Efficacy of eco-friendly plant products against tur pod borer, Helicoverpa armigera (Hubner) infesting pigeonpea under laboratory conditions

Introduction

Pigeonpea, [Cajanus cajan (L.) Millspaugh] (2n = 22) is an important pulse crop mainly grown under rain-fed condition s in the tropics and subtropics. In Asia, Africa and Latin America, pigeon-pea seeds have become the main source of protein especially for the vegetarians. Guandul in Latin America, Gungo peas in the Anglo Caribbean and Congo pea in Sub Saharan Africa are the names given to the pigeonpea (Carney and Rosomoff, 2009) [4] . In India, it is known by a variety of names including arhar, red gram, tur and tomarapayaru (Anonymous, 2016) [2] . Pigeon-pea appears to have originated in Peninsular India, with its nearest wild relative (Cajanus cajanifolia) growing in tropical deciduous woodlands. Pigeonpea is grown in over 25 tropical and subtropical nations, either as a stand-alone crop or in combination with cereals such as sorghum and maize, or other legumes such as peanuts. Pigeonpea is the most adaptable edible legume, with a wide range of use including food, feed, fodder and fuel. Grain comes in a variety of forms, including green seeds as vegetables and reconstituted dried split seeds. It is rich source of protein and fulfils a major protein requirement of vegetarian population of the country. It is a major source of dietary protein in South Asian vegetarian civilizations. Pigeon-pea provides 50% of all protein ingested by Indians in some areas (Ryan et al., 1984) [11] . The food value of pigeon-pea is due to its protein content (22.3%) along with iron, iodine and essential amino acids like lysine, cystine arginine, vitamins and minerals. It has better quality of fiber, 7 g/100 g of seeds (Kandhare, 2014) [6] ." A wide range of constraints (abiotic and biotic) are responsible for reduction in productivity of the country's pigeonpea. Among them biotic factors which include insect pests are most notable threat to the crop's potential yield. The havoc caused by insect pests is critical (Mishra et al., 2012) [8] . Though pigeonpea is inundated by more than 250 species of insect pests belongings to 8 orders and 61 families that appear at variousgrowth stages of the crop in India, only a few of these cause consistent and significant damage to the crop (Lateef and Reed, 1990 and Gopali et al., 2010) [7,5] . Worldwide, over 30 species of Lepidoptera feed on pods and seeds of pigeonpea (Shanower et al., 1999) [14] .

The pod borer complex, which also comprises Helicoverpa armigera, Etiella zinckenella and Maruca vitrata, has been identified as a significant threat to pigeonpea crop causing significant losses in grain yield ranging from 30 to 100 percent by targeting the reproductive sections of the plant. (Srilaxmi and Ravindra, 2010) [15] . The insect pod borer complex has a significant impact on the production of most pulses. Among these the H. armigera (Hübner) is the major pest in most parts of the country and it has attained the key pest prominence due to its direct attack on fruiting bodies, voracious feeding habits, high mobility, fecundity, multivoltine and overlapping generation with facultative diapauses, nocturnal "bahaviour, migration host selection and propensity for acquiring resistance against insecticides (Satpute and Sarode, 1995) [12] . It accounts for 90-95% of total damage. A single larva can damage 25-30 pods of gram in its life time. It feeds on tender shoots and young seeds. It makes holes in pods and inserts half of its body inside the pod to eat developing seeds "(Ojha et al., 2017) [9] .

Materials and Methods

The present experiment was conducted at the laboratory of Department of Entomology, College of Agriculture, IGKV, Raipur (C.G.) during 2023-25 to study the effectiveness of some bioformulations against tur pod borer, H. armigera infesting pigeon pea. The solution of bioformulations were prepared in distilled water with desired concentration and the pods of pigeonpea were dipped in the test solution for 30 seconds. Such treated pods were allowed to air dry on clean cloth. Further they were transferred to individual small plastic vials. The fourth and fifth instar larvae were transferred to each plastic vials containing treated pigeonpea pods. Each treatment was replicated three times along with an untreated control at 27±2 °C temperature and 70±10% relative humidity.

