BIOLOGICAL CONTROL OF PESTS THROUGH PADDY CUM FISH (MURREL) CULTURE IN PADDY ECOSYSTEM AND ITS PROSPECTUS

S. USHA MANI ANAND

Associate Professor, Department of Zoology, Maha Rajah (A) College, Vizianagaram, E-mail: [email protected]

Abstract - Pesticide usage is hazardous to human health. Pesticides will destroy the biodiversity of paddy field ecosystem, which leads to the degradation of fertility and yield from the soil. This can be rectified by paddy cum edible fish culture. Channa striatus (murrel) can tolerate high temperature due to the presence of accessory respiratory organs. Channa, being carnivorous found suitable for eradicating pests in paddy fields. The valuable, tasty, rejuvenating, therapeutic and pain reducing flesh of live murrel is available to rural at affordable price. Murrels were found to be biological control agents of pests in the fields.

Keywords - biological control; Channa striatus; murrel; carnivore; accessory respiratory organs; pesticide; paddy cum fish culture;

I. INTRODUCTION urbanization and deforestation (Aminur Rahman, 2013). According to IUCN status it has been listed While applying pesticides in rice fields, some farmers among the 66 LR-nt fish species in (Molur and are falling ill and getting admitted in to the hospitals, Walker,1998) The gene pool of this valuable species becoming a burden to their families instead of feeding should be protected to preserve the biodiversity. them, losing their livelihood and dying eventually Channa is used to reduce post natal and post surgery (Eenadu, 2017). Fish can be used as biological pains as its flesh has wound healing property ( Mat control agent to control pests. Pests use the stagnant Jais et al.,1994). The world production of murrel in water of rice fields as their breeding place and the 1991 was 4200 ton and 92% of which was produced adults infest the paddy plant (Chandra, et al 2008). in (FAO, 1993). The present study deals Paddy cum fish culture will reduce the usage of with the pest devouring nature of Channa striatus in pesticides, provides nutritious diet to the and the existing ecological conditions of the rice fields of protects the environment, fertility of the soil and Vizianagaram district. biodiversity In and rice was II. MATERIALS AND METHODS developed in the mid 1800s (Kuronoma, 1980).Experiments in indicate that the organic The study was carried out in kharif season from nitrogen, alkaline nitrogen and total nitrogen in the September to December 2017. soil are consistently higher in fields with fish than in 2.1. Field modification and design for paddy cum the control fields without fish (Wu, 1995). On an fish culture: average control plots used 23% more than 2.1.1. Experimental design the rice- fish plots (Li, et al., 1995).The fish affect Paddy plot was divided into two parts by constructing nitrogen cycle in rice field. Cagauan (1993) found a dyke between them. One part was the Experimental that a rice field with fish has a higher capacity to (EF) and the other was the Control farm (CF). produce and capture nitrogen than one without fish. 75% of the EF was developed for paddy cultivation Rice fish culture has received greater attention in and 25% of it was developed into trenches for fish recent times because of the benefits made possible farming. Whole control farm was developed for through this practice. Cagauan observed that the fish paddy cultivation. plays an important role in the nutrient cycle of rice 2.1.2. Construction of Trenches for fish dwelling field ecosystem: 1. Release of fixed nutrients from Trenches were dug on two adjacent sides of the soil to water when the fish swims about and disperses moderately sloping paddy field. These trenches had soil particles when disturbing the soil water interface, one foot depth to hold an average of 30 cm of water 2. Fishes make the soil more porous which facilitate in the field for three quarters of the growing season. the root penetration of rice plants. Fish also effect the 2.1.3. Construction of dykes of the field phosphorous cycle. Phosphorous is fixed in the soil. The soil obtained from the trenches was used for Fish by their movements disturb the soil, increase the dyke construction. The dyke was built in layers of 15 porosity and promote phosphorous transfer to the soil. to 25 cm in thickness and water was sprinkled over Murrel is an edible freshwater fish of Asia and Africa the previous layers. Each layer was rammed well (Ng and Lim, 1990). It is an endangered species until clods were flattened to have good adhesion because of overfishing and loss of habitat due to between successive layers. The dyke was

