Field efficacy of selected bio-pesticides against Helicoverpa armigera (Hübner) and their effect on pod damage and grain yield of chickpea (Cicer arientinum L.)

Introduction

Chickpea (Cicer arietinum L.) is one of the most important pulse crops cultivated in India because of its high nutritional value and its significant contribution to food and nutritional security. The crop is an excellent source of protein, carbohydrates, minerals and vitamins and plays an important role in maintaining soil fertility through biological nitrogen fixation (Bhatt and Patel, 2001; Lamesgen Yegrem, 2021) [3,11] . India is the largest producer of chickpea, cultivating the crop on 9.58 million ha with an annual production of 11.03 million tonnes during 2023-24 (Anonymous, 2023-24) [1] . In Maharashtra, chickpea occupied 2.82 million ha with a production of 3.53 million tonnes during 2024-25 (Anonymous, 2024-25) [2] . Despite its importance, the productivity of chickpea is considerably affected by several insect pests. Among the insect pests attacking chickpea, the gram pod borer, Helicoverpa armigera (Hübner), is recognized as the most destructive species owing to its wide host range, high reproductive potential and destructive feeding behaviour (Garg and Surendra Kumar, 2000) [6] . The larvae feed on leaves, flower buds, flowers and developing pods, causing severe quantitative and qualitative losses. Under severe infestation, yield losses may range from 25-30 per cent and may exceed 75 per cent under favourable conditions (Sarwar et al., 2009; Jeyarani et al., 2010) [16,7] . A single larva is capable of damaging up to 40 pods in a single feeding cycle, making the pest one of the major constraints to profitable chickpea cultivation (Khan et al., 2009) [8] . The management of H. armigera has largely relied on repeated applications of synthetic insecticides. Although these insecticides provide rapid suppression of the pest, their indiscriminate use has resulted in the development of insecticide resistance, pest resurgence, pesticide residues and adverse effects on beneficial organisms and the environment (Ningthoujam et al., 2015;

Mesnage and Seralini, 2018) [13,12] . Consequently, emphasis has shifted towards environmentally safer pest management practices that are compatible with integrated pest management (IPM) programmes. Bio-pesticides have emerged as promising alternatives because of their target specificity, environmental safety and compatibility with natural enemies. Several studies have demonstrated the effectiveness of Bacillus thuringiensis (Bt), Helicoverpa armigera nucleopolyhedrovirus (HaNPV), Beauveria bassiana, Metarhizium anisopliae and neem-based formulations in suppressing H. armigera infestation under field conditions (Rachna and Kaushik, 2018; Gaffar et al., 2024; Patel et al., 2025) [15, 14] . However, comparative information on the field performance of the PDKV-developed Bt formulation (PDKV SY-4 25% WP) in relation to commercially available Bt and other biopesticides under the agro-climatic conditions of Vidarbha is limited. Therefore, the present investigation was undertaken to evaluate the field efficacy of selected bio-pesticides against H. armigera on chickpea with respect to larval suppression, reduction in pod damage and improvement in grain yield under field conditions.

Materials and Methods

Experimental site

The field experiment was conducted during the Rabi season of 2025-26 at the Pulses Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra, India. The experimental farm is located at 20°42′ N latitude, 77°02′ E longitude and an altitude of 307.42 m above mean sea level. The chickpea crop was raised by following the recommended agronomic practices of the university.

Experimental design and treatments

The experiment was laid out in a Randomized Block Design (RBD) comprising eight treatments with three replications using chickpea variety JAKI-9218. The experiment comprised the following treatments, HaNPV (1 × 10⁹ POBs ml⁻¹) @ 10 ml/10 L of water, Bt commercial (Delfin) @ 10 g/10 L of water, (PDKV Bt strain) PDKV SY-4 25% WP (1.7 × 10⁸ spores g⁻¹) @ 10 g/10 L of water, neem oil 2% @ 7-8 ml/10 L of water, neem seed extract (NSE) 5%, Beauveria bassiana (1 × 10⁹ CFU ml⁻¹) @ 50 ml/10 L of water, Metarhizium anisopliae (1 × 10⁹ CFU ml⁻¹) @ 50 ml/10 L of water, and an untreated control (water spray). Two foliar sprays were applied using a knapsack sprayer with a spray volume of 500 L ha⁻¹. The first spray was applied at the 50% flowering stage of the crop, while the second spray was imposed 15 days after the first application.

