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Professor Jayashankar Telangana State Agricultural University, Hyderabad (Telangana State)

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20202
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Thesis Type: Ph.D × Author: BALA MURALIDHAR NAIK, RAMAVATH ×
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    ThesisItemOpen Access
    “SURVEY, SEASONAL INCIDENCE, SCREENING AND MANAGEMENT OF INSECT PESTS OF SOYBEAN IN NORTHERN TELANGANA ZONE.”
    (PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2020) BALA MURALIDHAR NAIK, RAMAVATH; SRINIVAS, C
    The research work was carried out on survey, seasonal incidence, screening and management of insect pests of soybean in Northern Telangana Zone of Telangana state during kharif, 2014 and 2015 to assess the insect pest status and management of major insect pests of soybean in this zone where soybean crop is predominantly cultivated. The survey was carried out in Northern Telangana Zone, while the seasonal incidence, screening and insecticide management studies against soybean insect pests were carried out under field conditions at Regional Agricultural Research Station (RARS), Jagtial during kharif, 2014 and 2015. The roving survey carried out in three districts of Northern Telangana Zone, viz., Adilabad, Nizamabad and Karimnagar comprising of five mandals and three villages under each district at vegetative, flowering and pod formation stages of the crop during kharif, 2014 and 2015 revealed the occurrence of seven insect pests viz., stem fly, Melanagromyza sojae, stem girdler, Obereopsis brevis, tobacco cutworm, Spodoptera exigua, tobacco caterpillar, Spodoptera litura, green semilooper, Chrysodeixis acuta, gram caterpillar, Helicoverpa armigera and whiteflies, Bemisia tabaci in all the mandals and villages, except gram caterpillar which was observed in few mandals. Among the pests, stem fly, stem girdler, tobacco caterpillar and whitefly incidence was more in all the three districts and their occurrence was reported during all stages of the crop growth. Among the districts, highest mean per cent stem fly (27.50%) was recorded in Adilabad district followed by Nizamabad district (27.08%) and less incidence (19.30%) in Karimnagar district.The highest mean stem girdler and whiteflies incidence (25.31% and 4.69/ 3 leaves/plant, respectively) was recorded in Nizamabad district followed by Adilabad district (24.54% and 4.49/3 leaves/plant, respectively) and Karimnagar district (15.40% and 4.17/3leaves/plant, respectively). The highest mean incidence of tobacco caterpillar was recorded in Karimnagar district (4.29 larvae/mrl) followed by Adilabad district (3.68 larvae/mrl) and Nizamabad district (3.61 larvae/mrl). The gram caterpillar incidence was very low in all the districts and the other two defoliators, green semilooper and cutworm incidence in different districts varied from 1.54 to 1.86 larvae/mrl and 0.99 to 1.07 larvae/mrl, respectively. The seasonal incidence studies conducted at RARS, Jagtial during kharif, 2014 and 2015 revealed the prevalence of eight insect pests viz., stem fly, Melanagromyza sojae, tobacco caterpillar, S. litura, green semilooper, C. acuta, tobacco cutworm, S.exigua, whitefly, B. tabaci, jassid, Empoasca kerri and thrips, Thrips tabaci and two natural enemies, coccinellid beetle, Cheilomenes sexmaculata and spider, Oxyopes sp. The peak activity of stem fly incidence during kharif, 2014 and 2015 (37.84 and 35.7% /mrl) was observed during 37th Standard meterological week, whereas the peak activity of caterpillar pests i.e. cutworm (1.6 and 1.4 larvae/mrl) during 32 nd and 31st SMW, S.litura (7.6 and 12.4 larvae/mrl) during 34th and 36th SMW, C. acuta (3.0 and 2.2 larvae/mrl) during 36th and 37th SMW and that of sucking pests i.e. whiteflies, B. tabaci (5.45 and 6.05/3 leaves) during 34th and 35th SMW, leafhopper, E. kerri (2.55 and 2.60/3 leaves) during 36th and 34th SMW and thrips (1.80 and 2.90/3leaves) during 34th and 33rd SMW, while the predators population was very low throughout the crop period. The correlation coefficients and multiple regression analysis studies indicated the significant influence of various weather parameters on the seasonal incidence of insect pests of soybean. The screening studies carried out with thirty genotypes against three major pests, stem fly, tobacco caterpillar and whitefly during kharif, 2014 and 2015 seasons resulted in the identification of some promising genotypes against the major pests. Among the