bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of daylength on vernalization of winter rye.
Authors: Hartman Th.A.
Published: June 2020

In 1958-61, germinating seeds, seedlings and young plants (10-14 days old) of winter rye cv. Petkuser were subjected to cold treatment (+6 degrees C) for varying periods, and to natural (winter), continuous or 8 hr photoperiod before, during and after cold treatment. Growth (fresh-and dry-weight) and development stage were periodically determined and plotted, and heading times (from end of cold treatment) recorded. In continuous photo-period treatments, growth was more pronounced and heading earlier with incandescent bulbs than with fluorescent tubes used for additional illumination. Inherent growth depressions (at the end of the vegetative phase and after the final spikelet number was reached) were found to interact with the treatments. The results as a whole led to the following conclusions for winter rye. Short-day treatment retards heading (R) by a direct depression of growth, but also accelerates it indirectly (A) by accelerating differentiation of flower primordia when plants are subsequently exposed to continuous photoperiod. (A) reaches a limit, but (R) goes on increasing; hence the net effect of prolonged short-day treatment is to retard heading. In plant vernalization, heading is earliest when cold and short-day treatments are combined. After optimum vernalization of seeds by prolonged cold treatment, short-day treatment will only retard heading, since the limit of (A) has already been reached; after a shorter cold treatment of seeds, short-day treatment, if not too prolonged, will accelerate heading.-W.M.S.R. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Improvement of the preparation of thin sections of soil by a new grinding, cleaning and polishing machine. [in German]
Authors: Kubiena W. , Beckmann W. , Geyger E.
Published: June 2020

The instrument is suitable for additional grinding work on thin sections of unequal thickness. It is useful when the section contains hard and soft parts. Cleaning is done by brushes. Special cutting work can be done by small diamond-mounted saws. Diamond-mounted small needles are used for special grinding. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Gross profit in relation to operational account analysis.
Authors: Van Booen B. , Kamminga J.
Published: June 2020

The need to define clearly the costs that are used to calculate gross profit for the purpose of operational account analysis is stressed. Gross profit should be measured by the difference between gross revenue and the costs related to one activity only, and to factors used solely in one production process. For a fair comparison of gross profits of different enterprises, each enterprise should be compared over the same unit of time. Therefore by definition only continually varying costs should be included as "variable " costs in the measurement of gross profit, and when there is a change in costs that do not vary continually there will be a new planning situation and a new optimal plan. D. A. E. (Abstract retrieved from CAB Abstracts by CABI’s permission)
On soil genesis in temperate humid climate. IV. The "low humus podzols".
Authors: Van Schuylenborgh J.
Published: June 2020

"Low humus podzols" do not possess a spodic horizon; podzol formation in conjunction with predominantly reducing conditions give rise to an eluviated profile. Low humus podzols have an umbric epipedon, the Fe and Al contents of the B horizon are intermediate between those of the A and C horizon, and their humus is mostly dispersed. Psammic Umbraquepts is proposed as a fifth subgroup for these soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Copper metabolism in milch cows. I. A proposed method of liver measurement after injection of radio-copper.
Authors: Binnert W.T.
Published: June 2020

A method is described for the external measurement of Cu-64 in the liver of cows after i/v or i/m administration. Radioactive uptake and biological half-life of the liver Cu were determined. Some preliminary results are discussed, mainly from the methodological aspect. (AS). (Abstract retrieved from CAB Abstracts by CABI’s permission)
Copper metabolism in milch cows. II. Some precautions to be taken when working with radio-copper.
Authors: Binnerts W.T.
Published: June 2020

The radioactivity of two commercial preparations of Cu-64 did not decay in a straight logarithmic line because of longer-lived, unidentified isotypes present as impurities. It was estimated that a residual activity of several tenths of a micro c could be expected from every 10 mc of such contaminated Cu-64. Cu-64 practically free from long-lived contaminants was produced by irradiation of very pure melted copper wire for only 20 min.-M.G.G. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Measurement of thermal conductivity in situ in mixed materials, e.g. soils.
Authors: Janse A.R.P. , Borel G.
Published: June 2020

The general theory of heat transfer, and a method for determining thermal conductivity are presented. A practical field apparatus is described, and suggestions are made for its use. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Poly-phylla fullo L. (Col., Melolonthidae) in the dunes.
Authors: Blankwaardt H.F.H.
Published: June 2020

