bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Long‐term Application of Farmyard Manure on Growth and Quality of Sugar Beet
Authors: Maidl F. X. , Fischbeck G.
Published: April 2008

Field trials were conducted for two years on two farms which differed in long‐term application of pig slurry in order to study the effects of long‐term organic manuring, timing of slurry application (no slurry, slurry autumn, slurry spring) and additional doses of mineral N‐fertilizer (0, 80, 160, 240 kg N/ha) on growth and quality of sugar beet.

The results can be summarized as follows:

1. The effect of slurry application on growth of sugar beets varied markedly with the long‐term differences in farm management. On the “arable farm” yield of beet roots increased substantially after slurry application and could not be replaced by higher doses of mineral N fertilizer. It is concluded therefore that “special effects” of farmyard manure are involved. On the “livestock farm”, however, highest beet yields were obtained on plots without slurry. Additionally slurry application caused a significant decrease in beet yields.

2. Sugar beets without slurry treatment always developed higher sugar contents and lower concentrations of alpha‐amino‐N, sodium and potassium as compared to beets from plots with slurry application.

3. Despite the decline in sugar content, sugar yield greatly increased by slurry application on the “arable farm”. The average increase in sugar yield was 10 dt/ha (=8%) with slurry application in autumn and amounted to 16 dt/ha (=14%) with spring application. On the livestock farm however, additional applications of slurry caused a decline in sugar yields in both years because of lower sugar contents and decrease in beet yields.

4. The utilization rate of slurry‐N, depending mainly on time of application, annual rainfall and soil N mineralization, varied from 6–41%. On the “livestock farm” the utilization of slurry‐N was only half of the rate obtained on the “arable farm”.

5. The application of small doses of slurry may cause a significant yield increase on farms without or only less livestock, while on farms with intensive livestock production continous slurry application needs to be considered as an expensive form of waste disposal. Therefore farms with high livestock density are advised to sell slurry to neighbouring farms without or only low animal production at a fair price for their mutual advantage.
Effect of Plant Spacing on the Productivity of Roselle (Hibiscus sabdariffa L.) Grown in Newly Reclamed Land
Authors: Shalaby A. S. , Razin A. M.
Published: April 2008

Plant spacing study has been conducted on two types of Roselle, namely Hibiscus sabdariffa var. Masri, and H. sabdariffa var. Sudani. The two types are traditionally used to be cultivated in Egypt in loamy rich soils at a distance of 60 to 70 cm between hills. In the present experiment, however, they were cultivated in a newly reclamed desert land. The spacing treatments were 30, 50 and 70 cm between hills. The results revealed that the wider spacing (70 cm) resulted in shorter plants with more branches and higher number of fruits per plant. However, the narrower spacing (30 cm) gave higher weight of fruits, fresh sepals and accordingly, higher yields of dry sepals, anthocyanins and acids compared with the treatment of 70 cm. The best results concerning the yield of sepals and active constituents per unit area were gained when Roselle plants were planted at 50 cm spacing. The spacing treatments did not affect the content of anthocyanins or total acidity as a percentage.
Einfluß eines steigenden N‐Angebotes auf die Knöllchenbildung bei Erbse (Pisum sativum L. ssp. sativum) in Nährlösungskultur
Authors: Liebhard P.
Published: April 2008

Influence of ascending nitrogen supply on the development of Rhizobium symbiotic bacteria on peas (Pisum sativum L. ssp. sativum) in nutritive culture solution

The effect of ascending N‐supply with 4 different levels from 0.1 to 1.56 mg atom/L culture solution on juncture, quantity and development of Rhizobium bacteria on peas variety Stehgolt was thoroughly investigated. Contemporaneously, all the inoculated plants set on several noduls. The number of nodules formed per plant was negatively and hasty influenced by the ascending N‐supply. Higher N‐provision lessen the number of Rhizobium nodules per plant, however, these few achieved their active N2‐Fixation phase (Leghämoglobin formation stage) earlier than those formed under insufficient N‐supply.
Auswirkungen der Züchtung bei Winterweizen in einem landwirtschaftlichen System mit geringer Betriebsmittelzufuhr von außen
Authors: Stöppler H. , E. Kölsch  , Vogtmann H.
Published: April 2008

Impact of Wheat Breeding in an Agricultural Low External Input System

Low external input systems, e.g. ecological agriculture, are able to solve problems concerning environmental pollution, diminishing ressources, and overproduction. Since growing conditions of winter wheat are very different in ecological agriculture as compared to conventional systems, the impact of genetic improvement of winter wheat in low external input systems is not well known. Investigations were carried out in two years at two ecologically managed farms using 24 genotypes of winter wheat of different periods of release (about 1900 to 1983). The results can be summarized as follows:

1. The tendency towards higher yields among modern varieties as compared to older cultivars in ecological agriculture was highly significant.

2. The rate of yield improvement was smaller under low external input as compared to conventional conditions results. Yield improvement was greatest in recent decades.

3. In ecological agriculture higher yields among modern varieties resulted from an increased harvest index along with an unchanged biomass production, improved resistance properties, and higher ear weight. Reduced plant height probably has negative effects.

