J. Hort. Sci. Vol. 1 (1): 33-38, 2006 Development of IPM package with safe pesticide residue: 1. Cabbage Debi Sharma, A. KrishnamoorthyS P. N. Krishna Moorthy', Girija GanesanS A. K. Ahuja and M. D. Awasthi Division of Soil Science & Agricultural Chemistry Indian Institute of Horticultural Research Hessaraghatta Lake Post, Bangalore-560089, India. E-mail; dsharma@iihr.ernet.in ABSTRACT An IPM module with safe pesticide residues on cabbage, with already proven treatments such as carbosulfan, dimethoate, cypermethrin+ profenofos and mancozeb under chemical method of control; NSP, Bacillus thuringiensis and Trichogramma bactrae under non chemical method of control were revalidated individually and in combination. Six releases of parasitoid T. bactrae at weekly intervals starting from 12 days after transplanting or spray of NSP 4% at 10-15 days interval, 4 times, starting from 20 days after transplanting, foliar spray of dimethoate and mancozeb gave good control of aphids, leaf blight and black rot respectively.Based on the effectiveness of the treatment and pesticide residues below their permissible levels in cabbage at harvest, a module was developed and tested in the field. The IPM package thus developed was found to control the pests effectively and at the same time the residues on the crop were within the safe limits. Key words: Cabbage, biological control, IPM, pesticide residues INTRODUCTION Cabbage (Brassica oleracea L. var. capitata) is an important vegetable crop, grown throughout the year and in many parts of India, under assured irrigation. The hybrids grown under intensive cultivation, indiscriminately receive very high doses of pesticides resulting in development of resistance in many pests, outbreak of secondary pests and accumulation of pesticide residues in the final produce. Pesticide residue studies carried out under All India Co- ordinated Research Project on Pesticide residues, ICAR, India, revealed that 62.6% of the farm gate samples of cabbage contained residues of which 7% were above legally permissible levels (Agnihotri, 1999). These residues on cabbage pose a health hazard for the consumer since it is consumed raw as salad and also added to a variety of preparations. International market standards demand very low or zero pesticide residues in exportable vegetables. Therefore, development of integrated pest management (IPM) package for vegetables having pesticide residues at or below permissible levels is necessary in the national context. While a great deal of work has been carried out on IPM of cabbage in India (Krishnaiah et at, 1981; Krishna Moorthy and Krishna Kumar, 2000, 2001) and abroad (Becker, 1989; Finch, 1993; Pollard, 1991), all of these deal with control of either a particular insect or disease. There is no single package for the integrated control of insects and diseases together while ensuring low pesticide residues in cabbage at harvest. The present study is thus aimed at development of an IPM package for cabbage with safe pesticide residue level. MATERIAL AND METHODS A study on the development of pesticide residue free IPM package for cabbage was carried out during the period 2000 - 2003 at Indian Institute of Horticultural Research, Hessaraghatta, Bangalore (12" 58' N, 77" 35' E). The major pests and diseases dealt with during the study were diamondback moth (DBM), Plutella xylostella (L.); borers, Helicoverpa armigera (Hubner), Spodoptera litura (R), aphid, Brevicoryne brassicae (L.), Altemaria leaf blight, Altemaria brassicae (Berk.) and black rot, Xanthomonas campestris pv campestris. Cabbage variety Krishna (F, hybrid) was grown as per recommended package of practices. Seedlings in the nursery were well protected using 80 mesh nylon net to avoid egg laying by DBM at seedling stage itself. The seedlings were transplanted in an area of 150 m^ after dipping in a solution containing