Showing papers in "Netherlands Journal of Agricultural Science in 1969"
TL;DR: In this article, it was found that on cropped arable land (350 mm drainage water per year) and from a soil profile of 100-125 cm with a clay content of 35% or more, little N was lost by leaching on sandy soils (0-10% clay), however, about 60 kg N/ha could be lost yearly and 20% of the applied fertilizer N was leached out of the profile on grassland, depending on time of application of the N.
Abstract: On cropped arable land, the nitrate content of drainage water showed a distinct maximum in spring (Mar-May) and a minimum in autumn (Nov) On grassland it was more constant during the year, except when N was applied in autumn or winter (liquid manure, fym, liquid ammonia) when the situation was the same as for cropped arable land An average content of 1-2 mg N/1 was found for grassland, and of 4-10 mg/1 for cropped arable land, depending on the clay content of the soil From lysi-meter experiments it was found that on cropped arable land (350 mm drainage water per year) and from a soil profile of 100-125 cm with a clay content of 35% or more, little N was lost by leaching On sandy soils (0-10% clay), however, about 60 kg N/ha could be lost yearly and 20% of the applied fertilizer N was leached out of the profile On grassland, leaching losses depended on time of application of the N A better distribution of the applied N during the growing season than on arable land and the high rate of N uptake by the grass greatly reduced the losses of applied N during the period Mar-June, even on sandy soils Later on, the losses could rise to a maximum of 40% for N applied in Nov-AGGH (Abstract retrieved from CAB Abstracts by CABI’s permission)
41 citations
TL;DR: In this article, faba plants were grown at 15 degrees or 25 degrees C in alternating wet and dry periods, and the root weight was not affected by dry and wet conditions.
Abstract: V. faba plants were grown at 15 degrees or 25 degrees C in alternating wet and dry periods. Drying of the soil promoted deeper root growth. Total root weight was not affected. Shoots grew less with a dry treatment in both the vegetative and the flowering phase.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
35 citations
TL;DR: The somatic chromosome numbers of 90 species of Begonia were established and it was found that there is also a considerable number of species with 2n = 38, including B. gigantea Wall, which has the lowest chromosome number reported so far in Begonia.
Abstract: The somatic chromosome numbers of 100 Begonia species were counted, of which 72 have been determined for the first time. Eighteen different numbers have been established, ranging between 22 and 156, fifteen of which could be fitted into a tentative scheme of five polyploid series. The most common numbers were 22 (14 species), 28 (35 species) and 56 (17 species). The species have been grouped into sections according to Irmscher. In some cases these sections appeared to have a characteristic chromosome number whereas in others, e.g. Pritzelia and Begoniastrum, a great diversity in chromosome number was encountered. [For earlier work see H.A., 39: 5182.]-Univ. Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
30 citations
TL;DR: In a severely pruned "shoot-fruit-root" system pronounced relations were observed between individual fruits and between root and fruit growth, viz. the dominance of a single fruit, usually the first, over subsequent fruits with marked inhibition of their growth, and a similar inhibiting effect of developing fruit on root growth as mentioned in this paper.
Abstract: In a severely pruned "shoot-fruit-root" system pronounced relations were observed between individual fruits and between root and fruit growth, viz. the dominance of a single fruit, usually the first, over subsequent fruits with marked inhibition of their growth, and a similar inhibiting effect of developing fruit on root growth. These effects, related to the individual organs, are probably of the same nature as the more indirect mass effects described by others in conventional plants under more normal growing conditions. The system described offers better possibilities for physiological studies.-Centre Plant physiol. Res., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
23 citations
TL;DR: In field trials at two sites, different levels of sodium arsenite were applied prior to crop planting and reductions in yield were recorded but, in subsequent years, residual effects diminished.
Abstract: In field trials at 2 sites, different levels of sodium arsenite were applied prior to crop planting. Reductions in yield were recorded but, in subsequent years, residual effects diminished. The arsenite half life was 6.5 _ 0.4 years. (Abstract retrieved from CAB Abstracts by CABI’s permission)
22 citations
TL;DR: In this article, the digestibility of 106 samples of hay, grass, grass silage and legume forage was estimated by regression from cell contents and cell wall constituents estimated chemically.
