Agriculture Reference
In-Depth Information
contradictory results were reported by Leece (
1978
), who observed that with high
levels of applied B, the concentrations of N, P, K, Ca, Zn, Cu, Fe and Mn (not Mg)
in maize crop were depressed. The reverse results were obtained when no B was
applied. Increasing B supply in soil resulted in the decrease of leaf N and P in
tomato, suggesting B antagonism. The contrary was the case with a B effect on
leaf K, Ca, Mg and Na (Aduayi
1978
). Yadav and Manchanda (
1979
) noted that
with an increase in the B content of soil, Ca and Mg concentration in wheat and
Gramineae crops significantly decreased, whereas N, P and K contents were
significantly increased.
Moreover, with differential supply of B in nutrient solution, the concentration of
Fe, Mn, P and Ca in the shoots and roots of tomato increased, and B reduced the
translocation of Mn, P and Fe whilst Ca remained unchanged (Alvarez-Tinaut
et al.
1980
). Addition of B in the nutrient solution decreased the absorption of N,
P Ca, Mg and B, induced K accumulation, while Na remained unaffected in lamina
stem and roots of
Cabernet sauvignon
wine plants (Downton and Hawker
1980
).
Gomez-Rodriguez et al. (
1981
) found a highly significant inverse correlation
between B and Mn concentrations in leaves of sunflower, while Cu, Fe and Zn
concentrations were not changed by different B levels in the nutrient solution.
Marked reductions in Fe and Mn adsorption, but an increase in Zn uptake were
recorded in bean plants grown in B deficient medium. The transport of Fe, Mn and
Zn was increased in the trifoliate leaves, while that in shoots was reduced. It appears
that, B is involved in the physiological processes controlling uptake and transport of
nutrients like Mn, Fe and Zn (Dave and Kannan
1981
).
Lombin and Bates (
1982
) found that with increasing B levels, the uptake of K,
Mn, Zn, Cu, Mo and B was increased in alfalfa, peanut and soybean crops, but had
no apparent effect on that uptake of Ca ad Mg in all crops. Similar detrimental
effects of B on the uptake of Ca and Mg were reported by Singh and Singh (
1983
),
who observed varying B level significantly increased the concentration of N, P, K,
Na and B and decreased Ca and Mg concentrations in lentil plants. Applied B
increased the N, P, K, Na and B content but decrease Ca and Mg contents of barley
crops, whilst uptake of N, P, Na and B in grain and straw significantly increased,
and K uptake remained unaffected (Singh and Singh
1983
). Francois (
1986
)
reported that with increasing B in the soil solution the concentration of B, P, K
and Mg tended to increase in tomato leaves, whilst Ca and Na showed inconsistence
trends. Studies on the chemical composition of radish, using sand culture tech-
niques, indicated that Ca and P concentrations decreased significantly and K, Mg
and Na remained unchanged with the increasing B levels (Francois
1986
). Morsey
and Taha (
1986
) reported that applied soil B and foliar application increased the
concentration and uptake of N, P, K, Mn and B in both shoots and roots of sugar
plants. Patel and Golakia (
1986
) demonstrated the effect of soil B on the uptake
of N, P, K, Ca, Zn, Cu, Fe and Mn by a groundnut crop. Interestingly they outlined
the mechanisms of action for some nutrients in relation to the B effect: for example,
B increased an uptake and could be responsible for a favourable effect on nodula-
tion. A positive effect of B and P uptake, which altered the permeability of plasma
lemma at the root surface, resulted in increased P absorption. Uptake of K increased
