Seasonal incidence of major insect-pests on mustard (Brassica juncea L.) and their correlation with weather parameters

Introduction

Indian mustard (Brassica juncea L.) belongs to the family Brassicaceae or Cruciferae originated from Asia or Egypt. Various varieties of mustard and rapeseed are cultivated around the nation. Mohori (Marathi) is a commonly produced oilseed crop in India, also known as Rai or Sarson in Hindi. A vital component of the human diet is mustard. Since allyl isothiocynates and related chemicals give mustard oil its distinct flavour and pungency, it is highly valued for frying vegetables and fish. Mustard oil is also frequently used for food purposes. (Anonymous., 2019) [1] Protein (28-36 percent), oil (28-32 percent), and essential amino acids (oleic acid, 20-28 percent), linolenic acid, (10-20 percent), and erucic acid, 10-20 percent) are all abundant in mustard seeds (30-40 percent) (Solvanee and Pathak 2016) [12] . With a volume of 68.87 million tonnes, mustard is the second-largest oilseed in the world and has grown to be a significant component of the Indian economy, ranking second in terms of acreage after peanuts (Anonymous, 2021) [2] . India made up 13.14 percent of global production with a total area of 6.23 m ha, an output of 8.57 MT, and a productivity of 14.99 q ha-1. Rajasthan contributes 38.07 percent of the country's land and 43.69 percent of its production. Rajasthan, Haryana, Uttar Pradesh, Madhya Pradesh, Gujarat, Assam, West Bengal, Punjab, and Maharashtra are the primary mustard and rapeseed producing states in India (Anonymous, 2019) [1] . About 43 insect species have been recorded infesting this crop (Khanal et al., 2020) [6] and among these aphids (Lipaphis erysimi L.), saw fly (Athalia lugens proxima L.), painted bug (Bagrada cruciferarum L.), leaf miner (Chromatomyia horticola L.), flea beetle (Phyllotreta Cruciferae L.), cabbage webber and pod borer (Crocidolomia binotalis L.) and cabbage butterfly (Pieris brassicae L.) are the important insect pests. Besides, insect pests like Bihar hairy caterpillar, Spilosoma obliqua L. Walker (Lepidoptera: Arctiidae), Cabbage head borer: Hellula undalis L. Fabricius (Lepidoptera: Crambidae) and Diamondback moth: Plutella xylostella L. (Lepidoptera: Plutellidae) also infest the crop sporadically. Recently tobacco caterpillar (Spodoptera litura L.) has been reported as the major insect pests of mustard in different locations of Orrisa. However, with increase in cropping intensity and the changing cropping patterns under different agro climatic conditions, the pest complex of the crop has changed (Divya et al., 2015) [3] . Brassica crops suffer from heavy damage in yield due to various biotic and abiotic components. Among abiotic factors, its environmental sensitivity is considered to be for most i.e. Instability of mustard plant under different environmental conditions. Kaur and singh (2023) [5] .

Materials and Methods

The present experiment was conducted to study the seasonal incidence of major insect pests on mustard. The field experiment was performed at Department of Entomology Research Farm, VNMKV, Parbhani, Maharashtra, during rabi 2022-23. Sowing was done on 01-12-2022 at research field. Variety Kranti was used for sowing. The sowing was done by dibbling method at spacing of 45 x 20 cm. The Seasonal incidence of major insect-pests of mustard: The observations were made on random selected 10 plants from each plot. The observations on Lipaphis erysimi kalt., Athelia lugens proxima klug. and leaf webber, Crocidolomia binotalis were registered. The number of Lady bird beetles (grubs or adults), green lace wings and syrphid fly maggots per plant/plot were recorded in natural enemies.

