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... Replicated field experiments have been carried out to determine the effectiveness of ammonium sulfate, sodium nitrate, potassium sulfate, and superphosphate sprayed singly or in different combinations in controlling annual weeds abounding in a wheat crop (Pusa 4). The relative significance of the different treatments was judged by comparing the mean square roots of weed densities after spraying. C ...
B horizons; Chenopodium album; Sorghum bicolor subsp. drummondii; Trifolium pratense; aluminum; anions; calcium; cation exchange; cation exchange capacity; energy; greenhouses; iron; iron phosphates; oats; phosphorus; rock phosphate; root systems; roots; silt loam soils; solubilization; total phosphorus; wheat
Abstract:
... Plants with root cation exchange capacities ranging from 10 to 60 me./100 g. dry root, were grown in greenhouse pots on B horizon Merrimac silt loam very low in available and total phosphorus. Rock phosphate at the rate of 1,000 pounds per acre was mixed throughout the soil. Plants with high cation exchange root systems (ragweed and smartweed) were more effective in obtaining phosphorus from soil ...
... Seed germination and plant community development on adjacent forest and prairie soils (Typic Hapludalf and Typic Halplaquoll) were studied to elucidate the causes of variation in plant community composition during the first growing season after crop harvest. The number of plant individuals in July on the forest soil was three times larger than on the prairie soil. Abutilon theophrasti, Chenopodium ...
... Weekly root extension of six successional annuals in glass—faced boxes was measured over a growing season in 42 soil resource states. Niche breadth and overlap were calculated and compared to values obtained from publish root diagrams of eight tall grass prairie species. Differences in use of soil resources by the successional species were found and interpreted as primitive niche separation to avo ...
Amaranthus retroflexus; Chenopodium album; germination; leaves; temperature
Abstract:
... A comparison was made of the germination, growth, and leaf CO₂-exchange rates of redroot pigweed (Amranthus retroflexus L.) and common lambsquarters (Chenopodium album L.) under varied temperature regimes. It was found that redroot pigweed had greater rates of germination, growth, and CO₂-exchange rates at high temperatures, whereas common lambsquarters performed better at low temperatures. The im ...
... To determine to roles of prior evolutionary divergence and competitive displacement of species in successional community organization, and aspects of the colonizing strategy, 6 co—occuring annuals were grown together and alone on a soil moisture gradient. The species had similar board vegetative and reproductive responses to the gradient. Interspecific competition reduced the niche breadth and sim ...
... Many crop plants and perennial weed species have been known for their allelopathic effects. The question of whether annual weed species can be allelopathic remains unanswered. Consequently, studies were conducted in laboratory, greenhouse, and in the field to determine the allelopathic potential of weed and crop residues (above ground biomass) on corn (Zea mays L.) and soybeans [Glycine max (L.) M ...
... This study was designed to find tree, shrub, and forb species that could be collected in the summer and early fall and be sown together sufficiently late in November to prevent fall germination, but early enough that some seeds could be properly stratified by winter conditions for germination the following spring. Germination and growth of tree, shrub, and forb species in association with grasses ...
... Patterns of electrophoretic variation in seven enzyme systems were investigated in one triazine‐resistant and nine susceptible populations of Amaranthus retraflexus L. collected along an 800 km north‐south transect in southern Ontario, Canada. The resistant population occurs in a field in which continuous maize production and intensive use of atrazine had been combined over a 15–year period. The n ...
... The effect of nitrogen availability on the plant growth was studied using nine plant species, some of which are commonly found in recently abandoned old fields while others are more characteristic of native prairie. Each species was grown by itself in nine different soil mixtures in which total soil nitrogen (as N) per unit soil mass ranged from 20 to 850 mg/kg, spanning the range of total soil ni ...
... Competitive interactions involve two separate processes: the effect of a species on others in the community and the response of a species to all others. Five species from a 1st—yr field were investigated to determine if there is any correlation between competitive effect and response and if the patterns of effect and response can explain the relative success of each species in the full community. ...
Chenopodium album; seed germination; models; temperature profiles
Abstract:
... When seeds of Chenopodium album are imbibed in 0–01 M potassium nitrate solution in the light at constant temperature, percentage germination increases to an optimum at 24 °C, above which it decreases. These relationships are linear if percentage germination values are transformed to normal deviates. At supra-optimal temperatures, alternating temperatures have little or no effect on this basic rel ...
... Buried seeds often show seasonal periodicity of dormancy. Dormancy patterns of Chenopodium album, Polygonum persicaria, Sisymbrium officinale and Spergula arvensis were studied by burying seeds under field conditions in sandy loam in December, 1986. Seeds were exhumed at regular intervals and germination was subsequently tested in the laboratory. It was shown that the conditions of the germination ...