الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
 |  | from | 101 |  |  |
| | | from | 101 | | |
Abstract
Experiments were conducted at the Agricultural Experimental farm of Sabahia Station,
Alexandria, Egypt. Seedlings of two tomato varieties (Castle rock and Super strain –B) were
transplanted. In this study, different compounds belonging to different groups were evaluated
for controlling the following main pests: the cotton leaf worm, S.littorallis and the semilooper,
Ch.chalcites that attack tomato plants. The evaluated compounds were Profenofos (Selecron®
72% EC), Emamectin Benzoate (Proclaim® 5 % SG) and Spinosad (Tracer® 24% SC) .three
natural products as azadirachtin (Achook®), B.t subsp. kurstaki (Diple 2X®) and Soybean oil
(Natrilo® ) were also evaluated. The performance of the insecticides was evaluated
individually during the successive growing seasons of 2005, 2006 and 2007. The side effect of
the tested insecticides was studied upon the parasitoid, A. ruficrus. The reduction percentages
of the target insect pests and/ or parasitoid induced by the insecticidal treatments were
calculated.
Both the insecticides of Selecron® and Proclaim® proved to the most efficient
insecticides in managing the insect pests. They have been used separately to appraise loss only
in the late summer tomato crops during 2007 and 2008 seasons, at different date’s posttransplanting
seedlings to create the ”so-called” varied levels of insects’ infestations, so that
relationships between yield and percentages of plant infestations could be based.
In both successive late summer seasons of this investigation, tomato yield (metric
ton/fed.), monetary return/fed., insecticide costs/fed., labor wages/fed., additional return over
untreated control and profit for one Egyptian pound investment (L.E) were taken into account
to determine the maximum profitable treatment.
5.1. Population dynamics of tomato insect pests
The population fluctuations of the assigned insect pests were studied in the late summer
cultivations of 2005 and 2006 in the untreated check plots. Population dynamics were also
studied in the summer cultivations of 2006 and 2007.
5.1.1. Late summer cultivation (season 2005)
It was found that the cotton leaf worm, S. littorallis was detected along the month of
May. The highest level of this insect was recorded in the first week of September (112 larvae /
15 plants).Statistical analysis showed a positive correlation between the prevailing
temperature and the number of the insect individuals (r2 = 0.6682), and the correlation
coefficient was also positive with the relative humidity (R.H.) (r2 = 0.7551).
In case of the semilooper Ch. Chalcites, the individuals of that insect were counted
during that season. The highest level of 69 larvae /15 plants was recorded in the second week
of September and then, the numbers of larvae decreased steadily after wards. The correlation
90
between the semilooper Ch. chalcites individuals and both the mean temperature and the
relative humidity were positive, (r2 = 0.4419) and (r2 = 0.4641), respectively.
In concern to the H. armigera, this insect was found almost absent on the tomato
plants during the late summer growing season.
5.1.2. Late summer cultivation (season 2006)
The high levels of the cotton leaf worm were shown along the month of September.
The highest level of this insect was recorded on 19th of September (90 larvae / 15
plants).Numbers were then decreased gradually to register 3 larvae/ 15plant corresponding to
the date 10th of October. Statistical analysis showed a positive correlation between the
prevailing temperature and the number of the insect individuals (r2 = 0.8121), and the
correlation coefficient was also positive with the relative humidity (R.H.) (r2 = 0.6631).
For the semilooper, Ch. Chalcites, the highest level of 39 larvae individual /15 plants
was recorded in the second week of September. Statistical analysis showed a positive
correlation between the prevailing temperature and the number of the insect individuals (r2 =
0.7670), and the correlation coefficient was also positive with the relative humidity (R.H.) (r2
= 0.6903).
The tomato fruit worm H. armigera was almost absent on tomato plants during the late
summer growing season .
5.1.3. Summer cultivation (season 2006)
The high levels of the cotton leaf worm were detected along the month of May. The
highest level of this insect was recorded in the first week of May (7 larvae / 15 plants).