4. Baking quality was improved clearly by wheat breeding.

5. Further genetic improvement of winter wheat yields in low external input systems may result from increased biomass production along with a constant or enhanced harvest index, improved resistance properties, increased plant height, and pronounciation of ear weight.
A Functional Growth Analysis Model for Grain Development in Oryza sativa L.
Authors: Kailasam C. , Chandra Babu R. , Vijayalakshmi C. , Sree Rangaswamy S. R.
Published: April 2008

The pattern of grain growth in two rice cultivars was assessed in terms of total dry weight of grain from anthesis upto maturity. Rice grain development followed a sigmoidal trend. Richards' function was found to more closely fie the data on grain growth and thus could serve as a suitable mathematical model for rice grain growth analysis.
Auswirkungen unterschiedlicher physiologischer Alter und Pflanzknollengrößen auf die oberirdischen Pflanzenorgane von Kartoffeln (Sorte Granola)
Authors: Szlavik I. , Caesar K.
Published: April 2008

In a two‐year field trial, the influence of the physiological age and the size of seed tubers on various growth parameters was determined

Emergence and senescence occurred earlier in plants of older physiological age. On the other hand the physiological age did not influence the number of stems, the stem dry weight, the leaf number, the leaf dry weight, the leaf area, and the specific leaf area. There was a positive correlation between seed tuber size and number of stems but a negative correlation to the stem dry weight. Bigger seed tubers and consequently a higher number of stems had initially a positive effect on the number of leaves, leaf area and leaf dry weight per plant but this was reversed in the course of the vegetation period. The specific leaf area was only influenced by the weather conditions. There was a strong, highly significant negative correlation between number of stems and branching. The correlation between number of stems and leaf area as well as leaf area duration was positive.
Diurnal Pattern of Plant Water Relations of Groundnut under Water Stress and Potassium Nutrition
Authors: Mohandass S. , Radhakrishnan R. , Panchanathan R. M. , Kandaswamy P.
Published: April 2008

Diurnal variations in plant water relations were studied in a field grown groundnut crop in water stressed and non stressed plants with and without potassium nutrition. The results indicated the possibility of mitigating the ill effects of water stress by means of potassium spray thus reducing the water demand especially during the critical phase of the crop.
The Response of Four Sorghum Accessions/Cultivars to Salinity During Plant Development
Authors: Azhar F. M. , McNeilly T.
Published: April 2008

Whole‐plant‐response of four sorghum accessions to increasing mM NaCl concentrations of 0, 100, and 150 was assessed at three growth stages (GS‐1, GS‐2, and GS‐3), in a sand‐culture experiment. Accession comparisons were made on the basis of absolute and relative salt tolerance values. Increasing salinity significantly reduced plant height at GS‐1, whilst shoot and root dry weight were less affected. The effect of NaCl on these characters was greater at GS‐2 and GS‐3, and accessions differed significantly in their responses to salinity. On the basis of plant height data, Giza 114 had the highest absolute salt tolerance at all three growth stages. However based on shoot and root dry weight data, Double TX and Giza 114 were both significantly more NaCl‐tolerant than INRA 133 and INRA 353 at GS‐2. Based on relative salt tolerance values of shoot and root dry weight, and plant height, Double TX and Giza 114 were more affected by salinity at GS‐3 than INRA 133 and INRA 353. INRA 133 and INRA 353 exhibited progressively higher tolerance at all growth stages, and produced more grains than Double TX and Giza 114, and consequently had higher grain yield per plant. NaCl salinity had little effect on grain weight. Plant sensitivity to NaCl at three growth stages differs in the four accessions, and is genotype‐specific. This suggests that there is considerable variation in salt tolerance in sorghum at the adult stage which may be exploited through selection and breeding of plants to effect further improvement in salinity tolerance in this species.
Use of a Disk Meter to Evaluate Continuously Grazed Pastures
Authors: Bryan W. B. , Thayne W. V. , Prigge E. C.
Published: April 2008

One of the greatest difficulties in pasture research is accurately measuring quality and quantity of the vegetation. The disk meter may be used to rapidly estimate herbage mass (DM) but its validity depends on a good relationship between disk meter height (DMH) and DM. The objective of this study was to determine the relationship between DMH and DM for continuously grazed pastures. Pastures of varied botanical composition were grazed by cows and calves from May through October. Paired data (DMH and DM clipped from under the disk) from seven cool season pastures were subjected to covariance analysis. Prediction equations were developed utilizing data from 2 years for different pastures and dates. Disk meter height accounted for a little over half the variability in DM (R2 of 0.54 and 0.59 for years 1 and 2, respectively). Regression coefficients of DM on DMH differed between dates in both years and between pastures in one year. To accurately predict DM the disk meter must be calibrated for each pasture and date. However, the disk meter can be used where an estimate of herbage mass is required and resources are limiting.
Grain Protein Accumulation During Grain Development in Barley (Hordeum vulgare L.)
Authors: Polisetty Raghuveer , Chandra R.
Published: April 2008