It is possible to reduce the loss of young saplings to a third by dipping the roots in aldrin emulsion before planting; addition of aldrin dust to the planting hole will eliminate almost all grub damage. Fairly good results follow if this treatment is combined with narrow spacing to ensure quick plant cover; vegetative growth might be hastened by fertilizing. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Animal behaviour in the sub-tropics. II. Grazing behaviour of sheep.
Authors: Sharafeldln M.A. , Shafie M.M.
Published: June 2020

The experiment was conducted during 5 consecutive days in Aug. 1961 under conditions simulating those of Tahreer Province, a newly reclaimed desert area in Egypt. Four groups of 30 ewes in early pregnancy were studied. They represented the folio wing breeds: Ossimi [Ausimi] (indigenous), Texel (imported from Holland), Caucasian Merino (imported from Russia), and Fleisch [Mutton] Merino (imported from Germany). The Ausimis covered the distance of 5 km. to the pasture in the shortest tune and showed no signs of fatigue until after reaching the pasture; their respiration rate did not start to accelerate until they had been made to walk 10 km. The imported breeds showed an increase in respiration rate much earlier, and during the 5th km. half of the imported ewes were panting and showing obvious signs of stress. The mucous membranes of the Texel were very sensitive to dust, and the ewes began coughing after walking for a short time in the sand. Various breed differences in grazing behaviour were also observed. Compared with the foreign breeds, Ausimi ewes were not heavy grazers, and were not fastidious about the plant material on which they grazed. They spent more time grazing in the sun than did ewes of the other breeds. Compared with the other breeds, the Mutton Merino grazed for the shortest tune in the sun and the longest time in the shade, and spent most time ruminating; the Ausimis spent the shortest time in rumination. [For Pt. I see A.B.A., 33, No. 3410. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effort and time in pipeline milking.
Authors: Vos H.W.
Published: June 2020

Effort and time spent in machine milking using pipeline vs. bucket milking methods were compared in a conventional cowshed and in a 2-level milking parlour. In each case 2 units were used and cows were machine-stripped. In the cowshed data were obtained for each of 6 milkers milking 20 low-yielding cows; in the parlour each of 3 milkers milked 21 moderate yielding cows. Total energy expenditure (measured at one milking only for each of the cowshed milkers) averaged 5.0 kcal./min., but considerable variation was shown between workers. In the cowshed mean heart rate was similar for the 2 milking methods but in the parlour heart rates were higher for bucket than pipeline milking; the former also involved greater increase in effort in carrying the filled cans and in cleaning the milking equipment. Milking time for the bucket method exceeded that for the pipeline method by 18% and 9% in cowshed and parlour respectively. Practical aspects are discussed. R.B.S. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Boron deficiency in cacao, bananas and other crops on volcanic soils of Ecuador.
Authors: Tollenaar D.
Published: June 2020

B deficiency destroyed imported varieties of cacao at the start of their productive stage; local varieties usually survived though B deficiency affected production and made them susceptible to disease. Bananas on young volcanic terraces were B-deficient and their leaf canopy and quality were affected. Arabica and robusta coffee, avocado pear, mango, Chinese cabbage, lucerne, trefoil, potato, sweet clover and apple were also deficient in B in these soils. The soil consists of thick layers of loose volcanic ashes; heavy rains during 4-6 months leach all the soil B and bring no fresh B with them. Drought occurs in the second half of the year; drought is known to aggravate B-deficiency by increasing the critical B content of plants. High Ca levels in the soil also worsen B deficiency. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Towards a soil fertility in dimensions.
Authors: Ferrari T.J.
Published: June 2020

The historical development of research methods applied at the Institute of Soil Fertility in Holland is described, and examples of the study of relationships between fertilizing or soil-management effects and soil factors are given. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Notes on the importance of proper husbandry in some tropical crops.
Authors: Ruinard J.
Published: June 2020

Trials were carried out to determine the relative effects of weed competition and fertilizer application on plant growth and crop yield; the crop was weeded frequently, once only or not at all. Cocoa seedlings were grown in boxes and dry weights of seedlings and weeds determined 22 weeks after planting. Fertilizers increased the weight of cocoa plants by 20% and clean weeding increased it by 500%. Groundnuts, also grown in boxes, were harvested 17 weeks after sowing and dry weights of nuts and weeds determined. Fertilizers increased yield by 30 % and clean weeding by 65%. In two field trials with maize, fertilizers increased the yields of dry grain by 13 and 47% whereas clean weeding gave increases of 43 and 265%. In groundnuts, an outlay of 10/ha on weeding yielded a net increment of 70/ha compared with only l9/ha for an outlay on fertilizers of 34/ha. In the maize trials, the cost of fertilizers reduced the net income, whereas weeding proved a lucrative investment. In conclusion, weeding is recommended as an alternative to radical modernization for farmers on a low income.-P.K. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The collection of natural soil profiles from arid regions- A field method and manual.
Authors: De Meester T. , Bouma J.
Published: June 2020

