page 120 Integrated management of the Yellow Mite, Polyphagotarsonemus latus (Banks), on sweet pepper grown under polyhouse S. G. Eswara Reddy1 and N. K. Krishna Kumar2 Department of Entomology University of Agricultural Sciences, GKVK, Bangalore - 560 065, India E - mail: ereddy2001@yahoo.com ABSTRACT Different IPM modules were evaluated for the management of yellow mite, Polyphagotarsonemus latus (Banks) on sweet pepper grown under protected cultivation at the Indian Institute of Horticultural Research, Bangalore. Results indicated that application of module 1(spray of abamectin followed by ethion and abamectin) or module 2 (spray of abamectin followed by profenophos and abamectin) was significantly more effective (3.91-6.58 mites/ leaf) than module 3 (spray of dicofol followed by pongamia oil and neem seed kernal extract (5.79 -6.95 mites/ leaf) in the first two trials (Sept. 2002- Mar. 2003 and June – Dec.2003). IPM modules like module 4 (spray of dicofol followed by release of Amblyseius tetranychivorus and spray of Verticillium lecanii and module 5 (spray of dicofol followed by release of A. tetranychivorus and spray of pongamia oil (9.25-15.53 mites/leaf) were marginally effective during the first two trials. However, in the third trial (Mar. - Sept., 2004) all the revised modules, viz., abamectin followed by dicofol (M 1 ), dicofol-fenazaquin (M 2 ), fenazaquin-pongamia oil (M 3 ) and organic module oxymetrin-neem soap (M 4 ) were effective (2.30-3.03 mites/leaf) against the yellow mite. Key words: IPM, polyhouse cultivation, Polyphagotarsonemus latus, sweet pepper INTRODUCTION Protected (polyhouse) cultivation is gaining popularity in India and is recognized as a useful technology to augment production of high quality vegetables. Sweet pepper, Capsicum annuum L., is one of the vegetables commercially suited for polyhouse cultivation, yielding 100 to 120 t ha-1 compared to 20 to 40 t/ha in open field (Prabhakara et al, 2004). Among different pests reported on sweet pepper, the yellow mite, Polyphagotarsonemus latus (Banks) is a major pest causing yield loss upto 96.4% in North Karnataka (Borah, 1987) and 25% in West Bengal (Ahmed et al, 1987) under open field is reported. Adults and nymphs suck the sap from terminal leaves, auxiliary shoots and developing fruits. Affected leaves become narrow and twisted resulting in downward curling (Eswara Reddy, 2005). Information on yield loss due to P. latus infestation and its management on sweet pepper grown under protected cultivation is lacking in the tropics. Hence, a study was carried out to study the effect of various IPM modules against P. latus on sweet pepper. MATERIAL AND METHODS Experiments were conducted under a polyhouse (30 x 7 m) during September 2002 - March 2003, June - December 2003 and March - September 2004 at the Indian Institute of Horticultural Research, Bangalore. Thirty five day old, indeterminate, hybrid sweet pepper seedlings raised under polyhouse (Indra, Syngenta India Ltd.) was transplanted as recommended (Prabhakara et al, 2004). Experiments were carried out in a Randomized Block Design (RBD) to evaluate six pest management modules in the first two trials. The third trial consisted of five modules. There were four replications and the plot size was 1.75 sq m. Modules were revised during the third season to accommodate one more variable with no chemicals/ pesticides or botanicals. Treatment sprays were imposed as soon as the first infestation of yellow mite, P. latus, was noticed (first spray was given 22 weeks after planting, second and third sprays) 23 and 25 weeks after plantings respectively in the first trial. Correspondingly, it was 12, 15 and 17 weeks in the