Grain protein accumulation during grain development was studied as a function of defoliation at anthesis in barley (Hordeum vulgare L.) genotypes grown under pot culture and non limiting nitrogen conditions. The data indicates that per cent grain protein did not decrease proportionally despite 50 % or more decrease in grain yield per plant. These data support the contention that shrivelling need not result in proportional increase in grain protein %. The data also suggests that accumulation of grain protein and carbohydrate during the grain development may not be negatively associated. The data also brings about the importance of grain protein yield per plant as a useful parameter for breeding high grain protein genotypes.
Leaf Growth and Chlorophyll Content of Oilseed Rape (Brassica napus L.) as Influenced by Nitrogen Supply
Authors: Ogunlela V. B. , Kullmann A. , Geisler G.
Published: April 2008

An experiment was conducted using a greenhouse hydroponics system to investigate the influence of N nutrition on leaf growth and chlorophyll content in oilseed rape (Brassica napus L.) during both vegetative and generative growth. Plants were treated continuously with one of three levels of N supply (30, 100 or 170ppm N). Leaf expansion in terms of lamina area of individual leaves and leaf area per plant, and chlorophyll content of leaves during both growth phases were increased significantly by N supply up to 100 ppm N, which was found to be the optimum level for oilseed rape. N supply of 30 ppm N resulted in N stress while 170 ppm N represents an excessive supply. N supply of 100 ppm N enhanced leaf expansion during H–6 weeks after transplanting by 88–260 % over that of 30 ppm N. Lamina areas of younger leaves responded to N nutrition better than did those of older leaves. Leaf area per plant increased 155–194 % due to increasing N supply but leaf number was increased less remarkably (by 25–44 %). N supply enhanced the contents of leaf chlorophyll a, chlorophyll b, and total chlorophyll but had very little influence on chlorophyll a/b ratios; except that increasing N supply tended to reduce these ratios. Results suggest that variation in leaf chlorophyll content of rape plants in response to N nutrition is a function of leaf age and position. The significance of these results in terms of certain physiological implications for the rape plant is discussed.
Growth Promotion of Wheat Seedlings by Streptomyces atroolivaceus
Authors: El‐Shanshoury A. R.
Published: April 2008

Treating grains and roots of wheat seedlings with supernatants of different aged cultures of Streptomyces atroolivaceus stimulated plant growth. The treatment resulted in increased shoot elongation, shoot fresh and dry weights, and root fresh and dry weights but suppressed the depth of the root system. The supernatants resulted in increased shoot DNA but not root DNA. Shoot and root contents of RNA and protein were also enhanced. Effects probably caused by activity of plant growth regulators.
Vergleich von Methoden zur Bestimmung der Wurzellängendichte bei Kulturpflanzen
Authors: Gäth S. , Meuser H.
Published: April 2008

Comparison of methods to determine the root length density of crops

In this paper, in a first step a comparison of the soil core or monolith method with the profile wall method was undertaken with data obtained for sugar beets.

Results show that differences between both methods, expressed as a factor, decline destinctly during the vegetation period. This means that the calibration of the profile wall method with the help of a time independent, average factor cannot be recommended.

In a second step, we compared the monolith method with a new procedure to estimate root growth.

Results for a soil derived from loess show that values measured and estimated correspond very well, while for a sandy soil, there was only a satisfactory correspondence.

The comparison led to the conclusion, that in field work the monolith method should be preferred to the profile wall method, and the root growth estimation procedure is available alternative to determine the root length density of cereals.
Auswirkungen unterschiedlicher physiologischer Alter und Pflanzknollengrößen auf Ertragsparameter und Ertrag von Kartoffeln (Sorte Granola)
Authors: Szlavik I. , Caesar K.
Published: April 2008

In a two‐year field trial, the influence of the physiological age and the size of seed tubers on yield parameters and yield of cv. Granola was determined

In the first trial year no influence of the physiological age on the number of tubers at the time of flowering was found. Plants from physiological older seed tubers had higher single tuber weight. The maximal number of tubers was reached at the time of flowering.

In the second year no influence of the physiological age on the single tuber weight was found although the tuber number varied. The physiological age had in the first year a weak, and in the second year no significant influence on the number of tubers after senescence.

Increasing size of seed tubers resulted in both years and at all harvesting times in higher tuber number, but the single tuber weight after senescence decreased with increasing size of seed tubers.

The final yield in both years was not influenced by the physiological age but it increased with the increase of the size of seed tubers.
Development and Yield Formation of Autumn‐ and Spring‐sown Faba Beans in Northern Germany as Affected by Seasons, Sowing Dates and Varieties
Authors: Herzog H.
Published: April 2008

Field trials were conducted with autumn‐ and spring‐sown faba beans in Northern Germany during four seasons to examine the expected preceding development of autumn‐sown plants, its possible transformation into a higher yield potential and its dependence on sowing dates and varieties. Height, appearance of leaves, inflorescences, mature flowers, potential and actual pot set was rated weekly, and flower initiation and tillering occasionally. Comparison was made for one winter type sown in autumn and spring, and between 6 winter types and 3 spring types, in two seasons each.

