　北部九州における安定的な穂いもち耐病性検定法の開発を目的として，散水と防風処理および遮光処理が穂いもちの発病程度に及ぼす効果について検討した。潅水チューブを用いた散水と防風ネットによる防風処理を組み合わせた検定法における穂いもちの発病程度は，いもち病常発地における発病程度と有意な相関が認められたものの，年次によっては発病程度が小さく品種間差が不明瞭であった。散水・防風にさらに寒冷紗による遮光処理を加えた検定法における穂いもちの発病程度は，無遮光区に比較して有意に大きく，散水・防風・遮光処理による穂いもち検定法が，穂いもち耐病性の品種間差の判定に有効であると考えられた。上記の方法による穂いもち耐病性の検定の結果，‘つやおとめ’，‘ちくし66号’，‘フ系2383’の3品種・系統は，穂いもちに強度の圃場抵抗性を示すことが明らかになった。

　Development of an Experimental Method Which Includes Sprinkling Water, Blocking Wind and Shading Sunlight for Evaluating Resistance to Panicle Blast Disease on Rice in the Northern Kyushu Region. WADA Takuya, Yuji HAMACHI, Masao TSUBONE, Yoshiteru KAWAMURA and Takefumi OGATA (Fukuoka Agricultural Research Center, Chikushino, Fukuoka 818-8549, Japan) Bull. Fukuoka Agric. Res. Cent. 25:5-9 (2006)

　In order to develop a novel method for evaluating panicle blast resistance of rice cultivars, we studied the effect of sprinkling water, blocking wind and shading sunlight for increasing the values of panicle blast disease.　The First study was performed at a paddy field in a lower region where blast diseases are rare, and at a paddy field in a mountainous region where blast diseases are severe. The test in the lower region was carried out with sprinkling water and blocking wind. The disease values in the lower region were significantly correlated with those obtained in the mountainous region, however, the values were not enough to ascertain varietal differences of panicle blast resistance in one year. The second study was performed to evaluate the effect of shading sunlight for panicle blast disease values in the lower region, and revealed that shading sunlight increased the values of panicle blast disease significantly higher than non-shading. Thus, the method composed of sprinkling water, blocking wind and shading sunlight, was effective to evaluate the varietal differences of resistance to panicle blast disease in rice breeding in the northern Kyushu region. In our final study, we evaluated the amount of the panicle blast resistance of the cultivars we developed, and concluded 'Tsuyaotome', 'Chikushi 66' and 'Fukei 2383' were resistant to panicle blast disease.　　