bluuebunny/crossref_metadata_2025 huggingface dataset:
Vergleichende Streßphysiologie von Tepary‐Bohnen (Phaseolus acutifolius A. Gray) als “Minor Crop” und Mwezi Moja‐Bohnen (Phaseolus vulgaris, GLP 1004) als Hochleistungsleguminose im tropischen Landbau
Authors: Hornetz B.
Published: April 2008

Comparative stress physiology of tepary beans (Phaseolus acutifolius) as “minor crop” and mwezi moja beans (Phaseolus vulgaris) as high‐yielding variety in tropical agriculture

The study deals with the ecophysiological demands of the “minor pulse” tepary beans (Phaseolus acutifolius) – possessing a high nutritional value – as well as of the high‐yielding kenyan bean variety mwezi moja (Phaseolus vulgaris, GLP 1004).

Special reference is dedicated on the drought resistance of the crops in order to make recommendations for potential cultivation in the semi‐arid and arid drylands of South and Southeast Kenya.

Newly constructed growth containers gave possibilities to simulate different durations and intensities of water stress under controlled environmental conditions in climatic chamber experiments.

It was observed and recorded that teparies possess different mechanisms of morphological and physiological adaptation to high temperature and water stress, apparently including the ability of osmotic adjustment. The patterns of adaptation to water stress are combined with defined hydrature periods closely connected with the reduction of soil moisture.

There was no evidence of morphological adaptation of mwezi moja leaves to water stress. It was observed and recorded that there is a partial drought resistance within the upper leaf unit, apparently caused by osmotic adjustment.

The crop seems to be less adapted than tepary beans to marginal cropping areas (e.g. in agroecological zone, AE2, L 6 or LM 6; ace. to: Jätzold and Schmidt 1982/83) of the drylands due to high crop water requirements (about 30 % more than the “minor pulse”), low drought resistance and a high relative yield decrease under water stress – in spite of a short vegetation cycle (about 60–65 days).
Relationship Between Storage and Germinability of Cardamom (Elatteria cardamomum Maton)
Authors: Sangakkara U. R.
Published: April 2008

Cardamom seeds are considered recalcitrant, with relatively low retention of germinability during storage. Thus, a study tested the effects of drying temperatures on moisture loss and reduction in germinability of cardamom seeds. In addition, the effect of storage material and temperatures on retention of germinability was evaluated. The mature seeds of cardamom contained a high percentage of water at harvest, and germinability at harvest was around 62 %, confirming the recalcitrant nature of the seeds. Seed germinability was completely lost at moisture levels below 50 % (dry wt. basis) and higher temperatures reduced moisture levels and germinability faster. Drying at 20°C retained some degree of germinability for 7 days. In terms of storage, sealed polythene containers and low temperature (5°C) was optimal for maintaining some degree of germinability of cardamom seeds during storage for approximately 15 days.
Agronomic Factors in Evaluating Forage Crops II. Predicting Fiber Components (NDF, ADF, ADL) from Crop Leafiness
Authors: Kalu B. A. , Fick G. W. , van Soest P. J.
Published: April 2008

The relationship of the stage‐to‐stage changes in alfalfa herbage leaf percentage and the corresponding changes in fiber components represented by neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) was tested in alfalfa crop diverse in stand and canopy ages, stages of maturity harvested across seasons in two separate years. Regression analyses showed that for all fiber components, leaf percentage consistently provided highly significant linear relationships for predicting herbage fiber content; NDF (r2= 0.915), ADF (r2= 0.937) and, ADL (r2= 0.851). These were highly comparable with the application of the mean stage by weight (MSW) system for predicting NDF (r2= 0.946), ADF (r2= 0.891) and ADL (r2= 0.841) thus indicating the practical use of leaf percentage as a good alternative approach for predicting fiber content of the alfalfa crop.
Growth Analysis, Herbage and Seed Yield of Certain Forage Legume Species Under Rainfed Conditions
Authors: AbdElMoneim A. M. , Khair M. A. , Cocks P. S.
Published: April 2008

The need to increase forage production for the growing livestock population in the Mediterranean region necessitates the evaluation of various promising forage species with respect to maximum herbage yield, optimum time for harvest and seed yield. Seven forage legumes, woolly pod vetch (Vicia villosa subsp. dasycarpa accession 683), narbon vetch (V. narbonensis accession 67), common vetch (V. sativa selections 2541, 2037, 2020), common chickling (Lathyrus sativus selection 439) and ochrus chickling (L. ochrus selection 104) were compared over two years with contrasting rainfall. In both years the entries were sown in November and their primary growths sampled periodically during growth. For each sample, phenology, total dry matter, leaf area index (LAI) and, at maturity, total dry matter, seed yield and harvest index, were recorded.

In both seasons, narbon vetch attained the highest dry matter and seed yields, and there was very limited variability in the maximum dry matter yield of the other entries. In general, the maximum dry matter occurred at 20–50 % podding in woolly pod vetch, 100 % podding in common vetch selection 2541 (local), narbon vetch and common chickling and at maturity in common vetch selection 2037, selection 2020 and ochrus chickling.