Development of autumn‐sown plants significantly preceded that of spring‐sown in each year, regardless of the plant material used. The mean advance, diminished considerably with time due to prolonged developmental phases in autumn‐sown plants which, however, did not improve vegetative, generative or reproductive potentials of main tillers. Potentials formed by the six winter types, interacted strongly with the seasons, at least in part due to changing plant densities. Thus, only a very few traits appeared typical: a short stature with few leaves for Avrissot and the opposite for Bourdon, a high number of ripening pods for Avrissot and a low number for Banner. Early compared to late sowing in autumn increased the number of leaves, and in one year even the number of mature flowers and ripening pods per tiller, but values of early sowing never exceeded those of spring sowing. Enhancement of tiller formation by early compared to late sowing diminished after spring; nevertheless about two reproductive tillers per plant in autumn‐sown stands always led to a higher density of tillers than in spring‐sown.
Effect of a Winter Cereal or Legume Crop on the Yield and Nutrient Uptake by Summer Maize/Cowpea Fodder
Authors: George M. , Prasad R.
Published: April 2008

A field experiment conducted at the Indian Agricultural Research Institute, New Delhi brought out that summer maize green fodder yield was 31.8 t/ha to 34.1 t/ha, while that of cowpea fodder was only 15.5 to 16 t/ ha. Maize fodder and crude protein yield and NPK uptake was more after a winter legume (lentil) than after a winter cereal (wheat).
Concentrations and Distribution of Some Mineral Elements in Oilseed Rape (Brassica napus L.) Plants in Relation to Nitrogen Supply
Authors: Kullmann A. , Ogunlela V. B. , Geisler G.
Published: April 2008

A greenhouse experiment was conducted to study the effect of N nutrition (30, 100 or 170 ppm N) on the concentrations and distribution of P, K, Ca, and Mg in oilseed rape (Brassica napus L.). Leaf K concentration increased with increasing N supply up to 100 ppm N, as did leaf Mg after the bloom stage. Leaf Ca decreased with increasing N nutrition but P concentration was unaffected. Lower leaves had higher P concentrations than did the upper leaves. P, Ca and Mg concentrations in the roots at 34 days before bloom (DBB) declined when N supply was increased but K concentration was unaffected. At 10 and 44 days after bloom (DAB) P concentrations in the roots, stem and branches increased with N supply; whereas K, Ca and Mg concentrations did not respond. Concentrations of P in the pods increased with N nutrition up to 100 ppm N but those of K, Ca and Mg in the pods, hull and seeds were unaffected by N nutrition. P concentrations in the hull and in the seeds also increased with N supply. Most of the K and Ca were in the leaves while the least were in the seeds. Most of the P accumulated in the seeds and roots; whereas the hull contained the least. Of the four nutrients analyzed for, P concentrations were generally the lowest in the various plant parts and K concentrations the highest. Ca/Mg ratios for the hull and branches were increased by 100 ppm N and the ratios for the leaves, pods and seeds were unaffected by N nutrition.
Changes in Soil Physical Properties After Intercropping as Against Sole Cropping
Authors: Mathan K. K.
Published: April 2008

Two field trials under irrigated conditions were conducted in red sandy loam soils of Palathurai series (Typic Haplustalf) at Coimbatore to evaluate the changes in physical properties when intercropping was introduced to a pure crop system. The results of the first crop indicated that intercropping of sorghum (CSH 5)‐lab lab (CO 9) system was found to improve the physical properties such as hydraulic conductivity, total porosity, aggregate stability and stability index when compared to pure crop of either sorghum or lab lab. The results of the second crop indicated that the bulk density of soil was not significantly altered by intercropping. When a legume was introduced as an intercrop to a cereal crop the physical properties such as total porosity, hydraulic conductivity, aggregate stability and stability index were not affected but when the cereal was introduced to a legume, the above parameter significantly improved.
Gene Action in Pearl Millet (Pennisetum americanum L. Leeke)
Authors: Pethani K. V. , Dave H. R.
Published: April 2008

Grain yield was largely governed by non‐additive (SCA) type of gene action with the significant existence of additive (GCA) type of gene action. GCA variance due to females was significant whereas due to males was non‐significant under all environments. SCA variance was highly susceptible to the changing environments as compared to GCA component of females, whereas GCA component of males was not at all interacting with environments. Proportion of SCA and GCA variances distorted on pooling the data and was contradictory. Such distortion of the proportion on pooling was observed due to large amount of g x e interactions. Impact of interaction of genetic variance components with environments, its proportion, utility and breeding approaches are discussed.
The Effect of Component Frequency and Plant Density on Yields of Cultivar Mixtures in Spring Faba Beans
Authors: Tarhuni A. M. , McNeilly T.
Published: April 2008

The effect of plant density and component frequency was examined in mixtures of two spring faba bean (Vicia faba L.) cultivars Donas and Minden grown in a replacement series experiment in the field. There were two densities, 44 and 25 plants m−2.

At low density mixtures yielded significantly more (+ 22.5 %) than the mean of the components grown in monoculture. The advantage was considerably reduced (+ 7.8 %) at high density. A frequency dependent advantage was observed when the proportion of the components in mixtures was varied. At high density and when averaged over the two densities, the greatest yield advantages were obtained when Danas, the high yielding component represented 75 % of the mixture, whilst at low density the greatest advantage was achieved at 50 : 50 mixture. Such gains were either due to component co‐operation or complementation type interactions.

