根瘤線蟲田間密度檢定試驗

Abstract

1. 本試驗係民國45~46年年在臺南棉麻試驗分所及臺灣中南部鐘麻栽培區域各縣舉行。鑒於鐘麻栽培適地，往往發生嚴重的根瘤線蟲病，常造成慘害，影響產量頗鉅，又因藥劑及栽培方面的防治工作，實際應用相當困難，因此研究一般農民容易採用的種植指示作物以檢定根瘤線蟲法，於栽培鐘麻前種植指示作物，檢定根瘤線蟲在農田的密度分佈而決定可否栽培鐘麻。 2. 秋季（8~10月）於鐘麻栽培預定地（次年春季播種鐘麻）栽植甘藷或花生等作物同時，在其行上株間種植蕃茄苗或米豆為指示作物，其行株距各為5~10公尺及2~4公尺。種植指示作物後，經1~1個半月（蕃茄）或1個半月～2個月（米豆）拔起根部，調查線蟲根瘤的多寡而判定根瘤線蟲之密度分佈情形。 3. 臺灣中南部的非水田地帶，據估計約有16~19%的面積，根瘤線蟲的密度很高，不適合於栽植鐘麻等易罹根瘤線蟲病的作物。 Nematode root-knot is one of the major diseases of kenaf (Hibiscus cannabinus L.) growing in the sandy soil in Taiwan. Various control methods were tested, but there are no significant effects except chemical treatment. As a matter of fact, however, on account of expensiveness the latter method is of little practical value as control measure. From this point of view, some experiments of indicator crop method for making clear field nematode population were carried out during 1956-1957 in Tainan Fiber Crops Experiment Station, Taiwan Agricultural Research Institute, Taiwan, China. During autumn (August to October) indicator plants such as tomato (Lycopersicon esculèntum L.) or cowpea (Vigna sinensis L.) were inter-planted at the same time as sweetpotato or peanut in the field where kenaf was scheduled to be cultivated next March or April. Seeds of cowpea or tomato seedlings were respectively sown or transplanted among sweetpotatoes or peanuts at the row distance 5 to 10 meters and plant distance 2 to 4 meters. After 30 to 45 days (tomato) or 45 to 60 days (cowpea) these indicator plants were dug out and their roots were examined for counting of nematode root-knot in order to judge the degree of infestation and decide the possibility of cultivating kenaf. It is estimated that the area of 16 to 19 per cent of cultivated land except paddy rice field in the central and south of Taiwan has very high population of root-knot nematodes highly injurious to kenaf or other susceptible crops.