Abstract: Digestibility of 106 samples of hay, grass, grass silage and legume forage was estimated by regression from cell contents and cell wall constituents estimated chemically. Cell wall constituents were cellulose, hemicelluloses, lignin, cutin, plant silica and soil contamination. Values were not as closely related to digestibility in vivo by sheep as were values obtained by digestion with rumen fluid in vitro. Correlation between digestibility of cell wall constituents and lignin content was poor, and this and other reasons for the poor results from chemical analysis are discussed.-T. D. B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
21 citations
TL;DR: A single application of CCC to the roots of young tomato plants reduced the growth rate for about three weeks after which the top internodes of the tomato plants were accelerated.
Abstract: 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)
21 citations
TL;DR: In this article, the actual and potential evapotranspiration from the potato crop during the growing season was calculated using standard meteorologie data, and the water-use by the crop for different periods was also derived from the water balance.
Abstract: Data from sprinkler irrigation experiments with potatoes were used to calculate the actual and potential evapotranspiration from the crop during the growing season, using standard meteorologie data. During the experiments the moisture extraction from the effective root zone was determined by soil sampling. The water-use by the crop for the different periods was also derived from the water balance and both values were in good agreement in periods without extreme conditions of precipitation, this showing that the derived relations between crop height and surface roughness, between soil cover, light intensity, crop characteristics, soil characteristics and diffusion resistance, and between maturation and internal plant resistance were reasonably established. F.s.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
15 citations
TL;DR: In the first trial 3 wethers were given in 5 periods lucerne meal alone or with 5, 10, 15 or 20% steamed destructor fat as mentioned in this paper.
Abstract: In the first trial 3 wethers were given in 5 periods lucerne meal alone or with 5, 10, 15 or 20% steamed destructor fat. Digestibilities were of crude protein 64.2, 63.4, 64.4, 59.3 and 58.3%, of crude fibre 57.7, 58.0, 58.1, 47.7 and 45.6%, of ether extract 52.9, 81.7, 86.8, 89.1 and 90.5% and of lipids extracted by tetrachloromethane 48.4, 64.9, 57.5, 61.4 and 69.6%. Formation of insoluble Ca and Mg soaps may have been the reason for difference in digestibilities of the fats extracted by different methods. In the second trial 3 wethers were given long hay and 2 wethers in 2 periods got the hay plus 10% linseed oil emulsified with an equal volume of water or not emulsified. There was no effect due to emulsifying, but there was a large difference between duplicates when hay plus oil was given although in both instances oil depressed digestibilities; digestibility of crude protein of hay alone was 60.3%, with 10% oil it was 59.2 and 56.8%. Values for crude fibre were 75.9, 69.0 and 60.8%. The third and fourth trials were with 3 wethers given 6 diets in 6 periods. They got 500 g hay alone or with 600 g concentrate with 12.1% crude protein. The concentrate was given without extra fat or with 5, 10, 15 or 20% lard. Percentage digestibilities were of crude protein 53.1, 62.8, 60.4, 57.8, 53.6 and 54.2, and of crude fibre 68.7, 63.9, 58.4, 51.4, 46.0 and 42.2.-E. O. (Abstract retrieved from CAB Abstracts by CABI’s permission)
13 citations
12 citations
TL;DR: The mean flow rate of duodenal contents over all experiments with both sheep was about 14 to 20 litres per day but there were appreciable between-day and between-sheep variations as mentioned in this paper.
Abstract: To each of two Texel sheep with re-entrant cannulae in the distal part of the duodenum were given daily in two equal feeds either 100 g straw pellets and 390 g of a concentrate mixture or 1000g hay and 120 g maizemeal. Polyethylene glycol 10 g and Cr2O3 2 or l.94g were mixed with the concentrates for 6 days before each collection period and throughout the 72 or 120h of collection. Water was given to appetite. The material which flowed out of the proximal cannula was collected, measured and sampled and returned to the gut at 40 degrees C. The mean flow rate of duodenal contents over all experiments with both sheep was about 14 to 20 litres per day but there were appreciable between-day and between-sheep variations. The highest flow rate was before and during feeding in one sheep. In both the rate tended to increase during the night. Overall recovery of both markers used was almost100% with the sampling technique used. A random sampling technique which was one of the two systems used and involved the withdrawal of 7 ml digesta every 4 h for 120 h yielded a representative sample of the soluble components, but was less suitable for the insoluble components, though modification could improve it. In this way it should be possible to use a simple cannula in place of re-entrant cannulae. J. G. G. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: Soil steaming caused an increase of 33 ppm mineral N There was no significant effect on water-soluble P2O5 The influence of steaming on buffersoluble Mg content varied with the treatment but there seemed to be a negative correlation with the P content.
