休闲与轮作对燕麦孢囊线虫种群动态的影响

Effect of Fallow and Rotation on the Population Dynamics of Heterodera avenae

为明确休闲与轮作对燕麦孢囊线虫病害的防治效果,通过盆栽模拟和田间试验相结合的方法,分析了土壤休闲、轮作和连作对燕麦孢囊线虫种群动态的影响。结果表明,燕麦孢囊线虫的孵化不受寄主或寄主种类的影响;不同处理土壤中二龄幼虫数量以及孢囊内的虫口密度变化趋势一致,河北地区燕麦孢囊线虫孵化高峰期主要在3-4月份。休闲一年后燕麦孢囊线虫的减退率为89.8%。小麦与茄子、甜瓜和冬瓜轮作一年后线虫减退率分别为93.8%、90.7%和90.7%,轮作二年后线虫减退率为98.8%。在自然病田,小麦连作一年后虫口密度上升36.8%,连作两年后虫口密度上升49.2%。说明小麦连作后燕麦孢囊线虫的发生呈上升趋势,休闲或轮作一年以上可有效地降低土壤中燕麦孢囊线虫的虫口密度。

Effect of fallow, rotation and continuous cropping of wheat on the population dynamics of Heterodera avenae were tested in pot experiment and natural disease field to understand the control efficacy of fallow and rotation on the cereal cyst nematode. The results showed that the hatching of H.avenae was not affected by the hosts. The population dynamics of the second stage juveniles （J2） in soil and nematode density within cyst were similar in all the treatments. Hatching peak of H.avenae was in the period of March to April in the area of Hebei province. Population of H.avenae reduced by 89.8% after one year＇s fallow, and it was reduced by 93.8% after rotation with eggplant for one year, while it was reduced by 90.7% after rotation with the muskmelon or melon for one year, and by 98.8% after rotation for two years. In the natural disease field, the population of the nematodes increased by 36.8% and by 49.2% after continuous wheat cropping for one and two years, respectively. In conclusion, the disease may become more and more severe after continuous wheat cropping, while the population of H.avenae could be significantly reduced by fallow or rotation one year or more.