Techniques are described for preparing "peels" of dry calcareous soils, particularly clays, and for preparing peels from vertical instead of sloping walls, especially of dry soils. Advice is given on transporting peels and estimating preparation costs. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Cation-exchange equations used in soil science-a review.
Authors: Bolt G.H.
Published: June 2020

A review with 41 references including a detailed examination of models of the exchange process underlying these equations and a discussion of the assumptions inherent to these models and the ensuing limitations of the resulting equations. Some suggestions are made on the direction of future developments in this field. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Marketing, modernising factor in agriculture.
Authors: Meulenberg M.T.G.
Published: June 2020

The dynamics of modern agricultural markets have considerable impact on farming. Some changes in demand and supply in agricultural markets are described, and application of the marketing mix-product, price, promotion, distribution-to these new developments is assessed. Modern marketing policy is shown to affect agriculture by: (1) promoting new organization of marketing channels to co-ordinate decision-making horizontally between farmers and vertically between farmers-processors-retailers; (2) stimulating new production techniques to meet producers' requirements, e.g. by specialization, and (3) forcing development of product research, e.g. on stocks and breeds, and especially of market research. P. H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Agricultural productivity in Western Europe.
Authors: Van den Noort P.C.
Published: June 2020

Two hypotheses on agricultural production are tested: (1) that productivity of European agriculture is low, but that there are large regional and national differences; and (2) that there is a pattern in these differences: productivity is high around the North Sea and declines with increasing distance and with altitude. The criterion used to evaluate the facts is the net total productivity index, and Dutch agriculture is the basis for comparison. Results appear to agree with the two hypotheses. A. abr. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Patterns of choice behaviour on peasant farms in Northern Nigeria.
Authors: Luning H.A.
Published: June 2020

A budget analysis was made of 28 peasant farms in: a region of N. Nigeria to determine motives underlying farm organization. The agricultural system is traditional and static; farmers are aware of the necessity of applying organic manure but use no fertilizer; some hired labour supplements family labour. It was found that the proportion of cash crops (groundnuts) and subsistence crops (mainly sorghum and pearl millet) was mainly determined by maximum cash income expectation; however, self-sufficiency in food had to be assured first of all. 'Thus, all land not allocated to groundnuts was planted to cereals in view of the risks of low yields in unfavourable years, and no land was left fallow. The absence of fallow land, however, may endanger the maintenance of soil fertility in the long run. T. A. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Choice of food crops in relation to actual and potential production in the tropics.
Authors: De Vries C.A. , Ferwerda J.D. , Flach M.
Published: June 2020

Average world productions of the most important tropical and subtropical grain and non-grain staple crops (rice, wheat, maize, sorghum, cassava, sweet potato, yam, colocasia and banana) were compared. The results were expressed in kcal edible per hectare and per day of vegetation. The root crops produce more bulk but mainly because of their higher water content; their energy food value amounts to about 30% of the grain crops per unit weight. Taking into account the percentage edible matter and the average period of vegetation, the figures for average world production for root and grain crops were much closer. The differences in average world production between the 2 groups of crops did not show clearly, perhaps due to the fact that in rice, wheat and maize more breeding has been done, and also that these crops are mostly grown on better and usually irrigated soils. The figures for average world productions were compared with maximum productions reached in selected experiments in the tropics, and large discrepancies were found, showing that greater yields could be obtained by improved cultivation. The protein content, expressed per 100 kcal edible portion, of the root crops tends to be slightly lower than that of the grain crops, but the contents of Ca, Fe, vitamin A, thiamine, riboflavine, nicotinic acid and ascorbic acid are generally higher. Most root crops have also edible leaves with considerable protein content, and it is thought that selective breeding could increase the protein content of root crops. It was therefore concluded that root crops should play a more important role in increasing world food production. E. P. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Sensitivity to copper deficiency of different cereals and strains of cereals.
Authors: Smilde K.W. , Henkens C.H.
Published: June 2020