Observations

Five plants were selected randomly and tagged in each plot for recording observations. The larval population of H. armigera was recorded one day before spraying and at 3, 7 and 14 days after each spray. The cumulative mean larval population was calculated using observations recorded after both sprays. Per cent pod damage was recorded at harvest by counting healthy and damaged pods from the selected plants and was calculated using the following formula:

Pod damage (%) = (Number of damaged pods / Total number of pods) × 100 Grain yield from each net plot was recorded after harvest and converted into quintals per hectare (q ha⁻¹).

Statistical analysis

The experimental data were subjected to analysis of variance (ANOVA) appropriate for a Randomized Block Design (RBD). Larval population and per cent pod damage data were subjected to square root transformation [√𝑥 + 0.5] prior to statistical analysis, whereas grain yield data were analysed on the original scale. Treatment means were compared using the Critical Difference (CD) test at the 5% level of significance.

Results and Discussion

Field efficacy of selected bio-pesticides against Helicoverpa armigera (Hübner)

The data presented in Table 1 revealed that the pre-treatment larval population recorded one day before the first spray did not differ significantly among the treatments, indicating a uniform distribution of H. armigera before the imposition of treatments. However, significant differences among the treatments were observed at all post-treatment observations following both the first and second sprays. Following the first spray, all the bio-pesticidal treatments significantly reduced the larval population of H. armigera compared with the untreated control. Based on the mean larval population, Bt commercial (Delfin) proved to be the most effective treatment by recording the lowest mean larval population of 0.33 larva plant⁻¹ and was significantly superior to all the remaining treatments. (PDKV Bt strain) PDKV SY-4 25% WP recorded the next lowest mean larval population (0.68 larva plant⁻¹) and was statistically at par with HaNPV (0.86 larva plant⁻¹). Neem oil 2%, NSE 5% and Beauveria bassiana recorded mean larval populations of 1.28, 1.28 and 1.33 larvae plant⁻¹, respectively, and were statistically at par with each other. Metarhizium anisopliae recorded a comparatively higher mean larval population (1.42 larvae plant⁻¹) and was significantly inferior to the above treatments. The untreated control (water spray) recorded the highest mean larval population (2.13 larvae plant⁻¹). The results obtained after the second spray also revealed significant differences among the treatments. Bt commercial (Delfin) again recorded the lowest mean larval population (0.15 larva plant⁻¹) and proved significantly superior over all the remaining treatments. (PDKV Bt strain) PDKV SY-4 25% WP recorded a mean larval population of 0.40 larva plant⁻¹ and was statistically at par with HaNPV (0.47 larva plant⁻¹). Neem oil 2%, NSE 5% and Beauveria bassiana recorded mean larval populations of 0.77, 0.75 and 0.80 larva plant⁻¹, respectively, and were statistically at par with one another. Metarhizium anisopliae recorded a comparatively higher mean larval population (1.13 larvae plant⁻¹), whereas the untreated control recorded the highest mean larval population (2.36 larvae plant⁻¹). The cumulative effect of two consecutive sprays clearly demonstrated the superiority of Bt-based treatments over the other bio-pesticides. The cumulative mean larval population differed significantly among the treatments. Bt commercial (Delfin) recorded the lowest cumulative mean larval population (0.24 larva plant⁻¹) and was significantly superior over all the other treatments. (PDKV Bt strain) PDKV SY-4 25% WP (0.54 larva plant⁻¹) was the next most effective treatment and was statistically at par with HaNPV (0.66 larva plant⁻¹). Neem oil 2%, NSE 5% and Beauveria bassiana recorded cumulative mean larval populations of 1.03, 1.02 and 1.06 larvae plant⁻¹, respectively, and were statistically at par with each other. Metarhizium anisopliae recorded a comparatively higher cumulative mean larval population (1.27 larvae plant⁻¹) and was significantly inferior to the above treatments but superior to the untreated control, which recorded the highest cumulative mean larval population (2.24 larvae plant⁻¹). The superior efficacy of Bt commercial (Delfin) observed in the present investigation may be attributed to the insecticidal Cry proteins produced by Bacillus thuringiensis, which disrupt the midgut epithelium of susceptible larvae, resulting in rapid cessation of feeding followed by larval mortality. The promising performance of (PDKV Bt strain) PDKV SY-4 25% WP indicates that this indigenous Bt formulation possesses comparable insecticidal potential under field conditions. HaNPV also provided satisfactory suppression of H. armigera, although its comparatively slower action may be associated with the time required for viral infection, multiplication and eventual mortality of the host larvae. The comparatively lower efficacy of neembased products and entomopathogenic fungi may be attributed to their slower mode of action and greater dependence on favourable environmental conditions for successful infection and persistence.

