were 97.0, 98.0 and 90.6 kcal per kg W0.75. The overall relation between heat production (H) and W0.75 was H=85.2 W0.75+16.6. The relation between daily energy retention (Y) in kcal per kg W0.75 and intake of metabolisable energy (ME) (X) in kcal per kg W0.75, established with 37 White Leghorn hens at peak and end of production, after 12 months, was Y= 0.642 X-65.7. The net availability of ME for egg production was 64.2+or- 5.5% and the daily maintenance requirement was 102+or-7.6 kcal per kg W0.75. The result was applied to a laying trial with 1020 hens in batteries and 300 on deep litter to get a measure of ME used for maintenance. After subtraction of ME used for production the calculated mean for maintenance was 131 and 138kcal per kg W0.75 for hens in batteries and on deep litter. ME for maintenance was greater in winter.-D. W. F. S. (Abstract retrieved from CAB Abstracts by CABI’s permission)
On soil genesis in temperate humid climate. VIII. The formation of a "udalfic" eutrochrepi.
Authors: Van Schuylenborgh J. , Slager S. , Jongmans A.G.
Published: June 2020

The active soil-forming processes occurring in a Holocene alluvial deposit were: the formation, along voids, of illuvial cutans consisting of clay minerals, Fe oxide and fine matric components (matriferriargillans), differential movement of clay minerals, kaolinite being most mobile; partial transformation of smectites into kandites; disturbance of cutans by biological activity resulting in the formation of papules; redox processes leading to the formation of micro-segregation of Fe oxide. The difference in character and location of matriferriargillans and ferriargillans is discussed. The former are thought to have been synthesized in the Holocene period and the latter in Pleistocene times. The soil is classifiable as a dystric eutrochrept, but as plasma movement generally occurs only in "dystric" (decalcified) material, the soil could be classified as a "udalfic" eutrochrept. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Historical notes on the zero-tillage concept.
Authors: Kuipers H.
Published: June 2020

In a brief review, earlier German and English attitudes to tillage research are contrasted, especially on the emphasis on soil structure v emphasis on weed control; the effect of the advent of zero tillage on this difference is discussed. It was concluded that chemical weed control gives greater freedom in tillage practice, and research is revealing risks that may be unacceptable for certain crops when tillage practices are changed. CCT. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Experimental studies on seed production of tropical grasses in Kenya. 1. General introduction and analysis of problems.
Authors: Boonman J.G.
Published: June 2020

Problems in seed production of Setaria sphacelata (2 cv.), Chloris gayana (3 cv.), Panicum coloration, P. maximum, Brachiaria ruziziensis and Melinis minutiflora are discussed. Low yields and quality were due to varying combinations of prolonged heading season per plant and per cultivar, prolonged flowering within a given head, low seed set, low number of fertile tillers, low seed retention, disease and bird damage. Actual yields were only about 5% of potential yields.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The Tara Irrigation Scheme: an integrated development project.
Authors: Baarspul J.A.
Published: June 2020

A cotton-growing scheme under irrigation at Galole in Kenya is described. Yields, 1000 lb seed cotton/ac with 40 lb N/ac before 1968, have increased to 1900 lb/ac with 60 lb N/ac. RB. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Chimerism of the tomato plant after seed irradiation with fast neutrons.
Authors: Verkerk K.
Published: June 2020

Sideshoots below the second truss of M1 plants of irradiated Moneymaker were rooted as cuttings and their progeny and those of the first 2 trusses of the mother plants were examined for the distribution of morphological and colour mutation. Seeds collected from the lowest parts of the plant produced most mutant seedlings; physiological reasons for this are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Relation between green area duration and grain yield in some varieties of spring wheat.
Authors: Spiertz J.H.J. , Hag B.A. ten , Kupers L.J.P.
Published: June 2020

Spring wheat cv. Opal, Orca and Gaby, sown in 1967-8 on various dates at different seed rates or with different levels of N and chlormequat, were assessed for green area of leaves, internodes and ears. Green-area duration (D) for flag leaf and for peduncle were closely correlated with grain yield, the combined value for the 2 parameters accounting for 81 and 61% of the variance in grain yield in the 2 years, respectively. Including all the values of D in a multiple correlation increased the predictive value to 83 and 74%. D for ears was closely correlated with grain yield in 1968 only. The grain: leaf ratio was higher for Gaby than for the other 2 cv. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The use of branch grafting for robusta coffee in Java. [French]
Authors: Coolhaas C.
Published: June 2020