In pot trials, wheat was most sensitive to soil Cu deficiency followed by barley, oats and rye. There were sufficient differences in sensitivity between the various varieties of wheat, oats and barley. Cu-deficient plants of oats and barley produced low grain and high straw yields, mainly through profuse tillering. In wheat, Cu deficiency resulted in a reduction in the number of developed grains. Applying CuSO4 at 50 kg/ha raised the Cu content of oats and wheat foliage until the crop reached a height of 20 cm, and thereafter it decreased until ear emergence. Responses to Cu of sensitive oat varieties compared with insensitive ones were larger in soil- than in water-culture.-M.S.M. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of sowing date and germination temperature on yield of spinach and chervil.
Authors: Parlevliet J.E.
Published: June 2020

Low temperatures during germination and in the young seedling stage induce earlier flowering in spinach and chervil (Anthriscus cerefolium). Seed vernalization reduced yields considerably in both crops, especially at later sowings. After germination at a higher temperature (20 degrees C) for four days, yields were considerably higher in both crops, this effect being strongest at early sowings for spinach and at 3ate sowings for chervil. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The interaction of nitrogen supply and plant density in potatoes.
Authors: Bodlaender K.B.A. , Reestman A.J.
Published: June 2020

In 1959-61, the total fresh weights of tubers of a late variety increased with increasing plant density up to 70 000-100 000 plants/ha. With denser planting, yields decreased if N was not applied, and there was little or no yield increase with 100 or 200 kg/ha N. The optimal plant density was increased by applying 100 kg/ha N but it was not increased further with higher rates of N. Generally, no favourable interaction of N supply and plant density on yield occurred in early liftings. Weights of >35 mm tubers and total dry weights of tubers were generally affected by N and spacing in the same way as total fresh weights. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Agricultural control measures against intestinal parasites in cattle.
Authors: Oostendorp D. , Harmsen H.E.
Published: June 2020

Six groups, each of 12 bull calves which were born in May, castrated, dehorned and vaccinated against lungworms, were put out to pasture in May. The groups varied as to grassland management, supplemental feeding, and prophylactic use of anthelmintics. Serious parasitic gastro-enteritis (PGE) occurred in the control group rotationally grazing previously grazed pastures; three animals died. Mowing the first cut and normal rotational grazing afterwards gave hardly any better live weight gains; one animal died with PGE. Feeding additional concentrates or prophylactic thiabendazole treatment only slightly improved weight gains and increased costs. The only effective method to obtain good weight gains and to keep worm infestations low and harmless was rotational grazing on aftermath. The applicability and effectiveness of this latter method were confirmed in field trials on 50 farms.-AWJ. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Citrus cultivation in Surinam.
Authors: Samson J.A.
Published: June 2020

Citrus is grown mainly on the rich heavy clay coastal soils. A top layer of peat about 30 cm in depth is necessary to give good physical properties and adequate root growth. Initially, responses to N fertilizing occurred but soon disappeared after growth of a Pueraria cover crop. There were indications of a response to rock P. K increased the number and size of fruits. On sandy soils, deficiency symptoms, especially of Zn, occurred. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Manganous oxide (MnO) as a fertilizer for controlling manganese deficiency in oats.
Authors: Smilde K.W.
Published: June 2020

In pot experiments with a polder soil low in reducible Mn (extractant: 1N NH4OAc + 0.2% hydroquinone at pH 7), 50 kg/ha Mn applied as MnO (55 or 63.5% Mn) or MnSO4 (32.5% Mn) were as effective for preventing Mn deficiency in oats as spraying with MnSO4 or Mn-Rayplex (a polyflavonoid); reducible Mn in the soil increased to 50-60 ppm. With a more recent polder soil where Mn deficiency was not closely related to reducible Mn, but to C/N ratio, applying up to 176 kg/ha Mn did not completely control Mn deficiency. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Opportunity costs and decision-making in peasant agriculture.
Authors: Clayton E.S.
Published: June 2020

Opportunity costs of labour and land in peasant agriculture are shown to be positive and often substantial. Opportunity costs are defined as the price that can be obtained for alternative uses of labour and land. This thesis is contrary to popular notions about zero opportunity cost of agricultural labour in poor countries. Quantitative illustrations are given on the factor opportunity cost arising out of farmer decisions relating to timeliness of operations, level of yields, choice of crops, cash-crop quality and levels of mulching. If these costs are taken into account, a divergence will frequently exist between technical and economic efficiency: lower technical levels in certain cases may be more economic. T. A. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The development of small scale farming: two cases from the Commonwealth Caribbean.
Authors: Edwards D.T.
Published: June 2020