Proceedings of ASAR International Conference, 11th March, 2018, Bengaluru, India 55 Biological Control of Pests through Paddy Cum Fish (Murrel) Culture in Paddy Field Ecosystem and its Prospectus strengthened and raised higher up to nearly 70 cm 105 120 29 91 76 height so that it was 30 to 35 cm above the water 110 115 28 87 76 level of the paddy cum fish culture area. Grass was grown on the sides of the dyke. Care was taken to prevent the presence of humus at the base of the dyke to facilitate proper adherence to the ground. 2.1.4. Transplantation of rice saplings The rice saplings were carefully pulled out from the nursery and transplanted in the entire farm leaving the trenches for fish in EF. In EF the distance between two saplings was reduced by two inches. So that the rice plants will form a canopy while growing and hide the fishes from predators. 2.1.5. Stocking of fish fingerlings Murrel fish was selected to be stocked in rice fields as Fig-1: The population density of Pest-Immatures in CF & EF this fish is a hardy one and can tolerate high temperature, low oxygen, high ammonia, high turbidity prevailing in shallow water (Ng and Lim, 1990). However some difficulty was faced in procurement of seed due to their scarcity in their natural spawning areas which needs intervention of the government. One week after transplantation of paddy seedlings murrel fingerlings were stocked in the EF. One thousand fingerlings were released in 0.5 acre. The murrrel seed was collected from natural spawning grounds. The fish seed were in late fingerling stage. Water temperature increased in the month of September but murrel fish were found to be Fig-2: Presumptive Percantage Consumption of Pest- tolerant. Water level was maintained through Immatures by fish of the field. The main food item of juveniles of Channa striatus 2.1.6. Sampling of pests and their immatures: was eggs, immetures and adults of insects, The samples of pest immatures were collected using a crustaceans, snails, and amphibians. It was also standard 350 ml dipper (John Victor et. al, 1994). observed that murrels feed on aquatic insects in The larval instars, pupae and adults of various pests stagnant waters of rice fields which are harmful to were counted in each dip. The sampling was carried paddy with great interest. Being a carnivorous fish it out thrice a week and the relative number of pests in was found to feed on various pests of paddy. The CF and EF were counted. planthoppers and leafhoppers usually rest on lower

parts of the rice plants to suck plant juices. Channa III. RESULTS AND DISCUSSION being an air breathing fish feeds on them.

Vizianagaram distict is characterized by high The pests, insects and their immatures were estimated humidity and oppressive summer. Water temperature throughout the cultivation of the paddy after increased in the month of September. High water transplantation. There was a considerable reduction in temperature is associated with low dissolved oxygen. the population of pests and their immatures in EF Murrel fingerlings survived at high temperature. when compared to CF (Table-I and Fig-I ). The After applying fertilizer, ammonia level of the EF presumptive percentage consumption of pests, insects increased. But that increase did not have any adverse and their immatures in EF are presented in (Fig-2). effect on murrel survival which indicated the

suitability of the species (Quin et.al., 1997 and Table-1. Population density and presumptive consumption of pest immatures Halwart and Gupta, 2004). According to Saikia et al., Presumptive (2012), most preferred food item for Channa fry and No. of Insect immatures in Consumption by Murrel juveniles was pests and their larvae. Laxmappa and fish Days Vijay Babu (2014) observed that murrels were so Control Experimental Farm Number Percentage significant in biological control of, aquatic insects Farm (FE) (CE) and all kinds of pest population in stagnant water of 1 155 152 0 0 rice fields. 15 150 141 9 6 30 145 120 25 17 CONCLUSION 45 140 80 60 43 60 135 53 82 61 75 132 40 92 70 The biological eradication of pests was clearly 90 120 32 88 73 evident from the observed results. The resultant

