@article{oai:repository.naro.go.jp:00001550,
 author = {伊藤, 賢治 and ITO, Kenji and 水久保, 隆之 and MIZUKUBO, Takayuki and 渡邊, 貴由 and WATANABE, Takayoshi and 皆川, 望 and MINAGAWA, Nozomu},
 journal = {中央農業総合研究センター研究報告, Bulletin of the National Agricultural Research Center},
 month = {Jan},
 note = {The relationship between population density of Pratylenchus penetrans and necrotic lesions on young edible burdock was examined by a pot experiment. Four cultivars of edible burdock, Takinogawa, Tegaru, Yanagawariso, and Watanabewase were grown in square concrete cubic pots (50 x 50 x 50 cm）filled with sterilized soil infested with 0 to 137 (average16.2) P. penetrans per 20 g soil Three weeks after sowing, roots of edible burdock were harvested ,washed and observed carefully. Necrotic lesions appeared on roots of edible burdock and numbers of lesions per 1 cm primary root were correlated with population densities of the nematode in soil assayed by both Baermann funnel technique and double-layer centrifugal flotation method. These results suggest that necrotic lesions on edible burdock roots provide adequate estimation of nematode densiy. After the harvest edible burdock, carrots were grown for four months and damaged taproots were examined. Few numbers of branched and shortened taproots were observed and no correlation was observed between these symptoms and nematode densities at the time of carrot planting. In the present experiment, this nematode caused small horizontal scratches and vertical cracks on surface of taproots, and amomts of these scratches were correlated with nematode densities. These damages were also correlated with necrotic spots on edible burdock grown before carrot. Amounts of necrotic spots on edible burdock were considered a useful index for rough prediction of P.penetrans densities and damages of carrot caused by this nematode.},
 pages = {17--24},
 title = {ゴボウえ死斑によるキタネグサレセンチュウ圃場密度の推定とニンジンの被害予測への応用},
 volume = {4},
 year = {2004},
 yomi = {イトウ, ケンジ and ミズクボ, タカユキ and ワタナベ, タカヨシ and ミナガワ, ノゾム}
}