抄録
数10年間の栃木県内の現地試験結果から,玄米外観品質の変動要因と,県内の水稲栽培の地域間差異を検討した.播種期,出穂期,成熟期,基肥窒素量,稈長,倒伏,穂いもち病,玄米重,玄米千粒重及び日照時間が,地域間差異を生じる要因であった.外観品質の変動要因は調査地により異なり,播種期を遅らせるか成熟期を早めると外観品質が向上する調査地や,通常は高品質で安定した品種が不安定に変動する調査地があった.倒伏や玄米重は適正域がありその前後では品質が不安定になっていた.いくつかの隣接調査他聞で類似性を認めた.
From the regional trials in Tochigi prefecture for dozens of years, we examined the factors causing variation of rice quality (appearance) and their regional difference in Tochigi prefecture. Sowing time, heading time, maturing time, basal dressing, culm length, lodging, panicle blast, brown rice weight, thousand-kernel weight and duration of sunshine hours were factors causing the regional difference. The factors causing a change in quality varied with the regions. In some regions, quality was improved when sowing time was delayed or maturing time was hastened. In some regions, normally stable and high quality cultivars became unstable. A certain range of lodging and brown rice weight, was necessary to obtain high quality rice, and the quality became unstable out of this range. We found similarity in rice quality in some adjacent regions.
