摘要:

AbstractThe effect of different shading densities on some chemical composition of the roots of two sugarbeet cultivars was studied out during 1984/1985 season. Plants were grown under 0, 37, 50 and 70 % shading treatments.Results showed that the capacity of root tissue in production or storage of sucrose was not directly dependent on light intensity as all the shading treatments did not change the sugar percentage. Therefore, it was suggested that the sucrose percentage in the root was a genetically‐dependent character more than an environmental one.Also, shading had no significant effects on the chemical composition (protein, fiber, fat, ash and dry matter) of fresh roots at maturity, except the fiber percentage which was significantly increased only under the 70 % shading treatmen

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00660.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe ontogenesis of Zea mays L. and their modification by plant growth regulatorsDuring a period of 2 years with the maize varietySantos, the effects of the plant growth regulators CCC and RSW 0411 upon vegetative and generative development were tested by pot experiments. The experiments were carried out to optimize the PGR application to maize and to interpret possible PGR effects. The application shah improve the resistance to lodging by a reduction of ear–and plant height as well as by an increase of stalk diameter. At the same time, the sink‐capacity of the ear shah increase because this is lucrative to all specializations of corn production.The PGR RSW strongly reduced the stem elongation during the growing season after an application in ES 21. The basal stem diameter increased highly significant. The PGR CCC did not obviously effect the vegetative development of maize.RSW suppressed the branching of the tassel after an application in ES 21. Later applications did not disturb the tassel development, because the tassel were completely differentiated at the application time in ES 31/32 and ES 34/35. High application rates of CCC, applied in ES 31/32 and ES 34/35, increased significantly the grain yield by a higher number of kernels per ear. The 1000 kernels weight remained unchanged. The results of the ear ontogenesis indicated, that the PGR CCC lessened the reduction of female spikelets in the ear during the post‐silking p

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00661.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA simple approach was undertaken to estimating bare soil evaporation in a soil column in a laboratory. The measurement of soil heat flux and soil water flux at various depths provides a practical means of assessing and evaluating the position of the drying front (evaporation zone) in the soil.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00662.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractPeriodic and Vertical Nitrate Distribution in Unsaturated and in Saturated Zone of Sandy Soils Close to Groundwater in North‐West GermanyInvestigations into the periodic and vertical distribution of nitrate were conducted in three geologically, pedologically and climatically comparable arable sandy soils lying close to the groundwater zone of the coastal moorlands of N.W. Germany. Periodical and vertical distribution of nitrate was observed in unsaturated and in saturated zones of the soil.The investigation concerns podzol‐brown earths. The depth of the water‐unsaturated zone is 2 to 3 m. The crops in two locations consisted of maize and winter rye; in one location, of maize only. N‐manuring consisted of mineral fertilizers and/or of organic liquid manure. At two locations the investigations were conducted over 3 years, at one location, over 18 months.The results from the three locations indicate a corresponding clear variability of nitrate amounts in the soil depending on weather conditions, on the course of growth of the crops, and on the date, the rate and the type of manuring.The dependence of nitrate content on the time span is most clearly expressed in the top soil. The peak values of NO3in the top soil appear in May, June and in the autumn months. Nitrate peaks in the top soil are continued in the subsequent ground levels with a time shift. Underneath the root zone, the nitrate peak values are transferred, largely without losses, by the seepage water through the capillary and groundwater zones close to the surface.In the capillary and groundwater zones the nitrate peak values are characterized by time‐dependent extension.The time‐span for transferring nitrate peak values from the top soil down to 4.00 m under the surface was determined to be approximately

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00663.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractMaize (Zea maysL.) plants were grown in the field and labelled with14CO2at four leaf positions from silking up to maturity. The ear leaf was the most important source of labelled photosynthates to the ear, followed by the first leaf blade above and below the ear. The movement of labelled assimilates from the second leaf blade below the ear was predominantly downwards. The ear became an important sink soon after silking and continued in importance till harvest.Initially assimilates were partitioned within the ear as husk

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00664.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractInvestigations into Characteristics of Winter Rye Varieties and Triticale in a Low External Input SystemLow external input systems, e.g. ecological agriculture, are able to solve problems concerning overproduction, diminishing resources, and environmental pollution. The suitability of varieties in ecological agriculture, and the transferability of results of investigations in conventional systems are almost unknown. Field trials with 9 genotypes of winterrye and 1 triticale were conducted from 1984 to 1986 at Neu‐Eichenberg. The results can be summarized as follows:1. The use of modern varieties, and their ability to establish a high plant density was most important to achieve high grain yields.2. Highest yielding modern cultivars had a very good baking quality.3. The findings corresponded well with conventionally obtained result

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00665.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractRoot growth of seedlings of old and new winter wheat cultivars and a spelt wheat at varying levels of nitrogenRoot growth of five old (time period 1882–1920) and five new (time period 1975–1982) winter wheal cultivars and a spelt winter wheat cultivar was investigated in two greenhouse trials. Nitrogen (NH4NO3) was supplied at six (Exp. I) and two (Exp. II) levels (sub‐ to supraoptimal for shoot growth). The seedlings were grown in sand‐filled polyethylene tubes of 4.5 cm diameter and 50 cm length at 20oC. The plants were harvested 11 (Exp. I) and 12 (Exp. II) days after emergence. At this early stage of development root growth o: old and new cultivars differed only slightly. The oldT. aestivumcultivars had more seminal roots. The longest roots of the modern cultivars penetrated into deeper layers of the substrate. For some traits, cultivar: seemed to respond specifically to the varying N‐supply. However, there were no significant difference: between old and new cultivars. Neither were old cultivars better adapted to low N‐fertilization nor were modern cultivars superior in tolerating toxic concentrations of NH4NO3. Increasing N supply changes root growth as follows: decline in root dry matter, increase in shoot/root ratio of dry weight, decrease in number of seminal roots, shortening of axes and more laterals, increase in diameter of the laterals and less significantly of the main roots, increase in density of laterals, decline in root surface area. The number of apices was affected only to a very s

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00666.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe effect of two nitrogen fertilizers applied at preplanting, three weeks after sowing (0.5 %), 6 weeks after sowing (1 %) and as a split application were tested on the emergence and growth of tobacco seedlings. Seedling emergence showed no response to fertilizer applications. The seedling growth was superior when ammonium sulphate was applied at preplanting, when compared to urea. The better growth of tobacco seedlings with a basal application of ammonium sulphate is attributed to the lower concentration of nitrogen which is at a non‐toxic level, and the presence of sulphur in this fertilize

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00667.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractOat cultivars (n = 22) varying in origin were examined in laboratory and field tests at Svalöv and Ultuna, Sweden, in 1985 and 1986. Comparisons were made between drought resistance characteristics of juvenile plants and drought responses in yield of crops grown in field. By using automatic, movable rain shelters in combination with drip irrigation systems, both high and low irrigation regimes could be effected in the field experiments.Black oat cultivars were more stable under water deficiency conditions, particularly on sandy soil. They possessed the highest drought resistance indices both in the laboratory and field. Modern white oat cultivars were found to be most drought sensitive.Drought resistance index (DRI) and seminal root length (RL), as assessed in seedling stage, were strongly correlated with field drought susceptibility index (S). It is suggested that DRI and RL could be used as selection criteria to increase drought resistance of oats

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00668.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Books Reviewed in this Article:Scheibe, A.: Bedeutung der wissenschaftlichen Institute für die private Pflanzenzühtung.Frohne, D., U. Jensen: Systematik des Pflanzenreichs unter besonderer Berücksichtigung chemischer Merkmale und pflanzlicher Drog

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00669.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY