. . . REPUBLIC OF SENEGAL, -__----- k.9. ...
. . .
REPUBLIC OF SENEGAL,
-__-----
k.9.
MINISTRY OF RURAL DEVELOPMENT
A
.--------
; ‘..‘;[ .il\\.,;i ::‘.y . . ,c-. :
SENEGALESE INSTITUTE OF
:+ +, $& !;; i”,. ‘C !
:x \\,fDEPARTMENT OF RESEARCH
<
L
AGRICULTURAL RESEARCH
ON CROP PRODUCTION
.-----
,:.
‘._>
ANNUAL REPORT
ON GROUNDNUT PATHOLOGY - 1987
BY
D.G. GAIKWAD
MARCH 1988
NATIONAL CENTRE OF AGRONOMICAL
i
RESEARCH, BAMBEY
During 1987 screening the germplasm entries against leaf spots and
chemical control were the main items of research. These studies were carried
out at Nioro which is a hot spot for leaf spots of groundnut. During the year
under report the leaf spots pressure at Nioro was quite high. The results of
these studies are discussed in the following pages.
1 - RESISTANCE SCREENING AGAINST LEAF SPOTS
1 .l - Screening germplasm entries
During 1986 season, 838 germplasm entries were screened at Bambey
against cercospora leaf spot under natural infection. 252 entries which exhibited
::.
low leaf spot infection during 1986 season were rescreened during 1987. The
.,I.‘.
..‘.
. , ; . : .
‘..
tria1 was conducted at Nioro where the natural infection of leaf spots is very
high due to humid cond.itions. Two rows of each entry were sown on 07-07-1987.
Row length was 3 m with 60 x 15 cm2 spacing.
The seeds were treated with granox
before sowing..One seed vas sown at each pocket.
. Observations were recorded thrice (28-08, 29-09 and 16-10-87) on
the natural infection of leaf spots. A scale of O-10 proposed by ICRISAT where
:.’
0 stands for no infection and 10 denotes 100% leaf area affected by leaf spots
was used for recording the observations. The first symptoms were noticed in
the second week of Aug’Jst on some of the entries. The disease pressure was deve-
loped considerably by ,the timeofmaturity. Final observations were recorded on
16.10.1987. Disease score for each entry is given in table 1.
2
Table 1
-
- : Leaf spot observations on germpl.asrr entries
--T-
N'
ENTRY
LVERAGE DISEASE SCORI
Ii
-
-
t
1
5’7-58
8.5
2
48-115
7.5
3
58-579
6.5
4
58-587
7
5
513-611
6. 5
6
58-654
7 . 5
7
58-665
7. 5
a
72-26
a. 5
9
28-24
a
10
28-236
6. 5
11
29-56
5. 5
12
42-44
4. 5
13
53-66
4
1 4
53-86
4
15
53-300
5
16
55-131
4. 5
1 7
57-67
4. 5
l a
57-94
6
19
57-279
5. 5
2 0
57-280
6
2 1
57-233
8
2 2
w-119
5. 5
23
58-121
6
2 4
59-154
5
25
59-155
5
26
59-238
4. 5
27
59-266
5
2 8
64-103
5.5
29
75-106
6
30
28-209 B
5. 5
3 1
28-219
5. 5
32
28-224
4. 5
33
28-229
6
Table 1
e.-.---L
: Cmtd.
T
-
N’
ENTRY
4VERAGE DISEASE SCORE
-
34
t
48-38 A
4.5
35
48-55
5
36
48-101
4.5
37
48-111
4
38
48-143
6
39
50-36
5
40
52-2
5
41
52-34
6. 5
42
53-42
7.5
43
53-68
5
44
53-136
6.5
45
55-203
6
46
55-23.4
5
47
55-238
5.5
48
55-479
4
49
55 H46 El7
5
50
56-70
5.5
51
56-181
6
52
56-222
4.5
53
56-233
4.5
54
56-282
6.5
55
56-286
5
56
56-295
4. 5
57
56-311
3.5
58
56-326
5
59
56-370
4.5
6 0
56-375
4. 5
61
56-379
4. 5
62
56-383
5
6 3
56-4O:l
6
64
56-40-j
8
65
56-423
4. 5
66
56-447
5
67
56-288
6
. . /. ~..
T a b l e 1 : C o n t d .
-
N’
T
t
ENTRY
\\VERAGE DISEASE SCORE
68
57-317
5.5
69
58-19
4.5
70
58-21
5 . 5
71
58-26
6
72
58-41
5.5
73
58-45
5
74
58-52
4.5
75
58-53
5
76
58-7 1
6
77
58-138
5
78
58-139
4
79
58-160
5
a0
58-167
5
a1
58-219
6
a2
58-233
5.5
a3
58-551
a
a4
58-254
7
a5
58-332
a
86
58-348
6
a7
58-351
4 .5
88
58-360
7
a9
58-368
6
90
58-577
6
91
58-396
6
92
58-399
5
93
58-402
5.5
94
58-404
6
95
58-408
5
96
58-445
6
97
58-619
7
98
59-48
6 .5
99
59-68
5
100
59-105
4 .5
101
59-110
6
/
. . . . . .
Table 1 : Contd.
N’
ENTRY
T14VERAGE DISEASE SCORE
102
59-118
t
5
103
59-121
6
104
59-123
4 -5
105
59-125
5
106
59-148
5
107
59-151
5
108
59-157
5.5
109
59-191
6.5
:.