Proceedings of ASAR International Conference, 11th March, 2018, Bengaluru, India 56 Biological Control of Pests through Paddy Cum Fish (Murrel) Culture in Paddy Field Ecosystem and its Prospectus benefit for the rural environment and health benefit to [6] John Victor T, B Chandrasekharan, and R Rueben, rural people are envisaged. The paddy cum Channa “Composite fish culture for mosquito control in rice fields in Southern India,” Southeast Asian. J. Trop.Med. Public (murrel) culture was proven to be beneficial to the Health, Vol 25 No 3, 1994,pp. 522-527. rural population. It was also found that murrel fish [7] Kuronoma, K. “Carp cultures in fields,” In can survive in the rice fields of Vizianagaram district R.S.V. Pullin and Z.H.Shehadeh (eds)1980. Proceedings of coping up with its harsh environment. The The ICLARM-SEARCA. Conf. on Integrated – farming systems, Manila, 6-9 Aug, government should take necessary steps to conserve 1979.pp. 167-174. the gene pool of this valuable fish. So that the various [8] Laxmappa. B and G.Vijay Babu, “Present status and advantages of murrels shall also be enjoyed by future prospectus of murrel farming in Andhra Pradesh, India,” Intl. generations. J. Fisheries and Aquatic studies, 2014, 1 (5), pp.22-31. [9] Li, X, W. Huaixun and Z.Yontail, “Economic and ecological benefits of rice-fish culture,” In K.T. Mackay (ed) Rice-fish ACKNOWLEDGEMENTS culture in China International Development Research Center (IDRC). Ottawa, Canada,1995, pp.129-138. The author is grateful to the University Grants [10] Mat Jais, A. M., McCullock and K. Croft, “ Faty acid and amino acid composition in Haruan as a potential role in Commission (UGC), SERO-Hyderabad for financial wound healing,” Gen. Pharmcol.Vasc. Syst., 25 pp. 947-950. assistance to carry out this work. [11] Molur, S and Walker,S “Report of the workshop on - Conservation Assessment and Management Plan (CAMP) for REFERENCES Fresh Water Fishes of India” , 1998. [12] Ng. P.K.L, and K.K.P.Lim, “Snakeheads (Pisces: Channidae): Natural history, biology and economic [1] Aminur Rahman,A.Arshad, S.M.N.Amin and Mariana Nor importance,” Essays in Zoology, Department of Zoology, Shamudin, “Growth and survival of fingerlings of a National University of Singapore, Singapore,1990,pp.127- threatened snakehead Channa striatus (Bloch) in Earthen 152. nursery ponds,” Asian J.Anim.Vet.Adv. 8(2), 2013, pp. 216- [13] , J.G., A.W. Fast, D. DeAnde and R. P. Weidenbach, 226. “Growth and survival of larval snakehead Channa striatus [2] Cagauan.A.G. “Overview of potential roles of pisciculture on fed different diets,” Aquaculture, 148,1997, pp.105-113. pest and disease control and nutrient management in rice [14] Saikia.A.K, Abujami.S.K.S and Biswas.S.P, “ Food and fields, ” Proc. Seminar on “The management of integrated feeding habits of Channa punctatus from the paddy fields of Agro-Pisciculture Ecosystems in Tropical areas, Brussels, Sivsagar District, ,” Bulletin of Environment, 1995, pp. 203-244. Pharmacology and Life Sciences Vol 1. Issue 5, April 2012, [3] Chandra, G, I. Bhatacharjee, S.N. Chettarjee and A. Ghosh, “ pp.10-15. Mosquito control by larvivorous fish,” Indian .J. Med. [15] Wu, L “Methods of rice-fish cultire and their ecological Res.127, Jan. 2008,pp.13-27. efficiency,” In K.T. Mackay (ed) Rice-fish culture in China [4] Eenadu, Telugu daily news paper, Visakhapatnam edition, International Development Research Center (IDRC). Ottawa, dated 14 Oct 2017. pp.15. Canada,pp.91-96. [5] Halwart, M. and M.V.Gupta, “Fish Culture in Rice fields” FAO and The World fish center,2004, pp.77

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