A summary is given of Indonesian work on the rejuvenation of robusta coffee trees by branch grafting and on the characters of whip and fan shoots. The work has previously only been published in Dutch [see H.A., 9: 1401; 10: 1452; 18: 1406, 14641]. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Developmental differences in rice plants in relation to photoperiodism.
Authors: Coolhaas C. , Wormer Th.M.
Published: June 2020

Two varieties of rice sensitive to the length of photoperiod, Nero di Vialone and Kameji, and 2 insensitive varieties, Fortuna and Karang Serang, were subjected to daily photoperiods of 12 and 18 hr. applied either throughout the growing period or at various stages of the growing period. Earlier formation of panicles was induced by 12 hr. than by 18 hr. photoperiods in the case of Nero di Vialone and Kameji, but not in the case of Fortuna and Karang Serang. Where early flowering was induced by the use of 12 hr. photoperiods the panicles on the main stem were smaller than corresponding panicles on plants grown with 18 hr. photoperiods. The length of photoperiod had no direct influence on the growth of leaves. In the case of the sensitive variety Nero di Vialone, all tillers subjected to 12 hr. photoperiods from the beginning of growth entered the reproductive stage, after which a proportion of them ceased development, whereas a proportion of the tillers subjected to 18 hr. photoperiods from the beginning of growth ceased development before they had formed an inflorescence. A change from 12 hr. to 18 hr. photoperiods in sensitive varieties at the time of initiation of inflorescences caused a delay, and a change from 18 hr. to 12 hr. photoperiods, a hastening, of the subsequent development of flowers. The morphological characters of the axillary buds of rice plants at various stages of growth are described.-W.J.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A calculation of potential rice yields.
Authors: Ittersum A. van
Published: June 2020

Gross photosynthesis of rice cv. Tainan-3, Peta and BPI-76 was calculated using the model developed by de Wit [see FCA 19, 515] and the results used to calculate total DM production during 4 seasons in 1962-3 at Los Banos, Philippines. Grain yields were calculated on the basis of a tracer experiment on carbohydrate translocation [see FCA 20, 2384]. Calculated total DM yields, grain yields and grain:straw ratios were in acceptable agreement with the experimental results, provided that the dates when a closed stand was obtained and when the growth rate started to decrease were known. Data are given on potential average growth rates, total DM production and grain yields for the seasons when rice can be grown and for the entire year for a typical modern non-lodging cv. given adequate N and grown at 17 sites with widely differing climates. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Water movement in layered soils. 2. Experimental confirmation of a simulation model.
Authors: Stroosnijder L. , Van Kuelen H. , Vachaud G.
Published: June 2020

For predicting the rain infiltration front in a layered soil the simulation model written in CSMP (Continuous System Modelling Program) described by van Keulen and van Beek (1971) gave results that were in good agreement with the predicted infiltration behaviour. [132.3: 968.114. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Simulating both aerial microclimate and soil temperature from observations above the foliar canopy.
Authors: Goudriaan J. , Waggoner P.E.
Published: June 2020

A simulation model is described for the daily course of microclimatic characteristics of foliar canopy and the soil underneath. The independent driving forces are the meteorological observations above the canopy. The canopy is described by its geometrical, optical and physiological properties, the soil by its thermal and hydraulic properties. Comparison with real data shows a good agreement for crop transpiration, soil evaporation and soil heat flux, and to a lesser degree for air temperature and humidity and leaf temperature. The simulations, covering a full day, were executed with a stratified model. The effect of stratification was investigated by a comparison with a model continuous in height. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Climate, nitrogen and grass. 5. Influence of age, light intensity and temperature on the production and chemical composition of Congo grass (Brachiaria ruziziensis Germain et Everard).
Authors: Deinum B. , Dirven J.G.P.
Published: June 2020

