Different IGRs concentrations against maize stem borer ( Chilo partellus Swinhoe ) in field condition of Faisalabad-Pakistan

The experiment was conducted at the Youngwala experimental area of the Department of Agri. Entomology, University of Agriculture, Faisalabad in a Randomized Complete Block Design (RCBD), with 24 treatments excluding one control. The data for maize stem borer population was recorded after 3 days, 7 days and 14 days post IGRs application. The results obtained are concluded that all the insect growth regulators were equally effective against maize stem borer at different concentrations and on the numerical basis lowest stem borer population and its infestation was recorded in the pyriproxyfen® and priority® at 2x concentration and at concentration of field recommended concentration followed by other treatments concentrations. So, among the entire tested insect growth regulators pyriproxyfen® and priority® were the most effective IGRs against maize borer. Among the entire tested insect growth regulators viper® and sitara® were the least effective IGRs against maize borer.


Introduction
Agricultural gross domestic product and 85% of export revenue and employment to a total of 25 to 50% of the labor force, according to Pakistan's economy is built on the national level.Corn (L Egypt), popular Pakistani food, feed and fodder crops.Pakistan produced only 8,92 t ha -1, the United States, Canada and 7.82 T, China and France, 7.14 tons of HA-1 [1] of 4.85 tons, and in Pakistan, corn planting 967,000 hectares, with an annual output of more than 3.0, the average yield of 1970 kg HA-1 of the 1731 tons 6.4% of corn grain production in the country [2].Agriculture being the backbone of Pakistan's economy employs 50% of the total labour force at national level, contributing 25 and 85% to GDP and export earnings, respectively.Maize (Zea mays L.) is a popular food, feed and fodder crop in Pakistan.Its yield in Pakistan is only 3.0 t ha -1 compared to USA 8.92 t ha -1 , Canada 7.82 t ha -1 , France 7.14 t ha -1 and China 4.85 t ha -1 [1] and in Pakistan, maize is grown over an area of 967 thousand hectares with an annual production of 1731 thousand tons with an average yield of 1970 kg ha -1 [2].Maize contributes about 6.4% of total cereal produce of the country.Maize or corn (maize), the grass family (Poaceae) plants alone.This is the cultivation of food crops around the world is not the most important.Corn for human nutrition and industrial products from the food and the raw materials necessary for the production of a lot of things, but not only.Corn starch, maltodextrin, corn oil, corn syrup, including industrial production and fermentation and distillation.In addition, most recently used as a biofuel.Wheat, grain crop after rice is the third annual ranking of Mecca.Irrigation and the Pakistani province of Punjab, but it is grown in almost all areas of the rain-fed areas.After the food source and the object of many industrial raw material, the yield has been cultivated mainly for the production of food is.Corn starch, 10% protein, 4.80% fat, 9.50% fiber, 3.0%, 1.70% sugar and 72% of ash, because they have a high nutritional value [3].Because, as well as the king of food crops, "wheat for its high yield.Pakistan is the greatest population growth, food security issues.In the last two decades, the population (3%) was offset by the increase in grain production.The expected growth rate of the corn wet milling and feed industries.With an annual output of 3,037 million tons of corn, and 2864 kg / ha, the average grain yield the 1,016 million hectares planted.Corn Pakistan, 66% water; rainfed farming conditions.Mainly because of a good harvest of 20-25% annual growth during the spring corn planting area, (6-7 t / ha) notice.Pakistan, corn is one of the success stories of agricultural prices.Seed and Pakistan, Egypt, the most important factor of production is limited.Improved seed and only 34%.Grain drying and storage facilities, due to the volatile and uncertain market.In 2001, poultry, corn, feed grain in 2007 to 23% in Punjab has increased by 55% [4].Global corn (L Egypt), Pakistan and other countries in the long-term and the most important and popular grain crop production per unit area of great importance to the whole, and as such, it is a very versatile fruit to feed people food, fuel, animal feed, poultry and cattle wish.Corn nutritional value, but also a rich source of raw materials for the production of industrial products.Pakistan, more than the 1,022 million hectares, producing 35.6 million tonnes, 3483 kg / ha average level of the corn planted in the area.Compared to the US average yield per unit area of less than 8990 kg [5].Corn plays an important role in the economy of the country.High-yielding, yet per hectare / per cent of the maize yield hybrid varieties.Pakistan, agriculture, growth in the world's food and feed used for any purpose.In Pakistan, more nutrients due to higher food and fodder production, and its high-yield corn leaves and thick meat.Pakistan's growth, but it is always the Fund's Northwest Frontier Province and Punjab [6], about 98% of the district is the most important works.This is a food, feed and feed use and for wet milling, paper, textiles, clothing, a lot of the food processing industry, and the food industry may be able to use, as well as the use of raw materials.Its oil is used in pharmaceutical and humans and animals hypochlestermic [3].Nutritional value, [7] and the corn starch (72%) of the cells, protein (10%), fiber (8.5%), petroleum (4.8), glucose (3%) and more than gray o 'them (1.7%).Approximately 64% of the