second trial and 6 and 9 weeks in the third trial. All pesticide sprays were applied with n adjuvant (Teepol, 0.5 ml/l) using a high volume sprayer. Observations on the incidence of P. latus were recorded a day prior to treatment and 7 and 14 days after J. Hort. Sci. Vol. 1 (2): 120-123, 2006 1Present address: Entomologist, E.I.D. Parry (India) Ltd., Research & Development Centre, # 145, Devanahalli Road, Off Old Madras Road, Bangalore–560 049 2 Division of Entomology and Nematology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore - 560 089, Karnataka, India page 121 each spray. The number of nymphs and adults of P. latus were counted under a stereo-binocular microscope from two terminal leaves/plant on 5 randomly selected plants/ treatment. Mature, green sweet pepper fruits were harvested 60 days after planting in all the trials and repeated at regular intervals. Data on incidence of mites were subjected to square root transformation and subjected to analysis of variance (ANOVA). Module details for the experiments are presented in the tables 1 and 2. Rationale of module selection The selected IPM modules were basically derivatives of similar modules evaluated for management of Tetranychus urticae on ornamental crops. This was necessary in the absence of similar work on vegetables. The main logic was to compare the efficacy of the most effective molecule (Abamectin) for management of P. latus and gradual, step- wise replacement of this molecule with moderately effective but less expensive (dicofol) molecules and, if possible, to develop a module using only botanicals and predators. Predatory mite Information regarding phytoseiid mite adults, Amblyseius tetranychivorus (Gupta), was supplied by M/s. Bio-Control Research Laboratories (BCRL), Bangalore, in plastic vials (200 mites/vial) containing artificial diet and bran. The predator was released by sprinkling the bran containing mites on leaves @ 20 mites/plant. RESULTS AND DISCUSSION Among the modules evaluated against P. latus on swet pepper, module 1 (abamectin followed by ethion and abamectin), module 2 (abamectin followed by profenophos and abamectin) and module 3 (dicofol followed by pongamia oil and neem seed kernel extract) were more effective in controlling P. latus (3.91-6.95 mites/leaf) (Tables 3, 4). Module 4 (dicofol followed by Amblyseius tetranychivorus and Verticilium lecanii) and module 5 (dicofol followed by A. tetranychivorus and pongamia oil) recorded moderately high infestation (13.99 -15.53 mites/ leaf). Release of A. tetranychivorus following application of dicofol did not significantly reduce the infestation of P. latus. Similarly, a comparison of module 4 and module 5 indicates that application of pongamia oil was more effective in suppressing P. latus numbers than the application of V. lecanii (Table 3, 4). The efficacy of module 1 and 2 can be attributed to the effect of abamectin on P. latus. Our results are in agreement with the findings of Honnamma Rani (2001) who Table 1: Modules evaluated against P. latus on sweet pepper under polyhouse (September 2002-March 2003 and June-December 2003) Module Spray sequence M 1 Abamectin 0.00095% - Ethion 0.05% - Abamectin 0.00095% M 2 Abamectin 0.00095% - Profenophos 0.05% - Abamectin 0.00095% M 3 Dicofol 0.037% - Pongamia oil 1% - Neem seed kernel extract 4% M 4 Dicofol 0.037% -Amblyseius tetranychivorus - Verticilium lecanii 0.30% M 5 Dicofol 0.037% - A. tetranychivorus – Pongamia oil 1% M 6 Control (No spray) Table 2: Modules evaluated against P. latus on sweet pepper in polyhouse (March -September 2004) Module Spray sequence M 1 Abamectin 0.00095% - Dicofol 0.037% M 2 Dicofol 0.037% - Fenazaquin 0.01% M 3 Fenazaquin 0.01% - Pongamia oil 1% M 4 Oxymetrin 0.0009%- Neem soap 1% M 5 Control (no spray) Table 3: Effect of various modules on management of P. latus on sweet pepper under polyhouse (September 2002- March 2003) Mean number of mites/leaf (Days after spray) Module I spray II spray III spray Mean Pre-count 7 14 Pre-count 7 14 7 14 M 1 46.55 (6.85) 0.00 (0.71)a 0.00 (0.71)a 24.55 (4.99) 0.00 (0.71)a 2.83 (1.82)a 0.00 (0.71)a 0.00 (0.71)a 3.91 (1.96)a M 2 47.55 (6.92) 0.00 (0.71)a 0.00 (0.71)a 28.58 (5.34) 4.68 (2.27)c 5.08 (2.35)c 0.00 (0.71)a 0.00 (0.71)a 5.48 (2.28)b M 3 35.75 (6.01) 0.00 (0.71)a 0.00 (0.71)a 33.43 (5.77) 1.85 (1.53)b 3.53 (2.00)b 0.30 (0.89)b 1.45 (1.40)c 5.79 (2.61)c M 4 36.98 (6.10) 0.00 (0.71)a 0.00 (0.71)a 26.38 (5.16) 23.00 (4.84)e 19.88 (4.51)e 16.50 (4.11)d 12.15 (3.54)d 13.99 (3.89)e M 5 40.93 (6.40) 0.00 (0.71)a 0.00 (0.71)a 24.03 (5.29) 20.43 (4.57)d 18.48 (4.35)d 0.48 (0.98)c 1.33 (1.35)b 9.25 (3.06)d M 6 41.63 (6.48) 73.25 (8.59)b 71.45 (8.48)b 41.00 (6.38) 51.05 (7.18)f 41.93 (4.07)f 24.15 (4.96)e 21.23 (4.66)e 46.29 (7.01)f SEM± 0.11 0.01 0.01 0.20 0.05 0.06 0.04 0.03 0.03 CD (P=0.05) - 0.02 0.03 - 0.10 0.14 0.09 0.08 0.18 Figures in parentheses indicate “x+0.5 transformations Figures in columns followed by the same letter are not significantly different J. Hort. Sci. Vol. 1 (2): 120-123, 2006 Integrated Management of Yellow Mite 121 page 122 reported that dicofol (0.05%), abamectin (0.0007%), ethion (0.1%) and wettable sulphur (0.2%) were more effective against P. latus on chilli and potato under the field condition. Green and Dybas (1990) Onkarappa (1999) and Mallik et al (2002) also reported effect of the same molecules against Tetranychus urticae on rose in polyhouse. Abamectin is also the acaricide of choice in India for control of mites in ornamentals and vegetables grown under protected and open field cultivations. The efficacy of abamectin persists for 35 to 40 days, while other molecules retain their efficacy for 10 to 15 days only. Several reports indicate that dicofol, ethion, profenophos and fenazaquin are also effective acaricides for the management of T. urticae and P. latus on a number of crops (Khalid Ahmed et al, 2000; Honnamma Rani, 2001; Jhansi Rani, 2001; Mallik et al, 2001; Mallik et al, 2002; Anon, 2005). Efficacy should be viewed from the point of reduction in pest population as well as persistence (of the efficacy). Thus, while dicofol may not meet the stringent requirement for export of roses where zero tolerance is advocated, it can be a very important component of IPM in the management P. latus on sweet pepper as this crop is not exported. Hence, use of abamectin may be more advantageous to the floriculture industry whereas the use of dicofol, ethion or pongamia oil is pragmatic for management of P. latus on sweet pepper grown under polyhouse. It is not surprising that in our trials, module 4 (dicofol followed by Amblyseius tetranychivorus and Verticilium lecanii) and module 5 (dicofol followed by A tetranychivorus and pongamia oil) were not effective as predators when released 30 days after the first application of dicofol. A number of workers have observed that A etranychivorus is an effective bio-control agent for control of T. urticae on rose under protected cultivation (Mallik et al, 1998; Jhansi Rani, 2001). Further, dicofol is highly toxic to the predatory mite, A. tetranychivorus, even at nine days from spray (Krishnamoorthy, 1983). Hence, it is likely that the potential of predatory mites is reduced in the presence of dicofol. All revised modules viz., abamectin followed by dicofol (M 1 ), dicofol - fenazaquin (M 2 ), fenazaquin – pongamia oil (M 3 ) and organic module oxymetrin - neem soap (M 4 ) during the third trial were significantly superior (2.30 -3.03 mites/leaf) (Table 5). One of the reasons for choosing polyhouse cultivation is to grow crops with higher yields besides being qualitatively superior. However, there is value addition if the produce is pesticide residue -free or is organically grown. Module 4 (spray of oxymetrin followed by neem soap) shows promise in this direction and may turn out to be extremely useful. Table 4: Effect of various modules on management of P. latus on sweet pepper under polyhouse (June - December 2003) Mean number of mites/leaf (Days after spray) Module I spray II spray III spray Mean Pre-count 7 14 Pre-count 7 14 Pre-count 7 14 M 1 69.60 (8.35) 0.00 (0.71)a 0.00 (0.71)a 25.55 (5.07) 0.65 (1.07)a 1.65 (1.46)c 15.30 (3.95) 0.45 (0.97)a 0.50 (1.00)a 5.51 (1.87)a M 2 72.60 (8.52) 0.00 (0.71)a 0.00 (0.71)a 26.40 (5.09) 0.80 (1.14)b 1.05 (1.24)a 23.10 (4.83) 0.63 (1.06)b 0.63 (1.06)a 6.58 (1.98)a M 3 73.70 (8.97) 0.00 (0.71)a 0.00 (0.71)a 29.30 (5.44) 0.70 (1.09)a 1.35 (1.36)b 21.33 (4.67) 1.23 (1.31)c 1.70 (1.48)b 6.95 (2.10)b M 4 77.23 (8.80) 0.00 (0.71)a 0.00 (0.71)a 27.75 (5.31) 19.55 (4.47)d 16.98 (4.18)e 22.80 (4.81) 21.15 (4.65)d 18.98 (4.41)d 15.53 (3.61)d M 5 76.90 (8.78) 0.00 (0.71)a 0.00 (0.71)a 26.90 (5.19) 16.15 (4.08)c 16.03 (4.06)d 24.33 (4.93) 1.20 (1.30)c 6.35 (2.61)c 10.70 (2.88)c M 6 75.28 (8.69) 94.18 (9.72)b 30.65 (5.57)b 21.90 (4.69) 23.45 (4.89)e 23.08 (4.85)f 25.15 (5.01) 31.10 (5.62)e 48.65 (7.00)e 37.89 (5.98)e SEM± 0.39 0.09 0.07 0.17 0.03 0.03 0.12 0.03 0.04 0.03 CD (P=0.05) - 0.19 0.15 - 0.06 0.06 - 0.06 0.09 0.17 Figures in parentheses indicate “x+0.5 transformations Figures in columns followed by the same letter are not significantly different Table 5: Effect of various modules on management of P. latus on sweet pepper under polyhouse (March - September 2004) Mean number of mites/leaf (Days after spray) Module I spray II spray Mean Pre-count 7 14 Pre-count 7 14 M 1 61.59 (7.87) 0.00 (0.71)a 0.38 (0.94)a 8.05 (2.88) 0.00 (0.71)a 3.05 (1.88)a 2.30 (1.42)a M 2 53.15 (7.32) 0.00 (0.71)a 1.60 (1.45)a 9.68 (3.15) 0.00 (0.71)a 2.38 (1.69)a 2.73 (1.54)a M 3 49.37 (7.04) 0.00 (0.71)a 1.28 (1.33)a 9.83 (3.16) 1.18 (1.29)a 3.23 (1.93)a 3.10 (1.68)a M 4 41.25 (6.36) 0.00 (0.71)a 0.63 (1.06)a 9.15 (3.07) 1.78 (1.51)a 3.58 (2.02)a 3.03 (1.67)a M 5 53.41 (7.33) 90.85 (9.51)b 26.25 (5.17)d 17.20 (4.20) 16.30 (4.10)c 11.45 (3.45)b 32.41 (5.29)b SEM± 0.19 0.42 0.18 0.15 0.14 0.08 0.17 CD (P=0.05) - 2.53 1.11 1.00 0.87 0.47 1.04 Figures in parentheses indicate “x+0.5 transformations Figures in columns followed by the same letter are not significantly different J. Hort. Sci. Vol. 1 (2): 120-123, 2006 Eswara Reddy & Krishna Kumar 122 page 123 Effect of module on yield Fruits harvested from polyhouse grown sweet pepper were completely free from feeding scars. Marketable fruit yield in different modules during the first and second trials indicated that module 1 (abamectin followed by ethion and abamectin) recorded significantly higher yield (97.17- 116.71 t ha-1) and was on par with module 2 (abamectin- profenophos- abamectin) (93.84-95.58 t ha-1) and module 3 (dicofol-pongamia oil-NSKE) (93.02-97.69 t ha-1), followed by module 4 (dicofol- A. tetranychivorus -V. lecani) and module 5 (dicofol-A. tetranychivorus- pongamiaoil). Control recorded significantly low yield (57.16-69.29 t ha-1). All the revised modules during the third trial viz., abamectin-dicofol (M 1 ), dicofol-fenazaquin (M 2 ), fenazaquin-pongamia oil (M 3 ) and oxymetrin-neem soap (M 4 ) were significantly superior (99.29-109.79 t ha-1) to control which recorded less yield (74.36 t ha-1) (Table 6). Resistance