Statistical analysis showed a positive correlation between the mean temperature and the
number of the insect individuals (r2 = 0.5514), and the correlation coefficient was also positive
with the relative humidity (R.H.) (r2 = 0.3319).
The semilooper, Ch. chalcites individuals were found during that season attacking
tomato plants. The highest level of 8 larvae /15 plants was registered in the end of the third
week of May. The correlation between the semilooper Ch.chalcites individuals and the means
of temperature and relative humidity were positive (r2 = 0.6411 and r2 = 0.3138, in respect).
The H. armigera was almost absent on the tomato plants during the late summer
growing season.
5.1.4. Summer cultivation (season 2007)
The highest levels of the cotton leaf worm were detected throughout the month of May.
The highest level of this insect was recorded in the fourth week of May (7 larvae / 15
plants).numbers of larvae decreased recording two larvae /15 plants 12th of June. Statistical
analysis showed a positive correlation between the prevailing temperature and the number of
the insect individuals (r2 = 0.5649),
and the correlation coefficient was also positive with the mean relative humidity (R.H.) (r2 =
0.4121).
91
A highest level of the semilooper, Ch. chalcites (8 larvae individual /15 plants) was
recorded in the fourth week of May. The correlation between the semilooper, Ch. chalcites
individuals were positive correlation between the prevailing temperature and the number of
the insect individuals (r2 = 0.2742), and the correlation coefficient was positive with the
relative humidity (R.H.) (r2 = 0.5943).
The H. armigera was almost absent on the tomato plants during the summer growing
season.
5.2. Biological performance of certain agrochemicals and natural
biological agents.
In general, the efficacy of the treatments against the cotton leaf worm, S. littoralis and
the semilooper Ch. chalcites during 2005 and 2006 seasons showed that the efficient
insecticides were Proclaim®, Selecron® and Tracer® followed by Dipel-2x® and Achook®.
The least efficient was Natirlo®.
5.2.1. The cotton leaf worm, S. littorallis
5.2.1.1. Late summer cultivation (season 2005)
Most of the evaluated treatments were found to have an effect on cotton leaf worm
throughout the inspection periods (3, 5, 7 days post- treatment). It is worth mentioning that
there were significant differences among the evaluated compounds. Proclaim® was the
superior compound followed by Selecron®, Tracer®, Achook® , Dipel –2x® and Natirlo® as
they gave 92.07 %, 89.98 %, 47.68 %, 33.42 %,28.66 %, 26.01 % of initial reduction of the
number of the cotton leaf worm individuals, respectively.
Selecron® was the superior compound in reducing the infestation giving a reduction of
94.45 and 84.79 %, followed by Proclaim® (86.82 and 81.94 %%), Tracer® (73.65 and 74.72
%) after 3 and 5 days, respectively. After seven days post-treatments, Proclaim® became the
superior compound followed by Tracer® and Achook® giving 72.91, 53.05, 49.46% reduction
of infestation. According to the general mean of reduction due to the residual effect all over
the period of inspection (3،5،7 Days), the treatments could be arranged in a descending order
as follows: Proclaim® (80.55 %) = Selecron® (74.07 %) = Tracer® (67.14 %) ≥ Achook®
(51.14 %) ≥ Dipel –2x® (47.99 %) > Natirlo® (23.07 %).
5.2.1.2. Late summer cultivation (season 2006)
The evaluated compounds significantly induced different initial reduction percentages.
Proclaim® and Selecron® showed the highest significant initial reduction percentages
followed by Tracer®, Natirlo®, Dipel–2x® and Achook®, successively.
After three days of treatment, both of Proclaim® and Selecron® highly induced
significant residual reductions giving > 90 %. After five days, Selecron® ranked the 1st place
showing a reduction of 86.85 %, Proclaim® came in the 2nd rank giving 83.90% and Tracer®
occupied in the 3rd rank (77.42%). On the other hand, Dipel–2x®, Achook® and Natirlo®
showed less value of reductions of 63.57, 47.96 and 41.89%, in respect. After one