Mixtures produced greater total dry weights and more podded nodes per plant than the mean of the components. The remaining characters had values which were more or less similar for monocultures and mixtures.
Effect of Sesbania rostrata on Nitrogen Uptake and Yield of Lowland Rice
Authors: Kalidurai M. , Kannaiyan S.
Published: April 2008

Nitrogen inputs into rice fields can be increased by cultivation of green manure crops. Many Sesbania species have been generally grown by the rice farmers in India and these green manures are capable of contributing significant amount of nitrogen in 45 to 90 days period by their association with the nitrogen fixing symbiotic bacterium –Rhizobium. Field experiments conducted at the Tamil Nadu Agricultural University, Coimbatore, India, during Dry and Wet seasons in 1987–88 with medium duration (145 days) rice variety CO 43. Sesbania rostrata produced higher biomass on 60th day after sowing and accumulated higher percentage of nitrogen. Application of fertilizer nitrogen with S. rostrata have increased the nitrogen uptake and yield of rice.
Stärke‐ und Amylosegehalte in blattreichen und blattarmen Sorten von Mark‐ und Futtererbsen
Authors: Haeder H. E.
Published: April 2008

Starch and amylose content in conventional and semi‐leafless cultivars of garden and field peas

Small‐plot experiments were carried out with conventional and semi‐foliated cultivars of garden and field peas (Pisum sativum, ssp. medulare and ssp. sativum) to investigate the effect of increasing potassium dressings on starch, amylose and sugars in mature seeds during two years.

Field peas compared with garden peas produced: (1) 2 times higher seed yields, (2) 1.6 times higher starch contents (41–44 % DM), (3) nearly comparable amylose contents (17 % DM), (4) 3 times higher amylopec‐tin contents (26 % DM), (5) 4 times lower sugar contents (1.6 % DM).

In the presently existing cultivars field peas are by far superior to garden peas with regard to amylose production per area. Compared with conventional cultivars the semi‐leafless types of both subspecies yielded the same seed weights, and they differed in no respect in the seed components analysed.

Improved potassium nutrition increased yields of seeds and straw, but had no significant effect on the seed components analysed.
Effect of Date of Planting, Genotype and Source of Seed on Disease Incidence, Yield, and Agronomic Performance of Soybean
Authors: Omer M. A. , Sapra V. T. , Pacumbaba R. P.
Published: April 2008

Four soybean genotypes chosen from four seed sources were planted in a factorial arrangement on four dates in a split‐plot design at the Alabama A & M Experimental Station on a Decatur silt clay loam soil. The highest vigor index was recorded from seeds harvested from the 4th date of planting. These seeds had the lowest level of Diaporthe phaseolorum var. caulivora infection, indicating that vigor index, as a measurement of seed quality, was negatively correlated with the level of infection by soybean stem canker pathogen. Seed yield was highest at the 2nd date of planting and lowest at the 4th date of planting. Tracy‐M and Bedford confirmed previous reports on their resistance and susceptibility, respectively, to soybean stem canker. All the genotypes performed their best at the 2nd date of planting. Source of seeds appeared to have little effect on the performance of the plant in the field.
Effect of Ten Successive Rollings on Soil Physical Properties and Yield of Groundnut (var. TMV 3) in a Very Permeable Sandy Soil in Southern India
Authors: Natesan R. , Mathan K. K. , Rajkannan B.
Published: April 2008

Trial in a farmer's holding, which was sandy containing 80‐90 per cent of fine and coarse sand fraction, was conducted to evaluate the effect of ten successive rollings by 400 kg stone roller (1 meter width) on the soil physical properties and yield of groundnut (var. TMV 3). By rolling, the bulk density was increased from 1.50 g/cc to 1.63 g/cc in the 20‐30 cm layer; Hydraulic conductivity was reduced from 36.7 cm/h to 17.3 cm/ h in the same subsoil layer (53 per cent over control) which resulted in higher moisture retension capacity of the soil, the increase being 51.5 per cent over control in the 30‐40 cm layer. The final dry pod yield increase was 19 per cent over control. The effect of compaction was seen at the post‐harvest soils also, in that the increase in bulk density, decrease in hydraulic conductivity were observed. The variations were more effective at 10‐20 cm laver.
Automatisierte Unterscheidung von Unkrautarten nach Formparametern mit Hilfe der quantitativen Bildanalyse
Authors: Petry W. , Kühbauch W.
Published: April 2008

Automatic distinction of weed species using form parameters by means of digital image processing

In former investigations the possibility to distinguish weed from soil background by computerized quantitative image analysis has been reported. In the present studies image analysis technique are applied to identify different weed species. From six typical winter weed species including various growth stages, 300 color slides were taken at the research station in Bonn on the 4th of February, 1988. From each slide a number of form parameters were measured automatically out of the digitized shape of each weed plant. Form parameters including area, perimeter, minimum and maximum diameter of the plants are taken from the digitized shape of each weed as well as figures representing the relative proportions of these parameters. For automatic discrimination up to 9 of the parameters were selected to compute five so‐called canonical variables. The values of these variables are typical for each weed species and can be interpreted as their “finger prints”. The average rate of correct identification was 82.3 %. The scientific and practical implications of the results are discussed.
The Influence of the Pea Plant Ideotype on Seed Protein Content and Seed Yield
Authors: Bertholdsson N. O.
Published: April 2008

The assimilation and translocation pattern of radioactive 14‐C‐assimilates and how it may affect nitrogen fixation was studied in conventional and semi‐leafless pot grown field peas (Pisum sativum L.). Leaf areas, plant development patterns and yield components and their influence on protein content, protein yield and seed yield were studied by using simple regression, multiple regression and factor analyses over a period of two years of field grown material.