Effect of selected bio-pesticides on pod damage and grain yield of chickpea

The data presented in Table 2 revealed that the different biopesticidal treatments significantly influenced both pod damage caused by Helicoverpa armigera and grain yield of chickpea. The extent of pod damage varied significantly among the treatments and was closely associated with their efficacy in suppressing the larval population throughout the crop growth period. Among the evaluated treatments, Bt commercial (Delfin) recorded the lowest pod damage (1.81%) and proved to be the most effective treatment. It was followed by (PDKV Bt strain) PDKV SY-4 25% WP (2.73%) and HaNPV (2.96%), both of which also recorded significantly lower pod damage than the remaining treatments. NSE 5% (4.37%) performed better than neem oil 2% (5.19%), whereas Beauveria bassiana (5.35%) and Metarhizium anisopliae (7.13%) were comparatively less effective in reducing pod damage. The untreated control (water spray) recorded the highest pod damage (11.97%), indicating severe infestation in the absence of effective plant protection. A similar trend was observed with respect to grain yield. Bt commercial (Delfin) recorded the highest grain yield (18.20 q ha⁻¹) and was significantly superior to all other treatments. The next highest grain yield was recorded in (PDKV Bt strain) PDKV SY-4 25% WP (16.72 q ha⁻¹), followed by HaNPV (16.31 q ha⁻¹) and NSE 5% (16.30 q ha⁻¹). These three treatments were statistically at par with one another. Neem oil 2% produced a grain yield of 14.20 q ha⁻¹, followed by Beauveria bassiana (13.89 q ha⁻¹) and Metarhizium anisopliae (12.72 q ha⁻¹). The untreated control recorded the lowest grain yield (9.69 q ha⁻¹).

The reduction in pod damage and the corresponding increase in grain yield observed under Bt commercial (Delfin), (PDKV Bt strain) PDKV SY-4 25% WP and HaNPV may be attributed to their superior suppression of H. armigera larvae during the reproductive stage of the crop. Effective management of the larval population protected developing pods from feeding injury, resulting in lower pod damage and improved grain yield. In contrast, higher larval infestation in the untreated control resulted in greater pod damage and consequently lower grain yield. [5] , who reported effective suppression of Helicoverpa armigera by HaNPV under field conditions. Singh and Yadav (2007) [18] also observed that Bacillus thuringiensis was more effective than neem-based treatments in reducing the larval population of gram pod borer. Khanna et al. (2009) [9] further reported that Bt application significantly reduced larval infestation and pod damage, resulting in higher grain yield in chickpea. Similarly, Sharma and Rajnikant (2023) [17] found that Bacillus thuringiensis recorded lower larval population and performed better than Beauveria bassiana, neem oil and NSKE in suppressing H. armigera. Gaffar et al. (2024) also reported that Bt-based treatments were superior to botanical bio-pesticides in reducing larval population, minimizing pod damage and producing higher marketable yield under field conditions. Likewise, Biradar et al. (2024) [4] observed that Bacillus thuringiensis recorded lower larval population than NSKE and Beauveria bassiana, indicating its greater effectiveness against gram pod borer. Patel et al. (2025) [14] reported that Bt formulations and HaNPV significantly reduced larval population and pod damage while improving grain yield compared with the untreated control, whereas Kumar et al. (2026) [10] found that Bacillus thuringiensis consistently recorded lower larval population, higher grain yield and better economic returns than neem-based treatments and entomopathogenic fungi. The results of the present investigation, therefore, substantiate earlier findings that Bt-based bio-pesticides, particularly Bt commercial (Delfin), followed by PDKV SY-4 25% WP and HaNPV, are highly effective in suppressing H. armigera, reducing pod damage and improving grain yield under field conditions.

Conclusion

The present investigation demonstrated that the tested biopesticides differed significantly in their effectiveness against Helicoverpa armigera under field conditions. Among the evaluated treatments, Bt commercial (Delfin) consistently proved to be the most effective by recording the lowest larval population, minimum pod damage and the highest grain yield. (PDKV Bt strain) PDKV SY-4 25% WP emerged as the next most effective treatment and exhibited performance comparable to HaNPV in suppressing gram pod borer infestation. Neem-based products and entomopathogenic fungi also reduced pest infestation compared with the untreated control, although their efficacy was comparatively lower than Bt-based treatments. The findings of the present study indicate that Bt commercial (Delfin), followed by PDKV SY-4 25% WP and HaNPV, can be effectively incorporated into integrated pest management programmes for sustainable management of H. armigera in chickpea under the agro-climatic conditions of Vidarbha.

