The host range and control of potato rot nematode, Ditylenchus destructor THORNE, in bulbous iris.

Abstract

This paper dealt with the host range of the potato rot nematode, Ditylenchus destructor, and its control.
1. In the developing period of the bulbous iris, the characteristic symptom on the plant above groundlevel was not observed. While some of bulbs showed a distinct symptom, but some not so. From the appearance, therefore, it is impossible to know whether it is infested or not.
2. Eighteen species of plants, Anemone coronaria, Allium tuberosum, Brassica campestris, B. chinensis, B. oleracea, Capsicum annuum, Centaurea cyanus, Cosmos bipinnatus, Chrysanthemum moritolium, Cucumis sativus, Cucurbita moschata, Cyclamen persicum, Lactuca sativa var. capitata, Lycopersicon esculentum, Raphanus saticus var. radicula, Spiranthes sinensis, Triticum aestivum, Vigna sinensis are added as new hosts.
3. To control bulbs, the water treatment with 0.5% formaline is more effective than the dipping method with pesticide. Hot water treatment, however, often injures the bulbs by mistaking heat control. Moreover, this method cannot treat a great number of bulbs at a time.
4. Dry heat treatment (53°C, 3 hrs) by using the ventilating dryer has also a good effect on its control. But this treatment is not perfect against the nematode. The grain dryer which is provided by every farmers is not effective at all because it is unable to rise at temperature 53°C.