It was shown that roots and nodules received most of the carbon assimilate from the lower leaves at the beginning of flowering. Four weeks later most of the assimilates came from the upper leaves. Furthermore, it was discovered that stipules were more important than leaflets in supplying the roots and nodules. Field studies supported the results obtained in pot grown material. They also showed that in order to achieve high seed and protein yield it is more important to have many generative nodes instead of a few with several pods on each. In semi‐leafless types, vegetative upper nodes and late flowering are also important factors. An ideotype suited for both high seed yield, high seed protein yield and high protein content is discussed.
Zur Eignung nicht eingesäter Teilflächen in Getreideschlägen für die störungsfreie, bildanalytische Ermittlung von Unkrautschadschwellen
Authors: Kühbauch W. , Petry W.
Published: April 2008

Suitability of not seeded test squares in crop fields for reliable ascertainment of weed threshold levels by quantitative image analysis

The possibility to measure weed ground cover using a computerized image analysis system has been reported in former investigations. In the present studies suitability of not seeded test squares in crop fields for reliable detection of weed ground cover for precise determination of weed threshold levels (beyond that crop yield losses are economically greater than costs for weed control) has been tested.

Test squares in which weed grew without competing crop as well as corresponding squares including both, growing crop and weeds, were examined for weed ground cover by computer assisted quantitative image analysis of color slides taken from the respective squares. In the squares, that includes crop and weeds, the former was removed immediately before taking the slides.

In both seasons from the beginning of weed growth in October to the latest feasible application time of herbicides in April weed growth as measured by ground cover in the not seeded test squares did not differ significantly from that grown under competition of winter barley.

Results indicate, that up to the growth stage of weed where herbicides if ever should be applied at the latest, crop‐free test areas in the same field could serve for correct determination of weed growth by image analysis.
Determination of Differences in Chilling Susceptibility of Two Soybean Varieties by Means of in vivo Chlorophyll Fluorescence Measurements
Authors: Neuner G. , Larcher W.
Published: April 2008

Chilling susceptibility of two soybean varieties, i.e. cv. Maple Arrow and cv. Evans, in the vegetative state (V 3.0) was determined by measuring in vivo chlorophyll fluorescence of leaves exposed to low positive temperatures. In the more susceptible variety Maple Arrow quite distinct deviations from the reference fluorescence data are seen at temperatures between 6.5 and 4.8°C, but not until 5.5. to 2.5°C in the variety Evans. Fluorescence characteristics, i.e. the fluorescence decrease Rfd, the appearance of low‐waves, the photochemical quenching coefficient at steady‐state and the initial slope of the non‐photochemical quenching coefficient qNP indicate that the two varieties differ in their susceptibility by about 1‐2°C at this stage of development. Our results suggest that measurement of in vivo chlorophyll fluorescence might serve as a suitable rapid monitoring method of pre‐screening soybean varieties for chilling susceptibility, as required in plant breeding.
Effects of Water Deficiency and Kinetin on Growth and Nitrogen Metabolism of Cowpea Plants
Authors: Khalil Sohair , Mandurah Hanan M.
Published: April 2008

Cowpea plants (Vigna sinensis Savi.) were grown in pots for two successive years. These plants were daily maintained water holding capacities (15, 25, 45, 65 %).

The foliage of plants grown at every level of soil moisture was sprayed till dripping with kinetin solutions (0, 10, 20, 40 mg/1) three times after, 3, 6 and 9 weeks from sowing. Samples were taken at the two physiological stages before flowering and during flowering for growth measurements and determination of nitrogen fractions.

Water shortage led to retardation of stem length, number of internodes, number of leaves and dry weight of shoots. Kinetin reduced stem length of cowpea shoots. On the other hand, it exhibited stimulative effect when applied at concentrations 10 and 20 mg/1 on number of internodes, and dry weight of shoots.

Water stress decreased total–N and protein–N contents of cowpea shoots. On the other hand total soluble–N content was increased under the same conditions. Kinetin increased total–N and protein–N contents of cowpea shoots. Meanwhile, the same growth regulator decreased total soluble–N when applied at 45 %, 25 % and 15 % W.H.C. levels.
Microbial Population and Yield of Wheat in Relation to Soil Salinity
Authors: Gour H. N. , Lal P. , Mathur J. R.
Published: April 2008

