Oka Yuji, Tkachi Nadia, Shuker Shimshon, Yerumiyahu Uri
Nematology Unit and Soil and Plant Nutrition Unit, Gilat Research Center, Agricultural Research Organization, M. P. Negev 85280, Israel.
J Nematol. 2007 Mar;39(1):9-16.
The nematicidal activities of ammonium sulfate, chicken litter and chitin, alone or in combination with neem (Azadirachta indica) extracts were tested against Meloidogyne javanica. Soil application of these amendments or the neem extracts alone did not reduce the root galling index of tomato plants or did so only slightly, but application of the amendments in combination with the neem extracts reduced root galling significantly. Soil analysis indicated that the neem extract inhibited the nitrification of the ammonium released from the amendments and extended the persistence of the ammonium concentrations in the soil. In microplot experiments, tomato plants were grown in pots filled with soils from the treated microplots. The galling indices of tomato plants grown in soil treated with ammonium sulfate or chicken litter in combination with the neem extract or a chemical nitrification inhibitor were far lower than those of plants grown in the control soil or in soil treated with chicken litter, neem extract or nitrification inhibitor alone. However, plants grown in the microplots showed only slight reductions in galling, probably because the soil amendments were inadequately mixed compared to their application in the pot experiments. The extended exposure of nematodes to ammonia as a result of nitrification inhibition by the neem extracts appeared to be the cause of the enhanced nematicidal activity of the ammonia-releasing amendments.
对硫酸铵、鸡粪和几丁质单独或与印楝（印楝）提取物组合的杀线虫活性进行了测试，以对抗爪哇根结线虫。单独施用这些改良剂或印楝提取物进行土壤处理，并没有降低番茄植株的根瘤指数，或仅略有降低，但将改良剂与印楝提取物组合施用则显著降低了根瘤。土壤分析表明，印楝提取物抑制了改良剂释放的铵的硝化作用，并延长了土壤中铵浓度的持续时间。在小区试验中，番茄植株种植在装有来自处理过的小区土壤的花盆中。在硫酸铵或鸡粪与印楝提取物或化学硝化抑制剂组合处理的土壤中生长的番茄植株的根瘤指数远低于在对照土壤中或仅用鸡粪、印楝提取物或硝化抑制剂处理的土壤中生长的植株。然而，在小区中生长的植株根瘤仅略有减少，可能是因为与盆栽试验相比，土壤改良剂混合不充分。印楝提取物对硝化作用的抑制导致线虫对氨的暴露时间延长，这似乎是释放氨的改良剂杀线虫活性增强的原因。