Abstract: 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)
TL;DR: Soil steaming increased fresh and dry weights and N and Mn contents of the plants as mentioned in this paper, but decreased yields and N content, and the addition of straw to the steamed soil did not affect growth or N content but reduced the Mn content.
Abstract: Soil steaming increased fresh and dry weights and N and Mn contents of the plants. Leaching the steamed soil caused a further increase in Mn content but decreased yields and N content. The addition of straw to the steamed soil did not affect growth or N content but it reduced the Mn content. Plants grown on steamed soil had darker coloured leaves and a greater incidence of leaf margin necrosis and bad heading than plants grown on unsteamed soil. See also Sous Fertil. 33 [1230]. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: The physical, chemical and micromorphological properties of a poorly drained soil profile developed on clayey parent material covered by a thin layer of loess are described in this paper, where the profile was classified as an aerie glossaqualf.
Abstract: The physical, chemical and micromorphological properties of a poorly drained soil profile developed on clayey parent material covered by a thin layer of loess are described. Clay skins on peds were absent in the B-horizon which is considered to be of Pleistocene age. In thin sections, however, oriented clay was observed inside peds occurring undisturbed as free grain and channel argillans, and disturbed by pedoturbation as quasicutans and papules. Clay was leached vertically through the B horizon along planar voids between prisms, leaving accumulations of skeleton grains. Some clay was also leached from the A2 horizon. Kaolinite was more mobile than illite or smectite. Reduction processes resulted in strongly bleached areas around prisms and in well developed mangans on ped faces and around channels. The profile was classified as an aerie glossaqualf. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: 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.
Abstract: 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)
TL;DR: Experiments were carried out under various conditions of elevation and climate, in which young vegetatively propagated plants of selected tea clones were subjected to pruning operations at or after transplanting Generally the removal of a substantial portion of shoot, root or both caused a temporary set back in growth and increased mortality.
Abstract: Experiments were carried out under various conditions of elevation and climate, in which young vegetatively propagated plants of selected tea clones were subjected to pruning operations at or after transplanting Generally the removal of a substantial portion of shoot, root or both caused a temporary set back in growth and, in many instances, increased mortality The subsequent reduction in total growth depended on the amount initially removed, except when only the immature apical part of the shoot was cut off, in which case the plants grew as well as the untreated ones Retarded root growth and mortality as a consequence of pruning were associated with a marked depletion of the carbohydrate reserves of the roots, which was more serious when the original level (in Ceylon primarily determined by altitude) was low Bringing a young tea plant into bearing as soon as possible requires the induction of lateral branching while avoiding growth restriction as far as possible; the practice of bending was found to be less detrimental to growth than other methods involving repeated pinching of apical shoots, cutting across at about two-thirds of the height of the plant, centering and modifications of these methods-Inst hort Plant Breed, Wageningen (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: In this paper, it was shown 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.
Abstract: 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)
TL;DR: In this article, temperature and light requirements for a satisfactory forcing of Brodiaea laxa 'Koningin Fabiola' were studied and the most acceptable results with regard to flower production were obtained at 18 degrees C in short photoperiods.
Abstract: Temperature and light requirements for a satisfactory forcing of Brodiaea laxa 'Koningin Fabiola' were studied Corms were planted under different temperature and light conditions in a phytotron and in different photoperiods in the open Long days accelerated flower development and the termination of growth and enhanced corm formation Considering both earliness and number of flowers, the most acceptable results with regard to flower production were obtained at 18 degrees C in short photoperiods Forcing at higher temperatures and in longer photoperiods resulted in a reduction in the number of flowers because of bud blasting This also occurred when the natural short day was extended by high light intensities Forced and retarded corms reacted similarly but the latter flowered sooner and more satisfactorily Flowering was preceded under all conditions by corm formation and in longer photoperiods even by senescence of the leaves Year-round production of flowers is possible if 25 cal/sqcm/day of light energy or more are available- Agric Univ, Wageningen (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: In this article, the growth regulators kinetin, gibberellin (A3 and a mixture of A4 and A7), Alar and CCC were applied by spraying on blossoms or fruitlets and by injection into the trunk.
