- Basic study on soil Disinfectors -

Study on Methods of Controlling Deep Soil Nematodes

Summary

The perpose of this report is to clear the effective method for controlling the nematodes which live in the deep depth of the soil.

The effective method of the controlling nematodes which live in the deep depth of the soil has been studied with the double injection type deep fumigator and the single injection type one. The results obtained as follows.

(1) As the soil structure of the cultivating field tillaged deeply and supplised much organic fertilizer are improveded to confortable conditions for crops and insects untill deep depth of the soil, the dencity of nematodes in the 25�`50cm depth is larger than those of normaly cultivated field and it was cleared to need the deeply fumigation.

(2) The DD gas concentration from the surface to 50cm depth of the soil showed more than 10 ppm at 7 days after the injection using the single and double injection type fumigator. But DD gas concentration between the soil surface to about 25cm were very small and it was investigated that the DD gas difussion from thesoil surface is very quickly(rapidly) at the high tempreture 25-30. The DD gas concentration of soil depth 25-50cm using the double injection type deep fumigator was larger than the vales of the single injection type and former injection�@method was expected the heigh performance for controlling the nematodes in living deeply depth.�@