:::::’
.‘...
.;.:.
110
59-196
5.5
111
59-231
4
112
59-243
4.5
113
59-355
5.5
114
59-502
5
115
61-81
8.5
116
58-618
7
117
61-w
5
118
73-28
6.5
119
75-67
6.5
120
75-68
7.5
121
75-70
5.5
122
75-72
5
123
75-84
5
124
75-88
8
125
75-99
7
126
75-104
4.5
127
75-114
5.5
128
75-118
5.5
129
75-135
9
130
79-l
9
131
79-9
8.5
132
79-23
7.5
133
79-37
0
134
79-42
6
. , . ,’ . . .
Table 1 : Contd.
6
-
-
N’
ENTRY
ZVERAGE DISEASE SCORE
-
135
58-646
7. 5
136
79-90
7
137
Altika
6, 5
138
Bir 16
8
139
EH 235
7 .5’
140
EH 247-2-2
6.5
141
EH 282 Bis 2
7
142
EH 332 Bis 3
7
143
EH 333-5
6.5
144
EH 336-4
7
145
GH 119-20
6
146
Israel 4
6.5
147
NC 5 erigée
6
148
NC 17
5.5
149
PR 23 B
6.5
150
PR 26 B
6
151
PR 64 B
5
i:::,.
2:::
152
R 295 B
7
153
R 299 Bl
6.5
154
R 299 B2
5.5
155
R 2919 A
6.5
156
Seneqal Oriental
5
157
UF 72-313
6
158
UF 72-405
5.5
159
UF 72-417
6
160
58-656
7.5
161
v 773
5
162
v 781
5
163
CH 79-73
6
164
E 58-331
7
165
E 55-265
6.5
166
79-10
6.5
167
58-668
6.5
168
72-24
6
.
..‘
/
.
.
.
Table 1 : Contd.
7
- - -
No
ENTRY
LVERAGE DISEASE SCORE
169
24-5
6 .5
170
28-234
6
171
30-86
6
172
42-94
6
173
52-10
5.5
174
5249
5.5
175
53-60
5.5
176
53-100
6
177
53-298
5
178
55-511
5
179
57-14
6 . 5
180
57-102
5
181
57-319
5
182
57-333
5 . 5
183
58-83
6
184
58-84
6.5
185
58-97
6.5
186
58-147
5
187
58-157
5
188
58-165
5. 5
189
58-173
4. 5
190
58-453,
4. 5
191
58-650
4. 5
192
59-133
5. 5
193
59-135
5. 5
194
59-147
5
195
59-163
55
1%
59-W
4. 5
197
59-260
5
198
59-267
5
199
59-503
5.5
200
61-92
4.5
201
28-210 A
5
/
. . . . . .
Table 1 : Contd.
-
No
ENTRY
4VERAGE DISEASE SCORE
-
-
202
48-21
4
203
48-38
4
204
48-44
4
205
48-62
5
206
48-87
5.5
207
48-151
4.5
208
48-154
4
209
48-108
4.5
210
50-16
6 . 5
211
50-33
6 . 5
212
51-40
5 . 5
213
52-8
6
214
52-13
6
215
52-32
6.5
216
52-35
7
217
53-40
6. 5
218
53-331
7
219
55-91
7. 5
220
55-93
7
221
56-69
6. 5
222
56-89
7
223
56-176
4. 5
224
56-188
5
225
56-221
6
226
56-2 36
6
227
56-242
4.5
228
56-277
5.5
229
56-293
4 : 5
230
57-23
5.5
231
57-327
5.5
232
57-376
7
233
58-11
5 . 5
234
58-18
5
235
58-31
5
. ../...
Table 1 : Contd.
[
-
N*
ENTRY
(AvERAOE rxswdx SCORE
:
236
58-54
5
237
58-68 4.5
2’38
58-156 6
239
58-238
5.5
240
58-682
5
241
59-92
I
5
242
59-112
5 “ 5
243
59-130
I
5
. : , : .
244
59-143
4
. . :
:
‘.
245
59-145
4.5
246
59-390
4.5
247
63-104
5
248
68-122
4.5
249
75-90 8.5
250
79-87 6.5
251
73-30
I 7. 5
252
)
73-33 6
Note : Entries with grades 1, 2 and 3 were considerci: âs
resistant , 4 and 5 moderately resistant, 6 and 7 n?oderately
susceptible, 8 and 9 susceptible and 10 highly susceptible.
10
The results in table 1 revealed that no
variety is free or resistant
t o l e a f s p o t s . However, 100 varieties exhibited moderate resistance. 127 varie-
ties were observed to be moderately susceptible while 25 were susceptible. The
distribution of germplasm entries amongst rarious intensity grades was as under.
Grade
.“-
Number of entry
--~
Grade
.--
Number of entry
3.5
1
4
11
4.5
35
5
53
5.5
39
6
40
6.5
31
7
17
7.5
11
a
7
8.5
5
9
2
:.:
.
..Y>_
Y:.
Moderately resistant entries with intensity grades from 3,5 to 5 are
listed in table 2. These entries Will be rescreened during 1988 rainy season.
11
Table 2 : List of moderately resistant entries
-
-
-
G r a d e 3 . 5 : - 56-311
Grade 4
: - 53-66,
53-86,
48-111, 55-233, 58-139
59-231,
48-21,
N-38, 48-44 > 48-154 & 59-143.
Grade 4.5 : ‘- 42-44, 55-131, 57-67 > 59-238 >
28-224,
48-38 A, 48-101, 56-222, 56-233,
S-295, 56-370, 5 6 - 3 7 5 , 56-379, 5 6 - 4 2 3 , 58-19,
58-52,
58-351, 59-105, 5 9 - 1 2 3 , 5 9 - 2 4 3 , 75-104,
58-173,
5 8 - 4 5 3 , 5 8 - 6 5 0 , w-258, 61-92,
48-151,
48-108, 56-176, 56-242, 56-293,
58-68,
fjg-145, 59-390 & 6 8 - 1 1 2 .
Grade 5
: - 53-300, 59-155, 59-238, 59-266,
4 8 - 5 5 , 50-36, 5 2 - 2 , 5 3 - 6 8 , 5 5 - 2 1 4 ,
55 H 46 E 17 > 56-286 > 56-326, 56-383,
56-447, 58-45, 58-53, 58-138, 58-160,
5 8 - 1 6 7 , 58-399, 5 8 - 4 0 8 , 59-68, 59-118,
59-125, 59-148, 59-151, 59-502, 61-99,
75-72, 75-84, PR 64 B, Senegal Oriental,
v 7 7 3 , v 7 8 7 , 59-298, 5 5 - 5 1 1 , 57-102,
57-319, 58-147, 58-157, 59-147, 59-260,
59-267, 2 8 - 2 1 0 A , 4 8 - 6 2 , 56-188, 5 8 - 1 8 ,
58-31, 58-54, 58-68, 59-92, 59-130 and
63-iû4.
:a:::. ‘..
12
II - CHEMICRL ~ g CQNTROL OF LEAF SPOTS :
Groundnut leaf spots are quite serious in Senegal causing about 30-
40% Ioss il: yield. Hence an experiment was initiated in 1986 Crop Season to
find out t h e efficacy @f some COLT~@~ fungicides f o r t h e e f f e c t i v e c o n t r o l o f
these diseases. During 1986, the experiment was conducted at Bambey and on
one variety (73-33). During 1987, the experiment was conducted at Nioro which
is a hot spot for leaf spots and on 2 varieties viz. 73-33 and 73-30. The
experimental details w’ere as under :
Design
: S p l i t p l o t Idesign
Location : Nioro du Rip
V a r i e t i e s : 2 viz., 1) ‘ 7 3 - 3 3
::;..<
:.:a;
‘*!.
2) 7 3 - 3 0
Treatments: 6 G, 1) Benomyl (Benlate )
200 g a,i./ha
2 ) I3enomyl (Benlate 1
100 g a.i./ha
3) Mancozeb (Mancozan blue)
1500 g a.i./ha
4 1 Copper t Zineb (Calimix)
4 0 0 g P.C./100
1
5) Maneb
160 g a.i./lOO 1
6) Absolute C o n t r o l
:...
. ‘.
Replications : Four
Plot Size
: 3 . 5 x 4 . 5 m2(7 l i g n e s o f 4 . 5 m length)
Spacing
: 50 x 15 cm2
.‘..
F e r t i l i z e r s : 6-20-10 %? 150 kg/ha as basa1 dose
..::
Date of sowing: July 8, ‘1987.
The fungicidal treatments were started after the appearance of the
leaf spots. The leaf spots had started appearing in the second week of August.
Altogether 3 fungicidal sprays were giver.. The first. spray was given on 22.08.87,
the second on 07.09.87 and the third on 29.09.87. Observations on leaf spots
incidence were recorded at the time of each fungicidal s p r a y i . e o n 2 2 . 0 8 , 07.09
and 29.09. The final observations were recorded on 16.10.87. The tria1 was
harvested on 28.10.1987 and the yield recorded. The summary of W3Ult;S for disease
score is presented in table 2 while that of yield data is given in table 3.
The results for both disease score and yield are depicted eimultane.ously in a
graph o n p a g e 15.
The disease pressure was quite high at the time of final observation.
The aversge leaf spots score in the scale of O-10 was 7 in untreated plots.
.*:
13
.-,
/
/
rC
Table 2 : Summary of results for disease score
Variety
73-33
73-30
file z3
S.E. C.D.
Fungicides
Benomyl
200 g a.i.,/ha
‘5.75
6.00
Cj ,875
O.OF;8-
0.1.ti7 (5%)
Benomyl
100 g a.i.,/ha
6.00
5.75
5.875
0*7?9 (1%)
Mancozeb
400 a.i./ha
g
5.75
5.75
5.750
Calimix
4 0 0g p.c./lOO 1
6.00
6.00
6 . 000
Maneb
160 ga.i./lOO 1
6.25
6.00
6.125
Control
7.00
7.00
7.000
Mean
6.125
6.083
SE, 0:006
::;:.::.
C,D. N.S.
S.E.for body
of the table = 0.116
C.D.for body of the table = N.S.
Coefficient of variation : 7.66 I%
Note :
N.S. = Non Significant
14
Table 3 : Summary of results for yield (Figures in kg/ha)
Variety
Fongicides
73-33
73-30
Mean
S.E. C.D.
