Spray - Afpp

Red palm weevil , Rhynchophorus ferrugineus (Olivier), chemical treatments
on date palms in Saudi Arabia: Results of extensive experimentations
Abdulrahman S. Aldawood1, Fahad Alsagan2, Hani Altuwariqi2, Amer Almuteri2, and Khawaja G. Rasool1
1Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, PO Box
2460,
2Ministry of Agriculture, Riyadh, Kingdom of Saudi Arabia. * Corresponding author: e-mail: [email protected].
Abstract
Treatments
Red palm weevil (RPW), Rhynchophorus ferrugineus, is a rapidly
spreading serious pest causing tremendous losses to date palms. The
objectives of the present study were to evaluate some chemical control
programs against RPW in the Kingdom of Saudi Arabia.
Date palm trees were selected at random, based on visual symptoms.
Two methods of chemical delivery were used: injection and spray. In the
injection method, trunks of the selected date palms were drilled up to 60
cm deep at 5-places around the trunk, in the area of 1.5 meters above the
ground level. Pesticides were delivered into the date palm trunk using
specialized pesticide delivering system. In the spray method, each tree
was thoroughly sprayed with pesticides using high pressure sprayers.
Treatments in both methods were done once or twice for each tree, with
one month interval. Treated date palm trees were chopped off to count
dead vs. live RPW stages.
Results indicated that programs comprising of both injection and
spray presented significantly greater RPW mortality in comparison with
only spray and control. No significant difference was observed among
two tested chemical control programs but greater RPW mortality was
observed in program-I Further studies are recommended with uniform
infestation level in quarantine green house.
Technique
Injection:
Mix of Azdar 10EC, Thripguard
50EC, Dozer 235 EC, and
Biorynktree Vital O10
Chemical
control
program I
Treatments
Once
10
Mix of Meco-Top 2% WP 0.6%
(w/v) + Bereal 0.6% (v/v)
Twice
Injection:
Once
10
Bioweevil 1% (v/v)
Twice
10
Injection:
Spray:
Once
10
Twice
10
Bioweevil 2% (v/v)
Spray:
Control
Chemical
control
program I
Water
Water
10
Mix of Meco-Top 2% WP 0.6%
(w/v) + Bereal 0.6% (v/v)
1
P-Value
0.87
0.08
0.87
NA
0.26
NA
Means followed by the same letter were not significantly different at α:0.05. All means were comparable
with each others across the columns and rows.
b
P-value less than 0.05 indicating significant different (*)for comparing Applications number for each treatment, ns:Not significant
c
Treatments is a combination of pesticide type and application techniques
Table 4. Effect of different chemical control programs on mortality percentage a,b,* of
different RPW stages present in inner and peripheral sides of date palm trunk.
Treatments
Trunk side
Chemical control
program I
Spray
Injection
Twice
10
Chemical control
program II
Twice
10
Larvae
Reps Mean ± SE
4
100 ± 0a
2
100 ± 0a
1
6
33 ± 17defg
5
43 ± 19cdefg
0.6
8
70 ± 14abcde
4
50 ± 29bcdef
0.31
3
51 ± 25abcdef
2
75 ± 25abcde
0.41
7
31 ± 9efg
6
0g
0.09
Inner
Peripheral
P-Value c
Inner
Peripheral
P-Value c
Inner
Peripheral
P-Value c
Inner
Peripheral
P-Value c
Inner
Peripheral
P-Value c
Inner
Injection
10
Spray
Injection
Control
Spray
Peripheral
Stages
Pupae
Rep Mean ± SE
Reps
NA
6
2
100 ± 0a
5
NA
0.47
2
0g
6
2
20 ± 20fg
7
0.5
0.6
5
93 ±7ab
8
2
75 ± 25abcde
6
0.5
0.23
NA
3
1
100a
4
NA
0.05
4
65 ± 24abcdef 6
5
75 ± 19abcde
7
0.7
0.31
NA
NA
Adult
Mean ± SE
94 ± 6ab
80 ± 20abcde
P-Value d
81 ± 5abcd
71 ± 16abcde
0.01
0.27
88 ± 7abc
66 ± 15abcdef
0.30
0.78
90 ± 6abc
41 ± 16cdefg
0.20
0.29
61 ± 15abcdef
79 ± 12abcde
0.21
0.01
0.45
0.73
a
Means followed by the same letter were not significantly different at α:0.05. All means were comparable with each others across the columns and rows.
Treatments are a combination of pesticide type and application techniques
*P-value c less than 0.05 indicating significant different (*) for comparing mortality percentage at Inner and periphery of date palm trunk for each treatment and stage,
ns:Not significant
*P-value d less than 0.05 indicating significant different (*)for comparing Stages in each treatment and trunk side, ns: Not significant
Results and Discussion
b
Table 5. Efficacy of different chemical control programs on RPW mortality percentage
a,b,c
present in different logs made by cutting date palm trunk at certain heights.