Two very different cases of small-scale farm development in the Commonwealth Caribbean are reviewed. One is Jamaican small farming, which responded little to considerable efforts made for its improvement by the Government agencies. The other is market gardening at Aranjuez, Trinidad where production grew at an extremely rapid rate in the face of intense and antagonistic competition between the market gardeners and without significant direct assistance by official agencies. The conclusions include a number of possible strategies for farm development, comprising individual or collective persuasion, coercion, creation of new farms, and environmental changes. T. A. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Agricultural problems in economically developed countries.
Authors: Maris A.
Published: June 2020

The chief concern in agriculture in the growing economies in W. Europe is cost reduction and adjustment of supply to demand. The economic growth and the technological development draw attention to the agricultural structure. In particular the farm size structure has obstructed improvements in the cost/return relations. Among the problems arising from agriculture in a growing economy are the uninterrupted rise in agricultural production, and the special structural problems in the prosperous countries. The increase in scale of agriculture and its effects on agricultural structure and other aspects of policy are discussed. E. A. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Farm mechanization and soil structure.
Authors: Van Ouwerkerk C.
Published: June 2020

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)
Influence of supplemented animal fats upon digestibility of ration components by ruminants.
Authors: Dijkstra N.D.
Published: June 2020

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)
Effects of temperature and water-regime on the emergence and yield of tomatoes.
Authors: Abdelhafeez A.T. , Verkerk K.
Published: June 2020

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)
Yield depressions due to lowering of the watertable on sandy soils in the Netherlands.
Authors: Groot J.M. , De Jager A.W.
Published: June 2020

A single parameter is described, comprising the moisture-holding capacity of the root zone and the capillary rise, giving the total water-supplying capacity and thus being a single characteristic of the drought sensitivity of a soil. Yields on soils with different water-supplying capacity could be compared and a relation could be derived between this parameter and yields. The parameter could not be adapted to yield depressions due to high watertables. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Leaching of arsenic from soil.
Authors: Tammes P.M. , De Lint M.M.
Published: June 2020

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)
Maturation in peas. 1. A visual method of maturity assessment.
Authors: Schippers P.A.
Published: June 2020

A method is described for assessing maturity in green peas based on visual estimates of pod maturity. Crop maturity as measured by average pod maturity showed a close correlation with maturity as measured by the average alcohol-insoluble solids of the peas, and the regression equations were reasonably stable. More needs to be known about the behaviour of varieties under various conditions before the method can be used to predict optimum harvest date.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Nitrate content and nitrogen loss in drainwater.
Authors: Kolenbrander G.J.
Published: June 2020

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, f.y.m., 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.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
A fattening trial with yearling rams of the Saudi Arabian Najdi and Arabi breeds.
Authors: Appelman H.
Published: June 2020

The major sheep breeds of the Eastern Province of Saudi Arabia, the Nejdi and Arabi, are described. The fattening performance and carcass characters of 8 yearling rams of each breed were studied and the data tabulated. Owing to the high variation among animals and the small numbers used, most interbreed differences were not significant. Over the 13 wk of the trial, for Nejdi and Arabi resp., av. daily gain was 128.6 and 154.9 g, and food conversion 13.83 and 11.04 g/g gain (P
Temperature and nitrogen nutrition in relation to flowering and fruiting in tomatoes.
Authors: Abdalla A.A. , Verkerk K.
Published: June 2020

Plants at the high temperature regime (35 degrees -day, 25 degrees C-night) had higher N contents than plants at the normal temperature regime (22 degrees -day, 18 degrees C-night). The difference was greater when plants were supplied with N-containing nutrient solution than when supplied with N-deficient nutrient solution. It was concluded that, at high temperatures, high N supply was not detrimental and may be beneficial. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of temperature of the root medium and of the growing point of the shoot on growth, water content and sugar content of maize leaves.
Authors: Kleinendorst A. , Brouwer R.
Published: June 2020

Maize seedlings were grown in nutrient solution under 18-h daylength and the temperatures of the root medium and of the growing points of the leaves were varied independently between 20 degrees and 5 degrees C; leaf growth rate and leaf water content were continuously recorded. The effect of root temperature on leaf growth was influenced by the plant water balance and was subject to osmotic adaptation which proceeded faster and was more complete at favourable growth temperatures.-G.M.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Crop husbandry on naturally compacted soils.
Authors: Bakermans W.A.P. , De Wit G.T.
Published: June 2020