Benomyl
200 g a.i./ha
4010
3514
3:762
7;~)
1t.4 (5%)
IFici (1%)
Benomyl
100 g a.i./ha
3595
2548
3071
Mancozeb
g 1500 a.i/ha
3110
2452
2781
Calimix
400 g P.C./100 1
3143
2405
2774
Maneb
160 g a.i./:Loo 1
3103
2738
2920
Control
2957
2367
2662
Mear
3319
2670
:,y.:
S.E.
4
::;::,:
C.D.
20 (5%)
36: (1%)
S.E:. for body of the table - 7?
C.D. for body of the table - N.S.
Coefficient of variation : 10.56%
..?
‘.
Note :
N.S. - Non Significant
::
15
.
P
8
44368
Ei
5
e
a
S
e
0
c
2Bee
0
h
P
a
e
-
-
181
0
1 : Benomyl (BenLate)
200 g ai/ha
2 : Benomyl (Benlate!
100 g ai/ha
3 : Mancozebc (Mancozan Bluei 1500 g ai/ha
4 : Copper t Zineb (Calimix)
400 g pc/100 1
5 : Maneb
160 K ai/130 1
6 : Absolute Control
From the results in table 2 it is seen that the differences in mean
disease score of various treatments were highly significant. Al1 the fungicides
were highly effective in reducing the leaf spots score.
Mancozeb exhibited the lowest score followed by Benomyl (both
200 and 100 g doses), Calimix and lastly Maneb. The results of 1986 had the
similar trend. In 1986 Benomyl 200 g a.i./ha had the least disease score followed
by Mancozeb and Calimix.
The disease score of two varieties did not dif’fer significantly indicating
that both the varieties are equally susceptible to leaf spots. The interaction
amongst the varieties and fungicides was also observed to be non significant. This
means the effect of fungicides was the same on both the varieties.
The results in table 3 indicated that the yield differences amongst
various treatments were highly signif icant S Benomyl 200 g a.i/ha had given the
highest yield (3762 kg/hla) which was significantly superior over a11 other
treatments. The next highest yield (3071 kg/ha) was obtained in Benomyl 100 g a.i.1’
ha treatment which was a.lso significantly superior to a11 other treatments’
‘_,
lflaneb (2920 ‘km’naJ’.~nd mancozeb (2781 koiha)gave sign.i fioanthv more yield +-ban
t;h,e absolute control , (2662 kgjha) . bu [, tbF: 1 ncreas& i r, yj.eld’due to earimix
was stati&t*icaliy nori-signi,fi.canL. Haw’sver i
i.
t, was apnroachinathe ‘levé&of significance.
.:.
‘<’
i
The differences amongst the overall yield of two varieties were highly
.:
significant.
This is due to difference in the yield potential of these two varieties,
::.,,
and not because of leaf spots infection. 7 3- 3 3 is comparat ively long durat ion
variety (about 110 days) than 73-30 (about 90 days) and has a high yield potentiai.
The interaction in between varieties and the fungicides was observed to
be absent. The fungicides had similar effect on both the varieties.
In case of disease score data, the trend of results is similar during
both the years viz., 1986 and 1987. However, there is variation in the yield data
obtained during 1986 and 1987. The yield differences amongst various treatments
were statistically non-significant during 1986. While they were highly significant
during 1987. In 1986, Mancozeb treatment had given the highest yield which was,
howerer , statistically on par with the absolute control while during 1987 Benomyl
200 g a.i. /ha gave the highest yield which was highly significant not only over
the absolute control but also over a11 other treatments.
In case of disease score similar trend was noticed during both the
years while in case of yield, the trend during 1987 was altogether different
from 1986. It is,therefore,proposed to repeat this experiment during 1988 rainy
season.
III - DETECTION OF SEED MICROFLORA :
Some studies on seed microflora were carried out in the past at Texas
University on the
kernels and shells collected
from Senegal. These studies
revealed the presence of 17 pathogens. In tne present studies attempts were
made to find out the percentage of root rots and seed:ling infection and detect
the pathogens associa’ted
with this seed rct and seedding infection.
Seeds of 2 varieties viz., 73-33 and 73-30 were used for these studies.
Seed microflora was detected by rolled towel method. Seeds were put on sets of
three blotter sheets previously moistened with water. The sheets were rolled
and kept at room temperature. The sheets were opened after 10 days and the
observations were recorded for seed rot and seedling infection. The microflora
associated with seed rot and seedling infection was examined under the microscope.
The results are presented in table 4.
I V - SURVEX OF GROUNDNUT DISEASES :
Groundnut leaf spots particularly early leaf spot was wide sprread during
1987 trop season. Late leaf spot was restricted to few locations. It was quite
high at Nioro. Seedling mortality due to Aspergillus niger and Macrophomina Pha-
seoli was less as compared to 1986 season. However, the infection of Macrophomina
SP. on the adult plants was wide spread. It was sporadic in nature but very seve-
re in the pockets affected. It was seen almost throughout the main groundnut area.
Peanut clump as usual
was very common in the fields around Bambey.
18
table 4 : Seed microflora in 2 varieties of groundnut
Variety
Healthy
Inf ected
Organisms àetected on the infected
seed
seed
seed with their percentage
(8)
CI)
7 3-33
90
10
Aspergillu-5
- -
sp. 1
Rhizopus sp.
----
5
Aspergilluw t Rhizopus 2
- -
Rhizopus t Bacteria
2
-
73-30
89
11
Rhizopus sp.
5
:.
3;:
Bacteria
6
:.
.‘.
These organisms were alao found in thti seed pathology
studies carried out at Texas Unuversity.
REPUBLIC OF SENEGAL,
-__-----
k.9.
MINISTRY OF RURAL DEVELOPMENT
A
.--------
; ‘..‘;[ .il\\.,;i ::‘.y . . ,c-. :
SENEGALESE INSTITUTE OF
:+ +, $& !;; i”,. ‘C !
:x \\,fDEPARTMENT OF RESEARCH
<
L
AGRICULTURAL RESEARCH
ON CROP PRODUCTION
.-----
,:.
‘._>
ANNUAL REPORT
ON GROUNDNUT PATHOLOGY - 1987
BY
D.G. GAIKWAD
MARCH 1988
NATIONAL CENTRE OF AGRONOMICAL
i
RESEARCH, BAMBEY
During 1987 screening the germplasm entries against leaf spots and
chemical control were the main items of research. These studies were carried
out at Nioro which is a hot spot for leaf spots of groundnut. During the year
under report the leaf spots pressure at Nioro was quite high. The results of
these studies are discussed in the following pages.
1 - RESISTANCE SCREENING AGAINST LEAF SPOTS
1 .l - Screening germplasm entries
During 1986 season, 838 germplasm entries were screened at Bambey
against cercospora leaf spot under natural infection. 252 entries which exhibited
::.
low leaf spot infection during 1986 season were rescreened during 1987. The
.,I.‘.
..‘.
. , ; . : .
‘..
tria1 was conducted at Nioro where the natural infection of leaf spots is very
high due to humid cond.itions. Two rows of each entry were sown on 07-07-1987.
Row length was 3 m with 60 x 15 cm2 spacing.
The seeds were treated with granox
before sowing..One seed vas sown at each pocket.
. Observations were recorded thrice (28-08, 29-09 and 16-10-87) on
the natural infection of leaf spots. A scale of O-10 proposed by ICRISAT where
:.’
0 stands for no infection and 10 denotes 100% leaf area affected by leaf spots
was used for recording the observations. The first symptoms were noticed in
the second week of Aug’Jst on some of the entries. The disease pressure was deve-
loped considerably by ,the timeofmaturity. Final observations were recorded on
16.10.1987. Disease score for each entry is given in table 1.
2
Table 1
-
- : Leaf spot observations on germpl.asrr entries
--T-
N'
ENTRY
LVERAGE DISEASE SCORI
Ii
-
-
t
1
5’7-58
8.5
2
48-115
7.5
3
58-579
6.5
4
58-587
7
5
513-611
6. 5
6
58-654
7 . 5
7
58-665
7. 5
a
72-26
a. 5
9
28-24
a
10
28-236
6. 5
11
29-56
5. 5
12
42-44
4. 5
13
53-66
4
1 4
53-86
4
15
53-300
5
16
55-131
4. 5
1 7
57-67
4. 5
l a
57-94
6
19
57-279
5. 5
2 0
57-280
6
2 1
57-233
8
2 2
w-119
5. 5
23
58-121
6
2 4
59-154
5
25
59-155
5
26
59-238
4. 5
27
59-266
5
2 8
64-103
5.5
29
75-106
6
30
28-209 B
5. 5
3 1
28-219
5. 5
32
28-224
4. 5
33
28-229
6
Table 1
e.-.---L
: Cmtd.
T
-
N’
ENTRY
4VERAGE DISEASE SCORE
-
34
t
48-38 A
4.5
35
48-55
5
36
48-101
4.5
37
48-111
4
38
48-143
6
39
50-36
5
40
52-2
5
41
52-34
6. 5
42
53-42
7.5
43
53-68
5
44
53-136
6.5
45
55-203
6
46
55-23.4
5
47
55-238
5.5
48
55-479
4
49
55 H46 El7
5
50
56-70
5.5
51
56-181
6
52
56-222
4.5
53
56-233
4.5
54
56-282
6.5
55
56-286
5
56
56-295
4. 5
57
56-311
3.5
58
56-326
5
59
56-370
4.5
6 0
56-375
4. 5
61
56-379
4. 5
62
56-383
5
6 3
56-4O:l
6
64
56-40-j
8
65
56-423
4. 5
66
56-447
5
67
56-288
6
. . /. ~..
T a b l e 1 : C o n t d .
-
N’
T
t
ENTRY
\\VERAGE DISEASE SCORE
68
57-317
5.5
69
58-19
4.5
70
58-21
5 . 5
71
58-26
6
72
58-41
5.5
73
58-45
5
74
58-52
4.5
75
58-53
5
76
58-7 1
6
77
58-138
5
78
58-139
4
79
58-160
5
a0
58-167
5
a1
58-219
6
a2
58-233
5.5
a3
58-551
a
a4
58-254
7
a5
58-332
a
86
58-348
6
a7
58-351
4 .5
88
58-360
7
a9
58-368
6
90
58-577
6
91
58-396
6
92
58-399
5
93
58-402
5.5
94
58-404
6
95
58-408
5
96
58-445
6
97
58-619
7
98
59-48
6 .5
99
59-68
5
100
59-105
4 .5
101
59-110
6
/
. . . . . .
Table 1 : Contd.
N’
ENTRY
T14VERAGE DISEASE SCORE
102
59-118
t
5
103
59-121
6
104
59-123
4 -5
105
59-125
5
106
59-148
5
107
59-151
5
108
59-157
5.5
109
59-191
6.5
:.