Throughout the vegetative to early flowering stages, woolly pod vetch had the highest dry matter yield and LAI. Possible uses of each species as animal feed are discussed.
Allelopathic Potential of Shoot and Root Leachates of Certain Weed Species
Authors: Seetha Rani M. , Chandra Babu R. , Moosa Sheriff M. , Pallikonda Perumal R. K.
Published: April 2008

The allelopathic potential of shoot and root leachates of seven weed species was assessed using sorghum and blackgram as test crops. Weeds differed significantly among themselves in their allelopathic effect. Shoot leachates of weeds, in general, showed more allelopathic effect than their root leachates. Phenolic content of weed leachates has positive association with the allelopathic potential of the weed species.
Effect of Genotypes and Plant Maturity on Forage Quality of Certain Forage Legume Species Under Rainfed Conditions
Authors: Abd El Moneim A. M. , Khair M. A. , Rihawi S.
Published: April 2008

Evaluation of plant species for animal feed requires the quantitative and qualitative comparison of different genotypes. Promising lines of annual legumes comprising seven genotypes of vetche (Vicia spp.) and chicklings (Lathyrus spp.) were compared for herbage quality. The content of crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in herbage and pods were measured at different stages of plant maturity. The proportion of the leaves to shoots (leafiness) and in vitro dry matter digestibility (IVDMD) were also determined. As plants matured IVDMD, CP and leafiness decreased and NDF and ADF increased. For all the genotypes maximum digestible dry matter (DDM) and CP yields were more or less attained at 50–100 % podding. Narbon vetch had the highest DDM. The possible uses of the different genotypes as animal feed are discussed based on the partitioning of the DDM and CP yield as plants matured.
Sensitivity to Drought Stress of Three Soybean Cultivars During Different Growth Stages
Authors: Kpoghomou B. K. , Sapra V. T. , Beyl C. A.
Published: April 2008

Three soybean (Glycine max L.) culivars, Lee‐74, Wright, and Ra 401, were subjected to 100 % (control), 75 %, and 50 % of field capacity during vegetative (VI), flowering (R2), and pod‐filling (R4) stages in greenhouse and field studies. Stress applied at R2 significantly reduced the yield in the greenhouse, while in the field, the maximum reduction was observed when the plants were subjected to stress at R4. Stress during VI reduced the yield components less than stress applied during R2 or R4 stages in both studies. The pod number and seed weight were the yield components most affected by drought stress, and the number of seeds per pod the least affected. Yield stress index was significantly correlated with the yield and its components. The reproductive stage was clearly more sensitive to drought than the vegetative stage. The cultivar Lee 74 had the highest yield and the second highest yield stress index whereas the cultivar Ra 401 had the lowest yield.
Das optimale N‐Angebot im Frühjahr bei unterschiedlicher Keimdichte von Winterweizen
Authors: Wollring J.
Published: April 2008

The optimal N‐supply in spring for different plant densities of winter wheat

The influence of plant density (plt./m2) on the optimal N‐supply in spring (Nmin‐content + N‐fertilization) has been tested at three sites. The different plant density was produced by different seed rates in autumn of about 150, 250, 350, 450 and 550 grains/m2. The N‐supply in spring was ‐ apart from a non‐fertilized field (Nmin‐content) 80, 100, 120, 140 and 160 kg N/ha. Additionally, 80 kg N/ha were applicated as N‐topdressing. Moreover the optimal N‐supply in spring has been tested on a winter wheat field thinned out due to winterkilling. In detail we got the following results:

1. The reduction of the Nmin‐content due to the N‐uptake by the plants slowed down in accordance with minor plant density.

2. The same N‐supply in the soil produced a higher N‐supply per individual plant in accordance with decreasing plant density and lead to a considerable increase of N‐nutrition.

3. Thin crops showed a higher tillering. The differences in plant density between 150 and 550 plt./m2 in spring diminished to about 90 ears/m2 at harvest.

4. Independently of plant density the maximum yield was obtained by a N‐supply (Nmin+ N‐fertilization) in spring of about 120 kg/ha N. Due to the abundant N‐nutrition of the individual plants and the minor increase of yield a higher N‐supply is not necessary with a minor plant density.

5. Essentially the yield level was only diminished with the lowest plant density (100‐140 plt./m2).
Screening for Drought Tolerance: Soybean Germination and its Relationship to Seedling Responses
Authors: Kpoghomou B. K. , Sapra V. T. , Beyl C. A.
Published: April 2008

Seventeen determinate soybean (Glycine max L.) cultivars from maturity groups V through VIII were screened for drought tolerance during germination and seedling stages. Germinating seeds and hydroponically‐grown seedlings were subjected to osmotic stresses of ‐0.3 and ‐0.5 MPa using polyethylene glycol M.W. 8000. Genotypic variability was found among the cultivars for all the parameters analyzed in both germination and seedling tests. Germination stress index was lower for seeds exposed to ‐0.5 MPa than for ‐0.3 MPa osmotic stress. Lower osmotic potential in the treatment medium was also correlated with lower leaf water potential in seedlings subjected to it. A significant relationship was found between fresh weight and height stress indices. The cultivars that grew taller under drought stress conditions had greater dry matter accumulation and higher germination stress indices indicating the reliability of height to predict cultivar performance under such conditions. The cultivars Lee‐74 and Wright had higher dry matter accumulation, greater height, and better germination under stress conditions than the other cultivars tested. Conversely, the cultivars Ra 401 and Bay performed poorly in the drought tests at both levels. In the seedling tests, there was no strong relationship between the leaf water potential and the overall performance of the plant suggesting no clear osmoregulatory mechanism. Based on results from germination and seedling tests, the cultivars Lee‐74, Wright, and Ra 401 were selected for further studies in greenhouse and field trials.
Effect of Whole Season CO2 Enrichment on the Cultivation of a Medicinal Plant, Digitalis lanata
Authors: Stuhlfauth T. , Fock H. P.
Published: April 2008

A versatile method was developed for the application of 1000 ppm CO2 during the whole growth period of plants. Temperature controlled water cooling and ventilation of the greenhouse resulted in a monthly CO2 enrichment time of 60 to 90 % of the total light period. Digitalis lanata, grown in greenhouses with CO2 enrichment during the whole growth phase from April to November, produced twice as much biomass as field cultivated plants.

The relative yield of the glycoside digoxin per gram Digitalis drug dry weight was 0.4% in field grown and 0.7% in greenhouse cultivated plants. The production of digoxin per hectare in the greenhouse at 1000 ppm CO2 was almost 3.5‐fold that by field cultivation. Drug yield and secondary metabolite production in D. lanata were remarkably influenced by increased temperature and elevated CO2 partial pressure in the greenhouse.
Response of Some Quality Traits of Sunflower Seeds and Oil to Different Environments
Authors: Kandil A. , Ibrahim A. F. , Marquard R. , Taha R. S.
Published: April 2008

Five sunflower hybrids and one open‐pollinated variety were sown at two locations in West Germany and at two‐sowings at Giza, Egypt (summer and winter seasons). Cultivars showed different response concerning oil and protein contents as well as fatty acid composition. Highest protein content was observed from Giza in winter season. Cultivars differed significantly with this respect under different environments. However, oil content was not significantly affected by environments X cultivars interaction.

Regarding fatty acid composition, palmitic and stearic acids were insignificantly affected. However, highest oleic acid percentage (57.5%) was observed at Giza in summer sowing by Nhy, hybrid, while at Giza in winter sowing the highest value (25.7%) was produced by Semu 209 hybrid. The differences between the two Germany locations were relatively low in range from 14.6–17.6%. Concerning linoleic acid, it showed an opposite trend.

Environments X cultivars interaction showed significant influence on total tocopherol content.
The Significance of Soil Burning (“Guie”) in Ethiopia with Special Regard to its Effects on the Agrestal Weed Flora
Authors: Pülschln L. , Koch W.
Published: April 2008

Soil burning (“guie”) is a traditional farming practice in restricted areas of the Ethiopian highlands. Sods with adherent soil of grazed fallows are burnt which leads to comparatively high yields of the subsequent barley (Hordeum vulgare L.) crop. The weed species coverage and steadiness on burnt and unburnt spots of guie fields have been surveyed within the 1984/85 and 1985/86 growing periods using the Braun‐Blanquet cover‐abundance scale. On burnt spots weeds developed just about 1/3 of the cover on unburnt ones with a comparatively low share of monocotyledonous species. The total number of species collected was 103 (of 33 families) on unburnt spots and 77 on burnt ones. The average number of species/site was 39 and 26 respectively. The Poaceae, Asteraceae, Fabaceae and Caryophyllaceae were the most diverse families recorded with 27, 12, 10 and 6 species respectively. Species of highest steadiness like Ranunculus multifidus Forsk., Polygonum nepalense Meissn., Guizotia scabra (Vis.) Chiov. and Dicbondra repens J. R. & G. Forst. were significantly reduced in cover due to burning.
N‐Dynamik des Bodens, Ertragsbildung und Stickstoffentzug von Winterweizen bei unterschiedlicher Höhe und Verteilung der mineralischen N‐Düngung
Authors: Fischbeck G. , Dennert J. , Müller R.
Published: April 2008

NO3 dynamics in the soil, yield formation and N uptake of winter wheat as influenced by dosage and distribution effects of N‐fertilizer application

In a 4 year series of field trials carried out with 9 regimes of nitrogen fertilizer application at two trial sites with rather shallow top soil layers but large deviations in soil characteristics, grain yield varied between 50 dt/ ha and 120 dt/ha with nitrogen doses from 0–170 kg N/ha. Soil nitrogen supply for wheat grain formation on unfertilized plots reached 80 kg N/ha/year within the narrow range of 75–95 kg N/ha in different years at both sites which amounts to 1.5 % and 0.5 % of the highly different N‐content of the trial sites.

The most successful nitrogen application regimes are characterized by modest fertilizer doses in early spring and the delay of supplemental fertilizer doses until growth stage EC 32. They resulted into modest NO) soil content from EC 29 to EC 32 and/or a noticable decrease of soil NO3 content during growth stage EC 30–32, which seems to be responsible for the development of only modest stand densities and reduced straw yield, while the delayed supplementation with nitrogen fertilizer overcompensated these effects mainly by increased grain numbers/ear and a remarkable improvement of harvest index.

The contribution of soil borne nitrogen to kernel yield formation started to decrease with even low dosages of supplemental nitrogen fertilization with the exception of the highest yielding season 1987/88. Top levels of grain yield have been regularly obtained with supplemental nitrogen fertilizer dosages about 40 kg N/ha below grain yield nitrogen extraction if they were added within favorable application regimes.
Effect of Thermal Energy Intensity on Time and Rate of Nitrogen Accumulation by Maize (Zea mays L.)1
Authors: Olness A. , Benoit G. R. , Sickle K. van , Rinke Jana
Published: April 2008

The effect of thermal energy intensity (TEI) on the rate of nitrogen (N) accumulation by maize from a Hamerly clay loam soil (Aerie Calciaquoll) was examined with and without supplemental irrigation. Soil‐ and air‐TEI expressed as cumulative growing degree days (GDD) was determined from hourly temperature measurements taken within each plot at soil depths of 0.05‐, 0.15‐, and 0.3‐m and at a height of 1.2‐m above ground surface. A daily mean TEI (GDD per day) was calculated for each growth period. Estimates of time coefficient(s), k, in uni‐ and diphasic tanh[k(time)] functions, plotted against mean TEI for the periods; 1) planting to emergence, 2) emergence to eighth leaf, 3) eighth leaf to time(s) of maximum N accumulation rate, (t0), 4) planting to t0, 5) emergence to t0, 6) first diphasic maximum accumulation rate (t01) to 50 % silking, and 7) silking to second diphasic maximum accumulation rate t02 showed several linear relationships. Uniphasic time coefficients were modelled as functions of air‐TEI. The first diphasic time coefficient, k1 was modelled as a function of pre‐ and post‐emergent soil‐TEI. Attempts to model k2, the second time coefficient of the diphasic model were unsuccessful; however, this time coefficient was linearly related to TEI for the growth period ‘t01, to 50 % silking’ and curvilinearly related to k1.
Variability and Correlations in Grain Sorghum Genotypes (Sorghum bicolor [L.] Moench) Under Drought Conditions at Different Stages of Growth
Authors: Bakheit Bahy R.
Published: April 2008

Twenty‐two genotypes of grain sorghum were grown under drought conditions by omitting one irrigation during stages of before flowering period, kernel filling period, and physiological maturity period at Assiut Univ. Farm in 1987 and 1988 seasons. The results obtained revealed that considerable variation existed among genotypes for all the studied traits. The most effective moisture stress treatment in reducing grain yield, panicle weight and plant height was during flowering stage. While 1000‐kernel weight was much affected by moisture stress during grain filling period. The genotype x year interaction (σ2gy) was large compared to genotype x irrigation treatment (σ2gl) indicated that genotypes responded differently when they were grown from year to year. The genotypic variance (σ2g) for all traits were large reflecting the importance of genetic variability. Both phenotypic and genotypic correlations among traits showed that plant height and 1000‐kernel weight were highly correlated with grain yield, while leaf area index was low associated with plant height.
Effect of Seedling Density and Shading Material on Germination and Early Growth of Tobacco (Nicotiana tabacum L.)
Authors: Sangakkara U. R. , Keerthi M. M.
Published: April 2008

The effect of four seedling densities developed soon after the emergence and two shading materials were studied in order to elucidate the response of seedling growth of tobacco. Germination and seedling emergence was better in beds under greycloth than under polythene. In contrast, shoot and root growth of tobacco seedlings was superior under polythene at all densities. This observation is attributed to optimal environmental conditions under polythene. The study also revealed that the highest shoot and root growth was at the lowest density. High plant densities hindered plant growth. Well developed plants were seen at the plant density of 165 plants per 0.1 m2 under polythene.
Effect of Gibberellic Acid on Seedling Growth and Carbohydrate Metabolism During Germination of Rice (Oryza sativa L. var. GR‐3) Under Saline Condition
Authors: Acharya Ujwala T. , Prakash L. , Prathapasenan G.
Published: April 2008

Interactive effect of NaCl salinity and gibberellic acid (GA3) on seedling growth and carbohydrate metabolism of rice was studied for five days. NaCl reduced the embryo axis growth and the rate of hydrolysis of starch in the endosperm. Parallel to this reduced rate of reserve carbohydrate mobilization, a decreased activity of α‐amylase, β‐amylase, maltase and invertase was also found in the endosperm of sale stressed seeds. Presoaking treatment of seeds with GA3 (10 mg l−1), however, increased the growth of seedlings and enhanced the hydrolysis of starch as well as the activities of said enzymes. Electrophoretic analysis revealed that NaCl inhibits the synthesis of amylase isozymes which, in turn, reversed considerably by GA3 application.
Changes in Polyamine Titer in Rice Seedlings Following NaCl Salinity Stress
Authors: Katiyar Sadhana , Dubey R. S.
Published: April 2008

Seedlings of four rice cultivars differing in salt tolerance were raised in sand cultures under increasing levels of NaCl salinity and metabolic levels of total polyamines, spermidine, spermine, agmatine and the diamine putrescine were determined in roots and shoots during 5‐20 days growth period. Salinity caused a remarkable increase in total polyamines level in rice seedlings. At similar level of salinity roots as well as shoots of salt sensitive cvs. Ratna and Jaya showed higher level of total polyamines than tolerants. Salinity of 14 dSm−1 NaCl caused more than 2 times polyamine level in shoots of sensitive cultivars compared to tolerants. Accumulation of polyamines was greater in salt stressed shoots than roots. In nonsalinized seedlings there appeared a gradual increase in putrescine level during 5 to 20 days growth period. Salt treatment caused sharp increase in putrescine level in all cultivars, however under similar level of salinization salt stressed seedlings of sensitive cultivars had higher putrescine level than tolerants. In nonsalinized seedlings of sensitive cultivars spermidine level increased gradually during 5 to 20 days growth period whereas a decline in the level was observed in seedlings of tolerant cultivars during this period. Higher level of salinity caused marked increase in spermidine level in sensitive cultivars. Specially during 5 to 10 days of growth salinity caused increase in spermine level in seedlings of sensitive cultivars. In all cultivars salt stressed seedlings had higher agmatine level compared to non‐stressed. Salinity led to greater accumulation of certain unidentified polyamines in seedlings of sensitive cultivars. Increased levels of total polyamines, putrescine, spermidine and unknown polyamines in rice seedlings under salinization suggest their possible role in combating the adverse effects of salinity stress.
Comments on the Calculation of Mean Harvest Indices
Authors: Hühn M.
Published: April 2008

The harvest index Z is defined, for example for cereals, as the ratio between grain yield X and total yield Y: Z = X/Y. For individual measurements xi of X and yi of Y the individual harvest index is calculated by zi= xi/yi. These individual measurements i are based on N different experimental units (single plants, random samples from plots or total plots).

Mean harvest indices are commonly calculated either by or by where the means of X, Y and Z are denoted by x̄, ȳ and z̄ respectively.

Both approaches are, in general, different. But, in this paper it is shown that for most situations which may occur in the field of practical applications in agronomy and plant breeding both procedures will lead to nearly identical results. Only in some special situations the two results differ significantly. These conditions are investigated and explicitly given.

Some explicit formulae (approximations) for the calculation of mean harvest indices are derived and discussed.

Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter‐rapeseed data.
Variation in Seed Yield and Quality Characters of Four Spring Oil Rapeseed Cultivars as Influenced by Population Arrangements and Densities
Authors: Shrief S. A. , Shabana R. , Ibrahim A. F. , Geisler G.
Published: April 2008

Variations of yield and quality characters of four spring oilseed rape cultivars (B. napus L.) arranged in 16 or 32 cm between drills and under three population densities (30, 60 and 90 plants/nr) were investigated in a split‐plot design with three replications in 1986 and 1987 in West Germany.

Cultivar Callypso gave the highest seed and oil yields per plot and the highest seed index, harvest index and seed yield/main stem, per branches and per plant. Differences due to arrangements were significant in 1986 only, i.e., the value of a special plant distribution was more pronounced under unsuitable weather condition (as in 1986). With respect to the three population densities, most of the characters showed significantly higher values with 30 plants/nr. Only seed yield and oil yield per plot that showed 7.27% and 5.6% increase, respectively, under the highest population density (90 plants/nr) but the differences were insignificant.

The highest oil content was obtained from cultivar Callypso and from the lowest population density. By contrast, higher protein content was obvious under higher population densities and the differences from the lowest density were significant in both years. Differences in fatty acid composition were not significant for the three main effects.
Effects of Root Zone Temperature on Root Activity of Two Potato (Solanum tuberosum L.) Clones with Different Adaptation to High Temperature
Authors: Sattelmacher B. , Marschner H. , Kühne R.
Published: April 2008

Under controlled environmental conditions, the effect of optimal (20 °C) and supraoptimal (30 °C) root‐zone temperature on root activity (respiration, soluble sugar content, ethylene release, nitrogen uptake and translocation) was studied in water culture with two potato clones differing in the heat tolerance of their root systems. Root respiration was little affected by raising temperature from 20 °C to 30 °C. However, in both clones assimilate allocation to the roots was strongly depressed. In the heat sensitive clone LT‐1 exposed to 30 °C root‐zone temperature, concentrations of soluble sugars in the apical root zone (0–10 mm) increased with time, presumably as a result of the cessation of root growth. The rate of nitrate absorption was not significantly affected by root‐zone temperature. However, the export of nitrogen (xylem exudate) was depressed in the heat tolerant clone whereas in the heat sensitive clone the export of total nitrogen and the proportion of nitrate increased. No effect of root‐zone temperature on ethylene release was observed in our experiments.
Correlation and Path Coefficient Analysis for Some New Released (00) Spring Rapeseed Cultivars Grown under Different Competitive Systems
Authors: Shabana R. , Shrief S. A. , Ibrahim A. F. , Geisler G.
Published: April 2008

The inter‐relationships between fifteen quantitative characters of spring oilseed rape were computed using four “free erucic acid” cultivars viz. Callypso, Semit 2080, Semu DNK 203/84 and Semu 304, grown under two different distances between drill rows (16 and 32 cm) and three population densities (30, 60 and 90 plants/m2). The experiments were carried out in Kiel, West Germany, in 1986 and 1987 seasons.

Positive and highly significant values were obtained in the two seasons between seed yield per plant and the characters: dry matter (DM) per plant, per main stem and per branches, number of branches, siliqua per plant or per branches and yield per branches. All the characters that showed strong association with yield/plant behaved in a similar way and similar magnitudes with yield/branches. By contrast, yield/main stem showed different magnitudes in the two years with the previous characters and the association was weak or absent in most cases.

Seed index and the quality traits (oil and protein %) did not correlate significantly with the majority of the characters studied. Only the association between DM/main stem and protein content showed highly significant negative values in both seasons.

Path coefficient analysis revealed that number of siliqua per plant had the highest direct effect on seed yield/plant in both years. The source character (DM) affected yield/plant indirectly through number of siliqua per plant and the indirect contribution was high m both years.
Die Wirksamkeit von Fungiziden auf Qualität und Ertrag der Sommergerste (Hordeum vulgare L.) im Voralpengebiet Sloweniens
Authors: Tajnšek T.
Published: April 2008

Effect of fungicides on fungus diseases and on the quality of the spring barley (Hordeum vulgare L.) in the subalpine area of Slovenia

The 1000 kernel weight of brewer's spring barley can be enlarged by using fungicides triadimephone or propiconazole. Propiconazole has better effects on the net blotch. The both fungicides reduce protein contents, however, these alterations hasn't great practical value. By using the above mentioned fungicides, the yield of spring barley was statistically remarkably higher that that of unsprayed control. The 3 years average yield of cv. Kraguj sprayed with propiconazole was statistically remarkable higher than any other cultivar in any other experimented variant.
Yield Reaction of Winter Wheat in Monoculture in Dependence upon Weather and Soil
Authors: Sieling K. , Hanus H.
Published: April 2008

On the basis of a long‐term field experiment with a progessive monoculture of wheat carried out on the research station Hohenschulen (University of Kiel), the yield reaction of wheat in monoculture was analysed with help of a multiple regression approach.

The mean yield of several years declines till the third resp. fourth crop, it increases later (‘decline‐effect’ in the larger sense) without reaching the initial level however.

The weather considerably influence the absolute yield level as well as the yield trend in dependence upon the number of successive wheat crops. Interactions between yield and soil conditions are only slightly marked if the absolute yield is considered. The yield components, however, react differently according to the soil conditions.

Crop management measures such as the choice of varieties and the application of BCM‐fungicides or N‐fertilization were only able to reduce yield losses, but not to prevent them.
Growth Characteristics of Contrasting Varieties of Perennial Ryegrass (Lolium perenne L.)
Authors: Taube F.
Published: April 2008

A field experiment was conducted to study growth characteristics of contrasting varieties of Lolium perenne (early heading: Gremie; late heading Vigor) in different growth/regrowth periods during 1984 and 1985. A growth function was fitted to data of weekly measurements of dry matter production (DM) and leaf area index (L) to derive the following parameters according to quantitative analysis of plant growth: crop growth rate (C), relative growth rate (R), leaf area ratio (LAR) and leaf weight ratio (LWR). Furthermore phenological development of the swards was recorded.

The chief differences in the growth potential of the varieties were found in primary growth on the one hand and in both investigated first regrowth periods on the other hand. In second and third regrowth periods no distinct differences were found either in DM nor in L regarding variety effects. In primary growth the early heading variety gained an advantage in DM, which was enhanced with prolonging growth period until the middle of June combined with a rapid reproductive development of the sward. Growth potential in the first regrowth period was determinated by the time of cutting in primary growth according to the development stage of the swards at cutting time. It was evident that highest values of DM and C were corresponding with a high amount of undamaged reproductive tillers in the sward. DM of vegetative summer regrowths were comparable, while in late summer/autumn under worsening environmental conditions a reduction in DM was observed. In opposite to that L developed rather similar in the investigated regrowth periods. According to this force of expression of L is discussed in relation to DM and phenological development of the swards.
Operational Research in the Ley‐Ruminant System
Authors: Torssell B. W. R. , Fagerberg B.
Published: April 2008

The concept of operational research in practical agriculture is introduced. Three aims of this approach are discussed and illustrated with actual examples in ley‐dairy farming

‐to help understand and manage dynamic systems, such as growth

‐to explain interactions and make predictions for current management measures, such as harvest time.

‐to find alternative input combinations by sensitivity analyses.

Prediction of ley growth and change in nutritional value illustrates the first point. It is shown that prediction of growth requires real time weather data but not necessarily weather forecasts. Alternatively, these can be substituted for data on normal weather conditions and some more extrem conditions of known probability.

The second point is illustrated by analysing the main interactions that result in the margin above feed costs in the ley‐ruminant system. It is claimed that if the model satisfies an observed farm situation, as in this case, the explanation of the interactions is valid.

The third point ‐ sensitivity analyses ‐ is illustrated by the higher margin over feed costs that is predicted in forage‐based feeding plans with 12‐15 kg DM forage, as compared to conventional feeding plans with 8 kg DM forage.

The Discussion centres on (1) deterministic and stochastic models, (2) scale and experimental replication, and (3) statistical problems in parameter estimates and model validation:

(1) When very dynamic systems are encountered, deterministic models may be difficult to validate. It is then far better to develop less precise stochastic models than to abolish the idea of model development. Such models would still predict risks and uncertainties.

(2) With large systems such as production chains, experimental replicates often become too costly. A validated systems model then provides the possibility to explain unreplicated observations and state their generality.

(3) Parameter estimates in mechanistic models require in many cases statistical developments because of problems encountered with non‐linear models where parameters may not be normally distributed.

Requirements on model validation may differ when the models are used for long‐term or short‐term planning. In the second case, the model may be repeatedly calibrated to a current situation, and validation then includes the entire calibration procedure.
Ratoon Growth and Development in Rice (Oryza sativa L.) Under Various Temperature Regimes
Authors: Chauhan J. S. , Lopez F. S. S. , Vergara B. S.
Published: April 2008

Plants exhibited differential response for ratoon growth and development under different temperature regimes before and after main crop harvest. Low temperature (23°/20 °C) before cutting induced ratooning whereas similar temperature after cutting delayed and reduced ratoon tillering. Ratoon grain yield and its attributes were significantly affected under various temperature regimes. Ratoon grain yield under low temperature regime before cutting did not differ from that of the control. Ratoon growth duration was maximum under low temperature regime after cutting. High temperature (37°/27 °C) after main crop cutting resulted in high spikelet sterility in the ratoon crop.
Effect of Water Status on Leaf Angle and Leaf Movement in Wheat
Authors: Peinetti R. , Ledent J. F.
Published: April 2008

Water stress was imposed by watering withholding or application of PEG during the period following ligule emergence of Hag leaves or fifth leaves. Treatment reduced markedly the downward rotation of these youngest fully expanded leaves, and the angle finally reached. Leaf angle changes appear to be sensitive indicators of water shortage in wheat.
Phototropic Leaflet Reorientation in Alfalfa Germplasm Selected for Leaf Color and Size
Authors: Travis R. L. , Reed R.
Published: April 2008

Solar tracking has been described in several agronomic and wild species, yet variation within a given species has not been reported. To address that issue, photoperiod leaflet reorientation in response to vectorial light was measured in three alfalfa (Medicago sativa L.) germplasm pools selected from the cultivar Ladak 65. Dark‐leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m2/s) with no detectable lag period. Following a 24‐h dark treatment only high PPFD (600 to 700μmol/m2/s) elicited reorientation. Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m2/s) and high PPFD in a similar manner; however, the low (100‐125μmol/m2/s) PPFD treatment had little effect on reorientation. The 24‐h dark treatment decreased reorientation at all PPFD. Small‐leaf germplasm responded equally to all PPFD and was not affected by the 24‐h dark treatment. The results suggest that available energy levels may influence the reorientation response. Carbonyl cyanide m‐chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, an inhibitor of non‐cyclic photosynthetic electron transport, reduced reorientation only in the pale‐leaf type. These results suggest that stored energy reserves were adequate to maintain leaflet reorientation in the absence of photosynthesis in all but the pale‐leaf germplasm. In that germplasm photosynthetically generated energy may be required to support reorientation.
Effect of Thermal Energy Intensity on Time and Rate of Nitrogen Accumulation by Maize (Zea mays L.)1
Authors: Olness A. , Benoit G. R. , van Sickle K. , Rinke Jana
Published: April 2008

The effect of thermal energy intensity (TEI) on the rate of nitrogen (N) accumulation by maize from a Hamerly clay loam soil (Aerie Calciaquoll) was examined with and without supplemental irrigation. Soil‐ and air‐TEI expressed as cumulative growing degree days (GDD) was determined from hourly temperature measurements taken within each plot at soil depths of 0.05‐, 0.15‐, and 0.3‐m and at a height of 1.2‐m above ground surface. A daily mean TEI (GDD per day) was calculated for each growth period. Estimates of time coefficient(s), k, in uni‐ and diphasic tanhfk(time)] functions, plotted against mean TEI for the periods; 1) planting to emergence, 2) emergence to eighth leaf, 3) eighth leaf to time(s) of maximum N accumulation rate, (t0), 4) planting to t0, 5) emergence to t0, 6) first diphasic maximum accumulation rate (t01) to 50 % silking, and 7) silking to second diphasic maximum accumulation rate t02 showed several linear relationships. Uniphasic time coefficients were modelled as functions of air‐TEI. The first diphasic time coefficient, k, was modelled as a function of pre‐ and post‐emergent soil‐TEI. Attempts to model k2, the second time coefficient of the diphasic model were unsuccessful; however, this time coefficient was linearly related to TEI for the growth period ‘t01 to 50 % silking’ and curvilinearly related to k1.

Der Einfluß thermaler Energieintensität auf Zeit und Rate der Stickstoffakkumulation bei Mais (Zea mays L.)

Der Einfluß der thermalen Energieintensität (TEI) auf die Rate der Stickstoffakkumulation (N) bei Mais auf einem Hamerly ton‐lehmigen Boden (aerie calciaquoll) wurde mit und ohne zusätzliche Bewässerung untersucht. Boden‐und Luft‐TEI, ausgedrückt als kumulative Wachstumstage (GDD), wurden aus stündli‐chen Temperaturmessungen, die innerhalb der Parzellen in Bodentiefen von 0,05, 0,15 und 0,3 m und in Höhen von 1,2 m über dem Grund ermittelt wurden, bestimmt. Eine tägli‐che mittlere TEI (GDD/Tag) wurde für jede Wachstumsperiode kalkuliert. Die Ermittlungen der Zeitkoeffizienten, k, in ein‐ und zwei‐phasigen tanh[k(Zeit)]‐Funktionen wurden ge‐gen die mittlere TEI für die Perioden aufgetra‐gen; 1) Pflanzzeit bis Auflaufen, 2) Auflaufen bis 8‐Blattstadium, 3) 8‐Blattstadium bis zum Zeitpunkt der Maximal‐N‐Akkumulationsrate (t0), 4) Pflanzzeit bis t0, 5) Auflaufen bis t0, 6) erste zweiphasige Maximalakkumulationsrate (t01) bis 50 % Seidenauswurf und 7) Seidenaus‐wurf bis zur zweiten diphasischen Maximum‐akkumulationsrate t02 zeigten zahlreiche linea‐re Beziehungen. Die einphasigen Zeitkoeffizienten wurden als Modelle der Funktionen der Luft‐TEI dargestellt. Der erste zweiphasige Zeitkoeffizient, k1; wurde als Funktion der Vor‐ und Nachauflaufphase der Boden‐TEI behandelt. Versuche Modelle k2, der zweite Zeitkoeffizient für das diphasische Modell, waren nicht erfolgreich; allerdings war der Zeitkoeffizient linear bezogen auf TEI für die Wachstumsperiode t01 bis 50 % Seidenauswurf und kurvenlinear bezogen zu k1.
Variability and Correlations in Grain Sorghum Genotypes (Sorghum bicolor [L.] Moench) Under Drought Conditions at Different Stages of Growth
Authors: Bakheit Bahy R.
Published: April 2008

Twenty‐two genotypes of grain sorghum were grown under drought conditions by omitting one irrigation during stages of before flowering period, kernel filling period, and physiological maturity period at Assiut Univ. Farm in 1987 and 1988 seasons. The results obtained revealed that considerable variation existed among genotypes for all the studied traits. The most effective moisture stress treatment in reducing grain yield, panicle weight and plant height was during flowering stage. While 1000‐kernel weight was much affected by moisture stress during grain filling period. The genotype X year interaction (o/y) was large compared to genotype X irrigation treatment (O2g) indicated that genotypes responded differently when they were grown from year to year. The genotypic variance (O2g) for all traits were large reflecting the importance of genetic variability. Both phenotypic and genotypic correlations among traits showed that plant height and 1000‐kernel weight were highly correlated with grain yield, while leaf area index was low associated with plant height.

Variabilitat und Korrelationen bei Korn‐sorghum‐Genotypen (Sorghum bicolor [L.] Moench) unter Durrebedingungen zu ver‐schiedenen Wachstumsstadien

22 Genotypen von Kornsorghum wurden unter Dürrebedingungen angezogen, indem eine Bewässerung vor der Blühperiode, wahrend der Füllungsperiode und der physiologischen Reife nicht angewendet wurde (Standort: As‐siut University Farm in den Jahren 1987 und 1988). Die Ergebnisse zeigen, daß eine erhebli‐che Variation zwischen den Genotypen für alle untersuchten Eigenschaften vorliegt. Der am stärksten ‐wirksame Wasserstreß trat während der Blühphase auf und reduzierte den Korner‐trag, das Rispengewicht und die Pflanzenhöhe. Das Tausendkorngewicht wurde stark durch Feuchtigkeitsstreß während der Kornfüllungs‐phase beeinträchtigt. Die Genotyp X Jahr‐Interaktion (o2gy) war im Vergleich zur Genotyp X Bewässerungsbehandlung (o2gy) hoch, was auf die unterschiedlichen Reaktionen der Genotypen zwischen den Jahren hinweist. Die genotypische Varianz (o2gy) war in alien Eigenschaften ausgeprägt, was auf eine erhebliche Bedeutung der genetischen Variabilität hinweist. Phänotypische und genotypische Korrelationen zwischen den Eigenschaften zeigten, daß die Pflanzenhöhe und das Tausendkorngewicht straff mit dem Kornertrag korreliert wa‐ren, während der Blattflächenindex nur lose mit der Pflanzenhöhe in Beziehung stand.
Influence of Seasonality on Certain Leaf Characteristics in Rice Cultivars
Authors: Mohandass S. , Natarajaratnam N. , Moosa Sheriff M.
Published: April 2008

Higher growth and grain yield in rice was obtained in February planting as compared to July and October plantings. This was achieved through favourable leaf characteristics. In all the three plantings, leaf number monitored the leaf area rather than ILS which showed minimal alterations by the seasonality. There was a considerable variation in the attainment of critical leaf area index (LAI) among cultivars in different seasons. Thus, attainment of critical LAI would be necessary to influence the sink strength positively.
Nitrogen Transportation in Oilseed Rape (Brassica napus L.) Plant during Flowering and Early Siliqua Developing
Authors: Zhang Q. Z. , Kullmann A. , Geisler G.
Published: April 2008

Nitrogen transportation from different organs was investigated by labelling pods, leaves and internodes of upper stem with 15N‐urea during flowering. Labelled plants were harvested one month after flowering and determined the amount of 15N in relative parts. The results of the experiment show the directions of 15N applied in different organs during flowering. Transportation of 15N applied in pods of lower terminal of the main stem and first branch was mainly directed to seeds inside the labelled pods, about 17 % of 15N entered into seeds 7 days after last labelling, a little transportation each other between the branch and terminal was found, more than 80 % of 15N applied on leaves during flowering was transported out of the leaves after flowering, 35 % and 67.93 % on average was translocated in pods for early and late flowering, respectively, while 55.97 % of 15N applied on surface of internodes of upper stem below terminal was found in pods. It was corroborated that nitrogen transportation also occurs within pods by labelling different parts of pods, much greater amount of nitrogen was transported from lower part to upper part of pods than those in opposite direction.