Brachiaria ruziziensis was grown in pots at 24/19, 28/24.5 and 33/25 deg C at 160, 279 and 621 cal/cm2 day with 15-16 h light/day, and cut after 2, 3, 4 or 5 weeks of regrowth. DM production was higher after the longer regrowth periods as a result of a small increase in tiller number and a large increase in tiller weight; this was accompanied by a decrease in percentage leaf and in percentage organic N and ash and by an increase in the CF content of stems, while the CF content of leaves did not change. Increased light intensity resulted in increased DM production because of a sharp increase in tiller number; average tiller weight was not affected, nor was percentage leaf or percentage organic N, but percentages of nitrate-N, ash and CF in leaf and stem were decreased. Higher temperatures increased DM production, and gave a sharp increase in tiller weight accompanied by a decrease in percentage leaf and percentage organic N and an increase in percentage CF, but tiller numbers were reduced. Temperature had a direct effect in increasing percentage CF in leaves and stems; this was considered to be a direct cause of poor quality herbage in warm climates. Result indicated that light and temperature affected herbage quality partly through effects on morphological composition and partly by direct effects on the composition of the various morphological fractions. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Influence of K/Ca ratio and drought on physiological disorders in tomato.
Authors: Boon J. van der
Published: June 2020

In pot trials with tomatoes cv. Renova the effects were assessed of low and high K:Ca ratios and 4 successive periods of water stress on fruit quality. Each drought period lasted 4 or 6 days and started when the fifth fruit of the first, second, third or fourth cluster, respectively, had attained 1 cm in diameter. Water stress lowered the Ca concentration and raised the K:Ca ratio in the fruit. There was little difference between the yields of droughted and normally watered plants, and the fruit quality of vigorously growing plants was enhanced by drought. The incidence of blossom-end rot was much higher with a high K:Ca ratio and was aggravated by drought, an effect associated with the reduced Ca content. By contrast, the incidence of blotchy ripening was lower with a high K:Ca ratio, and was lessened by drought. The incidence of green-back was little affected, either by differing K:Ca ratios or by drought. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Accumulation and distribution of mercury in Dutch soils.
Authors: Poelstra P. , Frissel M.J. , Klugt N. van der , Bannink D.W.
Published: June 2020

The eleven soils investigated were placed in the following groups: (1) foreland soils from the river Rhine with Hg contents ranging from 10.43 to 0.10 ppm, corresponding to a decreasing clay content from 40% to 2%, with increasing distance from the sea; (2) soils used for bulb culture, which had been treated with Hg fungicides and showed a Hg content of about 0.15 ppm in the top 20 cm; (3) soils used as permanent pastures for over 20 years which, despite widely differing soil characteristics show, with one exception, the same Hg content (about 0.09 ppm) in the top 20 cm; these soils were chosen as references. It appears that organic Mg-containing fungicides when added to soils are slowly transformed to metallic Hg, which escapes from the soil mainly by evaporation.[116.49]. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effects of light and temperature on lettuce seedlings.
Authors: Verkerk K. , Spitters C.J.T.
Published: June 2020

In the first of 2 experiments lettuces were grown either under natural light conditions in the glasshouse in December and January or under 8- or 16-h daylengths, with several temperature regimes, and the leaf area per plant was measured after 22 and 45 days. Under natural light growth during the first 22 days was slight but subsequent growth was greatest with a light/dark temperature regime of 13/13 deg C, followed by one of 17/17 deg . With an 8-h day growth with diurnally changing temperatures was much greater than with constant ones, the best results being obtained with a regime of 25/17 deg . With a 16-h day the effect of diurnal temperature was much less marked and a constant high temperature regime of 21/21 deg gave better results than one of 25/17 deg . In the second experiment the plants were grown for 4 weeks under the same temperature regimes with 8- or 16-h daylengths, but the light intensity was varied by placing the plants at 2 vertical distances from the overhead lamps and all plants receiving a 16-h daylength were shaded by cheesecloth. The best results were obtained with a 16-h daylength with the plants placed close to the lamps; the effects of temperature were not so marked, but regimes of 25/17, 21/13 or 17/17 deg were the most satisfactory. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Analysis of the effects of temperature and light after planting on bud blasting in Iris hollandica.
Authors: Fortanier E.J. , Zevenbergen A.
Published: June 2020