In long-term experiments on soils ranging from sand to peat, which had been ploughed or naturally compacted following the use of herbicides, crop yields and the variation with depth of OM, plant nutrients and roots were compared. It was concluded that temperate cereals, maize and many cover crops might be successfully grown on compacted soils, but the growing of sugar beet and potatoes, and to a lesser extent of peas and beans, was hazardous, though in many cases yields were not depressed. CCT. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Adultness in cuttings of brussels sprout plants.
Authors: Kronenberg H.G.
Published: June 2020

Four-week-old plants from bud cuttings taken from adult plants flowered within 3 weeks in response to low temperatures (5 degrees C.). Untreated plants remained vegetative.-Agric. Univ., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Observations on the translation process of trichostrongylid nema-todes.
Authors: Pacenovsky J. , Kloosterman A. , Antonisse H.W.
Published: June 2020

A series of artificial faecal pats containing a mixture of eggs of Cooperia spp. and Ostertagia spp. at 500 e.p.g. were deposited on grassland every 2 weeks through the grazing season. The grassland had carried no stock for at least 10 years. Weekly larval counts on grass in the immediate surroundings of the pats indicated that larval concentrations are positively related to soil temperature and rainfall, and negatively to air temperature and radiation. Maximum numbers of larvae occurred after 9 to 10 weeks, suggesting that it can be extremely dangerous to return to pasture when the grass has regrown after a previous grazing. Faecal pats deposited in autumn were the main source of overwintered infection. The experiment may be considered as a model of a pasture grazed continuously by calves which have a constant egg excretion during the entire season. C.W.G. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Effects of aeration and mineral supply on growth and mineral content of shoots and roots of apple trees (var. 'Golden Delicious' on M.IX).
Authors: Visser J. , Locher J.T. , Brouwer R.
Published: June 2020

One- or 2-year-old Golden Delicious apple trees on M.IX were grown either in a clay loam (in 60-1 containers) or in nutrient solution and the effects were studied of several aeration regimes. With the soil-grown trees these comprised flooding to various soil depths and for different times. With the trees grown in nutrient solution the aeration regimes compared were nutrient solution without aeration, tap water with or without aeration, and aerated nutrient solution (control). Shoot growth was depressed by high water tables, and that of trees receiving non-aerated nutrient solution or tap water (whether aerated or not) ceased after about 2 weeks. The root growth of trees receiving non-aerated nutrient solution or tap water was similarly depressed, but, by contrast, aerated tap water enhanced root growth. Details are given of treatment effects on the Ca, K, N and soluble sugar contents of the young and old leaves and of the young roots. The uptake of all mineral elements was similarly affected by lack of aeration, suggesting that the relationship between low Ca content and increased bitter pit incidence is not associated with differential absorption but rather with differential Ca distribution. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Influence of photoperiod and water supply on production of seed and dry matter in three varieties of soybean, Glycine max (L.) Merr.
Authors: Aquino O. , Makkink G.F.
Published: June 2020

In glasshouse experiments soyabeans cv. Improved Pelican, L.Z. and Pennsoy were grown at 30/20 deg C day/night temperatures and under the prevailing natural photoperiod (16.2, 14.2 and 12.7 h in July, Aug. and Sept., respectively) or a controlled 12-h photoperiod. Plants were given 25, 50, 75 or 100% of a standard water application. In a further laboratory experiment, rates of photosynthesis and transpiration were determined under different light intensities. DM production, seed production, water consumption and the rate of photosynthesis did not differ between cv. and there was a rectilinear relationship between seed production and DM production and between DM production and water consumption. Plants given a >12-h daylength did not flower. In the controlled 12-h daylength, productivity/unit of water consumption was smaller than in the prevailing daylength. The rate of photosynthesis was somewhat lower than the rate presented by de Wit for most agricultural crops and the relationship between the rate of photosynthesis and transpiration was curvilinear for short periods. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The influence of different Ca and P supplies on the vitamin A, Cu and Mn status of young cattle with additional effects of growth and season.
Authors: Van Leeuwen J.M. , Van Kluijve J.J.
Published: June 2020

