الفهرس 
Isolatio and adentification
Pthogeicity TestOnly 14 pages are availabe for public view
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Abstract
This investigation aimed to study damping off and root-rot disease of broad bean plants
faba L.) under calcareous as compared with normally clay soil.
The results obtained could be summarized as follow
I. The fungi isolated from infected roots of plants
collected from mariut were Fusarium solani Rhizoctonia solani
and Nobaria Agricultural Company
(Mart.), [.oxysporum (Schlecht),
{Kuehn (isolate No.I) R.solani
(isolate No. II).
(isolate II) was the most virulent pathogen to broad bean plants in causing pre-emergence
damping off and root-rot either in calcareous and clay soil.
3. Only R.solani (isolate II) decreased significantly the plant height, fresh and dry weight
of shoots,roots as well as the nodule of nitrogen fixing bacteria in both soils.
4. Maximum growth of R.solani was obtained at 80% of field
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capacity and at 20, also 100% at 30° respectively in calcareous and clay soils, respectively.
5. The optimum temperature for linear growth of g.solani was about 25°C regardless the different
field capacities or soil type.
6. R.solani caused the highest percentage of pre-emergence damping off and root rot at 40% of
field capacity both in calcareous and clay soils.
7. The lowest percentage of pre-emergence damping off were obtained at 100% and BO% of
field capacities in calcareous and clay soil, respectively.
8. The
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lowest percentages of root-rot were at 60, 100% and of field capacity in calcareous and clay
soil,
respectively.
9. Infection by .solani increased the root length at 60 and
80% field capacity in calcareous soil.
10. The percentage of pre-emergence damping off in plants previously inoculated with
R.leguminosarium sp. were higher than in uninoculated plants, specially in
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calcareous soils.
11. The percentage of root-rot was not affected by treatment of R.leguminosarium.
12. Addition ot Mycorrhiza decreased the percentage of damping off and root-rot with the
presence of solani pathogen than those inoculated with R.solani only in both used soils. Also,
the infection of R. deceased plant height, the shoot and root fresh weights and shoot dry
weight of inoculated plants than healthy ones in both soils.
13. Mycorrhiza enhanced plant height in the absence of the
R.solani pathogen.
14. Addition of soil amendments greatly affected the percentages of pre-emergence
damping off except sawdust and wheat hay when added to calcareous soil. At the same time, addition
of wheat hay or bitumen highly reduced the percentage of pre-emergence damping off in clay soil.
15. Soil amendments generally increase the percentage of root-rot in clay soil but the addition
of bitumen treatments and sawdust (at 5 g/kg soil) were without any
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marked effect when added to calcareous soil.
16. Different soil amendments used greatly increase plant height, root length, stem
diameter, shoot, root and nodules fresh and dry weights of plants grown in amendmented
calcareous soil than the unamendemented one.
17. The most effective fungicides in reduced the pre-emergence damping off and
root-rot in calcareous soil were Monceren (at 3 gjkg seed) followed by Rhizolex and Benlate
(at 3 g/kg seeds) after 45 and 60 day from sowing. On the other hand, after 60 days from
sowing, Rhizolex at both concentrations was much effective on reducing the percentage of
root-rot.
\8. Fungicide treatments reduced after 45 day the plant height and the root length
espcially Benlante (at 2 g/kg seed). While, Rhizolex and Monceren increased the number of
branches, stem. leaves, roots, and nodules fresh and
dry g/kg
weight of inoculated plants. Whereas, Monceren {at 2
seed) increased values of all the studied growth
characters compared with other fungicides.
19. The fungicides used showed significant decrease in number of flower/plant specially Benlatae
(at 2 g/kg seed).
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21. Benlate (at 3 g/kg seeds) and Monceren (at 2 g/kg seeds) increased bud and flower
shedding, on the contrary, Rhizolex (at 3 g/kg seeds) showed less decrease in bud and flower
shedding in inoculated calcareous soil. Also, all fungicides used showed a reduction in yield 1
plant than control.
22. Giza (3) variety had the lowest percentage of the Rhizoctonia root-rot either after
45 or 60 days from sowing, while, Giza (402) showed similar results after 60 days from sowing.
Also, Giza (2) variety was the highest percentage of root-rot after 60 days from sowing.
23. Infection by g.solani pathogen decreased the pl -•.t height and root length of the Giza
c,3 and 402 varieties of broad bean, also infe ’ion reduced the stem, leaves, root and nodules fn
ch dry weights, only in Giza (2) and (402
) varieties after 45 days from sowing. This depressive effect was clear on Giza {2) variety
at 60 days from sowing.
24. Giza (2) variety grown in Mariut calcareous soil showed significant reduction in the number of
flower/plant.