in an initial experiment with several iris cvs bulbs were planted at 9-24 deg C, with 8- to 16-h photoperiods. A first flower was produced with all treatments but the percentage of second buds that blasted (i.e. aborted partially or completely) was greater at high temperatures and with short daylengths. In another experiment bulbs held at 30 deg followed by 9 weeks at 17 deg were forced in summer with 8 h of sunlight, extended daily by 0-12 h of weak incandescent light. The percentage of second buds that blasted varied between 50% with Dominator and 100% with La Marquette. The mean percentage of blasted buds became greater with longer photoperiods, possibly associated with the slightly higher temperatures; the number of days to flowering was not, however, affected. In a further experiment with various combinations of daylength (4-16 h light) and light intensity (50-100%) the blasting percentage was lower with longer daylengths and higher light intensities. In other experiments the effects of higher temperatures in increasing bud blasting were similar for day and night. Air temperature was of greater importance than soil temperature. Temperature sums for flowering and the critical period for bud blasting are also discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Leaf spot and leaf drop of the apple cultivar Golden Delicious : a physiological disorder.
Authors: Jonkers H.
Published: June 2020

The results are given of several experiments on the effects of temperature, daylength and light intensity on the incidence of leaf spot and leaf drop on young pot-grown Golden Delicious apple trees on M.9 The number of spotted leaves was much the highest at 21 deg C and declined successively at the following temperatures: 17 deg > 25 deg > 9 deg > 13 deg . Plants grown in sunlight had the fewest spotted leaves at most temperatures, and those grown under fluorescent light with 16- or 8-h photoperiods the most. Differential effects of high or low light intensities were slight. The oldest leaves on long shoots were usually the first to be affected. Foliar sprays of K, Ca, Mg, Mn or sugars did not affect the disorder, neither did soil moisture variation. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Grading and sorting as a method of market segmentation for agricultural products.
Authors: Meulenberg M.T.G.
Published: June 2020

The concepts of market segmentation, grading and sorting are outlined and criteria are proposed. The application of these criteria to the sorting of cucumbers and tomatoes did not achieve effective market segmentation, and quality grading was only partially achieved. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Total nitrogen determination in plant material by means of the indophenol-blue method.
Authors: Novamsky I. , Eck R. Van , Schouwenburg C. Van , Walinga I.
Published: June 2020

[123.17.02]The indophenol blue method for the determination of NH3 in digests of plant material is modified by the introduction of a dilution step, which is necessary because of the sensitivity of the method, and the use of a phosphate buffer to suppress pH influence caused by slight variations in the acid content of the digests. EDTA is used to prevent the precipitation of hydroxides and phosphates in the alkaline region. The method is quick and simple since no heating is required for colour development. The straight calibration curve obtained permits direct automatic registration of the results. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The morphology and genesis of pseudogley phenomena in a Pleistocene loamy sand in the Netherlands.
Authors: Oosten M.F. Van , Slager S. , Jongmans A.G.
Published: June 2020

[183.64:141.791]In a loamy sand profile with deep watertable, developed in Pleistocene deposits and showing mottling patterns and fine-textured bands and tongues, four soil-forming processes were recognizable: illuviation of fine clay and iron oxides, biological activity, pseudogleying, and breakdown of the clay fraction at the upper side of the illuviation horizon. The genesis of this soil can be explained by assuming that soil formation started where frost wedges occurred in the profile during the late Pleistocene and proceeded further at these points than in other parts of the soil. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Tolerance of ryegrass to cadmium accumulation.
Authors: Dijkshoorn W. , Lampe J.E.M. , Kowsoleea A.R.
Published: June 2020

Freshly defoliated perennial ryegrass was transferred to nutrient solution containing Cd. Concentrations of 50-100 mg Cd/kg DM reduced top growth; in media rich in Cd (27 and 82 mg/l) the tops accumulated 100-500 mg Cd/kg DM during the first few regrowth periods, resulting in chlorosis, poor subsequent new growth and ultimately in the death of the plants. Because of the effects of Cd accumulation on subsequent growth and uptake, the level of tissue Cd toxic for plant performance and survival could not be precisely defined. Such levels would rarely if ever occur in contaminated pastures. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The Mukibat system, a high-yielding method of cassava production in Indonesia.
Authors: Bruijn G.H. de , Dharmaputra T.S.
Published: June 2020