Experimental details

The details of experiment are given below:

Preparation method of Neemastra-

A plastic container was taken in which 5 lit of water was filled then all the above ingredients were mixed and the mixture was stirred with the help of wooden stick regularly at an interval of 2 hours in both clockwise and anticlockwise direction. After that the container was covered with jute sack. Then the mixture was kept for 48 hours for fermentation and after 48 hours the mixture was stirred thoroughly and then filtered through a muslin cloth.

Treatment-2 B. Brahmastra

Materials Required for Brahmastra Preparation- 5 litres of cow urine  500 g of pulp of custard apple leaves  500 g pulp of papaya leaves  500 g pomegranate leaves pulp  500 g guava leaves pulp  1 kg crushed Neem leaves pulp

Preparation method of Brahmastra

A mud pot d was taken in which 5 lit of desi cow urine was filled then 1kg of crushed neem leaf pulp was added. After adding, the mixture was kept for 30 min and after 30 minutes the solution was boiled for 5 times in low flame then allowed it to cool down After cooling of the solution the mixture was left to ferment for 24 hrs then the mixture was stirred thoroughly and then filtered through a muslin cloth.

Treatment-3 C. Agniastra

Materials Required for Agniastra preparation- 5 litres of cow urine  500 g of pulp of Tobacco leaves.  500 g pulp of neem leaves  250 gm of Green chilly with strong pungency  250 Gram Local Garlic Preparation method of Agniastra-An earthen pot was taken in which 5 lit of desi cow urine was filled then all the above ingredients were mixed after mixing the all ingredients the mixture was stirred by the help of wooden stick regularly at an interval of 2 hours in both clockwise and anti clockwise directions, then the mixture was left to ferment for 24 hrs. Then, the mixture was stirred thoroughly and filtered through a muslin cloth.

Treatment-4 D. NSKE (Neem seed kernel extract) Materials Required for preparation:

 Neem seed kernels (well dried)  Water (reasonably good quality)  Detergent  Muslin cloth for filtering 1 kg quantity of neem seed kernel was taken a grinder machine @ 18000-23000 rpm for 3-5 minutes. 50 gm powder was soaked in 1 lit of water for 24 hours and in the next morning the soaked mixture was stirred with wooden stick and filtered with double layer muslin cloth. Then 20 g of detergent powder was added to it. The solution thus prepared was ready for use with required volume of water.

Treatment-5 Neem Oil

Neem Baan 1500 ppm is a bio-pesticide formulation derived from neem oil, containing 1500 ppm of azadirachtin.

Treatment-6 Plain Water Spray (Control)

In control pods only plain water was sprayed.

Method of recording observation-

The mortality and repellency of fourth and fifth instar larvae of H. armigera were assessed after 24-, 48-and 72-hours exposure of the larvae to the treated pigeonpea pods. The larvae were considered dead if they gave no response to stimulation by touch. The results were expressed as per-cent mortality with correction for untreated control mortality using Abbott's formula (Abbott, 1925) [1] . Data was analyzed statistically.

Abbott's formula

% test mortality-% control mortality Corrected mortality (%) = 100-% control mortality

Results and Discussion

The data recorded on the effectiveness of some bioformulations against tur pod borer, H. armigera infesting pigeon pea with corrected mortality (%) and repellency in various bioformulations at 24, 48 and 72 HAT revealed that the neem seed kernel extract exhibited highest mortality (30.00%) at 24 hours, followed by neemastra (20.00%) and bramhastra (15.00%) Again after 48 hours neem seed kernel extractand agniastrashowed highest mortality (30.00%), followed by bramhastra and neem oil (25.00%) while, after 72 hours agniastra exhibited highest mortality (65.00%) followed by neem seed kernel extract (55.00%) and bramhastra (50.00%).Similarly, in repellence, agniastra exhibited the highest repellency (85.00%) at 24 hours, followed by neemastra (80.00%) and neem oil (80.00%).