:::::’
.‘...
.;.:.
110
59-196
5.5
111
59-231
4
112
59-243
4.5
113
59-355
5.5
114
59-502
5
115
61-81
8.5
116
58-618
7
117
61-w
5
118
73-28
6.5
119
75-67
6.5
120
75-68
7.5
121
75-70
5.5
122
75-72
5
123
75-84
5
124
75-88
8
125
75-99
7
126
75-104
4.5
127
75-114
5.5
128
75-118
5.5
129
75-135
9
130
79-l
9
131
79-9
8.5
132
79-23
7.5
133
79-37
0
134
79-42
6
. , . ,’ . . .
Table 1 : Contd.
6
-
-
N’
ENTRY
ZVERAGE DISEASE SCORE
-
135
58-646
7. 5
136
79-90
7
137
Altika
6, 5
138
Bir 16
8
139
EH 235
7 .5’
140
EH 247-2-2
6.5
141
EH 282 Bis 2
7
142
EH 332 Bis 3
7
143
EH 333-5
6.5
144
EH 336-4
7
145
GH 119-20
6
146
Israel 4
6.5
147
NC 5 erigée
6
148
NC 17
5.5
149
PR 23 B
6.5
150
PR 26 B
6
151
PR 64 B
5
i:::,.
2:::
152
R 295 B
7
153
R 299 Bl
6.5
154
R 299 B2
5.5
155
R 2919 A
6.5
156
Seneqal Oriental
5
157
UF 72-313
6
158
UF 72-405
5.5
159
UF 72-417
6
160
58-656
7.5
161
v 773
5
162
v 781
5
163
CH 79-73
6
164
E 58-331
7
165
E 55-265
6.5
166
79-10
6.5
167
58-668
6.5
168
72-24
6
.
..‘
/
.
.
.
Table 1 : Contd.
7
- - -
No
ENTRY
LVERAGE DISEASE SCORE
169
24-5
6 .5
170
28-234
6
171
30-86
6
172
42-94
6
173
52-10
5.5
174
5249
5.5
175
53-60
5.5
176
53-100
6
177
53-298
5
178
55-511
5
179
57-14
6 . 5
180
57-102
5
181
57-319
5
182
57-333
5 . 5
183
58-83
6
184
58-84
6.5
185
58-97
6.5
186
58-147
5
187
58-157
5
188
58-165
5. 5
189
58-173
4. 5
190
58-453,
4. 5
191
58-650
4. 5
192
59-133
5. 5
193
59-135
5. 5
194
59-147
5
195
59-163
55
1%
59-W
4. 5
197
59-260
5
198
59-267
5
199
59-503
5.5
200
61-92
4.5
201
28-210 A
5
/
. . . . . .
Table 1 : Contd.
-
No
ENTRY
4VERAGE DISEASE SCORE
-
-
202
48-21
4
203
48-38
4
204
48-44
4
205
48-62
5
206
48-87
5.5
207
48-151
4.5
208
48-154
4
209
48-108
4.5
210
50-16
6 . 5
211
50-33
6 . 5
212
51-40
5 . 5
213
52-8
6
214
52-13
6
215
52-32
6.5
216
52-35
7
217
53-40
6. 5
218
53-331
7
219
55-91
7. 5
220
55-93
7
221
56-69
6. 5
222
56-89
7
223
56-176
4. 5
224
56-188
5
225
56-221
6
226
56-2 36
6
227
56-242
4.5
228
56-277
5.5
229
56-293
4 : 5
230
57-23
5.5
231
57-327
5.5
232
57-376
7
233
58-11
5 . 5
234
58-18
5
235
58-31
5
. ../...
Table 1 : Contd.
[
-
N*
ENTRY
(AvERAOE rxswdx SCORE
:
236
58-54
5
237
58-68 4.5
2’38
58-156 6
239
58-238
5.5
240
58-682
5
241
59-92
I
5
242
59-112
5 “ 5
243
59-130
I
5
. : , : .
244
59-143
4
. . :
:
‘.
245
59-145
4.5
246
59-390
4.5
247
63-104
5
248
68-122
4.5
249
75-90 8.5
250
79-87 6.5
251
73-30
I 7. 5
252
)
73-33 6
Note : Entries with grades 1, 2 and 3 were considerci: âs
resistant , 4 and 5 moderately resistant, 6 and 7 n?oderately
susceptible, 8 and 9 susceptible and 10 highly susceptible.
10
The results in table 1 revealed that no
variety is free or resistant
t o l e a f s p o t s . However, 100 varieties exhibited moderate resistance. 127 varie-
ties were observed to be moderately susceptible while 25 were susceptible. The
distribution of germplasm entries amongst rarious intensity grades was as under.
Grade
.“-
Number of entry
--~
Grade
.--
Number of entry
3.5
1
4
11
4.5
35
5
53
5.5
39
6
40
6.5
31
7
17
7.5
11
a
7
8.5
5
9
2
:.:
.
..Y>_
Y:.
Moderately resistant entries with intensity grades from 3,5 to 5 are
listed in table 2. These entries Will be rescreened during 1988 rainy season.
11
Table 2 : List of moderately resistant entries
-
-
-
G r a d e 3 . 5 : - 56-311
Grade 4
: - 53-66,
53-86,
48-111, 55-233, 58-139
59-231,
48-21,
N-38, 48-44 > 48-154 & 59-143.