References

1. Anonymous. Source: Ministry of Agriculture and Farmers Welfare, Government of India (ON3855) and past issues. indiastatagri. 2023-24. https://www.indiastatagri.com
2. Anonymous. Economic Survey of Maharashtra 2024-25. Directorate of Economics and Statistics, Planning Department, Government of Maharashtra; 2024-25. https://mahades.maharashtra.gov.in
3. Bhatt NJ, Patel RK. Screening of chickpea cultivars for their resistance to gram pod borer, Helicoverpa armigera. Indian Journal of Entomology. 2001;63(3):277-280.
4. Biradar BG, Yadav U, Mushinamwar DR, Rajpurohit S, Chavan V. Efficacy of certain biopesticides and chemicals against gram pod borer [Helicoverpa armigera (Hubner)] on chickpea (Cicer arietinum L.). International Journal of Advanced Biochemistry Research. 2024;8(5):339-342.
5. Cherry AJ, Rabindra RJ, Parnell MA, Geetha N, Kennedy JS, Grzywacz D. Field evaluation of Helicoverpa armigera nucleopolyhedrovirus formulations for control of the chickpea pod-borer, Helicoverpa armigera (Hübner), on chickpea (Cicer arietinum L.) in southern India. Crop Protection. 2000;19(1):51-60.
6. Garg DK, Kumar S. Insect pests of chickpea and their management. In: Insect pests of pulses and oil seeds and their management. Cuttack (India): CRRI, ICAR; 2000. p. 54.
7. Jeyarani S, Sathiah N, Karuppuchamy P. Field efficacy of Helicoverpa armigera nucleopolyhedro virus isolates against H. armigera (Hubner) (Lepidoptera: Noctuidae) on cotton and chickpea in Tamil Nadu. Plant Protection Science. 2010;46(3):116-122.
8. Khan SM, Inayatullah MY, Khan MA. Varietal screening of chickpea and the efficacy of different insecticides against chickpea pod borer Helicoverpa armigera. Gomal University Journal of Research. 2009;25:20-24.
9. Khanna V, Cheema HK, Taggar GK. Evaluation of some microbial and botanical biopesticides against Helicoverpa armigera in chickpea (Cicer arietinum). Indian Journal of Agricultural Sciences. 2009;79(3):195-198.
10. Kumar P, Singh DV, Singh R. Efficacy of bio-pesticides and insecticide against pod borer, Helicoverpa armigera (Hubner) in chickpea. Journal of Experimental Zoology India. 2026;29(1):381-389.
11. Lamesgen Y. Nutritional composition, antinutritional factors, and utilization trends of Ethiopian chickpea (Cicer arietinum L.). International Journal of Food Science. 2021;2021:1-10.
12. Mesnage R, Seralini GE. Toxicity of pesticides on health and environment. Frontiers in Public Health. 2018;6:268.
13. Ningthoujam K, Sharma K, Gujjar GT. Inheritance of resistance to Bacillus thuringiensis toxin, Cry1Ac in Helicoverpa armigera (Hubner). Annals of Plant Protection Sciences. 2015;23:205-209.
14. Patel RM, Panickar B, Patel PS, Chandaragi MK, Parmar DN. Field evaluation of bio-pesticides against gram pod borer (Helicoverpa armigera Hübner) infesting chickpea (Cicer arietinum L.) under North Gujarat conditions. Biochemical & Cellular Archives. 2025;25(2).
15. Rachna, Kaushik HD. Bioefficacy of biopesticides against Helicoverpa armigera in chickpea. The Pharma Innovation Journal. 2018;7(1):321-324.
16. Sarwar M, Ahmad N, Toufiq M. Host plant resistance relationships in chickpea (Cicer arietinum L.) against gram pod borer, H. armigera Hubner. Pakistan Journal of Botany. 2009;41(6):3047-3052.
17. Sharma D, Rajnikant TA. Bioefficacy of certain chemicals and biopesticides against pod borer [Helicoverpa armigera (Hubner)] on chickpea (Cicer arietinum L.). International Journal of Plant & Soil Science. 2023;35(18):49-54.
18. Singh SS, Yadav SK. Comparative efficacy of insecticides, biopesticides and neem formulations against Helicoverpa armigera on chickpea. Annals of Plant Protection Sciences. 2007;15(2):299-302.
19. Gafar BB, Yadav U, Mushinamwar DR, Rajpurohit S, Chavan V. Efficacy of certain biopesticides and chemicals against gram pod borer [Helicoverpa armigera (Hubner)] on chickpea (Cicer arietinum L.). International Journal of Advanced Biochemistry Research. 2024;8(5):339-342.