EFFECT OF SOME BIOLOGICAL AND CHEMICAL PESTICIDES IN CONTROLLING TUTA ABSOLUTA OF TOMATO

This study was conducted at the open fields of the Agricultural Research Station in Dohuk Governorate during the year 2019 on the tomato crop, a local variety. In this study, the effect of chemical pesticides ( Imidamex, Matrixine plus ) and biological pesticides (Antario KAB, Biocure ) were tested on the percentage of leaf infection, number of larvae, the percentage of fruit infestation and the rate of productivity of one plant. The results revealed that the lowest percentage of leaf infection and the lowest number of larvae appeared with plants treated with Biocure , with an average of 22.7% and 0.36 larva/leaf, respectively. Whereas, the lowest infection rate for fruits and the highest productivity of plants appeared of plants treated with Antariocap , as the rates were 2 fruits/plant and 7.32 kg/plant, respectively. The results showed the superiority of the Antariocap pesticide in controlling this insect, as it had the highest reduction rate in the infested tomato fruits, at a rate of 90.4%.


INTRODUCTION
Tomato Iycopersicum Solanum belongs to the Solanaceae family, and is considered one of the important vegetables grown in various countries. Its fruits are used for fresh consumption and manufacture of paste, and it is considered the third crop in terms of cultivated area in the world. In this respect, it is grown in tropical and subtropical regions, and the global production is estimated at 130 million tons, 85 million tons used for daily human consumption, and 42 million tons for industrialization (11). Tomatoes, considered one of the economic agricultural crops in Iraq, are grown in large areas ar various regions of Iraq, especially the central and southern regions, and the cultivated area is estimated at about 24,000 acres (2). Tomatoes are infected by many agricultural pests that kill them and reduce their production. Tomato leaf insect, Tuta Absoluta (Meyrick(, is one of the main pests in the countries of the Mediterranean basin; it causes great losses that may reach 100% in terms of quantity and quality (4,8,9). Moreover, it attacks leaves, branches, growing apices and fruits (10). Tomato plant is the main host for this insect, but it attacks many plants of the Solanaceae family, such as eggplant, tobacco and potatoes, in addition to many herbs (12). This insect infects both open tomatoes and the ones in the greenhouses (14, 21).The original or native source of this insect is in South America (17,18). It was recorded for the first time in Spain in 2006 (13) and is currently widespread in Europe (31), the Middle East (6,22) and in Africa (14,16). Each insect lays about 260 eggs on leaves, stems and fruits and has about 12 generations per year (30). To control this insect, several methods must be combined and used in combating it, including agricultural, biological, natural and chemical ones (19), Most of the studies and researches conducted in various countries of the world confirmed the emergence of resistance in insects, due to the use of chemical pesticides, as well as, the negative effect of these manufactured chemical pesticides on vital enemies and beneficial vertebrates (5,7,15,29). Given the danger of this insect on tomatoes and its resistance to some chemical pesticides, researchers recommend using an integrated control program to control this insect by using chemical pesticides with microbial pesticides (21,25). In this respect, the use of biological pesticides, especially bacterial pesticides, have an important role in controlling this insect, as they have little impact on the environment and the insect's vital enemies (28,32). Also, the insect pathogenic fungi are among the modern resistance methods to control this insect and are currently used (23). Therefore, the aim of the present study was to compare the effect of some biological pesticides (Antario KAB, Biocure) and chemical pesticides (Imidamex, Matrixine plus) in controlling tomato leaf and fruits diggers, Tuta absoluta, in open fields.

