Population dynamics of Pea pod borer (Helicoverpa armigera) Hub. In relation to weather parameters during Rabi season

Introduction

Pea, Pisum sativum L. is an important leguminous vegetable crop and mostly grown in all states of the country during Rabi season (Singh et. al. 2001) [7] . It is grown for it's taste, nutritive value and food. The high yield in vegetable pea could not be achieved due to large number of insect pests attacking vegetable pea. The crop is known to suffer from a number of insect pests like Pod borers (Etiella zinckenella Tr. and Helicoverpa armigera Hub.), pea stem fly (Melanogromyza phaseoli T.), pen leaf miner (Chromatomyia horticola G.), aphid (Acyrthosiphon pisum) and thrips (Caliothrips indicus B.). These are serious insect pests and often cause substantial loss to the crop. The insect pests i. e. Pea pod borer, Etiella zinc kenella, gram pod borer, Helicoverpa armigera appear in great in number during vegetative growth to pod maturation stage of pea (Lal et. al. 2006) [5] . It is considered to be a major limiting factor for the production of vegetable pea. Vaibhav et. al. 2018) [9] . The pea pod borer solely caused 50.9% pod infestation with 77.64 % seed damage which resulted in yield losses of about 23.9% (Yadav and Chauhan, 2000) [10] .

Materials and Methods

The present study was conducted at the college farm of Nalanda college of Horticulture, Noorsarai, Nalanda in Rabi season 2023-24. The vegetable pea variety, Harbhajan was sown in the first week of November in the 2.20 X 2.30 Sq.m. plot. The experiment was laid out with an RBD design with a 30 x10 cm² spacing.

Method of Recording Observations

The larval population of H. armigera present on the vegetable pea crop during experimental period was recorded in the morning hours at weekly interval, from sowing (DAS) to till the last picking of pods. The observation for the population of H. armigera larvae were recorded from ten plants per plot of each replication was selected randomly and the number of larvae calculated during each observation from untreated control plots. Weekly meteorological data on minimum temperature and maximum temperature in degree centigrade, relative humidity (%) and rainfall (mm) were recorded from Agro-meteorological observatory during the experimental period. To investigate how various abiotic factors affect the prevalence of pod borers, a straight forward correlation between the International Journal of Advanced Biochemistry Research https://www.biochemjournal.com pest population and abiotic factors was calculated using the normal statistical method (Steel and Torrie, 1980) [8] .

Results and Discussion

The occurrence of the data on the pea pod borer (Helicoverpa armigera) was noted at weekly interval and are presented in Table 1. The observation on the incidence of pea pod borer during the Rabi season 2023-24 revealed that the occurrence of H. armigera on pea started from 48th standard Metrological week and continued over the growing time of pea. The population of pea pod borer ranged from 0.75 to 6.18. The pest population increased and reaches it's peak (6.18 larvae/plant) in 6th meteorological week. The present finding was Similar to Kumar et al. (2018) reported that the pea pod bores population reached a peak level in the early February weeks. Mallikarjuna et. al. (2012) [6] and Abdallah et.al. (1998) [1] also reported that the pea pod borer is a pest of various leguminous crops attacked from February to March month attaining a peak level of population. Table 2 revealed that Morning relative humidity and Bright Sunshine hours showed significantly positive correlation with the population of pea pod borer where as rest of the Environmental factors are non-significantly negatively correlated with pea pod borer population. The present findings are similar to Arshad et al. (2018) [2] reported that the correlation between the population of pea pod borer and temperature was negative. Also Vaibhav et al. (2018) [9] reported that the maximum temperature was negatively correlated with pest population while evening relative humidity was found positively significant. Findings of Kumar et al. 2017) also confirm present studies who started that the pea pod borer population was negatively correlated with maximum temperature and positively correlated with minimum temperature, relative humidity and rainfall.

Conclusion

Based on results of present study, it can be concluded that pea pod borer (Helico verpa armigera) commenced from 3rd week of December and remained till 2nd week of February. Thereafter population declined in subsequent meteorological weeks. Morning relative humidity and bright sunshine hours showed significantly positive correlation with pea pod borer where as rest of the environmental factors were negatively correlated with the pest population.

References

1. Barakat SA, Sammour EA, Soliman MM. Field evaluation of certain insecticides against cowpea pod borer. Bull Entomol Soc Egypt. 1998;21:191-197.
2. Arshad M, Ahmad S, Abdin ZU, Maqsood S. Population dynamics of aphids and their natural enemies associated with strip-intercropping in wheat crop. Pak J Zool. 2018;50:1225-1230.
3. Kumar N, Singh H, Kumar L, Vaibhav V, Singh R, Kumar et al. Seasonal abundance and effect on insect pests associated with vegetable pea crop under abiotic factors of U.P. J Pharmacogn Phytochem. 2017;1:16891693.
4. Kumar N, Singh H, Kumar L, Vaibhav V, Singh R, Kumar et al. Seasonal abundance and effect on insect pests associated with vegetable pea crop under abiotic factors of U.P. J Pharmacogn Phytochem. 2018;7(1):1689-1693.
5. Lal C, Verma LR. Use of certain bio-products for insect-pest control. Indian J Tradit Knowledge. 2006;5(1):79-82.
6. Mallikarjuna J, Kumar CTA, Chakravarthy AK, Santosh R. Seasonal incidence and abundance of pod borer in Dolichos bean in Bengaluru, Karnataka. Curr Biotica. 2012;6(1):107-112.
7. Singh NK, Kumar D, Kumar N, Singh DN. Combining ability for yield and its components in pea. Ann Agric Res. 2001;22(24):570-575.
8. Steel RGD, Torrie JH. Principles and procedures of statistics. 2nd ed. New York: McGraw-Hill Book Company; 1980.
9. Vaibhav V, Singh G, Deshwal R, Maurya NK, Vishvendra. Seasonal incidence of major pod borers (Etiella zinckenella Treitschke) and (Helicoverpa armigera Hub.) of vegetable pea in relation to abiotic factors. J Entomol Zool Stud. 2018;6(3):1642-1644.
10. Yadav JL, Chauhan R. Evaluation of insecticides against larval population of Etiella zinckenella Treitschke on field pea. Int J Crop Agric. 2000;18(2):169-172.