D. A. Dar wesh, K. K. Mustafa / Agricultural Sciences 3 (2012) 738-744 743
sinoculateted treatments with mycorrhiza for nitrogen,
phosphorus, agnesium, iron and total dry weight, this may
be due to the fact that the mycorrhiza increase the ab-
sorption of phosphorus and other essential elements re-
quired for growth these results and explanation are similar
with those reported by [23]. Application of the fungicides
Prasamid and Antracol relatively enhance the plant to
mycorrhizal inoculation these fungicides essentially eli-
minated or reduced the beneficial effect of mycorrhizal
fungus on the growth of plant, macro and micronutrients
nutrition, mycorrhizal fungi can be relatively susceptible
to certain fungicides particularly when the fungicides is
applied to the seeds or into the soil, while other fungi-
cides can stimulate mycorrhiza growth [24]. When Pra-
samid and Antracol were applied half of the field rate
recommended for root diseases control the plant dry
matter nutrients content and nutrient balance were sig-
nificantly increased compared to field rate multiple field
rate application. These results are in agreement with
those of [25] who reported stimulatory effect of lower
concentration of some fungicides on mycorrhizal root
colonization and plant dry matter. It is of interest to note
that the increases in growth of mycorrhizal plants is not
strangely parallel with the concentration of both fungi-
cides, its mean that the dray matter production and nu-
trients uptake reduce with higher rate application of fun-
gicides, this could be explained on the basis that the
fungi toxicity of these fungicides when applied at higher
concentration may be injure fungal cell at many site and
it is also possible that may inhibited a number of en-
zymes involved in nutrient assimilation. [6] reported that
the application of higher concentration of fungicides af-
fect vesicular arbuscular mycorrhizal primarily by inhi-
bition spore germination and infection processes, also
[26]. Their results have indicated that root exudates may
be the factors governing mycorrhizal symbiosis, pesti-
cides that increase root exudation may increase my-
corrhizal infection. Both experimental factors and their
interaction significantly affected soy bean nutrients con-
centration and nutrients balance index. Inoculation of
soybean plants with vesicular arbuscular mycorrhizal
fungi was associated with alterations in the contents of
nutrients in the shoots. Total nitrogen, phosphorus, mag-
nesium and iron tended to be higher in vesicular arbus-
cular mycorrhizal-colonized soybean than in non-colo-
nized plants. the total amount of mentioned nutrients
accumulation in the shoots of soybean were greater when
low concentration of fungicides applied with higher con-
centration of fungicides there was less mycorrhizal effect
on nutrient accumulation. Soya bean plants colonized by
vesicular arbuscular mycorrhiza had no significant dif-
ference in Ca and K content than control, moreover Ca
and K contents of shoot in mycorrhizal and mycorrhizal
plants increase with increasing the concentration of fun-
gicides, however the combination between mycorrhiza
and fungicides enhance the nutrients balance index in
soybean plants. The enhancement of nutrient acquisition
by mycorrhizal infection can be attributed to direct hyphal
uptake or indirect effects brought about by morphological
a physiological changes in the host roots, in addition to
that the VAM differs when subjected to different fungi-
cides and some combination of AM and fungicides may
be more efficient under certain circumstances. According
to our result vesicular arbuscular mycorrhizal inoculation
can significantly alleviate the unfavorable effects of fun-
gicides on soybean yield and nutrients balance. These all
indicated that how using chemicals, among their other
unfavorable effects, particularly on the environments can
influence the nutritional quality of the plants [10].
5. CONCLUSION
The result of this study concluded that the metabolic
activities of the mycorr hizal fungus in infected soy bean
plants varied with treatments of soil by different fungi-
cides. Differences were reflected in the growth of my-
corrhizal plants, nutrients accumulation, nutrient index
and nutrients balance index. These results support previ-
ous reports on the variation in the toxicity of fungicides to
VA mycorrhiza.
6. ACKNOWLEDGEMENTS
Grateful acknowledgement is extended to biology department. Col-
lege of Scientific Education University of Salahaddin-Hawler for pro-
viding laboratory facility.
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