Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be...Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unap展开更多
建立了测定动物饲料中三唑仑、艾司唑仑、硝西泮、地西泮、异丙嗪、氯氮平、唑吡坦、甲硫哒嗪、氯丙嗪和咪达唑仑10种违禁精神药物的超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)方法。样品经混合溶剂甲醇-0.1 mo l/L HCl(9∶1,v...建立了测定动物饲料中三唑仑、艾司唑仑、硝西泮、地西泮、异丙嗪、氯氮平、唑吡坦、甲硫哒嗪、氯丙嗪和咪达唑仑10种违禁精神药物的超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)方法。样品经混合溶剂甲醇-0.1 mo l/L HCl(9∶1,v/v)振荡提取,再用MCX固相萃取柱净化处理后,采用UPLC-Q-TOF-MS分析检测。10种化合物在5～100μg/L范围内均呈良好的线性关系,线性相关系数均大于0.99。本方法的硝西泮、唑吡坦和甲硫哒嗪的定量限(LOQ,以信噪比为10计)为8μg/kg,三唑仑、艾司唑仑、地西泮、异丙嗪、氯丙嗪和咪达唑仑为10μg/kg,氯氮平为20μg/kg。3个添加水平(LOQ、2LOQ、4LOQ)的回收率试验结果表明,10种化合物的回收率在60.6%～108.5%范围内,相对标准偏差均小于10%。本方法可用于动物饲料中违禁精神药物的准确测定。展开更多
基金supported by Punjab Agriculture Research Board,Grant numbers PARB No.890received research support from Punjab Agriculture Board。
文摘Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unap
文摘建立了测定动物饲料中三唑仑、艾司唑仑、硝西泮、地西泮、异丙嗪、氯氮平、唑吡坦、甲硫哒嗪、氯丙嗪和咪达唑仑10种违禁精神药物的超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)方法。样品经混合溶剂甲醇-0.1 mo l/L HCl(9∶1,v/v)振荡提取,再用MCX固相萃取柱净化处理后,采用UPLC-Q-TOF-MS分析检测。10种化合物在5～100μg/L范围内均呈良好的线性关系,线性相关系数均大于0.99。本方法的硝西泮、唑吡坦和甲硫哒嗪的定量限(LOQ,以信噪比为10计)为8μg/kg,三唑仑、艾司唑仑、地西泮、异丙嗪、氯丙嗪和咪达唑仑为10μg/kg,氯氮平为20μg/kg。3个添加水平(LOQ、2LOQ、4LOQ)的回收率试验结果表明,10种化合物的回收率在60.6%～108.5%范围内,相对标准偏差均小于10%。本方法可用于动物饲料中违禁精神药物的准确测定。
