Management of shoot fly Atherigona soccata (Rondani) with different seed dressing chemicals

Abstract

Two micro plot field experiments were conducted at Chinnamathampalayam and Idikarai of Coimbatore district to test the bio efficacy of insecticides and biopesticides as seed dressers to control shoot fly Field experiment I-Chinnamathampalayam (Kharif) : The experiment was conducted to find out the bioefficacy of certain seed dressing chemicals viz., chlorpyriphos, endosulfan, dimethoate, Pseudomonas fluorescens, thiamethoxam and imidacloprid on the management of shoot fly. The required quantity of the chemicals for 100 gram of the seeds was mixed using dilute solution of gum acacia. After mixing, the treated seeds were shade dried and used for sowing. The trial was laid out with seven treatments and three replication in RBD (Table A). The observation on deadheart damage was recorded in 40 plants per plot selected at random. The data on deadheart damage was collected on 15, 21 and 30 days after sowing. From the number of plants showing dead heart damage and the total number of plants observed, per cent deadheart damage was worked out. The data gathered were statistically analysed for interpretation. Biometric parameters : The biometric observations on plant height and girth were recorded at 15, 21 and 30 days after sowing. Plant height : The height of the plant up to the tip of the top fully opened leaf from the ground level was measured using meter scale on 15, 21 and 30 days of sowing. In each replication ten plants were selected at random for recording the observation. Field experiment II-Idikarai (summer) : The efficacy of the seed dressing chemicals in checking the shoot fly incidence was assessed in the micro plot experiment laid out at Idikarai during summer. The incidence of shoot fly as dead heart damage was observed at 15, 21 and 30 days after sowing. The observation on dead heart incidence and biometric observations were recorded as described above. Impact of seed dressing chemicals on germination under laboratory condition: The effect of various seed dressing chemicals on seed germination, seedling vigour and other related parameters were assessed under laboratory condition using standard procedure. The impact of seed dressing chemicals on the germination of seeds and seedling vigour was assessed under laboratory condition. The seeds of known quantity were mixed with the gum and then the desired quantity of the chemical was added to the gum coated seed and mixed well. The seeds were dried in shade and used subsequently for the experiment. The germination test using paper towel method was carried out at the Table A : Details of micro plot experiments on shoot fly management Particulars Trial I Trial II Location Cultivar Season Design Plot size Spacing Number of treatments Number of replications Seed treatments tested Chinnamatham palayam SSV-84 Kharif Randomized Block Dcesign 1m 2 (1×1m) 45× 15 cm Seven Three T1-Chlorpyriphos 20EC (Dursban) 4ml/kg (0.04%) T2-Endosulfan 35EC (Thiodan) 4ml/kg (0.04%) T3-Dimethoate 30EC (Rogar) 4ml/kg (0.04%) T4-Pseudomonas fluorescens @ 10g/kg (0.1%) T5-Thiamethoxam 25WG (Cruiser) 1g/kg (0.01%) T6-Imidacloprid 70WS (Gaucho) 1g/kg (0.01%) T7-Untreated control Idikarai SSV-84 Summer Randomized Block Design 1m 2 (1×1m) 45× 15 cm Seven Three T1-Chlorpyriphos 20EC (Dursban) 4ml/kg (0.04%) T2-Endosulfan 35EC (Thiodan) 4ml/kg (0.04%) T3-Dimethoate 30EC (Rogar) 4ml/kg (0.04%) T4-Pseudomonas fluorescens @ 10g/kg (0.1%) T5-Thiamethoxam 25WG(Cruiser) g/kg (0.01%) T6-Imidacloprid 70WS (Gaucho) 1g/kg (0.01%)