Bio-efficacy of certain insecticide against Helicoverpa armigera (Hubner) on green gram (Vigna radiata L.)

Introduction

Green gram [Vigna radiata L. Wilczek. 2n=22], and belongs to family leguminaceae, it is an economically important legume food grown worldwide in tropical and sub-tropical regions and it is one of the leading pulse crops in India. The importance of this legume is related to desirable characteristics such as high protein content (25-28%) and less flatulent than other pulses, broad adaptation, low need for agricultural inputs and its ability to increase soil fertility. Sprouts and green pods of green gram are also rich in vitamins and minerals thus are good and in expensive source of dietary protein for poor people Mehandi et al., (2019) [4] . Among these only few are economically important as pests viz., Tur plume moth, Exelastis atomosa (Walsh), Tur pod borer, Helicoverpa armigera (Hubner) and Tur Pod fly, Melanagromyza obtusa (Mall). Which are collectively referred as "Pod borer complex" Lal (1998) [3] . This pod borer complex recorded economic damage at various places ranging 30 to 100 percent, as a result we had to import pulses from other countries by investing a huge amount, in addition direct loss to cultivators in the past years Patil et al., (1990) [5] . The gram pod borer, Helicoverpa armigera is a potential and polyphagous pest, with various characteristic features like high fecundity, migratory behavior, high adaptations to various agro climatic conditions and development of resistance to various insecticides, extensively damaging many crops including Greengram and chickpea (Kambrekar et al., 2009) [1] . The caterpillar not only defoliates the tender leaves but also makes holes in the pods and feed upon the developing seeds the anterior body portion of the caterpillar remains inside the pod and rest half or so hanging outside Gayathri and Kumar (2021) [6] . The gram pod borer, Helicoverpa armigera is a potential and polyphagous pest, with various characteristic features like high fecundity, migratory behavior, high adaptations to various agroclimatic conditions and development of resistance to various insecticides, extensively damaging many crops including greengram (Kambrekar et al., 2009) [1] .

Materials and Methods

Studies on the "Bio-efficacy of certain insecticide against Helicoverpa armigera (Hubner) on green gram (Vigna radiata L.)" at field condition was carried out during kharif season 2022 at Koirengei,Imphal, India, in a randomized block design with eight treatments replicated three times using Raiyur seeds in a plot size of 2m x 2m at a spacing of 30cm x 10cm with a recommended package of practices excluding plant protection. The soil of the experimental site was well drained and medium high. The experiment was conducted in randomized block design with three replications. A good tilth area will be divided into three main blocks. Each main block was sub-divide into 9 subplots each of which was be of 2m x 2m with maintaining 30cm orders as bunds and the treatments was assigned randomly. 3.1). The treatments were imposed by using hand compressor sprayer @ 400-500 liters of spray solution/hectare depending on stage of the crop. The crop received two sprays, the first being given at 50 per cent flowering stage (i.e.40 days after sowing) when the population crossed economic threshold level (one larvae/plant) while, the second spray was imposed 15days after spray. The economics of management of green gram pod borer was determined considering the cost of inputs, cost of application and additional return. Larval count was taken 24 hours before spraying on 5 tagged plants per treatment, which was further converted into per plant population subsequent observations were recorded at 3, 7 and 14 days after spraying on same plants.

Method of Recording Observations Thilagam et al., (2020) Results and Discussion

The present study entitled "Bio-efficacy of certain insecticide against gram pod borer Helicoverpa armigera L. in green gram" was under taken at Koirengei, Imphal, Manipur.

4.1 Efficacy of various treatment against pod borer on pod damage (%) of Helicoverpa armigera L. in green gram first spray

rd Days after spraying

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (6.31) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (6.41), Flubendamide 150gm/ha (6.52), Emamectin benzoate 0.4gm/lit (6.83) and Imidacloprid 0.50ml/lit (6.84). The least effective treatments were control with (11.53) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T6, T4, T5, T1, T3, T2) and (T6, T4, T5, T1, T3, T2) are significantly par with each other.

th Days after spraying

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (3.90) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (4.52), Flubendamide 150gm/ha (5.00), Emamectin benzoate 0.4gm/lit (5.43) and Imidacloprid 0.50ml/lit (6.00). The least effective treatments were control with (12.91) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T7, T5, T1, T3) and (T3 and T2) are significantly par with each other.

th Days after spraying

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (4.48) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (4.90), Flubendamide 150gm/ha (5.37), Emamectin benzoate 0.4gm/lit (5.71) and Imidacloprid 0.50ml/lit (6.38). The least effective treatments were control with (12.91) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T6, T4) and (T4, T7, T5), (T5, T1, T3) and (T3, T2) are significantly par with each other.