genotypes, ten genotypes were highly resistant to stem fly, while seven genotypes showed highly resistant reaction to whiteflies and fifteen genotypes were highly resistant to tobacco caterpillar. Among the highly resistant genotypes, KDS 869 was highly resistant to all the three pests while six genotypes, JS 20-98, RSC 10-46, NRC 116, RVS 2008-24, KDS 753, RVS 2008-8 were highly resistant to stem fly, whitefly and tobacco caterpillar. JS 335 was highly susceptible to whitefly and tobacco caterpillar while MACS 1454 was highly susceptible to stem fly and tobacco caterpillar. The field efficacy studies conducted with eight insecticides against three major pests of soybean conducted during kharif, 2014 and 2015 revealed that stem fly infestation was significantly controlled in chlorantraniliprole 18.5 SC @ 100 ml ha-1 and thiamethoxam 25 WG @ 100 g ha-1 treatments, while triazophos 40 EC @ 800 ml ha-1 and thiamethoxam 25 WG @ 100 g ha-1 showed greater efficacy against whiteflies and tobacco caterpillar infestation was significantly reduced in chlorantraniliprole 18.5 SC @ 100 ml ha-1 and profenophos 50 EC at 1250 ml ha-1 treatments. The two chemicals, quinalphos 25 EC @ 1500 ml ha-1 and spinosad 45 SC @ 200 ml ha-1 showed moderate efficacy against all the three major pests. The grain yield data obtained from insecticidal efficacy studies revealed that among the treatments, chlorantraniliprole 18.5 SC @ 100 ml/ha recorded higher grain yield of (1920 kg ha-1 & 1903 kg ha-1 ) followed by profenophos 50 EC @ 1250 ml ha-1 (1876 kg ha-1 & 1872 kg ha-1 ) and significantly less grain yield was recorded in acetamiprid 20 SP @ 100 g ha-1 (1621 kg ha-1 & 1603 kg ha-1 ) and imidacloprid 600 FS @ 5ml/Kg seed (1581 kg ha-1 & 1574 kg ha -1 ) treatments. The incremental cost benefit ratios worked out for various insecticidal treatments during kharif, 2014 & 2015 showed that profenophos 50 EC @1250 ml ha-1 which was highly effective against tobacco caterpillar recorded highest incremental cost-benefit ratio (4.41 & 4.32, respectively) followed by quinalphos 25 EC @ 1500 ml ha-1 (3.75 & 3.73, respectively) which showed moderate efficacy against all the pests. Chlorantraniliprole 18.5 SC @ 100 ml ha-1 which recorded the highest yield and showed greater efficacy against stem fly and tobacco caterpillar was considered as the third best chemical (2.45 and 2.49, respectively) when incremental cost benefit ratio was taken into consideration
  • Thumbnail Image
    ThesisItemOpen Access
    SURVEY, SEASONAL INCIDENCE, SCREENING AND MANAGEMENT OF INSECT PESTS OF SOYBEAN IN NORTHERN TELANGANA ZONE
    (PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2020) BALA MURALIDHAR NAIK, RAMAVATH; SRINIVAS, C
    The research work was carried out on survey, seasonal incidence, screening and management of insect pests of soybean in Northern Telangana Zone of Telangana state during kharif, 2014 and 2015 to assess the insect pest status and management of major insect pests of soybean in this zone where soybean crop is predominantly cultivated. The survey was carried out in Northern Telangana Zone, while the seasonal incidence, screening and insecticide management studies against soybean insect pests were carried out under field conditions at Regional Agricultural Research Station (RARS), Jagtial during kharif, 2014 and 2015. The roving survey carried out in three districts of Northern Telangana Zone, viz., Adilabad, Nizamabad and Karimnagar comprising of five mandals and three villages under each district at vegetative, flowering and pod formation stages of the crop during kharif, 2014 and 2015 revealed the occurrence of seven insect pests viz., stem fly, Melanagromyza sojae, stem girdler, Obereopsis brevis, tobacco cutworm, Spodoptera exigua, tobacco caterpillar, Spodoptera litura, green semilooper, Chrysodeixis acuta, gram caterpillar, Helicoverpa armigera and whiteflies, Bemisia tabaci in all the mandals and villages, except gram caterpillar which was observed in few mandals. Among the pests, stem fly, stem girdler, tobacco caterpillar and whitefly incidence was more in all the three districts and their occurrence was reported during all stages of the crop growth. Among the districts, highest mean per cent stem fly (27.50%) was recorded in Adilabad district followed by Nizamabad district (27.08%) and less incidence (19.30%) in Karimnagar district.The highest mean stem girdler and whiteflies incidence (25.31% and 4.69/ 3 leaves/plant, respectively) was recorded in Nizamabad district followed by Adilabad district (24.54% and 4.49/3 leaves/plant, respectively) and Karimnagar district (15.40% and 4.17/3leaves/plant, respectively). The highest mean incidence of tobacco caterpillar was recorded in Karimnagar district (4.29 larvae/mrl) followed by Adilabad district (3.68 larvae/mrl) and Nizamabad district (3.61 larvae/mrl). The gram caterpillar incidence was very low in all the districts and the other two defoliators, green semilooper and cutworm incidence in different districts varied from 1.54 to 1.86 larvae/mrl and 0.99 to 1.07 larvae/mrl, respectively. The seasonal incidence studies conducted at RARS, Jagtial during kharif, 2014 and 2015 revealed the prevalence of eight insect pests viz., stem fly, Melanagromyza sojae, tobacco caterpillar, S. litura, green semilooper, C. acuta, tobacco cutworm, S.exigua, whitefly, B. tabaci, jassid, Empoasca kerri and thrips, Thrips tabaci and two natural enemies, coccinellid beetle, Cheilomenes sexmaculata and spider, Oxyopes sp. The peak activity of stem fly incidence during kharif, 2014 and 2015 (37.84 and 35.7% /mrl) was observed during 37th Standard meterological week, whereas the peak activity of caterpillar pests i.e. cutworm (1.6 and 1.4 larvae/mrl) during 32 nd and 31st SMW, S.litura (7.6 and 12.4 larvae/mrl) during 34th and 36th SMW, C. acuta (3.0 and 2.2 larvae/mrl) during 36th and 37th SMW and that of sucking pests i.e. whiteflies, B. tabaci (5.45 and 6.05/3 leaves) during 34th and 35th SMW, leafhopper, E. kerri (2.55 and 2.60/3 leaves) during 36th and 34th SMW and thrips (1.80 and 2.90/3leaves) during 34th and 33rd SMW, while the predators population was very low throughout the crop period. The correlation coefficients and multiple regression analysis studies indicated the significant influence of various weather parameters on the seasonal incidence of insect pests of soybean. The screening studies carried out with thirty genotypes against three major pests, stem fly, tobacco caterpillar and whitefly during kharif, 2014 and 2015 seasons resulted in the identification of some promising genotypes against the major pests. Among the genotypes, ten genotypes were highly resistant to stem fly, while seven genotypes showed highly resistant reaction to whiteflies and fifteen genotypes were highly resistant to tobacco caterpillar. Among the highly resistant genotypes, KDS 869 was highly resistant to all the three pests while six genotypes, JS 20-98, RSC 10-46, NRC 116, RVS 2008-24, KDS 753, RVS 2008-8 were highly resistant to stem fly, whitefly and tobacco caterpillar. JS 335 was highly susceptible to whitefly and tobacco caterpillar while MACS 1454 was highly susceptible to stem fly and tobacco caterpillar. The field efficacy studies conducted with eight insecticides against three major pests of soybean conducted during kharif, 2014 and 2015 revealed that stem fly infestation was significantly controlled in chlorantraniliprole 18.5 SC @ 100 ml ha-1 and thiamethoxam 25 WG @ 100 g ha-1 treatments, while triazophos 40 EC @ 800 ml ha-1 and thiamethoxam 25 WG @ 100 g ha-1 showed greater efficacy against whiteflies and tobacco caterpillar infestation was significantly reduced in chlorantraniliprole 18.5 SC @ 100 ml ha-1 and profenophos 50 EC at 1250 ml ha-1 treatments. The two chemicals, quinalphos 25 EC @ 1500 ml ha-1 and spinosad 45 SC @ 200 ml ha-1 showed moderate efficacy against all the three major pests. The grain yield data obtained from insecticidal efficacy studies revealed that among the treatments, chlorantraniliprole 18.5 SC @ 100 ml/ha recorded higher grain yield of (1920 kg ha-1 & 1903 kg ha-1 ) followed by profenophos 50 EC @ 1250 ml ha-1 (1876 kg ha-1 & 1872 kg ha-1 ) and significantly less grain yield was recorded in acetamiprid 20 SP @ 100 g ha-1 (1621 kg ha-1 & 1603 kg ha-1 ) and imidacloprid 600 FS @ 5ml/Kg seed (1581 kg ha-1 & 1574 kg ha -1 ) treatments. The incremental cost benefit ratios worked out for various insecticidal treatments during kharif, 2014 & 2015 showed that profenophos 50 EC @1250 ml ha-1 which was highly effective against tobacco caterpillar recorded highest incremental cost-benefit ratio (4.41 & 4.32, respectively) followed by quinalphos 25 EC @ 1500 ml ha-1 (3.75 & 3.73, respectively) which showed moderate efficacy against all the pests. Chlorantraniliprole 18.5 SC @ 100 ml ha-1 which recorded the highest yield and showed greater efficacy against stem fly and tobacco caterpillar was considered as the third best chemical (2.45 and 2.49, respectively) when incremental cost benefit ratio was taken into consideration