SEASONAL INCIDENCE OF HELICOVERPA ARMIGERA ( HUBNER ) IN CHICKPEA ECOSYSTEM IN CORRELATION WITH WEATHER PARAMETERS

Chickpea (Cicer arietinum L.), commonly known as Bengal gram, gram or chana , originated from South Western Asia, is an important rabi pulse crop of India which has been considered as ‘King of Pulses’ (Bhatt and Patel, 2001). India ranks first in the production and consumption of chickpea (Cicer arietinum L.) in the world. Chickpea is a most important pulse crop of India which is mostly grown under dry land condition with heavy cloudy soil. It is a rich source of nutritional values in the diet of Indian people because of containing 21.5 per cent protein, 64.5 per cent carbohydrates and 4.5 per cent fat (Ahlawat and Omprakash, 1996) which is comparatively deficient in the cereals and oilseeds. Its green leaves and pods are used as green vegetables and germinated grains for breakfast and other delicious dishes by the people in their daily meals. In India, Madhya Pradesh, Rajasthan, Maharashtra, Uttar Pradesh, Andhra Pradesh, Karnataka, Chhattisgarh, Bihar and Jharkhand are major chickpea producing states. In Rajasthan chickpea is cultivated in an area 1923.00 thousands hectares with a production of 1640.40 thousands tones with a productivity of 853 kg/ha during 2013-14 (Anonymous, 2014-15). There is steady decline in the area, production and productivity of the crop. Various factors responsible for low production and productivity of chickpea are; poor genetic based, weeds, diseases and insects pests. Insect pests are the main constraints which limit the production of chickpea. Chickpea is infested by 57 species of insect pests and other arthropods in India; however, the major insect pest of chickpea is the gram pod borer, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) which is the most noxius, polyphagous, multivoltine and cosmopolitan pest commonly called as gram pod borer, tomato fruit borer or American boll worm ,Prabhakara Rao et al.(2001). It is most serious pest of important agricultural crops like tomato, cotton, chickpea, pigeonpea and besides cereals, oil seeds and vegetable crops etc, but it mainly attacks chickpea (Jat and Ameta, 2013). It is known to feed on 182 species of plants belonging to 47 families in India (Sithanantham, 1987 and Panwar, 1998). It has a wide host range, and feeds on more than 250 crop species, Kranthi et al. (2002). High polyphagy, mobility, reproduction rate, and diapause are major factors contributing to its serious pest status (Fitt, 1989 and Sharma et al., 2005). The gram pod borer begins infestation at the seedling stage and later feed on the flower and developing seeds in pods until crop maturity (Mandal and Roy, 2012). At the same time adequate ecological data is prerequisite for integrated pest management, which can therefore be enhanced after determining the seasonal abundance (Mathur et al., 2003). A single caterpillar of this insect can damage 25-40 pods (Sanap and Deshmukh, 1987). It has been reported as a prolific pest of chickpea and caused yield losses mainly due to pod damage which range from 1438 per cent, whereas if the environmental conditions are congenial to H. armigera, then pod damage goes up to 90-95 per cent in Madhya Pradesh (Sachan and Katti, 1994; Pandey and Ujagir, 2008). To control this insect pest numbers of chemical insecticides are used injudiciously which result lead ABSTRACT An experiment trail was conducted to determine the seasonal incidence of Helicoverpa armigera in chickpea ecosystem was carried out during rabi season at experimental farm, Rajasthan college of Agriculture, Udaipur (Rajasthan). It was observed that incidence and population fluctuation of this pest was much dependent on the prevailed weather parameters during the crop season. The population of H. armigera was recorded during entire crop season from 48th standard meteorological week (1.12 and 1.00 larva per meter row length) to 10th standard meteorological week (0.74 and 0.46 larva per meter row length) during 2013-14 and 2014-15 respectively. The highest mean larval population of H. armigera 1.48 and 1.68 larva per meter row length was observed in 6th and 7th standard meteorological week during 2013-14 and 2014-15 respectively. When the mean atmospheric temperature (oC) was 18.30 and 20.20 and relative humidity were 50.10 and 54.80 per cent. Population dynamics of H. armigera was significant positively correlated to temperature (r= 0.60 and r= 0.65) while non significant negative correlation was recorded with relative humidity (r=-0.46 and r= -0.20) during 2014-15 and 2015-16 respectively.