Results
The maize crop was treated with different concentrations of insect growth regulators when the pest population reached again at ETL.The details of the population count/percent are given as under with different intervals.The ANOVA parameters showed that the interaction of IGRs with concentrations had non-significant impact on infestation and all treatments had highly significant impact on infestation against maize borer before 24 hours of application of treatments (Table 1 and Figure 1).The ANOVA parameters showed that treatments induced highly significant (P<0.01)variation in percent infestation of maize stem borer and interaction of IGRs with concentrations had non-significant impact on infestation as shown in (Table 2).The (Figure 2) showed that those plots which were treated with Sitara® showed

Figure 2. Infestation of maize stem borer 3 days after application Days of application
The ANOVA parameters showed that treatments induced highly significant (P<0.01)variation in percent infestation of maize stem borer and combination of IGRs with concentrations had nonsignificant on infestation of maize borer as shown in (Table 3).The (Figure 3) showed that those plots which were treated with Sitara® showed 1.33-6.45%infestation at different concentrations.Minimum 1.33% infestation was recorded in those plots where Sitara® was applied at concentration of 1/2x of FRD; whereas at rest of the concentration Sitara®

Figure 4. Infestation of maize stem borer 14 days application
The ANOVA parameters showed that all the treatments on reduction in percent infestation had significant impact on their infestation.But the combination of IGRs with concentrations had nonsignificant impact on reduction infestation after 3 days interval as shown in (Table 5).The ANOVA parameters showed that all the treatments on reduction in percent infestation had highly significant impact on their infestation.But the combination of IGRs with concentrations had nonsignificant impact on reduction infestation after 7 days interval as shown in (Table 6).The ANOVA parameters showed that all the treatments on reduction in percent infestation had highly significant impact on their infestation.But the combination of IGRs with concentrations had nonsignificant impact on reduction infestation after 14 days interval as shown in (Table 7).Overall, Pyriproxyfen®, Priority® and Lufenuron® explained maximum (56.79%) reduction in infestation at 14 days post treatment interval.The ANOVA parameters showed that the interaction of IGRs with concentrations had nonsignificant impact on infestation of maize borer before 24 hours of second application and their treatments had highly significant impact on population fluctuation of maize stem borer as shown in (Table 8).In all treatments, maximum number of larvae of maize borer ranged from 1.67 to 2.67 larvae/five plants.The ANOVA parameters showed that treatments had highly significant impact on reducing the population of maize borer after 24 hours of second application of treatments (Table 9).The plots which were treated with Sitara® showed 0.66- The ANOVA parameters showed that all treatments had highly significant impact on larval population of maize borer but only interaction of IGRs between concentrations showed nonsignificant impact against larval density of maize borer as shown in (  The ANOVA parameters showed that interaction of IGRs with concentrations had nonsignificant impact but only the concentrations showed highly significant impact on tunnel length before second application.In all treatments, tunnel length (cm) ranging from 2.36 cm to 3.26 cm (Table 12).The ANOVA parameters showed that treatments had highly significant impact on reducing the tunnel length of maize borer and the interaction of IGRs and concentrations had nonsignificant impact on reducing the tunnel length as shown in (Table 13).The plots which were treated with Sitara® showed 0. The ANOVA parameters showed that all treatments had highly significant impact on tunnel length of maize borer but the interaction between IGRs and concentrations showed nonsignificant impact against tunnel length of maize borer as shown in (

Figure 1 .
Figure 1.Infestation of maize stem borer 24 hours Figure 2. Infestation of maize stem borer 3 days after application Days of applicationThe ANOVA parameters showed that treatments induced highly significant (P<0.01)variation in percent infestation of maize stem borer and combination of IGRs with concentrations had nonsignificant on infestation of maize borer as shown in (Table3).The (Figure3) showed that those plots which were treated with Sitara® showed 1.33-6.45%infestation at different concentrations.Minimum 1.33% infestation was recorded in those plots where Sitara® was applied at concentration of 1/2x of FRD; whereas at rest of the concentration Sitara® explained 4.0-6.45%infestation at 7 days post treatment intervals.Viper® demonstrated 1.66-5.5% infestation at different concentrations and at 7 days post treatment interval.Minimum infestation 1.66% was observed in those plots where Viper® was sprayed at concentration of 1/2x of FRD.Viper® at rest of concentrations demonstrated approximately 2.1-5.5% infestation by maize borer at seven days post treatment interval.Lufenuron® demonstrated 0.33-4.45%infestation at different concentrations and at 7 days post treatment interval.Minimum infestation 0.33% was observed in those plots where Viper® was sprayed at concentration of 1/2x of FRD.Lufenuron® at rest of concentrations demonstrated approximately 2.0-4.45%infestation by maize borer at seven days post treatment interval.A percentage infestation was recorded in the range of 0.3-4.4% in plots where Pyriproxyfen® was sprayed at different concentrations.Pyriproxyfen® demonstrated minimum infestation (0.3%) at 1/2x of FRD, whereas 2.0-4.4% for the rest of concentrations at post treatment intervals of seven days.Percentage infestation of maize borer ranged from 0.33-4.0% in those plots where Priority® was sprayed at different concentrations.Priority® demonstrated minimum infestation (0.33%) when applied at 1/2x of FRD.However, Priority® explained approximately 2.0-4.0%infestation when applied at FRD, 2x of FRD and 1/4x of FRD for a post treatment interval of seven days.The plots which were treated with Track® at different concentrations showed percentage infestation in the range of 1.33-6.45%at 7 days of post treatment intervals.Track® demonstrated minimum infestation when applied at concentration of 2x of FRD.Rest of this concentration of Track® explained approximately 4.0-6.45%infestation at a post treatment interval of 7 days.