MATERIALS AND METHODS
This research was conducted at the Agricultural Research Station of the Agricultural Research Directorate in Dohuk, where the seeds of the Hanin Tomato variety (hybrid variety) were planted in midday in the month of March, and after the land was prepared, the seedlings were trans plant to it on 5/5/2019. All the crop manegment such as dripping with irrigation, fertilizing and manual bush controlling, are implimented. The land was divided into fifteen lines (streaks), with three lines for each treatment, in addition to the comparison treatment. The lines were distributed randomly and marks were placed for this purpose, each line contains twenty tomato seedlings (experimental unit). The spraying of pesticides with recommended concentration was applied through( table 1) the use of the back sprinkler, taking into account the work of a barrier between one line and another, in order to avoid the occurrence of interference with the pesticide spray. Each three lines were sprayed with the pesticide concerned with the first spray on 7-22-2019. The reading was taken ten days after the date of the treatment and it was as follows: 1-Calculating the Percentage of Leaves Infection and the Number of Larvae on the Leaves. 50 leaves are taken from each treatment randomly and the following is calculated: the number of infected leaves, the number of healthy leaves, the number of larvae in the infested leaves, the number of eggs in the infested leaves. Leaves infection percentage = the number of infected papers in the sample / the total number of leaves in the sample * 100% 2-Calculating the Percentage of Fruits Infection five plants are randomly selected from each treatment and the following are calculated: the number of infected fruits, the number of healthy fruits, and the weight of the total yield of the plants in each treatment. 20 days after the first spray, the second spray is repeated on the treatments with the same pesticides, and the aforementioned readings will be taken 10 days after the spraying process. 20 days after the second spray, the spraying process is repeated, similar to the first and second spray. The results were analyzed statistically using the RCBD, and the difference between the averages was tested using the Duncan test at a probability level of 5% using the SAS system.

RESULTS AND DISCUSSION
The results of using Antario KAB, Imidamex, Matrixine plus and Biocure pesticides in combating Tuta Absoluta showed a difference between the treatments in the percentage of leaf infection, the number of larvae per leaf, the number of eggs, the percentage of fruit infection; in addition to, the number of total healthy fruits, and the rate of plant productivity.

3-Effect of the pesticide on preparing tomato leaf pest eggs
The pesticides differed among themselves in reducing the number of tomato leaf pest eggs, and the statistical analysis showed that there were significant differences among the treatments at a probability level of 0.05 (Table. 3). The rates of egg numbers ranged between (0.85 -1.45) eggs / leaf, while the rate in the comparison treatment was 1.57 eggs / leaf.
Antario KAB excelled in reducing the number of eggs, with a reduction rate of 45%, followed by Biocure 28%, while Imidamex recorded the lowest rate of reduction in the number of eggs at 7.6%. The lowest number of eggs was recorded when plants were treated with Antario KAB on 3/8/2019, at a rate of 0.34 eggs / leaf, while the highest number of eggs was recorded with the pesticide Imidamex, which was 1.9 eggs / leaf.

4-The Effect of the pesticide on the percentage of infecting fruits
The results of the experiment, given in Table  (4), showed a variation in the effect of pesticides in reducing the percentage of infestation of tomato fruits, as the rates ranged between (2 -3.57) fruits/plant, while the rate for the comparison treatment was 20.9 fruits/plant. Antario KAB pesticide surpassed the rest of the pesticides in reducing the incidence of infecting tomato fruits, with a reduction rate of 90.4%, followed by Imidamex, Matrixine plus, and Biocure at rates of 85.6, 82.9 and 81.8%, respectively (Table.  4).  (20) indicated that there was a synergy in affecting the larvae of tomato leaf pest between the bacteria Bt and the pesticide Abamectin. 5-Effect of pesticides on tomato plant productivity and its fruit number The results of the experiment showed that the number of tomatoes at the end of the season varied according to the type of pesticide used, but there were no significant differences among them. All of them significantly outperformed the comparison treatment, and reached the productivity rates of the three pesticides Antario KAB, Matrixine plus, Imidamex, Biocure; in addition to, the comparison treatment 20, 18, 17.6, 16.6, 12 fruits/plant, respectively (Table. 5). This variation in the number of fruits resulting from the use of pesticides was reflected in the amount of production per plant per kilogram, where the productivity of plants in the pesticide treatments ranged between (5.2 -7.3) kg / plant, while the productivity in the comparison treatment was 3 kg / plant (Table. 6). Plants treated with Antario KAB had the highest productivity, with an average of 7.3 kg / plant, and differed from the comparison with clear significant differences at a probability level of 0.05.