研究丁烯氟虫腈、啶虫脒、杀虫单、烯啶虫胺4种单剂以及丁烯氟虫腈·啶虫脒、丁烯氟虫腈·烯啶虫胺、啶虫·杀虫单3种复配剂对小菜蛾的室内生物活性和田间药效。室内生物活性测定结果表明,供试的4种单剂和3种复配剂对小菜蛾的毒力存在较大差异。单剂中以丁烯氟虫腈的毒力最高,LC50为18.51 mg a.i./L;烯啶虫胺和杀虫单次之,LC50分别为163.85、188.48 mg a.i./L;啶虫脒最低,LC50为260.94 mg a.i./L。丁烯氟虫腈·啶虫脒复配剂比例为4∶1、2∶1、1∶1时对小菜蛾毒力增效明显,共毒系数分别为133.65、123.11、120.45;啶虫·杀虫单复配剂比例为10∶1、5∶1时增效显著,共毒系数分别为133.18、122.62;丁烯氟虫腈·烯啶虫胺复配剂5个配比均表现为相加作用。田间药效结果表明,3种复配剂在药后3 d对小菜蛾的田间防效均高于75%,药后7 d防效均高于80%,高用量时可以达到90%以上。40%丁烯氟虫腈·啶虫脒乳油600 m L/hm2、40%丁烯氟虫腈·烯啶虫胺乳油300 m L/hm2、44%啶虫·杀虫单悬浮剂1 500 m L/hm2对小菜蛾的田间防效优于对照药剂5%丁烯氟虫腈乳油450 m L/hm2。3种复配剂以40%丁烯氟虫腈·烯啶虫胺乳油用量最少,防效最高,40%丁烯氟虫腈·啶虫脒乳油次之,与对照药剂相比,这2种复配剂均可以在降低农药使用量的同时达到同样的防治效果,从而大大减少农药单剂在蔬菜上的残留量,44%啶虫·杀虫单悬浮剂用量较大,但从剂型的安全性和用药成本考虑,也是较理想的选择。
The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging, 2, 2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS) radical scavenging and ferric reducing antioxidant power(FRAP). The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power(FRAP) with the values of 4 541.87 and 1 134.52 μmol of Fe(Ⅱ)/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows: cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.