Figure 3 .
Figure 3. Infestation of maize stem borer 7 days after application 14 days of applicationThe ANOVA parameters showed that treatments induced highly significant (P<0.01)variation in percent infestation of maize stem borer and combination of IGRs with concentrations had nonsignificant on infestation of maize borer as shown in (Table4).The (Figure4) showed that those plots which were treated with Sitara® showed 1.33-4.0%infestation at different concentrations.Minimum 1.33% infestation was recorded in those plots where Sitara® was applied at concentration of 2x of FRD; whereas at rest of the concentration Sitara® explained 2.7-4.0%infestation at 14 days post treatment intervals.Viper® demonstrated 0.66-3.65%infestation at different concentrations and at 14 days post treatment interval.Minimum infestation 0.66% was observed in those plots where Viper® was sprayed at concentration of 2x of FRD.Viper® at rest of concentrations demonstrated approximately 3.0-3.65%infestation by maize borer at 14 days post

Table 2 . ANOVA regarding the percent infestation of maize stem borer after 3 days of application
** = highly significant, ns non-significant

Table 3 . ANOVA regarding the percent infestation of maize stem borer after 7 days of application Source
** = highly significant, ns nonsignificant

Table 4 . ANOVA regarding the percent infestation of maize stem borer after 14 days of application
** = highly significant, ns nonsignificant

Table 6 . ANOVA parameters regarding the reduction in percent infestation after 7 days application
**= highly significant

Table 8 . ANOVA regarding the population of larvae of maize stem borer before the second application
** = highly significant, ns nonsignificant

Table 9 . ANOVA regarding the population of larvae of maize stem borer after the application
** = highly significant

Table 10 . ANOVA regarding the reduction in number of larvae on infested plants after application
**= highly significant

Table 12 . ANOVA regarding the tunnel lengths (cm) of maize stem borer before the application
** = highly significant, ns non-significant

Table 15 ) . Table 14 . ANOVA regarding the reduction in tunnel length (cm) on infested plants after the second application
**= highly significant

Table 15 . Tunnel length (cm) before and after application and its percent reduction at different concentrations Concentrations Tunnel length before application
Sitophilus oryzae and for the suppression of emergence of Aedes togoi respectively pyriproxyfen® showed best results against these insects.These results observation TRACK® 1,667 larvae, the larvae population decline and population in accordance with 0.000 priority®, and in the case of five factories [21, 22].When they investigated the effect of IGRs (pyriproxyfen and buprofezin) against egg laying production of citrus mealy bug (Planococcus citri).The result showed that pyriproxyfen actually lowered the egg production of citrus mealy bug and these results also revealed with the results of [23] when they evaluated the buprofezin® and pyriproxyfen® residues against B. tabaci eggs.Both IGRs reduced B. tabaci egg fertility, especially the higher rate of pyriproxyfen® and both rates of buprofezin® but also buprofezin® and pyriproxyfen® results against maize borer were not compatible with these results and these IGRs are dose dependent [24-26].Conclusion Insect growth regulators were equally effective against maize stem borer at different concentrations and on the numerical basis lowest stem borer population and its infestation was recorded future perspectives of the use of insect growth regulators for the control of stored product insects.J Stored Prod Res 33: 1-6.19.Kostyukovsky M, Chen B, Atsmi S & Shaaya E (2000).Biological activity of two juvenoids and two ecdysteroids against three stored product insects.Ins Biochem Mole Bio 30: 891-897.20. Lee DK (2001).Field evaluation of an insect growth regulator, pyriproxyfen, against Aedes togoi larvae in brackish water in South Korea.J Vec Eco 26(1): 39-42.21.Cloyd RA (2003).Effect of insect growth regulators on citrus mealy bug (Planococcus citri) egg production.