The studies on isolations of microorganisms from four different saline soils (ECe 1.85, 5.8, 9.4 and 13.4 dS/m) and roots of wheat (Kharchia‐65, a salt tolerant variety) plants grown in above soils reveal an interesting correlation between microbial population and soil salinity Vis‐a‐vis growth and yield. Though growth and yield of wheat decreased with an increase in the salinity of the soils, the fungal and bacterial populations concomitantly increased and the maximum microbial colonies were recorded from the soil, having highest salinity status. A maximum number of fungal colonies (predominantly of Aspergillus sp., Paecilomyces sp., Penicillium sp. etc.) was isolated from the root surfaces of the plants grown on soil having ECe of 1.85 dS/m, whereas a single colony of Fusarium oxysporum occurred from roots of plants of soils having an ECe of 13. 4dS/m.
Effect of CMH on Growth and Enzyme Activity in Wheat (Triticum aestivum L.) at Different Growth Stages and Light Intensities
Authors: El‐Fouly M. M. , Moubarak Z. M. , Fouad M. K. , Fawzi A. F. A.
Published: April 2008

Pot experiments were conducted over 3 successive seasons using wheat Giza 155 grown in normal or low (50 % of normal) light intensity. Concentrations of 50, 100, 500, 1000 or 2500 ppm CMH were sprayed at tillering, early stem extension, late stem extension or heading. Grain weight/plant, specific grain weight, grain number/ear and ear number/plant were increased with lower concentrations of CMH treatments only at the first 2 stages under varied light intensity. During both tillering and early stem extension, CMH spraying increased activities of α‐amylase and β‐fructofuranosidase in leaves leading to more accumulation of total carbohydrates in grains and consequently more grain production/plant. Such effect occurred with 50–500 ppm CMH under normal light intensity as well as with all concentrations of this compound under low intensity. Meanwhile, 1000 and 2500 ppm CMH resulted in growth inhibition.
Einfluß der Bestandesdichte auf Ertrags‐ und Qualitätskriterien sowie über mögliche Ursachen der Konkurrenz in Zuckerrübenbeständen
Authors: Märländer B.
Published: April 2008

Influence of Plant Density on Yield and Quality and Possible Causes of Competition in Sugar Beet Crops

In trials conducted over 9 years at 1 location plant densities ranged from 35,000 to 110,000 plants/ha. Root yield, sugar yield and white sugar yield reached maximum values at 92,700, 94,700 and 96,000 plants/ha, respectively. The decrease in yield per 1,000 plants/ha was greater as the plant density fell. The quality criteria (sugar concentration, white sugar concentration and sugar gain) were at their maxima at 107,000, 104,600 and 100,000 plants/ha, respectively, and they decreased at an almost constant rate as plant density declined. The concentrations of potassium, sodium and amino‐N, the main factors which determine quality in Germany, as well as the sugar loss were all minimized at about 110,000 plants/ha and they increased at a progressively‐greater rate per 1,000 plants/ha as plant density declined. The maximum differences between large and small plant densities were: root yield 13.6%, sugar yield 16.7%, white sugar yield 18.6%, sugar concentration 3.7%, white sugar concentration 5.3%, sugar gain 1.7%, sugar loss 9.3%, potassium concentration 8.4%, sodium concentration 30.5% and amino‐N concentration 25.4%. As well as a comparison of the yield and quality criteria, the paper considers competition within the foliage, particularly when different amounts of nitrogen are available, as the main cause for yield differences between sugar beet crops.
Evaluation of Polyethylene Glycol Test for Measuring Cell Membrane Stability in Maize
Authors: Premachandra G. S. , Saneoka H. , Ogata S.
Published: April 2008

Cell membrane stability (CMS) of ten maize (Zea mays L.) cultivars was measured by the polyethylene glycol (PEG) test and compared with other nutritional and physiological measurements to examine the nutriophysiological meanings of the test. Osmotic potential of leaf tissues was well correlated with CMS measured as percentage injury in the PEG test and it was suggested that it may have influenced on desiccation treatment in the PEG test. Leaf water potential, stomatal resistance and cuticular resistance did not show any correlation with CMS measured. Cultivars with high leaf water content were high in CMS and were tolerant to desiccation stress in the PEG test. They showed high excised‐leaf water retention capability. Sugar, K. and Ca were the major solutes which contributed to osmotic potential. Potassium concentration in leaf tissues was well correlated with CMS, while sugar was not. It was suggested that K may play another role in increasing CMS in maize apart from its role as an osmotic substance.
Procedure and General Features of Testing Breakage Resistance of Seedcoat in Euphorbia lathyris L.
Authors: Hondelmann W.
Published: April 2008

The breakage resistance of the seedcoat of Euphorbia lathyris was measured in terms of compressive force and deformation. Using an Instron Universal Testing Machine, seeds of genetically divergent descent were tested at a moisture content comparable to that at harvesting time in the field.

In comparison to other crop species breakage resistance of caper spurge is characterized by low values of force and medium ones for deformation. In connection with a likewise weakly expressed degree of elasticity the large portion of damaged seeds observed during mechanical harvesting becomes understandable. Regarding the descent of seed samples the eventual implication of an unsufficient variation of the character in question is becoming evident.
The Influence of Plant Water Stress on Net Photosynthesis and Leaf Area of Two Maize (Zea mays L.) Cultivars
Authors: Human J. J. , Du Preez W. H. , De Bruyn L. P.
Published: April 2008

The effect of plant water stress on net photosynthesis and leaf growth were investigated in order to determine to what extent leaf water potential during vegetative growth and silking affects maize development.