After 48 hours again neemastra showed highest repellency (70.00%) followed by neem seed kernel extract and neem oil (65.00%) while, after 72 hours neemastra exhibited highest repellency (50.00%) followed by neem oil (50.00%) and untreated control 40.00%. The present findings are supported by Patil et al., (2015) [10] , who reported NSKE as an effective botanical against H. armigera in pigeonpea ecosystem. Similarly, Neem-based products like neem oil and neem leaf extract have been shown to act as feeding deterrents and insect growth regulators by Schmutterer (1990) [13] , which corroborates the current findings. The results are also in conformity with the study of Bijewar et al., (2018) [3] , who observed that indigenous formulations a combination of plant-derived compounds, primarily from neem, tobacco, chilli, and garlic, with the cow based fermentation of desi cow urine acting as the solvent and fermentation agent like Neemastra, Bramhastra, and Agniastra. These plant materials contain vatrious alkaloids, chavicine, capsaicin and allicin that showed considerable effects on pod borer management. The present findings validate their potential role not only as insecticidal agents but also as eco-friendly pest repellents.

Conclusion

Thus, from the present investigation in which few plantbased bioformulations were evaluated against H. armigera, after 24, 48 and 72 hours after treatment in terms of mortality (%) and repellency (%), resulted, highest mortality in neem seed kernel extract and neemastra, whereas, highest repellency was observed in agniastra and bramhastra. Hence, these bioformulations can be included as an effective IPM strategy for the management of H. armigera. However, it is felt necessary to test the efficacy of bioformulations against the pest under field conditions.

References

1. Abbott WS. A method of computing the effectiveness of an insecticide. J Econ Entomol. 1925;18(2):265-267.
2. Anonymous. Pigeon pea production in India. Government of India, Ministry of Agriculture & Farmers Welfare; 2016.
3. Bijewar K, Patil S, Bhede BV, Rathod P. Evaluation of indigenous cow-based formulations against pod borer complex in pigeonpea. J Entomol Zool Stud. 2018;6(3):1475-1479.
4. Carney J, Rosomoff R. In the shadow of slavery: Africa's botanical legacy in the Atlantic world. University of California Press; 2009.
5. Gopali JB, Deshmukh AJ, Kumar NKK. Insect pests of pigeonpea and their management. Technical Bulletin, University of Agricultural Sciences, Dharwad, India; 2010.
6. Kandhare AD. Nutritional and phytochemical composition of pigeon pea. Int J Curr Res Rev. 2014;6(10):47-51.
7. Lateef SS, Reed W. Insect pests of pigeonpea and their management. In: Nene YL, Hall SD, Sheila VK, editors. The pigeonpea. Wallingford: CAB International; 1990. p. 193-242.
8. Mishra A, Prasad R, Sharma AK. Constraints in productivity of pigeonpea and their management. Indian J Plant Prot. 2012;40(2):103-108.
9. Ojha L, Sharma D, Singh A. Biology and management of pod borer, Helicoverpa armigera (Hubner): A review. J Pharmacogn Phytochem. 2017;6(6):670-674.
10. Patil SB, Hirekurubar RB, Basavanagoud K. Bioefficacy of botanicals and bioagents against pod borer complex in pigeonpea. J Exp Zool. 2015;18(2):655-659.
11. Ryan JG, Spencer DC, Spencer J. Pigeonpea research: A profile of its global importance. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India; 1984.
12. Satpute US, Sarode SV. Bioecology of Helicoverpa armigera (Hubner). PKV Res J. 1995;19(1):11-16.
13. Schmutterer H. Properties and potential of natural pesticides from the neem tree, Azadirachta indica. Annu Rev Entomol. 1990;35:271-297.
14. Shanower TG, Romeis J, Minja EM. Insect pests of pigeonpea and their management. Annu Rev Entomol. 1999;44(1):77-96.
15. Srilaxmi K, Ravindra H. Pod borer complex of pigeonpea and their management. Karnataka J Agric Sci. 2010;23(1):16-19.
16. Van der Maesen LJG. Pigeonpea (Cajanus cajan): Evolution, history, status, and taxonomy. In: Saxena NN, Johansen C, editors. Research for crop improvement. ICRISAT, Patancheru, India; 1995. p. 15-46.