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24. Giza (3} variety grown in uninoculated or inoculated Mariut calcareous soil recorded the
highest value in bud and flower in comparison with Giza (2) and (402) varieties. But
it was followed by the highest value of shedding percentage while Giza (402) variety was less in
number of flowers and shedding percentage than Giza ( in both inoculated or uninoculated soils,
this followed
by an increase in yield I plant for Giza (402) than Giza
(3) or Giza (2) varieties
25. Giza (2) yield/plant soil.
variety showed significant reduction in in plant grown under inoculated calcareous
26. Shoot and root extracts of plants grown under both calcareous and clay soils showed
significant levels of endogenous gibberellins-like substances (=GLS) at different
stages of growth and gradually decreased, only in root extract towards growth development
27. Shoot extract of plants at the beginning of growth (21 days from planting) and grown under
calcareous and clay soils and inoculated with g.leguminosarium sp. showed no significant levels
of GLS comparing with uninoculated plants which showed significant levels of GLS and
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insignificant levels of gibberellin inhibitors specially in clay soil.
28. Root extract of inoculated plants with .leguminosarium which grown under calcareous soil
generally recorded high significant levels of GLS comparing with untreated plants at different
stages of growth.
29 Inoculation plants with Mycorrhiza at age 21 days from planting showed significant levels
of GLS at only Rf
0.0-0.1 in shoot extract of plants grown in calcareous
soil. However, plants grown under clay soil showed no detectable levels of GLS comparing with
control plants, whereas, plants grown under both soils recorded significant levels of GLS
at Rf 0.6-0.7, O.B-0.9 and
0.9-l,Q in plants under calcareous soil and only at Rf
0.6-0.7 in plants grown under clay soil, and to be increased towards growth development
comparing with control plants.
30. Root extract of inoculated plants with Mycorrhiza and grown under both soils recorded
significant levels of GLS at the three ages of growth specially plants grown under
clay soil at the 3rd sample (50 days from sowing )
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31. Rhizoctonia lead to increase significantly the shoot content of gibberellin-like
substances in both plant grown under calcareous and clay soils specially at the beginning of
growth (21 days from planting)
32. Rhizoctonia lead to decreased GLS in root extracts of infected plants grown under both
soils comparing with healthy plants specially at the 2nd sample (35 days from planting) which
showed no GLS and followed by increasing the levels of gibberellin inhibitors than uninoculated
plants at this stage (35 days) in both soils.
33. Shoot and
extract of plants inoculated with both g.leguminosarium lead to reduced
M:ycorrhiza gibberellin
inhbitors at 1st and 3rd
samples specially in plants
grown under clay soil.
Whereas, it promoted
gibberellin-like substances
and their inhibitors at the
2nd sample under the same soil.
34. Root extracts of the plants inoculated with both Mycorrhiza and g.leguminosarium
lead to increase gibberelline- like substances in plants grown under calcareous soil at the 1st
and 3rd samples concomitant with the absence of gibberellin inhibitors. The reverse was detected
with root plants grown under clay soil.
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Since, the gibberellin inhibitors recorded an increase at this sample with least gibberellins
at the 1st and 3rd ones.
35. Shoot extract of plants grown under calcarous and clay soil and inouclated with both
Rhizoctonia and
g.leguminosarium
together detected significant levels of
GLS at different
stages of growth specially at the 1st
sample which showed no significant levels of
gibberellin-inhbitors comparing
with plants inoculated
with both Rhizoctonia or R.leguminosarium alone.
36. Root extract of inoculated plants with Rhizoctonia and R.leguminosarium together and
grown under calcareous soil and showed significant decrease in GLS compared with plants
inoculated with Rhizoctonia or R.leguminosarium alone at the Isample.
37. Shoot extracts of plants grown under calcareous soils and inoculated with Mycorrhiza +
Rhizoctonia detected significant levels of GLS specially at 1sample (21 days from planting)
and then gradually decreased with advancement of growth.
38. Shoot extracts of plants grown under clay soil and
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inoculated with Rhizoctonia + Mycorhiza recorded high significant levels of GLS at
different stages of growth higher than the levels of GLS in plants inoculated with Rhizoctonia or
Mycorrhiza alone.
39. Shoot extract of broad bean plants grown under calcareous soil and inoculated with both
Rhizoctonia, Mycorrhiza &
.leguminosarium detected significant levels of GLS at
1st and 3rd sample and the level of GLS in the same plants at 1 sample were
higher than of plants inoculated with either R.leguminosarium or Rhizoctonia or Mycorrhiza
alone.
40. Root extract of pints inoculated with Rhizoctonia, R.leguminosarium and Mycorrhiza
all together and grown under calcareous soil showed no gibberellin activity at the 1
sample and recorded significant levels of gibberellin inhibitors at Rf 0.3-0.4, 0.6-0.7,
0.7-0.8 and 0.8-0.9 and then recorded significant levels of GLS at the 2nd and sample.
41. Root extract of plants grown under clay soil and inoculated with Rhizoctonia,
.leguminosarium and Mycorrhiza all together showed similar observation yet GLS inhibitors as
that in root extract of plants grown
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under calcareous soil except at 2nd sample which recorded high significant levels of
gibberellin inhibitors comparing with plants inoculated with R.leguminosarium or Micorrhiza alone.
42. Infection by substances in
.solani reduced shoot extract of
the gibberellin-like plants and recorded
significant levels of gibberellin inhibitors in the three varieties under studies except
Giza (2) variety which showed no traces of gibberellin inhibitors at fruiting stage (72 days
from planting).