Grade 4.5 : ‘- 42-44, 55-131, 57-67 > 59-238 >
28-224,
48-38 A, 48-101, 56-222, 56-233,
S-295, 56-370, 5 6 - 3 7 5 , 56-379, 5 6 - 4 2 3 , 58-19,
58-52,
58-351, 59-105, 5 9 - 1 2 3 , 5 9 - 2 4 3 , 75-104,
58-173,
5 8 - 4 5 3 , 5 8 - 6 5 0 , w-258, 61-92,
48-151,
48-108, 56-176, 56-242, 56-293,
58-68,
fjg-145, 59-390 & 6 8 - 1 1 2 .
Grade 5
: - 53-300, 59-155, 59-238, 59-266,
4 8 - 5 5 , 50-36, 5 2 - 2 , 5 3 - 6 8 , 5 5 - 2 1 4 ,
55 H 46 E 17 > 56-286 > 56-326, 56-383,
56-447, 58-45, 58-53, 58-138, 58-160,
5 8 - 1 6 7 , 58-399, 5 8 - 4 0 8 , 59-68, 59-118,
59-125, 59-148, 59-151, 59-502, 61-99,
75-72, 75-84, PR 64 B, Senegal Oriental,
v 7 7 3 , v 7 8 7 , 59-298, 5 5 - 5 1 1 , 57-102,
57-319, 58-147, 58-157, 59-147, 59-260,
59-267, 2 8 - 2 1 0 A , 4 8 - 6 2 , 56-188, 5 8 - 1 8 ,
58-31, 58-54, 58-68, 59-92, 59-130 and
63-iû4.
:a:::. ‘..
12
II - CHEMICRL ~ g CQNTROL OF LEAF SPOTS :
Groundnut leaf spots are quite serious in Senegal causing about 30-
40% Ioss il: yield. Hence an experiment was initiated in 1986 Crop Season to
find out t h e efficacy @f some COLT~@~ fungicides f o r t h e e f f e c t i v e c o n t r o l o f
these diseases. During 1986, the experiment was conducted at Bambey and on
one variety (73-33). During 1987, the experiment was conducted at Nioro which
is a hot spot for leaf spots and on 2 varieties viz. 73-33 and 73-30. The
experimental details w’ere as under :
Design
: S p l i t p l o t Idesign
Location : Nioro du Rip
V a r i e t i e s : 2 viz., 1) ‘ 7 3 - 3 3
::;..<
:.:a;
‘*!.
2) 7 3 - 3 0
Treatments: 6 G, 1) Benomyl (Benlate )
200 g a,i./ha
2 ) I3enomyl (Benlate 1
100 g a.i./ha
3) Mancozeb (Mancozan blue)
1500 g a.i./ha
4 1 Copper t Zineb (Calimix)
4 0 0 g P.C./100
1
5) Maneb
160 g a.i./lOO 1
6) Absolute C o n t r o l
:...
. ‘.
Replications : Four
Plot Size
: 3 . 5 x 4 . 5 m2(7 l i g n e s o f 4 . 5 m length)
Spacing
: 50 x 15 cm2
.‘..
F e r t i l i z e r s : 6-20-10 %? 150 kg/ha as basa1 dose
..::
Date of sowing: July 8, ‘1987.
The fungicidal treatments were started after the appearance of the
leaf spots. The leaf spots had started appearing in the second week of August.
Altogether 3 fungicidal sprays were giver.. The first. spray was given on 22.08.87,
the second on 07.09.87 and the third on 29.09.87. Observations on leaf spots
incidence were recorded at the time of each fungicidal s p r a y i . e o n 2 2 . 0 8 , 07.09
and 29.09. The final observations were recorded on 16.10.87. The tria1 was
harvested on 28.10.1987 and the yield recorded. The summary of W3Ult;S for disease
score is presented in table 2 while that of yield data is given in table 3.
The results for both disease score and yield are depicted eimultane.ously in a
graph o n p a g e 15.
The disease pressure was quite high at the time of final observation.
The aversge leaf spots score in the scale of O-10 was 7 in untreated plots.
.*:
13
.-,
/
/
rC
Table 2 : Summary of results for disease score
Variety
73-33
73-30
file z3
S.E. C.D.
Fungicides
Benomyl
200 g a.i.,/ha
‘5.75
6.00
Cj ,875
O.OF;8-
0.1.ti7 (5%)
Benomyl
100 g a.i.,/ha
6.00
5.75
5.875
0*7?9 (1%)
Mancozeb
400 a.i./ha
g
5.75
5.75
5.750
Calimix
4 0 0g p.c./lOO 1
6.00
6.00
6 . 000
Maneb
160 ga.i./lOO 1
6.25
6.00
6.125
Control
7.00
7.00
7.000
Mean
6.125
6.083
SE, 0:006
::;:.::.
C,D. N.S.
S.E.for body
of the table = 0.116
C.D.for body of the table = N.S.
Coefficient of variation : 7.66 I%
Note :
N.S. = Non Significant
14
Table 3 : Summary of results for yield (Figures in kg/ha)
Variety
Fongicides
73-33
73-30
Mean
S.E. C.D.
Benomyl
200 g a.i./ha
4010
3514
3:762
7;~)
1t.4 (5%)
IFici (1%)
Benomyl
100 g a.i./ha
3595
2548
3071
Mancozeb
g 1500 a.i/ha
3110
2452
2781
Calimix
400 g P.C./100 1
3143
2405
2774
Maneb
160 g a.i./:Loo 1
3103
2738
2920
Control
2957
2367
2662
Mear
3319
2670
:,y.:
S.E.
