Nematology Unit, Gilat Research Center, Agricultural Research Organization, Mobile Post Negev, Israel.
Pest Manag Sci. 2020 Jul;76(7):2379-2387. doi: 10.1002/ps.5774. Epub 2020 Feb 18.
Nonfumigant nematicide efficacy is affected by several factors, such as nematode species and environmental conditions. However, the influence of nematodes' physiological status on nematicide efficacy is unknown. Inactive nematodes, such as those in quiescence or dormancy, seem to be more tolerant to nematicides than active ones. Second-stage juveniles of Meloidogyne species were inactivated by low temperatures and reversible nematicides before and during exposure to fluensulfone. The sensitivity of inactive juveniles to fluensulfone the nematicide was compared to that of active juveniles by EC (median effective concentration) for juvenile immobilization and root gall reduction.
Inactivating Meloidogyne hapla and Meloidogyne javanica juveniles at 5 °C increased the EC (median effective concentration) of fluensulfone for immobilization of and root galling by Meloidogyne spp. 3.6 to 9.5 times. When the exposure temperature was decreased from 25 to 15 °C, EC for M. javanica root gall reduction after 24 and 48 h exposure increased 3.1 and 4.9 times, respectively, whereas for M. hapla, it increased 2.3 and 2.0 times, respectively. Juveniles of M. javanica and M. incognita immobilized by fenamiphos were as sensitive to fluensulfone as active juveniles based on the number of root galls. However, juveniles of these species immobilized by fluopyram were more tolerant to fluensulfone than untreated active juveniles. An interaction of fluopyram and fluensulfone activities is suggested.
Changes in the sensitivity of inactive Meloidogyne spp. juveniles to fluensulfone depend on the inactivation method. Fluensulfone could be better applied when nematodes are active in the soil. © 2020 Society of Chemical Industry.
非熏蒸性杀线虫剂的效果受多种因素的影响，如线虫种类和环境条件。然而，线虫生理状态对线虫剂效果的影响尚不清楚。处于静止或休眠状态的不活跃线虫似乎比活跃线虫对杀线虫剂更具耐受性。在暴露于 fluensulfone 之前和期间，通过低温和可逆杀线虫剂使 Meloidogyne 种的 2 龄幼虫失活。通过 EC（半数有效浓度）比较了不活跃幼虫和活跃幼虫对 fluensulfone 杀线虫剂的敏感性，用于幼虫固定和根瘤减少。
在 5°C 下失活 Meloidogyne hapla 和 Meloidogyne javanica 幼虫将 fluensulfone 对 Meloidogyne spp. 的固定和根瘤的 EC（半数有效浓度）增加了 3.6 至 9.5 倍。当暴露温度从 25°C 降低到 15°C 时，M. javanica 根瘤减少的 EC 在暴露 24 和 48 小时后分别增加了 3.1 和 4.9 倍，而对于 M. hapla，分别增加了 2.3 和 2.0 倍。基于根瘤数量，被 fenamiphos 固定的 M. javanica 和 M. incognita 幼虫与活跃幼虫一样对 fluensulfone 敏感。然而，被 fluopyram 固定的这些物种的幼虫比未经处理的活跃幼虫对 fluensulfone 更具耐受性。建议 fluopyram 和 fluensulfone 活性之间存在相互作用。
不活跃 Meloidogyne spp. 幼虫对 fluensulfone 的敏感性变化取决于失活方法。当线虫在土壤中活跃时，fluensulfone 的应用效果可能更好。© 2020 化学工业协会。