cypermethrin (0.5 ml/1) and mancozeb (2 g/1) for 30 minutes. A spacing of 50 cm X 50 cm was followed and a dose of 120 N: 80 P: 80 K was applied to the soil. A paired row of Indian mustard 'Division of Entomology and Nematology ^Division of Plant Pathology mailto:dsharma@iihr.ernet.in Debi Sharma et al was sown for every 25 rows of cabbage at the time of transplanting (Srinivasan and Krishna Moorthy, 1991). Chemical Control Although several insecticides were used for the control of pests on cabbage, carbosulfan (Brown and Hargreaves, 1979) and cypermethrin + profenofos (Mohan, 1987) were evaluated using exploded design. In the first trial, carbosulfan @ 0.025% was sprayed on the crop at fortnighdy intervals from 7* day after planting (DAP) for control of all the pests. A total of 5 sprays were given. To assess the efficacy of the pesticide, a control treatment with 25 m^area was also maintained simultaneously without any pesticide spray. Observations were made on the population of DBM, aphids and a DBM parasitoid, Cotesia plutellae Kurdj. A combined insecticidal formulation containing cypermethrin and profenofos (Mohan, 1987) was sprayed @ 0.08% from 12 DAP at fortnightly intervals for the control of pests of cabbage in the second trial. A total of 5 sprays were given. Two foliar sprays of dimethoate @ 0.5 ml/1 (Mallapur et al, 1994) at an interval of 15 days was given to control aphids. Foliar spray of the fungicide mancozeb @ 2.0 g/1 was given at 60 days after transplanting to check the incidence of Altemaria leaf blight and black rot (Jayakumar et al, 1995). Disease scoring was done as per the 0-5 scale (Wheeler, 1969). Validation of non-chemical control Several botanical insecticides and biocontrol agents were evaluated singly or in combination for control of cabbage pests in the third trial. These were ( i ) neem seed powder (NSP) 4% (Krishna Moorthy and Krishna Kumar, 2000) - 4 sprays, (ii) Bacillus thuringiensis var. kurstaki (Bt) (Krishnamoorthy et al, 2003) -4 sprays @ 1 g/1, (supplied by Wockhardt life Sciences Ltd. Mumbai, India) (iii) 6 releases of laboratory mass-bred egg parasitoid, Trichogrammatoidea bactrae Nagaraja and Nagarkatti @ 40,000 to 60,000 adults/ha (Singh et al, 2004) at weekly interval from 12 DAP for the control of DBM and (iv) three sprays of Bt and six releases of T. bactrae. (Anon., 2001). Statistical analysis of the data obtained was carried out between treatment and control, in each case. Residue analysis The pesticides used in chemical control trials were evaluated to find whether such applications resulted in persistence of harmful residues on the cabbage heads at harvest. Cabbage heads ready to harvest were collected after 3 and 5 days of the last foliar spray treatment of each pesticide. These were chopped into ~ 1 cm pieces, mixed and quadrisected. A representative sample of 50 g was drawn in triplicate for analysis of residues of each pesticide. Residues of carbosulfan and its major metabolite carbofuran were determined by blending the cabbage sample in hexane - isopropanol (1: 1, V/V) solvent mixture in a Waring blender. The residues were thereafter partitioned into hexane, cleaned up from other co-extractives by florisil adsorption column chromatography and determined by GLC (Leppert et al, 1983). Residues of dimethoate in cabbage heads were analyzed by GLC (Anon., 1984). The residues of mancozeb were extracted by hydrochloric acid digestion followed by trapping of evolved carbon disulfide (CS^) into Viles reagent. The residues were finally determined as total quantity of CS^ evolved by spectrophotometric method (Keppel, 1971). The residues of ethylene thiourea (ETU), a toxic metabolite of mancozeb, were also analyzed in the samples by HPLC (Smith et al, 1982). The residues of profenofos were analyzed by extraction in acetone + hexane and determined by GLC as per Chen et al (2001). All the analytical methods were standardized in the laboratory and their efficiency ascertained by suitable recovery experiments. RESULTS AND DISCUSSION Chemical control In the first trial (2000 -2001), DBM population was observed throughout the cropping period but at low level. The mean population of DBM was 1.66/plant in treatment as compared to 0.89/plant in control. Similarly, population of aphids was higher in treated plot (0.16/plant) as compared to control (0.00/plant) (Table 1). Carbosulfan treatment seemed to suppress the population of parasitoid, C. plutellae in cabbage as no cocoons of Cotesia were observed in treated plots (Table 1). Observations made on the population of S. litura, H. armigera and leaf webber showed that the population of these were uniformly low in all the trials. In the second trial, it was observed that the aphid population in cypermethrin + profenofos treated plot ranged from 0 to 4 with a mean value of 0.62/plant throughout the crop period, whereas, in control it ranged from 0.2 to 14 with a mean of 4.32/plant. The mean DBM population, however was higher in treated plot (1.08/plant) as compared to the control plot (0.31/plant). The combination insecticide had no effect on the population of Cotesia (Table 1). Thus, carbosulfan and combination insecticide, cypermethrin + profenofos, had no effect in controlling these pests of cabbage with the former having deleterious effect on the J. Hon. Sci. Vol. 1(1): 33-38, 2006 34 Development of IPM package with safe pesticide residue: 1. Cabbage Table 1. Effect of Treatment various treatments on the incidence of DBM, No of DBM / plot Treated Control cabbage aphid and DBM parasitoid No. of cabbage aphid / plot Treated Control in cabbage. No. of DBM parasitoid Cotesia plutellae / plot Treated Control Carbosulfan Profenofos + Cypermethrin NSP Bt T. bactrae NSP + T. bactrae Bt + I bactrae 1.66 1.08 0.61 0.76 1.53 0.48 0.51 0.89 0.31 2.88 2.88 2.88 1.43 1.43 0.16 0.62 0.27 1.15 10.48 1.36 4.71 0.00 4.38 3.07 3.07 3.07 5.71 5.71 0.00 0.16 0.00 0.07 0.10 0.02 0.06 0.10 0.10 0.20 0.20 0.20 0.14 0.14 principal natural enemy, C. plutellae. It was not possible to assess the efficacy of carbosulfan against aphid population as no aphid population was observed in control for comparison. However, combination insecticide profenofos + cypermethrin was found to be effectively controlling aphid in a separate trial. Spray of mancozeb resulted in considerable reduction of the incidence of disease, Altemaria leaf blight in treatment as compared to that in control (Table 2). Similar observations for disease incidence of black rot of cabbage also showed reduction of disease incidence in treatment as compared to control. The per cent disease index (PDI) for blight was 19.25 as compared to 52.25 in control while the same for black rot was 15.45 as against 36.01 in control. Non-chemical control The incidence of DBM was less in treatments in which NSP 4%, Bt and egg parasitoid {T. bactrae) were used alone or in combination, compared to control. These treatments were also better than the chemical control (Table 1). Among non-chemical methods of control, NSP 4 % controlled DBM as well as aphids better than egg parasitoid and Bt applications. The aphid population in treatments where egg parasitoid or Bt was used remained the same or slightly higher. There were fewer cocoons of C. plutellae available in treatments than in control. But it was not due to direct toxic effect on C. plutellae; rather, there was indirect deleterious effect of NSP on egg parasitoid. The population of C. plutellae was found to be less because of fewer number of DBM larvae available for the larval parasitoid to parasitise in these treatments. However, among the various treatments, use of egg parasitoids along with Bt or NSP resulted in better reduction of DBM population than release of egg parasitoid alone. Residue analysis The results obtained from residue analysis (Table 3) revealed that repeated foliar application of carbosulfan resulted in persistence of carbosulfan as well as its toxic metabolite, carbofuran in cabbage heads above the prescribed maximum residue limit of 0.1 ppm. It is thus not advisable to apply carbosulfan on cabbage heads at harvest as its residues (0. 