Result and Discussion

To study the seasonal incidence of major insect-pests on mustard Seasonal incidence of aphid (Lipaphis erysimi) on mustard

Aphid population data is displayed both table. 2. In Rabi 2022-2023, the number of aphids on mustard varied from 22.12 to 90.25 aphids per 10 cm central twig. Beginning on the 51 st SMW (17-23 Dec.), the aphid infestation persisted until the 12 th SMW (19-25 March) Aphid activity peaked on the fifth SMW, with the following conditions: wind speed, 0.00 mm, evaporation, strong sun shine hours, 3.6 mm, 8.6 hours, 26.7 percent, maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, and prevailing rainfall, respectively. According to Sahoo's (2012) [15] report, the mustard aphid emerged in crops during the 52 nd SMW, with an average population of 3 aphids per 10 cm shoot. SK Mishra and PM Kanwat (2018) [7] suggested that the fourth SMW had the highest reported aphid activity. According to Singh et al., (2018) [11] , the mustard aphid peaked in the eighth SMW with 225.5 aphids/10 cm shoot/plant, having first arrived in crop in the 51 st SMW with a mean population of 2.25 aphids/10 cm shoot/plant. Patel et al., (2019) [10] documented that the mustard aphid population peaked during the 8th SMW with an aphid index of 5.0, started from the 51st SMW.

Seasonal incidence of leaf webber (Crocidolomia binotalis) on mustard

The data on leaf webber larval population is presented in table.2, On the 52 nd SMW, the population of leaf webber on mustard during Rabi 2022-2023 was first noted (24 Dec-31 Dec). Larval infestation varied from 1.35 to 6.45 per plant, and attacks were observed up to the tenth SMW (05-11 March). On February 19-25, the 8th SMW had the highest incidence. At that time, the following conditions were observed: 0.00 mm of precipitation, 30.6 °C of maximum temperature, 12.1 °C of minimum temperature, 88.7 percent, 26.7 percent, 3.6 mm, 8.6 hours, and 3.4 Kmph of wind speed. Nayak et al., (2022) [8] indicated that the leaf webber began infesting the crop in the third or fourth week following sowing, or perhaps the second or third week of December. Following that, the pest population grew until it peaked in the seventh or eighth week following seeding (1 st to 2 nd week of January). After that, the pest population gradually dropped until it vanished during harvest.

Seasonal incidence of mustard sawfly (Athalia lugens proxima)

The data on larval population is represented in table.2. The infestation of sawflies began on the 52 nd SMW (24-31 Dec) and lasted until the 8th SMW (19-25 March), with 2.90-7.45 larvae per plant. The maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, evaporation, bright sun shine hours, wind speed, and prevailing rainfall were all recorded at 0.00 mm, 30.6 °C, 12.1 °C, 88.7 percent, 26.7 percent, 3.6 mm, 8.6 hours, and 3.4 Km ph, respectively, on the 7 th SMW (19 Feb-25 Feb). Pradhan et al., (2020) [16] indicated that a sawfly infestation with a larval population of 0.27 to 1.01 per plant began during the 51 st SMW (17-23 Dec) and lasted until the 9 th SMW (26 Feb-04 March). On the fourth SMW, the peak incidence was noted (22 Jan-28 Jan). Pal & Debnath (2020) [9] concluded that sawfly infestation was initiated from 52 nd SMW (24-31 Dec) Vinyas et al., (2022) [13,14] suggested that the peak incidence of mustard sawfly appeared at the 7th SMW.

Seasonal incidence of natural enemies

The natural enemies played an important role in minimizing the pest population. In the present study, the population of lady bird beetle, Syrphid fly and Green lace wing were recorded. The data is given in table.2, The lady bird beetle was seen to be active during the aphid infestation. The range was 1.20 to 7.34 adults and grubs per plant. The fifth SMW was the day of peak activity. Conversely, the Syrphid fly was seen to be between 1.00 and 2.60 maggots per plant; the maximum number was noted on the fifth SMW. Mishra & Kanwat (2018) [7] concluded that the final week of January saw the pinnacle of coccinellid activity. The second week of January saw the first appearance of syrphid fly maggots, and by the fourth week, their population had peaked. Pal et al., (2018) [9] documented that the 5 th SMW was the location of the lady bird beetle's peak activity.