Yields of cassava roots were greatly increased by grafting or budding Manihot glaziovii on to cassava stocks. The system, developed in 1952 by a Javanese farmer named Mukibat, is described and illustrated. Yields, at about 96 t/ha year, are about double those from conventional cassava. The cuttings can be replanted after harvest, and the Satrawi modification, in which 1 M. glaziovii scion is grafted on to 3 cassava rootstocks, is reported to yield well in shade where conventional cassava will not grow. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Trace element problems on Scottish soils.
Authors: Mitchell R.L.
Published: June 2020

The soils of Scotland are varied and relatively young, developed from glacial tills laid down about 12 000 years ago. The complex geology has produced varied trace element contents, usually related directly to their contents in the parent rock. Many of these elements are mobilized readily in soils with impeded drainage. Deficiencies of Co, Cu, Mn, B and Se have been recorded in plants or animals. Mo and Ni levels occasionally cause problems in animals and plants respectively. The trace element status of a soil can seldom be related to its total content: an extraction technique appropriate to the element in question is used to assess availability to plants. The Soil Survey of Scotland has reached the stage at which soil associations and soil series can be used to assess the probable trace element situation, particularly on arable land. Trace element contents of soils and plants are determined largely by spectrochemical methods. 19 references. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of the method of preservation of forages on the digestion in dairy cows. 1. Composition of the forages and digestibility of dry matter, organic matter and nitrogen.
Authors: Tamminga S. , Koelen C.J. van der
Published: June 2020

1. Grass from the same sward was ensiled without additive, with 14.6 g formic acid/100 g crude protein or 10.8 g formic acid and 10.6 g formaldehyde/100 g crude protein. Similar grass was dried and pelleted. Drying or ensiling with the mixture reduced solubility of N in the preserved grass but formic acid increased it, and ensiling without additive increased it even more. Apparent digestibility of N in the rumen of cows tended to decrease with decrease in solubility. Digestibility in vitro of the mixed diet given to the cows, calculated from digestibility of the separate components, agreed well with the values in vivo for diets with silages, but was high for that with dried grass. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Carbonate in soil; a theoretical consideration on, and proposal for its fabric analysis. 1. Crystic, calcic and fibrous plasmic fabric.
Authors: Bal L.
Published: June 2020

The pedological features of seven soils formed in calcareous parent materials located in Afghanistan (serozem), USSR and Germany (chernozems), and in the Netherlands (marine deposits) are described. The distinction between the fabrics is based largely on Brewer's concept (1964). (Abstract retrieved from CAB Abstracts by CABI’s permission)
Availability of anions in the growth medium to roots of an actively growing plant.
Authors: Keulen H. Van , Seligman N.G. , Goudriaan J.
Published: June 2020

Analysis of anion transport to the root of an actively growing plant with a normally dense root system showed that virtually the whole of the anion store in the rooting zone is available to the plant within a few days at the most. Transport by diffusion only is enough to account for most of the depletion, but mass flow will speed up the process. The effect of mass flow will be considerable in soils with a high dispersion coefficient (loess), but very small in soils with a low dispersion coefficient (clay and sand). A rule is proposed to determine whether a given root density is sufficient to supply the nitrogen and water needs of the plant by diffusion only. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Artificial irradiation for lettuce plant raising - technical and economic aspects.
Authors: Visser A.J. de , Vooren J. van de
Published: June 2020

In November and December lettuce seeds were sown direct in soil blocks and the seedlings raised under natural light alone or supplemented with 200 W/m2 for 16 h daily. A night temperature of 7 deg C and a day temperature of 12, 15, 18 or 21 deg plus a 3 deg light-dependent increase were maintained. The seedlings were planted out in mid-January and harvested in mid-March. Plant growth was far more rapid, resulting in early maturity, where supplementary lights had been used initially and in addition the foliage was sturdier and broader. However, a comparison of the costs of production for lighted and unlighted plants of the same weight at planting showed that the extra cost of lighting was not justified by a marked increase in yield under the conditions of the trial. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Application of a new calibration method to an unventilated dynamic diffusion porometer.
Authors: Stigter C.J. , Visscher G.J.W.
Published: June 2020

It is shown that a new calibration method that appeared to be valid for a ventilated dynamic diffusion porometer can be used for the unventilated types as well. A discussion on the method and the results obtained in the determination of dummy epidermal resistance (nickel multipore membranes) is given. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Computer-aided interactive soil suitability classification - a simple Bayesian approach.
Authors: Bie S.W. , Lieftinck J.R.E. , Lynden K.R. Van , Waenink A.W.
Published: June 2020