14 - 0.65 ppm) persist at non permissible levels for upto 5 days after the last spray . Carbosulfan residues (0.05 - 0.27 ppm), have been similarly found to persist above permissible levels even on 15* day after last spray in brinjal (Rajeswaran et al, 2004). Treatments of combination pesticide cypermethrin + profenofos resulted in persistence of 1.26 and 0.72 ppm of residues of profenofos at harvest carried out at 3 and 5 days after last treatment (DALT) respectively. The MRL of profenofos in cabbage is 1 ppm; therefore, the cabbage heads were safe only at 5 DALT from the point of residue persistence of profenofos. Residues of 0.025 ppm of profenofos have been found on the 6 DALT in spring onion (Talebi and Ghassami, 2004), however, no reports regarding profenofos residues in cabbage have been found in literature. Cypermethrin residues present on cabbage heads were 0.389 and 0.216 ppm at 3 DALT and 5 DALT respectively, and since MRL of cypermethrin in brassica and leafy vegetables (MRL of cypermethrin in cabbage heads is not yet established) is 1 ppm, the cabbage heads could be considered safe for consumption at 3 DALT itself from the point of view of residue persistence of cypermethrin on cabbage heads. Similar results have earlier been obtained by Babu et al (2001) who recommended a Table 2. Effect of mancozeb on Alternaria leaf blight and black rot in cabbage SI. No. Treatment 1 Before mancozeb spray 2 Three days after mancozeb spray 3 Per cent reduction in disease incidence / Hort. Sci. Vol. 1(1): 33-38, 2006 Treatment (Mean Alternaria leaf blight 30.05 19.25 33.00 35 PDI) Black rot 20.53 15.45 20.56 Control (Mean Alternaria leaf blight 40.35 52.25 PDI) Black rot 30.03 36.01 Debi Sharma et al Table 3. Persistence pattern of pesticide residues in cabbage heads Sl.No. 1 2 3 4 Pesticide Mancozeb ETU (Metabolite) Carbosulfan Carbofuran (Metabolite) Profenofos Cypermethrin Ditnethoate BDL = Below detectable limit; DALT = Table 4. Sl.No. Rate of application 2.0 g/1 1.0 ml/1 1.5 ml/1 0.5 ml/1 = Days after last treatment No. of sprays 1 5 5 5 2 Mean residues (mg kg-') 3 DALT 5 DALT BDL BDL BDL BDL 0.650 0.140 0.340 0.560 1.261 0.720 0.389 0.216 1.264 0.647 Pesticide residue free/safe IPM module for cabbage (seed treated previously) Stage Operation MRL (mg kg-') 3.00 0.10 0.10 1.0 1.0 1.0 Target pests Remarks Safe Unsafe Safe at 5 DALT Safe Safe at 5 DALT 1 Nursery preparation 2 Nursery Nursery one day before transplanting Transplanting 5 Transplanted crop Drench nursery with captan @ 2g/l Apply carbofuran @ 0.5 kg a.i/ha to nursery Spray nursery with copper oxychloride @ 3 g/1 on IS"" and SO"" days after sowing Spray nursery with Bt @ 1 g/1 on 10* days after sowing Netting with 80 mesh Spray nursery with Bt @ 1 g/1 and metalaxyl-mancozeb @ 2 g/1 1. Sow paired row of mustard for every 25 rows of cabbage at the time of transplanting. 2. Plant cabbage at 50 x 50 cm instead of 50 X 45 cm as followed by farmers. Six releases of parasitoid Trichogrammatoidea bactrae (50,000 adults/ha) at weekly intervals from 12 days after transplanting. Or Spray pulverized NSP 4 % at 10-15 days interval 3-4 times from 20 DAP. Or Spray Bt @ 1 g/1 at 10-15 days interval 3-4 times 20 DAR Spray dimethoate, 0.5mlA Two to three sprays of dichlorvos, 1 ml/1 to border mustard to protect the foliage as and when required (2 - 3 sprays). Removing basal disease affected leaves in the morning Need based application of mancozeb 0.25 % Damping off Soil borne insects like ants, termites etc. Damping off and downy mildew DBM DBM etc. DBM Downy Mildew DBM and other pestsLike aphids, leaf webber etc., (optional). Bacterial rot and Altemaria. DBM DBM and other pests like aphids, leaf webber etc. DBM and other lepidopterous pests. Aphid (need based) Saw fly and other pests (optional) Bacterial rot, Altemaria and Downy mildew Bacterial rot, Altemaria and Downy Mildew. waiting period of 3 days for cypermethrin in cabbage. 