Two commercial maize hybrids grown in pots in a glasshouse were subjected to leaf water potentials of ‐1300 and ‐1700 kPa during the eighth leaf stage and during silking to ‐1700 and ‐2300 kPa to previously unstressed, moderately and severely stressed plants. The effect of stress on inhibiting CO2 uptake rates and leaf areas, as well as the recovery after alleviating stress, were compared to that of unstressed plants.

No substantial differences in CO2 uptake rates were found between medium and long seasoned cultivars. The CO2 uptake rates per unit leaf area decreased to negative values under both moderate and severe stress conditions during both growth stages. During silking, the recovery of CO2 uptake rate was much lower than during the eight leaf stage. Leaf area decreased proportionally with increased stress but did not recover after alleviating stress on plants stressed during both the eighth leaf and silking stages.
Nitrogen Fixation by Irrigated Berseem Clover versus Soil Nitrogen Supply
Authors: Williams W. A. , Graves W. L. , Cassman K. G.
Published: April 2008

Nitrogen fixation was estimated by the difference method for two cultivars of berseem clover (Trifohum alexandrinum L.), using annual ryegrass (Lolium multiflorum Lam.) as the control in field trials from 1983 to 1988. Five or six cuttings were obtained each year under supplemental irrigation, and dry matter production and uptake of nitrogen into harvested forage were measured.

Estimates of nitrogen fixation by berseem clover ranged from 272 to 400 kg N/ha depending on year and cultivar, while plant N derived from soil (based on N uptake by the ryegrass) ranged from 50 to 235 kg N/ha. Graphs of nitrogen fixed versus available soil nitrogen had a reverse linear‐plateau shape with a plateau at lower soil nitrogen levels that broke sharply in a linear decline as available soil N surpassed a minimum threshold. Such a two‐phase response suggests that nitrogen fixation by the clover was limited by soil N supply above this threshold and by other limiting factors at low soil N levels, perhaps genetic traits controlling carbon assimilation or environmental limitations other than nitrogen. Seasonal nitrogen process patterns showed abundant nitrogen fixation by the clover after it had depleted most of the soil nitrogen supply.
Sward Height and a Capacitance Probe for Estimating Herbage Mass
Authors: Bryan W. B. , Thayne W. V. , Prigge E. C.
Published: April 2008

Estimation of herbage mass is essential in pasture research and in making practical grazing management decisions. Sward height and a capacitance probe were evaluated as non‐destructive measures of herbage mass at seven dates from April 16 to July 30 on continuously grazed predominantly Kentucky bluegrass (Poa pratensis L.) pasture. Paddocks were 1 ha in size and were stocked at 3, 4 or 5 steers ha−1 (average initial weight 312 kg). Four to six, sampling points were located randomly in each paddock at each date. Sward height was measured with a ruler, the vegetation in a 0.2 nr area visually designated “high” or “low” according to legume percentage, ten readings using a single capacitance probe were made and the herbage clipped. Paired data with clipped dry weight as dependent variable and height and/or the average corrected probe reading as covariates were analyzed statistically. The relationship between clipped dry weight and nondestructive measures of herbage mass was found to be linear. There was a small effect of sampling date in Spring on the relationship between destructive and non‐destructive measures of herbage mass, but each of the measures, including herbage mass predicted from probe and height measurements, resulted in the same inferences being made about differences between treatments. Neither stocking rate nor small differences in percentage legume affected the relationship. Thus, sward height and capacitance probe show promise as nondestructive measures of pasture herbage mass.
Effect of Seed Size on Germination and Seedling Growth in Greengram (Vigna radiata L. Wilczek) and Blackgram (Vigna mungo L. Hepper) Cultivars
Authors: Chandra Babu R. , Muralidharan V. , Seetha Rani M. , Nagarajan M. , Sree Rangasamy S. R. , Pallikonda Perumal R. K.
Published: April 2008

The effect of seed size on germination and seedling growth was assessed using cultivars of greengram and blackgram. Significant positive correlation was noticed between seed size and germination, seedling height, root length, primary leaf size and seedling weight. The possible advantages of choosing cultivars with heavier seeds for attaining better crop stand especially under rainfed situation are discussed.
15N Studies of the Behavior of Fertilizer Nitrogen in Three Different Soils (Lysimeter Trials)
Authors: Dressel J. , Jung J.
Published: April 2008

A lysimeter trial is described in which the fate of 15N was monitored in a sand, loam and clay soil by using it over a period of 6 years. The following results were obtained.

1. The uptake of fertilizer nitrogen by plants, determined by using 15N, is lower than by using the conventional method (“difference method”). Nitrate 15N is better utilized by the plants than is ammonium 15N. The total nitrogen uptake only gives hints of these differences.

2. The extent to which plants utilize fertilizer 15N is between 38 and 58%; in the case of the method of differences this figure is between 48 and 68%.

3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.

4. After a trial period of six years between 26 and 54 % of the fertilizer 15N remains in the soil. The resulting sequences are clay > loam > sand > and ammonium > nitrate.

5. The immobilization of the fertilizer 15N is most pronounced in the first four years but then decreased considerably; in the case of the sandy soil it is then even slightly regressive.

6. The biggest part of the 15N is deposited in the uppermost layer of the soil. The amount of 15N in the deeper layers is diminished appreciably. The type of soil has a greater influence than the form of nitrogen.

7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil.