bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth Analysis of Onion (Allium cepa L.) in Relation to Irrigation and Nitrogen Fertilization
Authors: Hegde D. M.
Published: April 2008

Studies were carried out at the Indian Institute of Horticultural Research, Bangalore during winter seasons of 1982—83 and 1983—84 to analyse the growth rhythm of onion in relation to irrigation and N fertilization. It was observed that irrigation at 0.45 to 0.65 bar soil water potential recorded higher dry matter accumulation and distribution, leaf area index (LAI), leaf area duration (LAD), leaf area ratio (LAR) and crop growth rate (CGR) during most of the stages, while net assimilation rate (NAR) and relative growth rate (RGR) were not markedly affected. Highest harvest index was noticed with irrigation at 0.65 bar.

Nitrogen fertilization significantly increased dry matter accumulation and distribution into different parts, LAI, LAD, LAR, CGR and harvest index. Although NAR and RGR showed an increasing trend with N fertilization, the effect was not significant during most of the stages. There was no significant interaction between soil water potential and N fertilization on any of the growth parameters.
Modification of the Sink/Source Relationships in Bread Wheat and its Influence on Grain Yield and Grain Protein Content*
Authors: Borghi B. , Corbellini M. , Cattaneo M. , Fornasari M. E. , Zucchelli L.
Published: April 2008

Artificial manipulation of sink and source was carried out in several bread wheat varieties in order to study the variations in the pattern of storage products accumulation in the grain.

In a first experiment, partial ablation of the laminae did not cause any significant variation in the yield components, while total elimination of the laminae resulted in a decreased fertility of the spikelets and in a lower kernel weight. The protein content of grain turned out to be a function of the amount of vegetative organs left in the different treatments, and ranged from 11.1 % in leafless plants to 16.5% in the control.

The halving of the spikes led to a 14% increase in the size of the kernels, while the protein content per spike showed a 20 % drop in comparison to the control.

Reduction of sink affected nitrogen accumulation to a lesser extent than carbohydrates storage in the grain.

Reduction of sink induced remarkable increases in the protein fractions: gliadins +59%, glutelins +44%, insoluble residue +30%, non‐proteic nitrogen +28%, albumins and globulins + 16%. The increase of GPC or of specific solubility classes did not influence significantly the quality of the flour evaluated by the Zeleny and Pelshenke indices.

The presented data suggest some caution in adopting kernel size and GPC as main selection criteria in early generations. It seems more convenient to select for a prolonged grain filling period and for a higher biomass without increasing plant height.
Leaf Anatomy of Maize Inbred Lines and Crosses at Extreme Temperatures for Active Growth
Authors: Geisler G. , Thiraporn R. , Stamp P.
Published: April 2008

Inbred lines and crosses from cool temperate regions (C) and from warm regions (W) were grown at 14, 22, 30 and 38°C up to the same physiological age, the full expansion of the third leaf. The laminae of the second leaf were studied for anatomical traits. For all traits the genotypic variability was high over the whole temperature range, but the rank order was influenced by temperature. Leaf thickness and cross sectional area of epidermal cells were smallest at 22°C. Stomatal frequency increased in inbred lines from 14 to 38°C and in crosses from 30 to 38°C. In crosses stomatal length was low at 22°C and high at 38°C while inbred lines either did not react to temperature at all (C) or had low to very low values over the whole temperature range (W). Cross sectional area of chlorenchyma cells (mesophyll, bundle sheath) was high at 14°C. For mesophyll cells of inbred lines and generally for bundle sheath cells a second maximum occurred at 30°C. Cross sectional area of both chloroplast types was high at 14°C and low at 22 or 30°C. Positive heterosis was seldom observed but negative heterosis occurred for chlorenchyma cell size at 14°C. This might indicate an improved fitness for photosynthesis at suboptimal temperature because of small cells, especially as W‐genotypes generally had large cells at this temperature. A negative heterosis for the stomatal frequency over the whole temperature range might stand for a good fitness of hybrids for photosynthesis, too.

The investigations have shown that the expression of some important anatomical traits is dependent on temperature as well as on origin and genetic structure of maize genotypes.
Einfluß der Bestandesdichte auf Ertrag und Qualität der Zuckerrübe bei unterschiedlichem Erntetermin
Authors: Bürcky K. , Winner C.
Published: April 2008

The effect of plant population on yield and quality of sugar beet at different harvesting date

Optimum plant population of sugar beet in respect of corrected sugar yield in Central Europe ranges from 70 000 to 90 000 plants/ha. It is known that extending the length of growing period by later harvesting causes an increase in yield and quality of sugar beet depending on location and weather. There is a lack of information, however, about the effect of plant population on yield and quality increase with postponed harvesting date.

The objective of this study was to investigate the influence of plant density and harvesting date on yield and quality of sugar beet.

Four trials were carried out at Göttingen (Lower Saxony) from 1982 to 1985 which included each year four plant populations and three harvesting dates (end of September to middle of November).

Depending on seed lot, plant spacing and field emergence, plant populations varied between 87 000 and 27 000 plants/ha. Averaged over the years, the plant populations for the different treatments reached 71 000, 51 000, 40 000 and 31 000 plants/ha.

Later harvesting date and increasing plant population resulted in higher yield of beet and/or higher sugar content of beet. The increase in corrected sugar yield with extending the length of growing period was highest in plant populations with high density.

From the results it can be concluded that by having the choice, a beet crop with the highest plant population should be harvested at the end, a crop with a lower plant population at the beginning of the harvesting period, unless there have to be observed some other aspects (location, crop sequence, field condition).
Perennial Spring Rye as a Crop Alternative*)
Authors: Reimann‐Philipp R.
Published: April 2008

Due to recent research results breeding of perennial rye to‐day seems possible and in so far desirable as changed premises in agricultural production ask for the invention of new farming systems. Accordingly, the farmer would have to earn his livelihood more by decrease of expenses in a constant production level than by further increase of production quantity. Then, agricultural crops with newly designed characters or even absolutely new crop species particularly with low demands for cultivation, water supply, fertilizer or other agrochemicals (low‐input varieties) could be very helpful. For that a project of breeding “perennial rye” (Secale cereale × Secale montanum), for different farming systems respectively, is presented which has already been performed in some details and which could surely be realized in total if only a small part of the means were invested in this project as for example were spent into the development of Triticale as a new crop plant. Because of its high tolerance to poor sandy soils and water stress a perennial green forage rye may also be expected to be well suited in a spring rye variant for the improvement of dry pastures in the subtropical countries. A corresponding research project has been supported since 1985 by GTZ (Deutsche Gesellschaft für Technische Zusammenarbeit GmbH).
Critical Leaf Area Index in Pigeonpea
Authors: Balakrishnan K. , Natarajaratnam N. , Rajendran C.
Published: April 2008

Experiment conducted with six pigeonpea cultivars over three seasons revealed that the critical leaf area index was 5.3 which coincided with the maximum crop growth rate and optimum net assimilation rate. It was also evident that the crop growth rate was influenced more by NAR rather than LAI. This study also suggests that by maintaining higher photosynthesis upto harvest, there is ample possibility to increase the crop growth rate till harvest.
Infiltrability of an Oxisol in Paraná, Brazil as Influenced by Different Crop Rotations
Authors: Roth C. H. , Vieira M. J. , Derpsch R. , Meyer B. , Frede H.‐G.
Published: April 2008

Infiltrability of various soybean and maize rotations under conventional tillage and no‐tillage was studied to evaluate these rotations with respect to soil conservation practices. Measurements were carried out with a rainfall simulator on an Oxisol in two trials in northern Paraná, Brazil.

Differences between rotations were greatest in the conventional tillage treatments and here maize/soybean rotations showed a higher infiltrability than continuous cropping. In the no‐tillage treatments, there were hardly any significant differences. On the whole, rotations grown with maize at the time of measurement resulted in the lowest infiltrabilities. Tillage effects were of greater importance than rotation effects, infiltrability being consistently highest under no‐tillage.

Soil surface sealing in dependence of the degree of soil cover was shown to be the prime factor governing infiltrability.
Senescence and its Role in Soybean Productivity
Authors: Manian K. , Natarajaratnam N. , Ramasamy P. , Mohanasundaram K.
Published: April 2008

Chemical manipulation was able to induce higher productivity in soybean through improved dry matter accumulation, increased source activity, retarding leaf senescence and yield components. The senescence percentage was negatively correlated with yield (r =−0.7669**) while the source activity was positively associated (r =+0.9167**). All the yield components had significant positive correlation with yield. The low cost urea and coconut water, foliar feeding at peak flowering and late grain filling stages improved the productivity in soybean. The maximum beneficial effect of foliar feeding was noticed in the soil where the absence of native nodulation was observed.
Characterisation of Physical Condition of Puddled and Nonpuddled Soil
Authors: Bhadoria P. B. S.
Published: April 2008

Field study indicates that initial infiltration of puddled soil was higher by 1.1 mm/h and the final infiltration rate decreased by 0.6 mm/h, when compared to nonpuddled soil. The clod of larger size and soil moisture was found to be more in puddled soil. However, seedling emergence was maximum under nonpuddled soil.
Agronomic Performance and Nutrient Concentration of Maize (Zea mays L.) as Influenced by Nitrogen Fertilization and Plant Density
Authors: Amoruwa G. M. , Ogunlela V. B. , Ologunde O. O.
Published: April 2008

A field experiment was conducted at Samaru, Nigeria to study the influence of nitrogen fertilization and plant density on the agronomic performance and nutrient concentration of maize (Zea mays L.). The treatments were factorial combinations of five nitrogen fertilization rates (0, 50, 100, 150 and 200 kg N/ha) and three plant density levels (25000, 50000 and 75000 plants/ha).

Nitrogen fertilization up to 150 kg N/ha enhanced grain and stover yields and increased kernel number and weight up to 100 kg N/ha. Nitrogen supply also increased maize ear length. Increased N fertilization rates increased concentrations of N, K and Mg but had no effect on P and Ca concentrations. Higher grain yield was closely associated with higher N concentration in ear leaf; with 0.1 % change in N concentration causing 177 kg/ha change in grain yield. Increased plant density increased stover yield up to 50 or 75 thousand plants/ha but depressed kernel number and weight and ear length.
Intercropping Maize with Climbing Beans, Cowpeas and Velvet Beans
Authors: Bryan W. B. , Materu M. B.
Published: April 2008

When one of the crops is a legume, intercropping has potential to reduce fertilizer nitrogen (N) needs and increase food quality. Total dry matter (DM) and grain yields of different plant populations of intercropped maize (Zea mays L.) and climbing beans (Phaseolus vulgaris L.), cowpeas (Vigna unguiculata [L.] Walp.), or velvet beans (Mucuna pruriens [L.] DC. var utilis [Wight] Bruck.) were compared in two experiments. Maize populations were 40,400 and 50,500 plants ha−1 in combination with climbing bean populations of 0, 20,200, 40,400 and 80,800 plants ha−1 in Experiment 1. In the second experiment, climbing beans, cowpeas and velvet beans at 215,200 plants ha−1 were intercropped with maize at 64,600 plants ha−1. Climbing beans contributed up to 5% to total DM yields in the first experiment. In the second experiment legume contributions to total DM were 20% for climbing beans, 12% for cowpeas and 8% for velvet beans. Increasing populations of maize and climbing beans increased grain and DM yields. Dry matter yield of maize was lowered by intercropping. However, DM yields of the intercrop were not different to maize sole cropped. Maize/cowpeas produced more total DM than maize/climbing beans. Cowpeas increased the total yield of crude protein by over 15% without lowering total DM yield of the intercrop compared to maize alone and are promising as a legume for intercropping with maize. Climbing beans show little promise as a possible legume for intercropping with maize.
Incited Effectiveness of EMS in Hibiscus cannabinus L. by Excised Mature Embryo Treatment
Authors: Hazra S. K. , Shome A.
Published: April 2008

In H. cannabinus mutagenic efficiency and effectiveness of EMS decreased with increase in concentration after excised mature embryo treatment whereas, a reverse trend was observed following seed treatment. Comparatively, maximum effectiveness vis‐à‐vis mutation induction was obtained at 0.1 % EMS after mature embryo treatment. The chlorophyll and other mutational spectra were also examined and discussed.
Shoot and Root Production and Nitrogen Uptake in Barley, with and without Nitrogen Fertilization
Authors: Hansson A.‐C. , Pettersson R. , Paustian K.
Published: April 2008

Two barley crops, one fertilized with 120 kg N ha−1 (B120) and the other without nitrogen fertilization (BO), were cultivated for the second year on the same plot. In 1981 the growth and nitrogen content of the whole plant, above‐ and below‐ground parts were measured by sampling every second week. Production was calculated as the difference between annual maximum and minimum amounts of biomass found above‐ and below‐ground. Nitrogen uptake was estimated as the sum of the peak amounts of nitrogen present in the roots and shoots. The amount and concentration of nitrogen in partly decomposed plant debris in the soil was estimated simultaneously with the biomass.

Total net production in B120 was 1004 g m−2 of which the roots constituted 16%. The unfertilized barley produced 558 g m−2 of which 23% were produced below‐ground. The maximum amount of living roots found in B120 was 160 g ash‐free dry mass m−2 and 128 g m−2 in BO.

In the fertilized treatment 15 g N m−2 (21% in roots) was taken up by the plant, compared to 5.8 g N m−2 (28% in roots) in the unfertilized crop.
A Quantitative Method to Assess Freezing Resistance in Faba Beans
Authors: Herzog H.
Published: April 2008

In order to quantify freezing resistance (R50) of winter faba beans from a limited number of plants, leaves were exposed to artificial freezing stresses with different test temperatures (TTi). Injury (Ii) was assessed by rating (score: 0—8) and by conductivity measurements. The basic assumption that Ii depends almost linearly on TTi over a sufficiently broad range with a constant ΔI/ΔTT could be verified and hence a formula is presented to compute freezing resistance R50= (Ii—I50) ×ΔTT/ΔI + TTi with I50 being a medium injury. This formula allows to quantify resistance by assessing Ii after freezing test(s) with definite TTi. About 25 leaves are required. Rating appeared preferable to conductivity measurements because of easier and quicker performance and a slightly better discrimination between samples of different resistance. Based on a standardized freezing test, ΔI/ΔTT was determined. Application of the formula with ΔI/ΔTT = 2.5 units/°C for unhardened and hardened leaves, restrictions and experiences are discussed.
Gaseous Loss of Nitrogen in Paddy Soils
Authors: Hanif M. , DeMooy C. J.
Published: April 2008

Irrigation practices for rice (Oryza sativa) that are common in South Asia were simulated under greenhouse conditions, and the resulting range of gaseous N losses was determined. The interaction of water and fertilizer management for growing paddy rice was quantitatively evaluated at several rates of N fertilization. Continuous flooding, alternate flooding and drying, and dry periods before, after, and during flowering were combined with 3 rates of N, i.e., 0, 50, and 100 mg kg−1 by uniform incorporation and by mud ball placement.

Gaseous loss of native soil N was small (10 mg kg−1) when no fertilizer was applied and the crop stand was adequate. Loss increased to 32 mg kg−1 when stands were halved. Gaseous loss of 41 to 58% were found when fertilizer was applied. Alternate flooding and drying was the least desirable irrigation practice with losses of 40 to 87 mg N kg−1. Placement of N in mud balls reduced gaseous N loss under all irrigation procedures by 14 to 32% compared to uniform application at the low N application rate. Under continuous flooding only 28% of a second increment of 50 mg kg−1 of applied N was lost compared to 82% loss with alternate flooding and drying.
Einfluß langjähriger Winterweizen‐Monokultur auf Ertragsbildung, Krankheitsbefall und Nematodenbesatz im Vergleich zum Winterweizenanbau in der Fruchtfolge
Authors: Claupein W. , Zoschke M.
Published: April 2008

Influence of winter wheat grown continuously on grain yield, foot rot infection and nematodes compared with winter wheat in rotation

The field trial, started in 1968 at the experimental‐station in Rauischholzhausen, was intended to give informations about winter wheat in continuous cultivation. The question was if intensification of growing culture enables monoculture wheat to yield as high as winter wheat in rotation (sugar‐beet, winter wheat, spring barley). Influence of green manuring with additional nitrogen, straw manuring with additional nitrogen, straw burning and fungicid treatment against eyespot was investigated.

The following results have been obtained in the years 1969 to 1985:

1. In the 17 years average winter wheat in rotation yielded with 50.1 dt/ha a higher amount of grain dry weight than wheat in monoculture (43.6 dt/ha). Only in 3 years wheat in monoculture reaches the grain yield level of wheat in rotation.

2. The incidence of Pseudocercosporella herpotrichoides was in wheat after wheat about 10% higher than in wheat after sugar‐beets.

3. The use of fungicides against culm base diseases caused in monoculture an increase in yield of about 2.7 dt/ha which was not higher than in rotation (+2.5 dt/ha).

4. The first 12 years indicated a decline‐effect with continuously decreasing differences in the yield of wheat in monoculture compared with rotation. But until the 17th year of the trial grain yield differences were as high as in the beginning.

It is not possible either by means of intensification of fertilizing or chemical plant protection treatment to reach the grain yield level of winter wheat in rotation with winter wheat in monoculture. Even the use of modern agronomical methodes remains crop rotation as a central part of an effective plant culture.
Effect of some Herbicides on Oil Seed Rape (Brassica Napus L.) and Associated Weeds
Authors: Ibrahim A. F. , Shaban Sh. A. , El‐Metwally El. A.
Published: April 2008

Two field experiments were conducted during 1984/1985 and 1985/1986 seasons to study the effect of Alachlor, Metolachlor, Pendimethalin, Diphenamid, CGA 10832 and Oxadiazon as pre‐emergence herbicides and EPTC as presowing herbicide at two doses as well as hand‐hoeing treatment on weed spread and rapeseed yield under Egyptian conditions. All the tested herbicides except “Oxadiazon” gave satisfactorily good annual grass weed control up to harvest time. While, Oxadiazon and Diphenamid at both doses controlled adequately the growth of annual broad‐leaved weeds. The highest rapeseed yield was achieved under the application of Metolachlor at 2.4 and 3.6, Pendimethalin at 1.8, Diphenamid at 1.8, CGA 10832 at 2.4 and Oxadiazon at 1.2 kg a.i./ha. While, Pendimethalin at 2.4, Diphenamid at 2.4, CGA 10832 at 3.6, Oxadiazon at 1.8 and EPTC at 5.5 kg a.i./ha exhibited an obvious phytotoxic effect on rapeseed plants.
The Influence of Simulated Subtropical and Temperate Climates on Hot and Cold Climate Wheat Varieties for Ensiling
Authors: Ashbell G. , Wermke M. , Sklan D.
Published: April 2008

Two wheat varieties, developed for hot and cold climates, respectively, were grown in climatological chambers programmed to simulate subtropical and temperate climates. The plants were tested, their composition was determined, and they were ensiled in test tubes at five different maturation stages.

The hot‐climate variety required 25–82 % more time to reach the same maturation stage in temperate climates in comparison with in subtropical climates, but developed well in both climates. However, the cold‐climate variety failed to mature under subtropical climatic conditions and only reached the flowering stage; temperate‐climatic conditions increased its height and yield. Differences in volatile fatty acids, lactic acid and ethanol were recorded between the two silages.
Wirkung verschiedener organischer Düngemittel auf die Effizienz der VA‐Mykorrhiza
Authors: Brechelt A.
Published: April 2008

Effect of different organic manures on the efficiency of VA‐mycorrhiza

Under greenhouse conditions, it was examined how different organic manures influence the efficiency of the VA‐mycorrhiza Glomus macrocarpum cultivated with Capsicum annuum. The used organic manures: grassmulch, stablemanure as well as 3 different kinds of compost had been added in 5 stages of concentration: 50, 100, 150, 200 and 300 dt/ha.

The mycorrhiza fungi inoculation caused greatest yield and P‐uptake increase at the lowest organic manure addition. Higher amounts of all types of manures led to decreasing mycorrhiza efficiencies. This tendency was least pronounced with the grassmulch‐variant. How fast this decrease took place was not only dependent on the nutrient contents of the manures. Further important factors of influence were the kind of starting‐material, which was used at the compost preparation, and the fact whether the manures were mixed up rotten or not rotten.
Erfassung von Wurzelmerkmalen bei Mais‐Inzuchtlinien und Hybriden unter kontrollierten Bedingungen und im Feldversuch
Authors: ÜLger A. C. , Kahnt G. , Becker H. C.
Published: April 2008

Root characteristics of maize inbred lines and single crosses in controlled environments and in field trials

Shoot and root dry matter yield and root surface of eight maize inbred lines and eight single crosses were investigated in nutrient solutions with low and high nitrogen content. In a seedling test root length was determined, and in field trials the vertical root‐pull resistance, kernel yield, lodging resistance and root dry matter in soil cores were measured.

Nitrogen concentration had a positive effect on root growth in nutrient solution as well as under field conditions. For all root traits there exist a significant genotypic variation. No interactions occurred between genotype and nitrogen supply. Root dry matter in nutrient solution, vertical root‐pull resistance, and lodging resistance were positively correlated among one another. No correlation was observed between root weight in nutrient solution and root weight under field conditions.
Über den Einfluß von Trockenstreß in unterschiedlichen Entwicklungsphasen auf Wachstum, Blütenabwurf und Ertrag der Sojabohne (Glycine max [L.] Merr.)
Authors: Bartels M. , Caesar K.
Published: April 2008

The influence of droughtstress during various growth phases on yield parameter and flower drop of the soybean (Glycine max [L.] Merr.) was studied in a pod trial under arid conditions at Alexandria/Egypt. The two cultivars Calland and Williams do not differ in their reaction to droughtstress.

The seed yield was decreased by ca. 18% when two weeks of drought occurred. Droughtstress during the seed filling phase reduced the yield by 25%. This decrease in yield is due to a decrease in pod number and seed number per plant. Flower drop on the main stem is not influenced by droughtstress and there is no relation to the seed yield per plant.
Influence of Seed‐Bed Preparation and Straw Utilization on Root Growth of Barley in Monoculture
Authors: Římovský K. , Chloupek O.
Published: April 2008

Root system size of spring barley as measured by means of its electrical capacity was evaluated in the 12th till 14th year of monoculture. It was significantly greater in variants with burnt straw in situ or with turned under straw than in variant with straw cleared away. The kind of seed‐bed preparation did not influenced root system size significantly, but its interaction with straw utilization and with term of measurement was significant. The larges root sytem was found in combination with minimal seed‐bed preparation and burnt straw (relatively 100) and the smallest in combination with minimal seed‐bed preparation and straw cleared away (relatively 62).
Peroxidase Activity in Relation to Plant Height and Seed Yield in Indian Mustard (Brassica juncea L. Coss)
Authors: Kumar R. , Gupta V. P.
Published: April 2008

Peroxidase levels were assayed in 12 genotypes and in 36 F1cross progenies of Indian mustard (Brassica juncea L. Coss) at twelve stages of development, starting from seed germination till seed formation. The levels of peroxidase activity and the coefficient of variation emphasized the role of differential enzyme activity at different stages of development. Genotypes were also evaluated for plant height and seed yield. The correlations of peroxidase activity in 24 h soaked seeds with plant height and seed yield were significantly positive while those of enzyme activity in 45 days old plants with these traits were significantly negative. The study suggests the changing role of enzyme at two critical stages of plant development.
Nomogramm zur Keimung von Wintergerste (Hordeum vulgare L.) zwischen Teigreife und Ernte in Abhangigkeit von Temperatur und Niederschlag
Authors: Rauber R.
Published: April 2008

Nomogram of germination of winter barley (Hordeum vulgare L.) between dough stage and harvest, as influenced by temperature and rainfall

Winter barley, cv. Katja, was cultivated on loess soil near Göttingen in three seasons (1982–1984). After passing the dough stage, barley seeds were separated at regular intervals and incubated at 12 °C for germination.

For the germination (Y, in probits), the following regression equation was found: Y = 3.91 + 0.1186 X1– 0.0267 x2, where x1= daily mean temperature (°C), and x2= quantity of rainfall (mm) in the four days before the separation of the seeds.

The relationship among germination, temperature and rainfall was presented in the form of a nomogram which shows a convenient method to solve the regression equation graphically.
Der Einsatz von Sortenmischungen zur Reduzierung des Krankheitsbefalls und zur Ertragsstabilisierung bei Sommergerste
Authors: Hengstmann U.
Published: April 2008

Introducing varietal mixtures to reduce mildew attacks and to stabilize yields in spring barley

Cultivation of varietal mixtures of spring barley aims at producing a growing crop resistant to barley mildew (Erysiphe graminis DC. f. sp. hordei Marchal). The so far rather short life of current varieties showing vertical resistance should be prolonged by using mixtures of several varieties.

By using varietal mixtures, stabilization of crop yields is obtained due to the decrease of mildew‐related variability range of spring barley yields. Furthermore, labour and material are saved by reducing, or omitting, fungicide application.
Allelopathic Effects in the Maize‐Quelites‐Agroecosystem of the Tarahumara Indians
Authors: Kahl H.
Published: April 2008

The Tarahumara Indians of the north‐west Mexican Highland practice a method of using several weeds for food which are called “quelites”. These weeds play an important role in the Tarahumara diet and seem to be connected with maize‐cultivation in a special way.

In bio‐assays with two quelites species, Bidens pilosa sens. lat. (Cobblers' pegs) and Lepidium virginicum (Pepper grass) and different cultivars of maize (Zea mays L.) it could be demonstrated that water extracts of leaves of B. pilosa and L. virginicum cause a significant stimulation of seedling growth of maize. Different cultivars of maize showed no differences in being stimulated by extracts of B. pilosa. This indicates an allelopathic potential of the two tested quelites species.

Extracts of leaves of older plants of B. pilosa (shortly before flowering) do not show this effect. Different water extracts of maize snowed an indifferent influence on germination and seedling growth of B. pilosa and L. virginicum.

Considering these results the practice of the Tarahumara Indians — leaving the quelites a certain amount of time among their maize and harvesting them after that — appears to be a stimulatory method for growing maize. The maize‐quelites double‐crop system seems to be highly tuned and may be understood as a result of a process of cultural learning among the Tarahumara Indians.
Comparative Ammonium and Potassium Fixation by some Wetland Rice Soil Clays as Affected by Mineralogical Composition and Treatment Sequence
Authors: Bajwa M. I.
Published: April 2008

Comparative fixation of NH4 and K by wetland rice soils in relation to clay mineral composition and treatment sequence is of agronomic interest, but information on the subject is scanty. An attempt has been made to clarify this relationship by employing the normally recommended doses of fertilizers, 3 application sequences, and 5 soil clays of divergent mineralogies. The results show that montmorillonitic clay is the greatest fixer of NH4, but least of K. X‐ray amorphous clay also prefers NH4 over K. Vermiculitic and beidellitic clays strongly fix both NH4 and K. Soil clay consisting of hydrous mica, chlorite, and halloysite fixes low proportions of applied NH4 and K. The sequence in which NH4 and K are applied does not appear to affect the relative amounts that are fixed.
Response of Yields and Yield Variability of Wheat and Barley to Nitrogen Fertilizing and Fungicide Treatments
Authors: Hanus H. , Schoop P.
Published: April 2008

From the results of a long term experiment with wheat and barley and different fungicide treatments it could be concluded that the variability of yield did not increase with higher application rates of nitrogen until the maximum yield was reached. The relative variability even decreased due to the increasing yields and the nearly constant standard deviations of yields. Only if the fertilization exceeded the optimum and yield depressions occurred the yield variability increased especially for barley and on plots without fungicide treatments. Whether the yield variability increases with increasing intensity or not depends on the factors of intensification and whether these factors increase the yield potential (higher yielding varieties for example) or whether they only realize more of a given potential (like higher amounts of nitrogen). In the first case yield variability will increase while in the second a higher yield stability has to be expected. The changes in yield variability within time series raise from both factors and, therefore, the individual situation may be very different from one country to another and may also change within a country with time.
Wachstumsanalytische Untersuchungen an Knaulgras (Dactylis glomerata L.) unter besonderer Berücksichtigung des phänologischen Entwicklungsstadiums bei der Nutzung im ersten Aufwuchs
Authors: Kornher A. , Taube F.
Published: April 2008

Regrowth characteristics of a cocksfoot (Dactylis glomerata L.) sward after initial defoliation at different stages of development

Over 2 two‐year period (1984‐1985) the productivity of Dactylis glomerata (cv. Baraula) swards as influenced by variations in time of the initial defoliation was studied. The stages at which the initial cuts were taken were: (a) before stem apices were raised to defoliation level (5 cm), (b) about two weeks later, when the reproductive tillers reached ear emergence, (c) about 4 weeks after (a), when the reproductive tillers reached flowering stages. Subsequent production was measured by weekly harvesting of representative sward samples over a 6‐7 weeks lastening growth period. Furtheron patterns of growth in a second regrowth in August and a third regrowth in September/October were studied.

The growth behaviour in the investigation was described by calculations of curves concerning mainly the development of dry matter yield (DM), leaf area index (LAI), crop growth rate (C), relative growth rate (R) and net assimilation rate (E) during the growth period. The leaf area ratio (F) and leaf weight ratio (LWR) were derived from fitted curves.

The highest dry matter yield and the highest growth rate (more than 20 g m−2day−1) was estimated in the spring growth and in the earliest regrowth (a). About 30 % of the tillers in these swards became reproductive.

The main difference between regrowths of primary defoliations at successively later dates was between the earliest, after cutting on 8.‐13. May, on the one hand, and, on the other hand, the two later regrowths after primary cuts from 31. May to 12. June. The two latter and the second regrowth in August were in most respects very similar: no reproductive development; herbage yield of about 400‐500 g m−2; highest C of about 15‐20 g m−2day−1; maximum LAI‐ values from 8‐9.

In respect to the E there were some differences between the stands. The E was at the time when C was highest somewhat higher in the reproduction stands (spring growth and first regrowth) compared with the vegetative regrowths.

The relationship between C and LAI could in all stands be described by an relatively optimum curve, which means that C did not differ much within a wide range of LAI.
Zinc, Lead and Copper Concentrations in Plants and Soils from two Mines in Chalkidiki, North Greece
Authors: Babalonas D. , Karataglis S. , Kabassakalis V.
Published: April 2008

Plant materials and soil samples from metal‐bearing sites (Madem‐Lakko, Plyntirio, Skouries) of N. Greece (Chalkidiki) were analysed while their content in Zn, Pb, Cu, Ca, Mg, Mn, Co, Ni, Cr and Cd was determined. Zn, Pb and Cu regarded as the basic metals of these sites were found in plant materials in the following concentrations: 28–1079 ppm Zn (the highest in Cistus incanus), traces‐313 ppm Pb (the highest in Campanula ligulata) andtraces‐817 ppm Cu (the highest in Rumex acetosella). The corresponding ones detected in soil samples were: 80–10547 ppm Zn, 15–7349 ppm Pb and 112–5288 ppm Cu.

Only traces were detectable of the elements Co, Ni, Cr and Cd contained in considerably smaller amounts in the soil (Co: 12–45 ppm, Ni: 33–272 ppm, Cr: 17–228 ppm, Cd: 5–45 ppm). Mn whose concentrations in the soil differentiate the site of Madem‐Lakko from the other two, occurred between 51–1079 ppm.

Finally while Ca and Mg generally manifest the order CaMg.

Although the 36 plant materials examined show great diversity in the behaviour towards soil metals, however it seems that, at times, the amount of metal taken up is proportional to that already existing in the soil. Consequently the overall quantity of metals in the soil is rather analogously related to the quantity available and to the tolerance degree of plant populations.

Zink‐, Blei‐ und Kupfer‐Konzentrationen in Pflanzenmaterial und Böden von zwei Minen in Chalkidiki, Nord‐Griechenland

Pflanzenmaterial und Bodenproben wurden von metallhaltigen Standorten (Madem‐Lakko, Plyntirio, Skouries) in Nord‐Griechenland (Chalkidiki) analysiert und auf ihren Gehalt an Zn, Pb, Cu, Ca, Mg, Mn, Co, Ni, Cr und Cd bestimmt. Zn, Pb und Cu, die als die Hauptmetalle dieser Standorte zu betrachten sind, fanden sich im Pflanzenmaterial in folgenden Konzentrationen: 28–1079 ppm Zn (die hochste in Cistus incanus), Spuren bis 313 ppm Pb (die höchste in Campanula ligulata) und Spuren bis 817 ppm Cu (die höchste in Rumex acetosella). Die hierzu korrespondierten Werte in den Bodenproben waren: 80–10547 ppm Zn, 15–7349 ppm Pb und 112–5288 ppm Cu.

Von den Elementen Co, Ni, Cr und Cd waren nur Spuren im Boden nachzuweisen (Co: 12–45 ppm, Ni: 33–272 ppm, Cr: 17–228 ppm, Cd: 5–45 ppm). Mn, dessen Konzentrationen im Boden den Standort Madem‐Lakko von den anderen beiden zu unterscheiden erlaubt, traten mit Werten zwischen 51–1079 ppm auf.

Schließlich wurde festgestellt, daß grundsätzlich im Boden mehr Mg als Ca vorlag, bei Pflanzen wurde die gegenteilige Beziehung nachgewiesen, d. h., mehr Ca als Mg. Obwohl die 36 Pflanzen große Unterschiede in ihrem Verhalten gegenüber den Metallen im Boden zeigten, scheint die Menge des aufgenommenen Metalls proportional zu dem bereits im Boden vorhandenen zu sein. Danach entspricht die Gesamtmenge an Metallen im Boden der verfügbaren Menge und der Toleranz der Pflanzenbestände.
Estimation of Leaf Area in Greengram by Non‐destructive Linear Measurements
Authors: Manian K. , Balakrishnan K. , Natarajaratnam  , Mohanasundaram K.
Published: April 2008

The leaf area by non‐destructive linear measurements have been made in eight cultivars of greengram. The regression equation was Y = 1.58 + 1.79 (X), r = 0.9988** while X = L × W. L and W are the maximum length and width of the terminal leaflet of a trifoliate leaf respectively. Y = leaf area of a trifoliate leaf. This study indicated that this equation can be used for a measuring of the leaf area in situ irrespective of the position of the leaves and variety in greengram.

Abschätzung der Blattfläche von Mung‐Bohne mit Hilfe einer nichtdestruktiven linearen Messung

Die Untersuchungen zu einer nichtdestruktiven linearen Messung wurden bei acht Sorten der Mung‐Bohne durchgeführt. Die Regressionsgleichung war Y = 1,58 + 1,79 (X), r = 0,9988**, während ×= L × W war. L und W sind die Maximumlängen und Breiten des terminalen Blattes eines dreifach gefiederten Blattes. Y = Blattfläche eines dreifach gefiederten Blattes. Die Untersuchung zeigt, daß die Gleichung für die Messung der Blattfläche in situ bei Mungo‐Bohnen verwendet werden kann, unabhängig von der Position des Blattes und der Sorte.
Berechnung der Biomasseproduktion von Grünland mit einem Photosynthese‐Wasserhaushaltsmodell
Authors: Wessolek G. , Duynisveld W. H. M. , Renger M. , Strebel O.
Published: April 2008

Calculation of biomassproduction of grassland using a photosynthesis‐water use simulation model

Using a simple model of field water use and photosynthesis the gross, potential and actual biomassproduction of grassland could be quantified. A comparison of measured and calculated yields from grassland for different water supply conditions shows that the model satisfactory describes the water‐use crop‐yield dynamics.

Further results demonstrate the influence of capillary rise on grassland yield with special regard to different conditions.

Mit Hilfe eines einfachen Photosynthese‐Was‐serhaushaltsmodells lassen sich die Brutto‐, potentielle und aktuelle Biomasseproduktion von Grünlandbeständen ermitteln. Ein Ver‐gleich von gemessenen mit berechneten Grün‐landerträgen unterschiedlicher Jahre und Was‐serversorgung zeigt, daß die getroffenen Mo‐dellannahmen eine befriedigende Beschreibung der Ertrags‐Wasserdynamik widerspiegeln.

Anhand von Berechnungen kann der Ein‐fluß unterschiedlicher Wasserversorgung aus dem Grundwasser auf den Ertrag von Grün‐land dargestellt und in Beziehung zum Klima‐verlauf gebracht werden.
Einfluß von Bewuchs auf die Mobilisierung von spezifisch gebundenem NH4+ im Boden*
Authors: Scherer H. W.
Published: April 2008

Influence of the plants on the mobilization of nonexchangeable NH4+

It is well established that significant changes in the content of nonexchangeable NH4+ take place during the growing season. However it is unknown whether the release of this N fraction is influenced by the N uptake of the plants. For this purpose the present experiments were conducted. Following results were obtained:

During the period of the highest N demand of the plants a correlation is existing between the N uptake and the amount of NH4‐N released from the clay minerals.

In experiments with 15N labelled soil, conducted under field conditions, 97 % of the nonexchangeable 15NH4‐N were released on the plot planted with oats and only 15 % on the plot without plants. From autumn till spring no significant change in the content of nonexchangeable NH4+ was determined.

Es wurde der Frage nachgegangen, ob die Mo‐bilisierung des spezifisch gebundenen NH4+ durch den N‐Entzug der Pflanzen beeinflußt wird.

Folgende Ergebnisse wurden erzielt:

Während des Zeitraumes des höchsten N‐Bedarfs der Pflanzen bestand eine Beziehung zwischen dem N‐Entzug und der Menge an freigesetztem spezifisch gebundenem NH4‐N. In einem unter Feldbedingungen durchge‐führten Versuch mit 15NH4‐N‐belegtem Bo‐den wurden unter Bewuchs 97 % und unter Brache nur 15 % des markierten spezifisch gebundenen NH4+ im Laufe der Vegetations‐periode mobilisiert.

Während der vegetationslosen Zeit traten keine signifikanten Veränderungen im Gehalt an spezifisch gebundenem NH4+ auf.
Untersuchungen zur Assimilatverteilung in Ackerbohnen (Vicia faba L.) während der Blühphase
Authors: Haisch A. , Pommer G. , Forster S.
Published: April 2008

Investigations about the distribution of assimilates during flowering in broad beans (Vicia faba L.)

The distribution of assimilates during flowering was studied on single plants exposed to 14CO2 in the field. The plants were harvested 1, 3, 15 days after exposition and at ripening. Results:

1. At the begin of flowering the nodes with flowers assimilated much 14C with a tendency of higher contents in the more above situated nodes. The concentration of 14C was similar in blades, stalks and flowers.

2. The assimilates incorporated after 24 hours were only to a small amount translocated afterwards. Only 3 % went to the apical region. An intensive restorement out of the blades took place at the time of ripening.

3. In the midst of flowering the concentration of 14C was lower in the nodes with open flowers than in those with shut or with pods. At that time pods are already strong sinks that withdraw assimilates from blades and stalks.

4. At the time when large and small pods are growing on the lower and middle nodes, the nodes in the apical region will be deprived of assimilates (effects of dominance).

5. Roots and nodules had low but stable contents and concentrations of 14C during flowering. These descended distinctly at ripening.
Evaluation of Maize Germplasm for Tolerance to Low Temperature Stress under Field and Laboratory Conditions
Authors: Dhillon B. S. , Sharma R. K. , Malhotra V. V. , Khehra A. S.
Published: April 2008

Sixty‐four inbred lines of maize (Zea mays L.) were evaluated for their tolerance to low temperature stress in three experiments at Punjab Agricultural University, Ludhiana. All the 64 inbred lines were evaluated under laboratory conditions. Forty‐four of these were also studied under field conditions. In the laboratory test the materials were exposed for four hours to 1, 0, −1, −2, −3 and −3.5°C on six successive nights. Significant genotypic differences were observed for freezing injury in laboratory test and for frost and non‐freezing (yellowing) injuries in field evaluation. Expression of frost injury under field condition and freezing injury in laboratory test at −2, −3 and −3.5 °C showed positive correlation in one experiment. The range and mean square for freezing injury of inbred lines were the largest either at −3 or at −3.5°C. The correlation of yellowing with frost injury in field and freezing injury in laboratory at −3 and 3.5°C was not significant suggesting the lack of association between yellowing and frost/freezing injury.
Effect of GA, CCC and B‐9 on Morphophysiological Characters and Yield of Kidney Beans (Phaseolus vulgaris L.)
Authors: El‐Fouly M. M. , Sakr R. , Fouad M. K. , Zaher A. M. , Fawzi A. F. A.
Published: April 2008

A pot and 2 successive seasons field experiments were conducted on bean, by spraying 25,50 or 100 ppm GA, 100, 250 or 500 ppm of either CCC or B‐9, one month after sowing. Results showed that:

GA induced stem elongation and thinning through cell elongation and decrease of both of ground tissue cell‐size and vascular cylinder cell layers in the stem. On the other hand, CCC and B‐9 led to stem shortening and thickening, as a consequence of increased number of cell layers leading to widening the vascular cylinder of the stem.

Leaf area was much more increased by CCC and B‐9 than by GA.

GA increased amylase activity and had no effect on invertase, meanwhile CCC and B‐9 mostly decreased the former's and increased the latter's enzyme activity, 30 days after spraying.

GA and CCC increased number of seeds/pod, while B‐9 had no effect on this character.

CCC and B‐9 increased pod number/plant, specific seed weight, leading to increment of seed yield/plant, while GA had no effect on these characters.
Seedling Growth of Cowpea and Mungbean as Affected by Seed Size and Seeding Depth
Authors: Sangakkara U. R. , Bieler P.
Published: April 2008

The germination and seedling growth patterns of different sized seeds of cowpea and mungbean when planted at different depths were evaluated by the modified Hiltner method. All seeds placed on the surface showed poor seedling growth, although small seeds were less susceptible than larger seeds. Seedling growth of small seeds declined rapidly beyond a planting depth of 4 cms, while the larger seeds showed similar results beyond a depth of 6 cms. The value in using uniform seed material and placing the seed at a uniform depth is presented.
Path Analysis of Important Growth Functions of Indian Mustard (Brassica juncea L. Czern and Coss)
Authors: Ghosh R. K. , Chatterjee B. N.
Published: April 2008

Field experiment conducted at the Viswavidyalaya Farm during the winter seasons of 1980—81 to 1983—84 to study the effects of major six productive functions viz. number of inflorescence bearing primary branches, number of inflorescence bearing secondary branches, leaf area indices at flowering, number of seeds/siliqua, number of siliqua/m2 and test weight of grains on the grain yields of eight elite varieties of Indian mustard (Brassica juncea L. Czern and Coss) when sown on three different times revealed that correlations between them were close and positive in all the varieties. Path analysis of the data, further, showed that except the inflorescence bearing primary branches and the seeds/siliqua all other attributes showed high direct influences on grain yield; the maximum direct influence was obtained from number of siliqua/m2.