1.26 and 0.65 ppm were the residues of dimethoate present in cabbage heads at 3 and 5 DALT respectively. The MRL of dimethoate in cabbage is 1 ppm, therefore, the cabbage heads were safe for consumption at 5 DALT if sprayed with dimethoate. In Rumania, a study had recommended a waiting period of 7 days for dimethoate residues in tomatoes, cucumbers and egg plants (Flora and Isac,1972). The residues of mancozeb and its major metabolite, ethylene thiourea were found to be below detectable limit at 3 and 5 DALT (Table 3). Jayakumar et al (1995) had also recommended a waiting period of 2 days for mancozeb residues in tomato. Thus, it was observed that considering residual persistence among the chemicals used for control of cabbage pests, dimethoate can be recommended for control of aphids and mancozeb can be used for the control oi Altemaria leaf blight and bacterial rot as these are safe to be applied at harvest stage of cabbage. Thus, it was seen that, six releases of parasitoid, T. bactrae (50,000 adults/ha) at weekly intervals from 12 days / Hort. Sci. Vol. 1(1): 33-38, 2006 36 Development of IPM package with safe pesticide residue: 1. Cabbage after transplanting or spray of NSP 4 % at 10-15 days interval (4 times) from 20 DAP gave good control of pests. Among insecticides, dimethoate could be used for the control of aphids as need based pesticide in all parasitoid release plots as its residue is within the safe limit at 5 DALT (Table 3). Incorporating the above results a pesticide residue free or safe IPM module was developed (Table 4). Earlier, numerous reports have indicated the efficacy of various plant protection agents for cabbage IPM, for instance, Bt products in combination with insect growth regulator, chlorfluazuron, have been highly recommended for control of DBM in Papua New Guinea (Saucke, 1994) and as an important option for IPM in cabbage. Similarly, Setiawati (2000) indicated that Spinosad 25 SC was suitable for controlling DBM and cabbage head caterpillar. However, in this study, for the first time a complete cabbage IPM module was developed taking consumer safety into account. The cabbage heads grown using this module will be free from harmful pesticide residues. A C K N O W L E D G E M E N T The authors gratefully acknowledge financial assistance received from the National Agricultural Technology Project (NATP) under ICAR for carrying out the above study. R E F E R E N C E S Anonymous, 1984. Indian Standard Method for determination of dimethoate residues in food commodities. IS: 11021-1984. Anonymous, 2001. IIHR Annual Report, 2000-2001, p 83, IIHR, Hessaraghatta, Bangalore, India Agnihotri, N.P. 1999. Pesticide safety evaluation and monitoring. AICRP on Pesticide Residues, Division of Agricultural Chemicals, lARI, New Delhi, 173p. Babu,T.R., Sultan, M.A., Reddy.K.N., Reddy, D.J. 2001. Dissipation of quinalphos and cypermethrin residues in cabbage. Indian J PI Prot., 29:144-145. Becker, R.F. 1989. Cultural practices and cultivar selection as the foundation of a cabbage IPM program. Trans.Illinois State Hortil. Soc, 123:28-31. Brown, J.D. and Hargreaves, J.R. 1979. Control of cabbage pests. Queensland Agril J., 105:222-228. Chen, Y.J., Lu, Y.H., Zhang J., Liu J and Wen X.M. 2001. Extraction and analysis of profenofos residue in tomato and cabbage by gas chromatography - flamephotometric detector. Se Pu, 19:283-5. Finch,S. 1993. Integrated pest management of the cabbage root fly and the carrot fly. Crop Prot., 12:423-430. Floru, S. and Isac, M.1974. Persistence of dimethote residues in fruits and vegetables. Analele Institutului de Cercertari pentru Protectia Plantelor, 19:487-490. Jayakumar, R., Habeebullah, B and Regupathy, A. 1995. Evaluation of mancozeb residues in tomato. Pestic. ResJ.,7:Sl-8S. Keppel, G.E. 1971. Collaborative study of the determination of dithiocarbamate residues by a modified carbon disulfide evolution method. / . Assoc Offic Anal Chem., 54:528-532. Krishnaiah, K., Mohan N.J. and Prasad, V.G. 1981.Efficacy of Bacillus thuringeiensis Ber for the control of lepidopterous pests of vegetable crops. Entomon. 6:87-93. Krishnamoorthy, A., Rama, N., Mani, M., Pattar, G.L. 2003. Biological control of diamond back moth, Plutella xylostella (Linnaeus) in cabbage, integrating egg parasitoid, Trichogrammatoidea bactrae Nagaraja with trap crop. 2003. In : Biological control of lepidopteran pests-Proc. Sym. Biol. Cont. Lepidopteran Pests, July, 17-18, 2002, p. 275. Krishna Moorthy, P.N. and Krishna Kumar, N.K. 2000. Efficacy of neem seed kernel powder extracts on cabbage pests. Pest Manag Hortil. Ecosys., 6:27-31. Krishna Moorthy, PN. and Krishna Kumar, N.K. 2001. IPM in crucifer, legume and cucurbit vegetables. In : P.Parvatha Reddy, Abraham Verghese and N.K.Krishna Kumar (eds.). Integr Pest Manag. Hortil. Ecosys. Capital Publishers, New Delhi, pp. 81-92. Leppert, B.C., James, CM., Robert, C.H. and Glenn,H.F. 1983. Determination of carbosulfan and carbofuran residues in plants, soil and water by gas chromatography. J. Agric. Food Chem., 31:220-223. Mallapur, C.P, Bhat, N.S. and Lingappa, S. 1994.Control of cabbage pests by insecticides. J Maharashtra Agril. Univ., 19:259-261. Mohan, N.J. 1987. Evaluation of new insecticides for the control of cabbage pests. Pesticides, 21:49-54. Pollard, GV. 1991. Constraints to IPM development and a strategy for management of tomato and cabbage pests in Trinidad, West Indies. Trop Pest Manag., 37:59- 62. Rajeswaran, J., Merlinkamala, I., Chandrasekharan, S., Jayakumar, R. and Kuttalam, S. 2004. Harvest time residues of carbosulfan in brinjal fruits. / Fd. Agric. Environ., 1:216-211. Saucke, H. 1994. Selective bioinsecticides selective chemical insecticides: Important options for integrated pest management (IPM) in cabbage. J. Hort. Sci. Vol. 1 (1): 33-38,2006 37 Debi Sharma et al Harvest-Port Moresby, 16:16-19. Setiawati, W. 2000. Controlling of diamondbackmoth (Pleutella xylostella L) and cabbage head caterpillar {Crocidolomia totalis Zell) by using Spinosad 25 SC and its effect on parasitoid Diadegma semiclausum Hellen. Jurnal Hortikultura (Indonesia), 19:30-39. Singh, K.J., Jalali, S.K., Rabindra, J.R., Rao, N.S. and Lalitha, Y. 2004. Role of egg parasitoid, Trichogra- mmatoidea bactrae Nagaraja alone and in combination with dichlorovos in the management of Plutella xylostella (L.) on cabbage. / Biol Cont., 18:135-139. Smith, R.M., Madahar, K.C., Salt W.G. and Smart, N.A. 1982. Degradation of ethylene thiourea on lettuce. Pestic. Sci., 23:337-349. Srinivasan, K. and Krishna Moorthy, RN. 1991. Mustard plants trap major cabbage pests. Indian Farming, 40:11-12. Srinivasan, K. and Krishna Moorthy, RN. 1993. Evaluation of neem products and other standard chemicals for the management of major pest complex on cabbage: Comparison between standard spray regime and IPM involving mustard as a trap crop. In: Neem and Enviornment, Vol.1, (eds.) R.R Singh, M.S.Chari, A.K. Raheja, and W.Kraus. Oxford and IBH Publishing Co. (Pvt.) Ltd., New Delhi and Calcutta, pp. 447-458. Telebi, K. and Ghassami, M.R. 2004. Residues of Profenfos in spring onion. Commun. Agric. Appl Biol. Sci., 69:799-802. Wheeler, B.E.J. 1969. An introduction to plant disease. John Wiley, London, U.K., 301 pp (MS Received 6 March, 2006 Revised 2 May, 2006) J. Hon. Sci. Vol. 1 (1): 33-38, 2006 38