Correlation of major insect-pests on mustard with weather parameters

Correlation of major insect pests and their natural enemies with the weather parameters are presented in the Table 3

Correlation between aphid and weather parameters

Aphids showed negatively significant correlation with rainfall (r=-0.60*), minimum temperature (r=-0.61*), wind speed (r=-0.55*) and EVP (r=-0.73*). While positively non significant correlation was noted by maximum temperature (r=0.39), morning relative humidity (r=0.61), evening relative humidity (r=0.24) and BSH (r=0.31). Kalita et al., (2016) [4] suggested that aphids showed negatively significant correlation with minimum temperature (r=-0.68*) and positively nonsignificant correlation with BSS (r=0.02).

Multiple regression of weather parameters with mustard aphid

References

1. Anonymous. Agricultural statistics at a glance. Ministry of Agriculture & Farmers Welfare, Department of Agriculture Cooperation & Farmers Welfare, Directorate of Economics and Statistics, 2019. Available from: https://e&s.dacnet.nic.in/PDF/At%20a%20Glance%202 019%20Eng.pdf
2. Anonymous. Worldwide oilseed production, c20202021. 2021.
3. Divya C, Kalasariya RL, Kanara HG. Seasonal incidence of mustard painted bug, Bagarda hiliaris (Burmister) and their correlation with abiotic factors on mustard. J Insect Sci. 2015;28(1):92-95.
4. Kalita RK, Avasthe R, Gopi C, Kapoor C. Seasonal abundance of mustard aphid, Lipaphis erysimi (Kalt.) and saw fly, Athalia lugens proxima (Klug) in relation to abiotic factors and their eco-friendly management. Int J Bio-resource Stress Manag. 2016;7(2):252-257.
5. Khanal D, Maharjan S, Lamichhane J, Neupane P, Sharma S, Pandey P. Efficacy of biorational compounds against mustard aphid (Lipaphis erysimi Kalt.) and English grain aphid (Sitobion avenae Fab.) under laboratory conditions in Nepal. Adv Agric. 2020;4:1-7.
6. Mishra SK, Kanwat PM. Seasonal incidence of mustard aphid Lipaphis erysimi (Kalt) and its major predator on mustard and their correlation with abiotic factors. J Entomol Zool Stud. 2018;6(3):831-836.
7. Nayak US, Das CK, Khuntia A, Pati P, Mohanty TR. Major insect pests of mustard and their integrated management. 2022;9:579-584.
8. Patel RM, Chaudhari SJ, Rabari PH, Patel BC, Dodia DA. Incidence of aphid (Lipaphis erysimi Kalten) in mustard and their fluctuation with biotic and abiotic factors. J Entomol Zool Stud. 2019;7(5):946-950.
9. Singh AK. Foraging by pollinators in pigeon pea. Indian J Entomol. 2018;80(3):711-714.
10. Solvanee OP, Pathak H. An economic analysis of production and marketing in rapeseed mustard crop in Bastar plateau of Chhattisgarh, India. Plant Arch. 2016;16(1):37-44.
11. Vinyas SN, Neharkar PS, Matre YB. Eco-friendly management of major insect pests of mustard (Brassica juncea L.). Biol Forum. 2022;14(3):1577-1551.
12. Vinyas SN, Neharkar PS, Bantewad SD, Matre YB. Varietal screening against major insect pests of mustard (Brassica juncea L.). Biol Forum. 2022;14(4):7-10.
13. Sahoo N, Singh PV, Mukhopadhyay T. A hidden Markov model for collaborative filtering. MIS quarterly. 2012 Dec 1:1329-1356.
14. Pradhan D, Biswasroy P, Naik PK, Ghosh G, Rath G. A review of current interventions for COVID-19 prevention. Archives of medical research. 2020 Jul 1;51(5):363-374.