A simple Bayesian algorithm is used to calculate for each soil suitability class the probability that a soil individual belongs to it. This is done by comparing the values of the assessment factors to an existing set of already classified individuals using an interactive computer program. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effect of sowing date and seed rate on crop development and grain production of winter wheat.
Authors: Darwinkel A. , Hag B.A. ten , Kuizenga J.
Published: June 2020

In a field trial in 1973-5, winter wheat cv. Lely was sown on 3 dates at 3- to 4-wk intervals from end-Sept. at low (80-90 kg seed/ha) or high (160-180 kg seed/ha) sowing rates. Delaying the sowing date decreased grain yield. This decrease was caused by a smaller number of grains/ear and a lower grain wt. Sowing rate had a positive influence on the number of ears, but a negative effect on the number of grains/ear and the grain wt. With early sowing, sowing rate was found to have no effect on grain yield, due to mutual compensation of changes in yield components. With late sowing, a higher sowing rate increased the number of ears so much that a higher grain yield was achieved. The grain yield/ear depended on the age of the tiller. Tillers that emerged earlier produced more and heavier ears. The number of grains/ear and the grain wt. could be related to the rate of development of the ear-bearing shoot. The pattern of tillering was affected by the sowing date. With early sowing, most tillers emerged in autumn and winter, whereas the late-sown wheat tillered in spring. Also, the early-sown crop consisted largely of ears from early tillers, whereas the late-sown one had many ears from late-formed tillers. (Abstract retrieved from CAB Abstracts by CABI’s permission)
An installation for transport and accumulation studies on undisturbed soil columns under controlled conditions.
Authors: Bannink D.W. , Poelstra P. , Frissel M.J.
Published: June 2020

An adjustable but constant water flux can be maintained in the apparatus described and water is applied in the form of drops to the top of the soil column by means of a rain simulator. The soils are not normally saturated with water, but saturation can be effected if required. Aerobic conditions, or anaerobic conditions (produced by storing the columns in an atmosphere of N) can be maintained. A cheap, easy and reliable method is described for removing soil columns down to a depth of 1 m from the field. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Some thoughts on the role of social sciences in the agricultural research centres in developing countries.
Authors: Dusseldorp D.B.W.M. van
Published: June 2020

Agricultural research pays relatively little attention to the effects that the implementation of the research results will have on society. The posting of more social scientists at research stations is therefore advocated. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The significance of gypsum applied to mushroom compost, in particular in relation to the ammonia content.
Authors: Gerrits J.P.G.
Published: June 2020

With gypsum treatment the nitrogen loss in the compost is slightly reduced and the pH is decreased. Curvilinear relationships were established between the NH4 content of the compost at filling and the yield in the presence or absence of gypsum and with or without supplementation with soya bean meal. These curves (four parabolas) give a clear picture of the significance of gypsum under various circumstances. The optimum gypsum treatment was 25 kg per 1000 kg of horse manure. Time of application of the gypsum was not very important, but an early application favoured a more uniform distribution and prolonged its action. The drop in pH caused by gypsum influences the dissociation of NH4+ ions considerably, i.e. in the presence of gypsum less NH3 is present in the compost. A possible mechanism by which gypsum lowers the pH is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of flowering date and temperature on embryo development in sweet cherry (Prunus avium L.).
Authors: Braak J.P.
Published: June 2020

Experiments involving the exposure of the early variety Kassins Fruhe [Kassin's Early] and the late-ripening seedling rootstock Limburgse Boskriek [Limburg Gean] to temperatures of 14-23 deg C during fruit development, and of the very early variety Fruheste der Mark [Earliest of the Marches] and Kassins Fruhe to low-temperature shocks during their incubation at 17 and 20 deg C, are described, and reanalysed field data on the embryo quality of 15 varieties during 1954-65 are presented. The results indicate that fruit development at temperatures below 16-18 deg C resulted in a deterioration of embryo quality, and the temperature sensitivity of the embryo generally increased as the period from flowering to fruit ripeness shortened. It is suggested that more efficient breeding for earliness could be achieved by maintaining trees at temperatures above 18 deg C during the period from flowering to the completion of embryo growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)