Treatments
Reps
Chemical control
program I
Chemical control
program II
Control
Injections
Spray
Injections
Spray
Injections
Spray
4
2
5
1
Bottom
Mean ± SE
100 ± 0a
100 ± 0a
98 ± 2a
0d
NA
Reps
9
7
9
4
5
Log 1
Mean ± SE
93 ± 6a
66 ± 15abc
83 ± 9ab
58 ± 22abc
61± 13abc
Date Palm Trunk Logs
Log 2
Reps Mean ± SE
Reps
NA
NA
5
50 ± 15abcd 1
4
48 ± 22abcd 2
3
63 ± 32abc
1
3
53 ± 12abcd
NA
Log 3
Mean ± SE
Reps
Top
Mean ± SE
27bcd
60 ± 0abc
45abcd
NA
NA
4
4
2
3
55 ± 22abcd
25 ± 25cd
61 ± 2abc
70 ± 30abc
P-Value
0.40ns
0.47ns
0.02*
0.78ns
0.83ns
a
Means followed by the same letter were not significantly different at α:0.05. All means were comparable with each others across the columns and rows.
P-value less than 0.05 indicating significant different (*) for comparing RPW mortality percentage in LOGs for each treatment, ns: Not significant
c
Treatmens are combination of pesticide type and application techniques
b
Materials and methods
 Chemical control programs presented significantly greater RPW
mortality percentage in comparison with control.
 Significantly greater RPW mortality was observed in the
chemical control programs comprising of injection with spray in
comparison with only spray.
 No significant difference was found for RPW mortality
percentage between once and twice applications.
 Injection with spray caused significantly greater RPW mortality
in both inner and peripheral area of date palm trunk but only
spay caused greater mortality in periphery of date palm trunk
accept adults stage.
Fig 2. Levels of damage of RPW infested date palms
Date palm trees were selected at random, based on visual
symptoms, and when trees were cut to take observation some of
them were found completely healthy. Therefore, we got less
number of replicates than reported in the experimental design.
Table 1. Overall efficacy of different chemical control
programs on RPW mortality percentage
Mortality percentage
Reps
Mean ± SE
21
75 ± 8a
16
74 ± 7ab
7
50 ± 10b
Treatments
Chemical control program I
Chemical control program II
Control
Pesticide Spray Machine
*Means followed by the same letter in column were not significantly different at α:0.05
Table 2. Effect of different chemical control programs application
techniques on the RPW mortality percentage a,b
2
Injections
Spray
Injections
Spray
Injections
Spray
Control
Spray:
Bioweevil 1% (v/v)
Reps
4
5
5
Applications Number
Once
Twice
Mean ± SE
Reps
Mean ± SE
96 ± 4a
5
93 ± 7a
78 ± 15ab
7
48 ± 16bc
80 ± 10ab
6
77 ± 8ab
NA
5
65 ± 18ab
20 ± 0c
6
55 ± 10abc
NA
NA
a
Once
Spray:
Chemical
control
program II
The Kingdom of Saudi Arabia is one of the major producers of
fine quality dates. KSA ranks third in the World having over 23 million
date palm trees. This important fruit crop is under threat due to highly
invasive pest, the red palm weevil (RPW) (Rhynchophorus ferrugineus).
Among various control tactics attempted against RPW, chemical
control is essential quick and reliable way of recovering infested date
palm trees.
The objectives of the present study were to evaluate some chemical
control programs against RPW in the Kingdom of Saudi Arabia.
Pesticide Injection Machine
Chemical control
program I
Chemical control
program II
Spray:
Chemical
control
program II
Introduction
Date palm trees were selected at random, based on visual symptoms.
Two methods of chemical delivery were used: injection and spray. In the
injection method, trunks of the selected date palms were drilled up to 60
cm deep at 5-places around the trunk, in the area of 1.5 meters above
ground level. Pesticides were delivered into date palm trunks using
specialized pesticide injection delivering system. In the spray method,
each tree was thoroughly sprayed with pesticides using high pressure
sprayers. Treatments in both methods were done once or twice for each
tree, with one month interval. Treated date palm trees were chopped off
to count dead vs. live RPW stages.
Table 3. Effect of different chemical control programs applications
number on the RPW mortality percentage a,b,c
Application
Replications
Number
Treatments
Chemical control
program I
Chemical control
program II
Control
a
Pesticide application techniques
Injection
Spray
Reps Mean ± SE Reps Mean ± SE
P-value
9
95 ± 4a
12
60 ± 12b
0.01*
11
79 ± 6ab
5
65 ± 18b
0.37ns
7
50b
NA
NA
Means followed by the same letter were not significantly different at α:0.05. All means were comparable
with each others across the columns and rows.
 Both chemical programs caused significantly greater mortality to
RPW present in the basal part of the date palm trunk followed by
log 1, log2, log3 and top part of trunk.
 As the study was carried out under filed conditions with natural
infestation to get the real efficiency of the designed chemical
control programs. Programs comprising of both injection and
spray provided better coverage that resulted into significantly
greater RPW mortality as compared to only spray.
 Greater mortality at the base can be attributed to the
accumulation of more pesticide at the base. Though there was no
statistical difference between both control programs, but control
program-I presented higher RPW mortality percentage.
Conclusion
Chemical control can be an effective technique to control RPW
in all stages when applied through injection and spray
simultaneously. Further studies are recommended with uniform
infestation level in quarantine green house.
Acknowledgments
Fig 1. Methods for pesticide application and efficacy observation
This study was supported by the Ministry of Agriculture,
Riyadh, Kingdom of Saudi Arabia. Special thanks for the first
author’s graduate students for their help in field and lab work.
Especially, PhD graduate students, Alan Soffan Biniljas and
Sukirno Hadi Prasetyo.