4
::;::,:
C.D.
20 (5%)
36: (1%)
S.E:. for body of the table - 7?
C.D. for body of the table - N.S.
Coefficient of variation : 10.56%
..?
‘.
Note :
N.S. - Non Significant
::
15
.
P
8
44368
Ei
5
e
a
S
e
0
c
2Bee
0
h
P
a
e
-
-
181
0
1 : Benomyl (BenLate)
200 g ai/ha
2 : Benomyl (Benlate!
100 g ai/ha
3 : Mancozebc (Mancozan Bluei 1500 g ai/ha
4 : Copper t Zineb (Calimix)
400 g pc/100 1
5 : Maneb
160 K ai/130 1
6 : Absolute Control
From the results in table 2 it is seen that the differences in mean
disease score of various treatments were highly significant. Al1 the fungicides
were highly effective in reducing the leaf spots score.
Mancozeb exhibited the lowest score followed by Benomyl (both
200 and 100 g doses), Calimix and lastly Maneb. The results of 1986 had the
similar trend. In 1986 Benomyl 200 g a.i./ha had the least disease score followed
by Mancozeb and Calimix.
The disease score of two varieties did not dif’fer significantly indicating
that both the varieties are equally susceptible to leaf spots. The interaction
amongst the varieties and fungicides was also observed to be non significant. This
means the effect of fungicides was the same on both the varieties.
The results in table 3 indicated that the yield differences amongst
various treatments were highly signif icant S Benomyl 200 g a.i/ha had given the
highest yield (3762 kg/hla) which was significantly superior over a11 other
treatments. The next highest yield (3071 kg/ha) was obtained in Benomyl 100 g a.i.1’
ha treatment which was a.lso significantly superior to a11 other treatments’
‘_,
lflaneb (2920 ‘km’naJ’.~nd mancozeb (2781 koiha)gave sign.i fioanthv more yield +-ban
t;h,e absolute control , (2662 kgjha) . bu [, tbF: 1 ncreas& i r, yj.eld’due to earimix
was stati&t*icaliy nori-signi,fi.canL. Haw’sver i
i.
t, was apnroachinathe ‘levé&of significance.
.:.
‘<’
i
The differences amongst the overall yield of two varieties were highly
.:
significant.
This is due to difference in the yield potential of these two varieties,
::.,,
and not because of leaf spots infection. 7 3- 3 3 is comparat ively long durat ion
variety (about 110 days) than 73-30 (about 90 days) and has a high yield potentiai.
The interaction in between varieties and the fungicides was observed to
be absent. The fungicides had similar effect on both the varieties.
In case of disease score data, the trend of results is similar during
both the years viz., 1986 and 1987. However, there is variation in the yield data
obtained during 1986 and 1987. The yield differences amongst various treatments
were statistically non-significant during 1986. While they were highly significant
during 1987. In 1986, Mancozeb treatment had given the highest yield which was,
howerer , statistically on par with the absolute control while during 1987 Benomyl
200 g a.i. /ha gave the highest yield which was highly significant not only over
the absolute control but also over a11 other treatments.
In case of disease score similar trend was noticed during both the
years while in case of yield, the trend during 1987 was altogether different
from 1986. It is,therefore,proposed to repeat this experiment during 1988 rainy
season.
III - DETECTION OF SEED MICROFLORA :
Some studies on seed microflora were carried out in the past at Texas
University on the
kernels and shells collected
from Senegal. These studies
revealed the presence of 17 pathogens. In tne present studies attempts were
made to find out the percentage of root rots and seed:ling infection and detect
the pathogens associa’ted
with this seed rct and seedding infection.
Seeds of 2 varieties viz., 73-33 and 73-30 were used for these studies.
Seed microflora was detected by rolled towel method. Seeds were put on sets of
three blotter sheets previously moistened with water. The sheets were rolled
and kept at room temperature. The sheets were opened after 10 days and the
observations were recorded for seed rot and seedling infection. The microflora
associated with seed rot and seedling infection was examined under the microscope.
The results are presented in table 4.
I V - SURVEX OF GROUNDNUT DISEASES :
Groundnut leaf spots particularly early leaf spot was wide sprread during
1987 trop season. Late leaf spot was restricted to few locations. It was quite
high at Nioro. Seedling mortality due to Aspergillus niger and Macrophomina Pha-
seoli was less as compared to 1986 season. However, the infection of Macrophomina
SP. on the adult plants was wide spread. It was sporadic in nature but very seve-
re in the pockets affected. It was seen almost throughout the main groundnut area.
Peanut clump as usual
was very common in the fields around Bambey.
18
table 4 : Seed microflora in 2 varieties of groundnut
Variety
Healthy
Inf ected
Organisms àetected on the infected
seed
seed
seed with their percentage
(8)
CI)
7 3-33
90
10
Aspergillu-5
- -
sp. 1
Rhizopus sp.
----
5
Aspergilluw t Rhizopus 2
- -
Rhizopus t Bacteria
2
-
73-30
89
11
Rhizopus sp.
5
:.
3;:
Bacteria
6
:.
.‘.
These organisms were alao found in thti seed pathology
studies carried out at Texas Unuversity.