茶苗根结线虫的季节动态观察

Observation on the Seasonal Variation of Meloidogyne Infesting Young Tea

研究了茶苗南方根结线虫(Meloidogyne incoguita)虫口密度的季节消长规律和在不同深度根系中的分布,以及茶圃杂草作为其保虫寄主的感染情况。感染率10～12月最高,8月最低,平均感染强度10月最高,7月最低;从上到下在第10～15 cm处雌虫最多,第20～25 cm侵袭期幼虫最多;10种杂草感染该虫种。虫口密度随月积温的上升而上升,而雄性比则随月总雨量的升高而下降。

Observation was made on the seasonal variation of density of Meloidogyne incog nita in vegetatively propagated clonal tea plants collected from Fengtian Farm. The results show t hat highest infection rate occurs from October to December and the lowest in August; the highest infectivity of parasite appears in October and lowest in July. Infection may take place from July t o November and from April to May of the next year. The peak of infection is revealed to be in October and the peak of oviposition in November. Refering to local meteorological records, we can co nclude that population increase with the increase of monthly accumulated temperature and that the ratio of the mate parasite decreases with increasing monthly rainfall. We examined 25 cm tea root perpendicularly with 5 cm as unit and found that most female parasites appeared at the interval of 10-15 cm, most infective larvae at 20-25 cm(distal end)and the least of the both at 0-5 cm. M. incognita was also found in ten species of weeds growing in tea nursery, two of the which gave harbor to M. javanica as well.