www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 14.139.226.146 on dated 12-Nov-2013 PROGRESSIVE HORTICULTURE 227 PROGRESSIVE HORTICULTURE Vol.40(2) :227-228, 2008 SCREENING OF CHILLI GERMPLASMS AGAINST YELLOW MITE AND THRIPS ON THE BASIS OF LEAF SYMPTOMS S. Satpathy * , Akhilesh Kumar, T. M. Shivalingaswamy ** and A. B. Rai Indian Institute of Vegetable Research, Jakhini, Shahanshahpur, Varanasi – 321 005 (Uttar P radesh The yellow mite, Polyphagotarsonemus latus Banks and thrips, Scirtothrips dorsalis Hood are two important sucking pests of chilli with 30-55 per cent severity causing extensive leaf curl and yield loss (Rai et al,. 2007). Routine schedule application of insecticide at short intervals increases the cost of protection and chemical toxic residues in fruits. Many commonly used pesticides like monocrotophos, thiometon, phosphamidon, methyl-o-demeton, ethion, cypermethrin, deltamethrin, caused the pest resurgence in chilli (David, 1991). Imidacloprid, a systemic insecticide of neonicotinoids group recommended in chilli is known to cause resurgence in mite (Srinivasulu et al., 2002). Identification of resistant or tolerant sources in the existing gerrmplasms is the primary objective to develop pest tolerant varieties. Eighty one chilli germplasms consisting of local and indigenous collections, released varieties and local cultivars with diverse phenotypic and genetic make up were evaluated under field condition on the basis of extent of leaf curl for relative resistance against yellow mite and thrips complex in the research farm of Indian Institute of Vegetable Research, Varanasi, India. The study was carried out during the peak activity period of yellow mite and thrips. The grading method used for leaf symptoms includes; symptom less (0-resistant), terminal leaves showing eruption in internal leaf area (0.01-1.0- moderately resistant), terminal and few basal leaves showing eruption in internal area and curling along the margin (1.01-2.0- slightly resistant), severe curling along the leaf margin in terminal and few basal leaves (2.01-3.0- moderately susceptible), all the leaves showing severe curling and reduced leaf area (3.01-4.0- susceptible), stunted plant, brittle, severe curled leaf with reduced area (4.01-5.0- highly susceptible) (Krishna Kumar et al., 1996). Among these germplasms screened, only one line, i.e. PDG-1 (A) did not show any symptom of mite infestation and was rated as resistant (Table-1). Out of rest 80 cultivars, nine were found to be moderately resistant, out of which PDG-1B showed least symptom (0.15). Other lines in this group were IC-119474 (0.35), IC-119310 B (0.78), PDC-53 A (0.96), PDC-50 (0.33), PDC-24 (0.67), Ramnathpur Local (0.60), Arka Lohit-2 (1.0), Sungro-86235 A (0.72). Number of slightly resistant, moderately susceptible and susceptible lines was 24, 30 and 11, respectively. Six cultivars were found to be highly susceptible among which VNS-4 was most susceptible with maximum grade (4.34).There are many reports of field evaluation of chilli for resistance against leaf curl caused by thrips and mite. This study considered the symptoms expressed in the individual plants of a line to calculate the grade. None of the lines was completely free from infestation of yellow mite. The line PDG-1A * Central Research Institute for Jute and Allied Fibres. Barrackpore, Kolkata- 700 120 ** National Bureau of Agriculturally Important Insects, HA Farm post, Bengaluru-560 024