Abstract: To increase yields of pear and apple trees the growth regulators kinetin, gibberellin (A3 and a mixture of A4 and A7), Alar and CCC were applied by spraying on blossoms or fruitlets and by injection into the trunk Kinetin and particularly gibberellins were effective in stimulating fruit set in pears Doyenne du Cornice pear set more fruits with a mixture of gibberellin A4 and A7 than with gibberellin A3 Although the majority of stimulated fruits abscised during the June drop period, the crop was markedly increased The growth retard-ants Alar and CCC were inactive in increasing fruit set, but prevented excessive drop of fruits when applied after a gibberellin application-Lab TuinbPl, Wageningen (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: In this paper, tomato seeds were grown at 9, 18 and 24 degrees C with soil moisture content 10 and 20 % below field capacity or brought to field capacity at the beginning of the experiment and never rewetted.
Abstract: In pot experiments tomato seeds were grown at 9, 18 and 24 degrees C with soil moisture content 10 and 20 % below field capacity or brought to field capacity at the beginning of the experiment and never rewetted. Both temperature and water-regime influenced emergence but temperature had the more pronounced effect and the driest treatment at 24 degrees C gave higher percentage emergence than any at 18 degrees C. Seeds at 9 degrees C failed to emerge even after 42 days. In a second experiment, month-old tomato seedlings were grown at 35 degrees C day temperature and 18 degrees C night temperature or 20 degrees C day temperature and 15 degrees C night temperature under the same moisture conditions as before except that the driest treatments were brought to field capacity when the plants showed severe signs of wilting. Plants at 20 degrees C day temperature received only 80% of the incoming radiation that plants at 35 degrees C day temperature received. Plants with the 35 degrees /18 degrees C temperature regime and receiving most water gave the earliest yield, soon followed by those receiving the medium water treatment. Those in the driest treatment yielded much later. Plants under the 20 degrees /15 degrees C regime yielded in the same order and were all later than plants at the corresponding water treatments at the higher temperature. Plants in the higher temperature treatment had higher fresh weights of tems, leaves and fruit than those at lower temperatures but the latter were slightly taller probably due to the lower light intensity. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: The genetics of two radiation-induced mutants of cv.
Abstract: The genetics of two radiation-induced mutants of cv. Moneymaker, "easy peeling" and "oblong fruit with strong skin", were studied. Both were governed by a single recessive gene. The combination of both traits was achieved by crossing, but it was impossible to break the association between oblong fruit and strong skin. Hybrid easy peeling material with round or oblong fruit shape was selected for yield and improvements up to 30% over Moneymaker were reached under experimental conditions. The easy peeling trait may be of interest both for the canning industry and for fresh consumption.-Univ. Wageningen & Neth. Inst. atomic Sci. Agric. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: In this paper, the short-run and long-run elasticities for US agriculture are estimated for various periods, and then used to test some hypotheses on supply behavior of US farmers.
Abstract: Some of the problems involved in knowledge of the agricultural supply function can be solved by applying such concepts as net product, net price and net productivity and a new interpretation of the " normal price" concept for dynamic conditions From this the short-run and long-run elasticities for US agriculture are estimated for various periods, and then used to test some hypotheses on supply behaviour of US farmers A (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: Pore space was 0.25-1.5 vol. % higher in fine-textured soils on farms using horse-traction only than on farms with tractor-drawn implements only as mentioned in this paper.
Abstract: Pore space was 0.25-1.5 vol. % higher and air content at pF 1.9 was 0.5-1.9 vol. % higher in fine-textured soils on farms using horse-traction only than on farms using tractor-drawn implements only. The differences were greater in wet years when the general level of soil structure was low than in dry years. (Abstract retrieved from CAB Abstracts by CABI’s permission)
TL;DR: A review of the problems limiting the accuracy of determinations of thermal properties and moisture contents of soils can be found in this article, where the authors present a set of problems limiting accuracy of soil thermal properties.
Abstract: A review of the problems limiting the accuracy of determinations of thermal properties and moisture contents of soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)