Six 9-month-old female Dutch Friesian cattle were given hay and pelleted concentrates with added 130 g CaCO3 or 100 g Na2HPO4 daily for periods of 50 days each. The supplements did not significantly influence growth or vitamin A, Cu or Mn in liver or blood plasma, although more P tended to retard growth. Liver vitamin A, Cu and Mn generally decreased significantly with time. Cu was more closely related to growth than vitamin A or Mn. A fall of Cu in blood plasma and liver was associated with a fall in the vitamin A in liver and with an increase of vitamin A in plasma.-V. J. B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of an iodinated casein fraction on the milk yield of goats.
Authors: Weits J. , Houtman A.C. , Roborgh J.R.
Published: June 2020

The authors found that intramuscular in-jections of the thyroxine-free B fraction of iodinated casein [see D.S.A. 13 (3) 301 (1951), POULSEN] into lactating goats, whilst causing marked increases in the milk and butterfat yields, resulted in an average decrease in live weight of 10 per cent and in a rise in both heart rate and body temperature. The effects showed little difference from those obtained with the oral administration of whole iodinated casein. Their findings thus disagree with those of Poulsen who found that the B fraction of iodinated casein had little or no effect on live weight. E.J.M. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The effect of spacing and thinning on the yield of Cinchona ledgeriana.
Authors: Ebes K.
Published: June 2020

The layout of an experiment started in Indonesia in 1933 to determine the effect of spacing and thinning on yield of Cinchona ledgeriana is described. The experiment was planned to last 25 years but was interrupted in 1942 by the Japanese occupation. Data recorded during these first 9 years are tabulated and the results summarized as follows. The production of clone Tjib. 5 was about 20% higher than that of Tjin. 1. Planting of 7, 200 and 8, 600 trees per ha. produced less than the widest spaced plantings of 5, 000 per ha. and the closest spaced plantings of 12, 600 per ha. The difference in yield between plots of very different spacings was relatively small, but the plots with the densest stand gave the greatest average production of quinine sulfate. The economics of dense planting are discussed. Height of tree was found to be practically independent of spacing, in contrast to girth which was a function of it. Close spacing produced slender trees with thin bark, but expressed as a percentage of the radius such bark was not relatively thinner than that of widely spaced trees. The ring content of quinine (pure quinine in dry bark from samples cut 1 m. above the ground) showed a slight tendency to decrease with age, after reaching a maximum in the sixth year. The preliminary conclusion is reached that, with regular thinning and fertilization, close spacing of cinchona is technically desirable and gives the highest yield. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Thinning research in forestry.
Authors: Becking J.H.
Published: June 2020

An account in English of research already described [cf. For. Abstr. 14 (No. 1453)] on the effect of thinning grade on increment, costs and value for Douglas Fir. KEYWORDS: Costs thinning \ forest economics \ forest management \ Pseudotsuga taxifolia \ Pseudotsuga menziesii \ thinning \ Thinnings economics \ Thinnings research (Abstract retrieved from CAB Abstracts by CABI’s permission)
Reclaiming land flooded with salt water.
Authors: Van Beekom C.W.C. , Van den Berg C. , De Boer Th.A. , Van der Molen W.H. , Verhoeven B. , Westerhof J.J. , Zuur A.J.
Published: June 2020

Controlled experiments and field experience in the Netherlands have shown that the maximum concentration of salt (NaCl) in the moisture of the 5-20 cm. soil layers at which a given spring crop may be sown without risk of failure varies from year to year according to the climatic conditions prevailing in the summer. Crops which succeed in a normal season when sown at a given salt concentration in the soil moisture, may fail when a hot, dry summer follows a spring sowing at the same concentration. A table is presented showing the maximum spring salt concentrations at which various crops may be sown, under average Dutch climatic conditions, with a reasonable chance of success (i.e. of obtaining a yield at least 75% of normal). In general the figures given coincide with those already quoted by C. van den Berg in " The reaction of crops to soil salinity " Verslag. Landbouwk. Onderzoek. 1950, Vol. 56, No. 16. The maximum salt concentration permissible for the planting of fodder-potatoes is 3 g. of salt per 1. of soil-moisture, whereas in the case of potatoes for consumption, owing to the deleterious effect of salt on eating-quality, the maximum concentration permissible at planting time is 1.5 g. per 1. It is pointed out that winter-sown crops such as cereals and oil-seed rape may be sown at much higher concentrations of salt in the soil-moisture than spring crops, because winter rains leach the salt from the soil and because crop plants are able to tolerate much higher concentrations of salt at winter than at summer temperatures. In cool weather, cereals can germinate at salt concentrations as high as 20 g. per 1.-W.J.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Feeding layers with different levels of energy and protein in the Eastern Province of Saudi Arabia.
Authors: Appelman H. , Bonhof B.J.
Published: June 2020

