BIOEFFICACY OF CHEMICAL INSECTICIDES AGAINST EARIAS

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1 Agric. Sci. Digest., 31 (1) : 25-29, 2011 AGRICULTURAL RESEARCH COMMUNICATION CENTRE ccjournals.com / indianjournals.com nals.com BIOEFFICACY OF CHEMICAL INSECTICIDES AGAINST EARIAS VITTELLA (FABRICIUS) ON OKRA A.M. Pardeshi, R.K. Bharodia, D.M. Jethva, R.T.. Rathod and P.V.V.. Patel Department of Entomology, Junagadh Agricultural University, Junagadh , India. Received : Accepted : ABSTRACT A field experiment was conducted to determine the efficacy of eleven chemical treatments against Earias vittella (Fabricius) infesting okra at Junagadh Agricultural University campus, Junagadh during kharif season of Among tested insecticides, profenophos + cypermethrin (0.044%), chlorpyriphos + cypermethrin (0.055%), cypermethrin 0.006% and profenophos 0.05%, were found to be the most effective in reducing the fruit infestation to 6.47 to % against 43.5% in the control. The highest yield of healthy fruits was recorded in the treatment of profenophos + cypermethrin 0.044% ( kg/ha) followed by chlorpyriphos + cypermethrin 0.055% ( Kg/ha), cypermethrin 0.006% ( Kg/ha) and profenophos 0.05% ( Kg/ha). The highest cost benefit ratio (1: 20.3) was obtained in the treatment of cypermethrin 0.006%, followed by profenophos + cypermethrin (1:11.9), chlorpyriphos (1:10.4), chlorpyriphos + cypermethrin (1:10.2), profenophos (1:8.7), acephate (1:5.1) and methomyl (1:4.1). Key words : Field efficacy, E. vittella, Okra, Insecticids. INTRODUCTION Okra is an important vegetable crop grown all over India and tropical and sub-tropical parts of the world. The crop however, is vulnerable to attack of important insect pests, among which fruit borer (E.vittella and E. insulana) is the noxious one causing direct damage to the marketable fruits. It alone causes 57.1 % fruit infestation and % net yield loss in okra (Chaudhary and Dadheech, 1989). At present many new and insecticide combinations are available in the market and there is no much precise information available about their efficacy against okra fruit borer. Attempts were therefore made to find out the efficacy of some new such formulations against okra fruit borer under the field conditions. MATERIALS AND METHODS An experiment was conducted at the farm of College of Agriculture, Junagadh during kharif season of 2006 in a randomized block design with a view to determine the efficacy of eleven insecticides. Each treatments including untreated control was replicated thrice. Ten rows of okra variety Gujarat bhendi-2 were sown in a plot size (gross) 6.00 m x 3.60 m with a spacing of 60 cm x 30 cm. All the recommended agronomic practices were adopted. The spraying of insecticides was done with the help of knapsack sprayer to get uniform coverage of insecticides in each plot. The first spraying was given at fruit formation stage and the second 15-days after first spray. Observations on number of healthy and infested okra fruit were recorded from ten randomly selected and tagged plants in each plot before 24 hours of the spray. Subsequently, observations on infested and healthy okra fruit and yield of healthy okra fruit were also recorded at each picking after spraying. On the basis of number of damaged and healthy okra fruits, the per cent infestation was calculated and the data were

2 26 AGRICULTURAL SCIENCE DIGEST statistically analyzed after angular transformation by the Fisher s analysis of variance techniques (Panse and Sukhatme, 1985). RESULTS TS AND DISCUSSION Effect on fruit infestation After first spray The data on per cent fruit infestation (Table 1) recorded at each fruit picking after spraying the various insecticides indicated that all the insecticides were significantly superior over the control for minimizing the fruit infestation due to E. vittella. Among the various insecticides tested, the lowest infestation (8.48%) of fruit borer was recorded in the treatment of profenophos 40 EC + cypermethrin 4 EC at 0.044%. However, it was at par with the treatments chlorpyriphos 50 EC + cypermethrin 5 EC at %, profenophos 0.05% and cypermethrin 0.006% as they registered 9.90, and per cent fruit infestation, respectively. The next better treatments were methomyl 0.05%, aceptate 0.05% and chlorpyriphos 0.05% with infestation of 17.7%. The treatment of triazophos 35 EC + deltamethrin 1 EC at 0.036% recorded 22.9 per cent fruit infestation. The remaining treatments viz., azadirachtin 0.003%, Bacillus thuringiensis sub sp. kurstaki 1.5 kg/ha and neem seed kernel extract 5% were found to be least effective with borer infestation of 27-30% against 41.2% in the control. After second spray Perusal of data (Table 1) indicated that the profenophos 40 EC + cypermethrin 4 EC at 0.044% recorded the lowest (4.67%) fruit infestation by this pest. However, it was at par with the treatments chlorpyriphos 50 EC + cypermethrin 5 EC at 0.055%, profenophos 0.05% and cypermethrin 0.006% as they registered 7.27, 8.76 and 8.33 per cent fruit infestation, respectively. The less effective treatments were azadirachtin 0.003%, B.t. 1.5 kg/ ha and neem seed kernel extract 5% with the fruit infestation % over control. Looking to the overall mean per cent fruit infestation (Table 1) after two sprayings, the insecticidal treatments of profenophos 40 EC + cypermethrin 4 EC at 0.044% and chlorpyriphos 50 EC + cypermethrin 5 EC at 0.055% exhibited minimum fruit infestation i.e and 8.56 %, respectively due to this pest and they were statistically at par with each other. Nevertheless, treatments cypermethrin 0.006% and profenophos 0.05% were at par with chlorpyriphos + cypermethrin 0.055%. Effect on yield and economics The data (Table 1 & 2) indicated that profenophos 40 EC combined with cypermethrin 4 EC at 0.044%, chlorpyriphos 50 EC combined with cypermethrin 5 EC at 0.055%, cypermethrin 0.006%, profenophos 0.05% were found significantly superior over rest of the treatments and gave the higher yield of okra fruits. Yield of healthy fruits in these treatments was recorded , , , Kg/ha, respectively. The insecticidal treatments viz., chlorpyriphos 0.05%, acephate 0.05%, methomyl 0.05% and triazophos 35 EC + deltamethrin 1 EC at 0.036% were found effective and next in order as they registered , , and Kg/ha yield of okra fruits, respectively. The remaining treatments viz., azadirachtin 0.003%, B. t. 1.5 Kg/ha and neem seed kernel extract 5% were found the least effective. Considering the per cent increase in the yield of healthy fruits over control due to the insecticidal treatments, profenophos 40 EC combined with cypermethrin 4 EC at 0.044%, chlorpyriphos 50 EC combined with cypermethrin 5 EC at 0.055%, cypermethrin 0.006% and profenophos 0.05% gave 113.5, 94.4, 91.9 and 89.8 per cent increase in yield over control, respectively. It can be seen from the data (Table 2) that the highest Net Incremental Cost Benefit Ratio (1:20.3) was obtained with the treatment of cypermethrin 0.006%, followed by profenophos 40 EC combined with cypermethrin 4 EC 0.044% (1:11.9), chlorpyriphos 0.05% (1:10.4), chlorpyriphos 50 EC combined with cypermethrin 5 EC 0.05% (1:10.2), profenophos 0.05% (1:8.7), acephate 0.05 % (1:5.1), methomyl 0.05% (1:4.1)

3 Vol. 31, No. 1, Table 1 : Efficacy of newer and ready mixed insecticides against E. vittella on okra. Treatment Conc. (%) Per cent fruit infestation Yield of healthy Percentage Before spray After first spray After second spray Mean fruits (Kg/ha) increase in yield over control Acephate 0.05 % (26.55) (17.67) (15.14) (16.39) Azadirachtin % (30.73) (27.05) (25.81) (26.43) B. t. 1.5 kg/ha 1.5 g/ha (30.11) (27.19) (26.6) (26.90) Chlorpyriphos 0.05 % (23.74) (17.7) (14.66) (16.16) Chlorpyriphos % (23.74) (9.90) (7.27) (8.56) Cypermethrin Cypermethrin % (28.10) 20.8 (12.61) (8.33) (10.39) Methomyl 0.05 % (26.08) (17.66) (13.91) (15.75) NSKE 5 % (30.97) (29.97) (27.8) (28.88) Profenophos 0.05 % (26.86) (12.4) (8.76) (10.52) Profenophos % 31.77* (27.72) 16.93* (8.48) 12.48* (4.67) 14.74* (6.47) ** Cypermethrin Triazophos % (27.41) 28.6 (22.91) (20.47) (21.68) Deltamethrin Control (32.06) (43.43) (51.04) (47.33) S. Em. ± C. D. at 5 % - NS C. V. % *Angular transformed values **Average of three replication Figures in parentheses indicate the retransformed values.

4 28 AGRICULTURAL SCIENCE DIGEST Table 2 : Economics of different insecticidal treatments against E. vittella on okra. Treatment No. of Total quantity Price of Cost of Total cost of Yield of Gross Net NICBR Spray of insecticide insecticide insecticide insecticide healthy okra realization realization (Kg/l or ml/ ha) (Rs/l or Kg) (Rs/ha) including Labour fruits (Kg/ha) (Rs/ha) charges (Rs/ha) Acephate 0.05% :5.1 Azadirachtin 0.003% :2.5 Bt 1.5 kg/ha Kg :1.9 Chlorpyriphos :10.2 +Cypermethrin 0.055% Chlorpyriphos 0.05% :10.4 Cypermethrin 0.006% :20.3 Methomyl 0.05% :4.1 NSKE 5% 2 5 Kg :0.9 Profenophos : Cypermethrin 0.044% Profenophos 0.05% :8.7 Triazophos :4.1 + Deltamethrin 0.036% Control The labour charge has been Rs. 100/ha/spray Price of okra fruits has been Rs. 8/Kg.

5 Vol. 31, No. 1, and triazophos 35 EC + deltamethrin 1 EC 0.036% (1:4.1). These results are in close agreement with the works of Rai and Satpathy (1999), Singh and Jayswal (2001), Misra et al.(2002), Bagade et al.(2005), Dubey and Ganguli (1998) and Das et al. (2001). Hence, these can be used for management of shoot and fruit borer in okra ecosystem in decreasing order of preference. REFERENCES Bagade, A. S., Ambekar, J. S., Bhagavati, V. Y. and Bade, B. A. (2005). J. Maharashtra Agric. Univ., 30 (2): Chaudhary, H.R. and Dadheech, L.N.(1989). Ann. Arid Zone, 28 (3-4): Das, S. N., Subhrajyoti, Ray. and Chatterjee, M. L. (2001). J. Interacademicia, 5 (3): Dubey, V. K. and Ganguli, R. N. (1998). Insect Environment, 4 (1): 25. Misra, H. P., Dash, D. D. and Mahapatra, D. (2002). Ann. Pl. Prot. Sci., 10 (1): Panse, V. G. and Sukhatme, P. V. (1985). Statistical Methods for Agricultural Workers, I. C. A. R., New Delhi, pp Rai, S and Satpathy, S. (1999). Vegetable Sci., 26 (1): Singh, S. P. S. and Jayswal, A. K. (2001). J. Insect Sci., Ludhiana, 14 (1/2):