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Researcher Joshi, M. D.
Advisor Patel, V. N.
Source KrishiKosh-Indian National Agricultural Research System
Content type Text
Educational Degree Master of Science (M.Sc.)
Publisher JAU
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology
Subject Keyword Entomology ♦ Population Dynamics ♦ Varietal Screening ♦ Yield Losses and Efficacy of Eco-friendly Pesticides Against Major Insect Pests of Soybean [glycine Max (l.) Merrill]
Abstract Investigations were carried out on seasonal incidence, varietal screening, yield losses and efficacy of eco-friendly pesticides against major insect pests of soybean [Glycine max (L.) Merrill] at Instructional Farm, College of Agriculture, Junagadh Agricultural University, Junagadh during kharif season of 2006. Studies on seasonal incidence of the major insect pests revealed that the whitefly (Bemisia tabaci Gennadius) commenced from 2nd week after sowing (1.9 whiteflies per three leaves per plant) i.e. 4th week of July and the population fluctuated with four peaks (6.98, 7.2, 8.32 and 5.8 whiteflies per three leaves per plant) during 4th, 6th, 8th and 13th week after sowing. All the weather parameters were non-significantly correlated with the pest population, except the minimum temperature (r=0.5000), which exhibited significant positive correlation with the pest population during kharif season of 2006. The infestation of jassid (Empoasca kerri Pruthi) initiated from 2nd week after sowing (0.32 jassid per three leaves per plant) i.e. 4th week July and maximum pest density was recorded with a peak during 8th week after sowing (3.78 jassids per three leaves per plant) i.e. 1st week of September. None of the weather parameters was significantly correlated with the jassid population. Incidence of tobacco leaf eating caterpillar (Spodoptera litura Fabricius) commenced from 4th week after sowing (1.1 larvae per plant) i.e. 2nd week of August and maximum pest density with a peak of 6.8 larvae per plant was observed during 10th week after sowing i.e. 3rd week of September. All the weather parameters were non-significantly correlated with the population of S. litura during kharif season of 2006. Gram pod borer (Helicoverpa armigera Hubner) commenced from 3rd week after sowing (0.6 larva per plant) i.e. 1st week of August and maximum pest population was observed with a peak of 4.5 larvae per plant during 10th week after sowing i.e. 3rd week of September. None of the weather parameters was significantly correlated with the population of H. armigera. Incidence of leaf miner (Aproaerema modicella Deventer) started from 3rd week after sowing (1.2 larvae per plant) i.e. 1st week of August and reached to the maximum pest population with a peak level of 6.9 larvae per plant during 10th week after sowing i.e. 3rd week of September. All the weather parameters showed non-significant correlation with the population of A. modicella during kharif season of 2006. Studies on screening of ten genotypes/varieties of soybean against major insect pests revealed that the genotype AMS-32 recorded lowest population of whitefly (1.83 whiteflies per three leaves per plant), jassid (2.27 jassids per three leaves per plant), H. armigera (2.03 larvae per plant) and leaf miner (2.20 larvae per plant), while the genotype JS-84-1recorded lower number of S. litura (1.77 larvae per plant). Genotype JS-79-277 recorded minimum percentage of pod and grain damage (7.53 and 7.11 per cent, respectively). Studies on estimation of yield losses of soybean due to major insect pests revealed that 13.20 per cent pod damage and 12.47 per cent grain damage were recorded in protected plots while unprotected plots recorded 24.20 per cent pod damage and 16.13 per cent grain damage. The grain yield received from the protected plots was 1573.33 kg/ha while in unprotected plots, it was 1142.67 kg/ha. The result clearly indicated that by providing protection with the effective insecticides (triazophos 0.06 per cent and endosulfan 0.07 per cent) against the major insect pests infesting soybean, 433.66 kg/ha grain yield with 27.37 per cent avoidable yield loss can be saved. The results of two applications of nine different insecticidal treatments against major pests infesting soybean revealed that the treatments with triazophos 0.06 per cent, endosulfan 0.07 per cent and quinalphos 0.05 per cent were the most effective for the control of white fly. Among the eco-friendly pesticides, NSKE 5 per cent was found most effective against whitefly on soybean followed by neemazol @ 2 ml/litre, emamectin benzoate @ 5 gm/10 litre and Beauveria bassiana @ 5 gm/litre. The treatments with endosulfan 0.07 per and triazophos 0.06 per cent and quinalphos 0.05 per cent were the most effective for the control of jassid. Among the eco-friendly pesticides used against jassid, NSKE 5 per cent proved to be most effective followed by neemazol @ 2 ml/litre and emamectin benzoate @ 5 gm/10 litre. Triazophos 0.06 per cent, spinosad 0.01 per cent, quinalphos 0.05 per cent and endosulfan 0.07 per cent were effective against tobacco leaf eating caterpillar. Among the eco-friendly pesticides, only spinosad 0.01 per cent was found significantly effective against S. litura on soybean during kharif season of 2006. The treatments with quinalphos 0.05 per cent, emamectin benzoate @ 5 gm/10 litre, spinosad 0.01 per cent, Beauveria bassiana @ 5 gm/litre and endosulfan 0.07 per cent and triazophos 0.06 per cent were most effective for the control of pod borer larvae. The eco-friendly pesticides viz, emamectin benzoate @ 5 gm/10 litre and spinosad 0.01 per cent were the most effective treatments against pod borer, H. armigera on soybean. Emamectin benzoate @ 5 gm/10 litre and Beauveria bassiana @ 5 gm/litre recorded the minimum pod damage, while emamectin benzoate @ 5 gm/10 litre, Beauveria bassiana @ 5 gm/litre, NSKE 5 per cent, endosulfan 0.07 per cent and spinosad 0.01 per cent recorded the minimum grain damage. Quinalphos 0.05 per cent, endosulfan 0.07 per cent, triazophos 0.06 per cent and NSKE 5 per cent were the most effective for the control of leaf miner. Among the different eco-friendly pesticides used NSKE 5 per cent was found most effective against leaf miner on soybean followed by neemazol @ 2 ml/litre Considering the yield of soybean, the spraying with quinalphos 0.05 per cent gave the maximum grain yield (2000 kg/ha), followed by emamectin benzoate @ 5 gm/10 litre (1972 kg/ha), endosulfan 0.07 per cent (1944 kg/ha) and triazophos 0.06 per cent (1938 kg/ha). Among the eco-friendly pesticides, emamectin benzoate @ 5 gm/10 litre gave higher yield as compared to others. As far as the economics of these insecticides are concerned, quinalphos 0.05 per cent gave the highest cost benefit ratio (1:10.83) followed by endosulfan 0.07 per cent (1:9.30) and triazophos 0.06 per cent (1:8.19). Among the eco-friendly pesticides, Beauveria bassiana @ 5 gm/litre gave the cost benefit ratio of 1:2.22.
Educational Use Research
Education Level UG and PG
Learning Resource Type Thesis
Publisher Place Junagadh
Size (in Bytes) 137.86 MB
Page Count 194