Three hundred day-old Single Comb White Leghorn hybrid chicks were kept in insulated units with ventilators and 930 in traditional open-air units under a corrugated galvanised sheet roof in Saudi Arabia. All were fed on a standard diet. Growth in both groups was almost equal, but feed conversion was slightly more favourable in the insulated house. Overall mortality was considered to be favourable. The remaining 995 pullets, when of laying age, were divided into 8 groups, 2 of which were kept in the insulated units, and the rest in open-air units. During the laying period, 4 groups were fed on a high-energy (HC) mash and 4 on low-energy (LC) mash. A 17-h lighting schedule was maintained. Feed intake and energy and protein conversion were higher in the LC groups, while gross feed conversion was better in the HC group and the hens tended to be slightly heavier. There was no difference in egg production between feed groups, but that of hens in insulated units was higher than that of hens in open units. Mortality was higher in the HC group, the main cause being visceral lymphomatosis, and higher in the open housed groups, where 33 died from heat stroke in July, than in the insulated units. The authors conclude that the favourable aspects of the HC feeding were offset by the higher mortality and the higher feeding costs, and so the LC mash might be more profitable. I. F. la C. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Dry matter yield response of pasture grass to application of Nemafos (thionazin).
Authors: Ennik G.C.
Published: June 2020

Results of several field trials on the response of permanent grass swards and of sown swards with and without clover to application of thionazin (as Nemafos) at about 8 ml/m2 before each cut are described. Where N was the main factor limiting growth, plots with Nemafos grew better than the controls because of an increase in available soil N. At high levels of N, growth was improved because of direct stimulation of regrowth after cutting. Nemafos had a favourable effect, which lasted longer with successive cuts, on the development and vigour of tillers. The yield responses were unrelated to control of nematodes. [See also HbA 39, 422]. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Experimental studies on seed production of tropical grasses in Kenya. 4. The effect of fertilizer and planting density on Chloris gayana cv. Mbarara.
Authors: Boonman J.G.
Published: June 2020

Rhodes grass sown broadcast or in rows 25-100 cm apart at 0.2-1.8 kg pure germinable seed/ha was given 0-80 kg seedbed P2O5 and 0-200 kg N/ha for each seed crop. Yields of DM in the establishment year were significantly higher at high seed rates and close spacing, whereas yields of clean seed were decreased from 145 kg/ha (50-cm rows) at the lowest seed rate to 110 kg/ha at the highest. Seed yields were highest, 160 kg/ha, from broadcast sowings at 1 kg/ha. Yields of pure germinable seed were not significantly affected by treatment. In 6 seed crops taken after establishment, the only factor of importance for seed yield was N; yields of pure germinable seed increased from 6.2 kg/ha without N to 36.7-41.0 kg/ha at 100 kg N/ha and 41.2-43.2 kg/ha at 150 kg N/ha. DM yields from these 6 crops were higher at the wider row spacings. Increased N and wider spacing accelerated the onset of heading. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Experimental studies on seed production of tropical grasses in Kenya. 5. The effect of time of nitrogen top dressing on seed crops of Setaria sphacelata cv. Nandi.
Authors: Boonman J.G.
Published: June 2020

Effects of date of applying top-dressings of N to early-season and late-season seed crops of Setaria sphacelata cv. Nandi were studied in 4 trials in 1967-71. Highest seed yields were obtained when N was applied as soon as possible after the onset of the rainy season; a delay of 4 weeks reduced yields of pure germinating seed by >60%. Total yields of herbage DM and number of heads were also reduced, but to a lesser extent; the main adverse effect was on seed set/head. In late-season crops, applying N 2 weeks after the earliest possible date proved beneficial in 2 out of 3 years. (Abstract retrieved from CAB Abstracts by CABI’s permission)
The significance of the fallow year in the dry-farming system of the Great Konya Basin, Turkey.
Authors: Janssen B.H.
Published: June 2020

About 20% of the area is irrigated and about 35% dry farmed using a fallow period of stubble to prevent wind erosion and hold snow in place in winter. In about 30 trials on farmers' fields during 1966-68, the contribution of moisture stored during the fallow year to the transpiration of a following wheat crop was 45 and 65%, indicating the indispensability of the fallow period. A tentative scheme for the area recommends the following: with an annual precipitation of 450mm precipitation, permanent cultivation, with N dressings replacing the fallow year.[281:132.2]. (Abstract retrieved from CAB Abstracts by CABI’s permission)