The toxicity of aluminum (Al) to wheat (Triticum aestivum
Host) was studied under controlled conditions using a technique
designed to evaluate the recovery of root growth following a relatively
brief (48 hour) exposure to nutrient solutions containing
Al, When wheat seedlings were exposed to a minimum critical
concentration of Al,...
The time-concentration interaction of Al toxicity in the root
meristems of Brevor wheat was studied using the L.D. 50 as a criteria
for Al damage. The L.D. 50 represented a precise, well defined
degree of biological damage which was easily reproduced under conditions
where factors like temperature, pH, nutrient concentration,...
Cucumber, pea, bean, and corn excised roots were used to
assess species differences in metabolic uptake of calcium It was
found that Ca was mostly taken up by these root systems by non-metabolic
processes. The apparent free space ranged from 26 to 28
percent of the total root volume and...
The relationships between zinc, iron, and phosphorus in sweet
corn were investigated under field and greenhouse conditions. The
soils used in this study (both acid and calcareous) were low in available
zinc and phosphorus.
The experiments received standard, uniform rates of nitrogen
potassium, magnesium, and sulphur. Corn was used as...
An investigation of Mn uptake by five-day-old excised barley
roots revealed that a metabolically-mediated process was involved.
In short-term experiments, the rate of Mn absorption was comparable
to that of the macronutrient cations. Like other metabolically
absorbed cations, the Mn absorption rate was a direct function of
the ambient concentration...
Wheat varieties of differential tolerance to Al were used in a
series of nutrient solution experiments to study the inhibitory effects
of Al on growth and nutrient uptake. The pH and the Al and P concentrations
were rigorously maintained to prevent the confounding
effects of Al and P precipitation and...
The phenomena known as "phosphorus-induced zinc deficiencies"
are poorly understood. Conclusions drawn from research efforts
designed to identify the mechanism of the phosphorus-zinc interaction
are, in many cases, incompatible. Similarities in the data from
a number of literature reports of "phosphorus-induced zinc deficiencies"
have led to the development of the...
The effects of zinc and phosphorus treatments on five different
plant species were investigated in a greenhouse experiment. A
second greenhouse experiment extended these investigations in sweet
corn over a broad range of phosphorus treatments with and without
adequate zinc nutrition to study phosphorus induced zinc deficiency.
The plant responses...
The progression and consequences of aluminum toxicity were
studied microscopically in the root tips of four wheat varieties
representing different classes of Al tolerance. The root tips studied
were collected from seedlings grown in nutrient solution cultures containing
either sublethal or lethal Al treatments which were unique for
each variety....
The purpose of this study is to illuminate the presence
and rhetorical effect of anecdotes in President Clinton's
major health care address. It is the health care debate that
shows most clearly how Clinton tries to direct a multi-level
campaign that attempts to identify his interests (passage of
the Health...