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (4.31) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (4.69), Flubendamide 150gm/ha (5.12), Emamectin benzoate 0.4gm/lit (5.52) and Imidacloprid 0.50ml/lit (6.13). The least effective treatments were control with (14.29) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T6, T4, T7) and (T7, T5), (T5, T1, T3) and (T1, T3) are significantly par with each other.

th Days after spraying

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (3.16) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (3.51), Flubendamide 150gm/ha (3.94), Emamectin benzoate 0.4gm/lit (4.60) and Imidacloprid 0.50ml/lit (6.13). The least effective treatments were control with (15.24) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T6, T4, T7) and (T7, T5), (T5, T1, T3) and (T1, T3) are significantly par with each other.

th Days after spraying

The data reveals that all the treatments were significantly superior over untreated control. Among the treatments, Chlorantraniliprole (0.3ml/lit) was found to be superior to the rest of treatment by recording (4.14) pod damage percentage of Helicoverpa armigera L. in green gram followed by Spinosad 0.6ml/lit (4.50), Flubendamide 150gm/ha (4.91), Emamectin benzoate 0.4gm/lit (5.31) and Imidacloprid 0.50ml/lit (5.90). The least effective treatments were control with (15.24) pod damage of Helicoverpa armigera L. over control and at par with each other. The treatment (T6, T4, T7) and (T4, T7, T5), (T5, T1) and (T1, T3) are significantly par with each other.

The data revealed that all the insecticide treatment gave significantly higher yield compare to control. The highest yield was recorded with the spray application of Chlorantraniliprole (0.3ml/lit) (15.36 q ha-1) followed by Spinosad 0.6ml/lit (14.15 q ha-1), Flubendamide 150gm/ha (13.44 q ha-1) and Emamectin benzoate 0.4gm/lit (12.21 q ha-1). The low yield was recorded from the plots sprayed with T0 Control (Water) (4.97q ha -1 ).

Conclusion

It could be concluded that for the management of green gram pod borer and yield Chlorantraniliprole 0.3ml/lit on green gram crop, recommended insecticide schedule of Chlorantraniliprole 0.3ml/lit proved to be most effective and economical followed by Spinosad 0.6ml/lit, Flubendamide 150gm/ha, Emamectin benzoate 0.4gm/lit and Imidacloprid 0.50ml/lit. The highest yield was recorded in Chlorantraniliprole 0.3ml/lit (15.36 q ha-1) followed Spinosad 0.6ml/lit, Flubendamide 150gm/ha, Emamectin benzoate 0.4gm/lit and Imidacloprid 0.50ml/lit.

References

1. Kambrekar DN, Kulkarni KA, Giraddi RS, Kulkarni JH, Fakrudin B. Management of chickpea pod borer, Helicoverpa armigera (Hubner) through Nuclear Polyhedral Virus isolates. Prec Agric. 2009;10:450-457.
2. Lakshmi G, Ashwani K. Field efficacy of certain insecticides against pod borer, Helicoverpa armigera (Hubner) on chickpea in Prayagraj. J Entomol Zool Stud. 2021;9(3):280-283.
3. Lal SS, Katti G. IPM of pod borer complex infesting pigeonpea. In: IPM system in agriculture. New Delhi: Aditya Books Pvt. Ltd.; 1998. p. 79-128.
4. Mehandi S, Quatadah S, Mishra SP, Singh I, Praveen N, Dwivedi N. Mungbean (Vigna radiata L. Wilczek): retrospect and prospects. In: Legume crops characterization and breeding for improved food security. London: IntechOpen; 2019. p. 49-66.
5. Patil CS, Khaire VM, Mole UN. Comparative performance of different insecticides against pigeonpea pod borer complex on short duration pigeonpea. J Maharashtra Agric Univ. 1990;15(3):337-339.
6. Gayathri, L. & Kumar, A. (2021). Field efficacy of certain insecticides against pod borer, Helicoverpa armigera (Hubner) on chickpea in Prayagraj. Journal of Entomology and Zoology Studies, 9(3), 280-283.