to insecticides under polyhouse cultivation has been documented earlier (Anon, 2005). Intensive polyhouse cultivation is practiced round the year and resistance can easily surface in mines under repeated selection pressure. Modular approach for the management of mites can contribute to greater selection pressure. Need based chemical application is a better approach in IPM of vegetables than a modular approach that is better suited for export in floriculture. Based on efficacy, economics and persistence, dicofol application followed by pongamia oil and NSKE, or, fenazaquin followed by pongamia oil, or, oxymetrin followed by neem soap, can be recommended for control of P. latus on sweet pepper grown under polyhouse. ACKNOWLEDGEMENTS Authors are thankful to World Bank aided NATP- MM project on “Protected Cultivation of Vegetables and Flowers in Plains and Hills” for providing funds. Our thanks to Director, Indian Institute of Horticultural Research (ICAR), for providing the facilities. We are grateful to M/s Bio-Control Research Laboratories (BCRL), Bangalore, for providing the predatory mite and Verticilium lecanii for the study. REFERENCES Anonymous, 2005. Annual report, Indian Institute of Horticultural Research (IIHR), Bangalore. Anonymous, 2005. Technical folder, All India Network Project on Agricultural Acarology (ICAR), Department of Entomology, UAS, Bangalore, Karnataka, India. Ahmed, K., Mohamed, M. G. and Murthy, N. S. R. 1987. Yield loss due to various pests in hot pepper. Sweet pepper News Letter. No. 6: 83-84. Borah, D. C. 1987. Bio-ecology of Polyphagotarsonemus latus (Banks) and Scirtothrips dorsalis (Hood) infesting chilli and their natural enemies. Ph.D. thesis, UAS, Dharwad. Eswara Reddy, S. G. 2005. Comparison of pest incidence and management strategies on capsicum and tomato grown under protected and open field cultivation. Ph.D. thesis, UAS, Bangalore. Honnamma Rani, R. 2001. Bio-ecology and control of yellow mite, Polyphagotarsonemus latus (Banks) infesting potato and chilli. M.Sc. (Agri.) thesis, UAS, Bangalore. Jhansi Rani, B. 2001. Efficacy of phytoseid predator, Amblyseius longispinosus Evans, against the spotted spider mite, Tetranychus urticae Koch, on carnation. 7: 64-65. Khalid Ahmed, Purna Chandra Rao, P. and Rao, N. H. P. 2000. Evaluation of new insecticides against yellow mite, Polyphagotarsonemus latus (Banks), in chillies. Pestology 24: 54-57. Krishnamoorthy, A. 1983. Effect of some pesticides on the predatory mite, Amblyseius tetranychivorus (Gupta), (Acari: Phytoseiidae). Entomon 8: 229-234. Mallik, B., Anil, K .N. Onkarappa, S., Shaila, H. M. and Puttaswamy 2002. Management of Acarine and other pests of horticultural plants grown under controlled conditions. International Symposium on Hitech Horticulture, Bangalore, 240-246. Prabhakara, B. S, Prabhakar, M., Hebbar, S. S., Krishna Kumar, N. K., Krishna Murthy, P. N., Girija Ganeshan, Sreenivasa Murthy, D., Srinivas, V., Eswara Reddy, S. G. and Anjula, N. 2004. Greenhouse production of capsicum. Technical Bulletin 22, Indian Institute of Horticultural Research, Bangalore. J. Hort. Sci. Vol. 1 (2): 120-123, 2006 Integrated Management of Yellow Mite 123 Table 6: Effect of various modules on yield for management of P. latus on sweet pepper under polyhouse Module Yield (t ha-1) Sept. 02 –Mar. 03 June-Dec.2003 Mar.-Sept 2004 M 1 97.17a 116.71 a 109.79a M 2 93.84ab 95.58ab 105.00a M 3 93.02ab 97.69ab 102.63a M 4 83.22c 86.71b 99.29a M 5 91.33b 82.01b 74.36b M 6 69.28d 57.16c —— S. Em ± 0.88 8.78 2.71 C.D (P=0.05) 5.32 18.72 16.38 Figures in columns followed by the same letter are not significantly different (MS Received 27 February 2006 , Revised 22 December 2006)