杉木缺硼症的诊断和发生规律研究

STUDY ONUSE AND OCCURRENCE REGULARITY OF BORONDEFICIENCY IN CHINESE FIR

经过光镜检查、电镜分析、易地栽培、嫁接试验、探索性防治试验以及元素分析和施肥诊断等手段，证明了发生在邵武杉木上的被称之为“大头病”的病害是一种由于缺硼引起的生理性病害。对不同地方发病圃地发病率与土壤、气候等环境因子进行相关分析。结果指出质地较轻、有机质含量少的酸性土容易发病，发病季节的高温、干旱使病害发生更加严重。杉苗稚冠比测定结果表明较低的根冠比与杉木缺硼症有较密切的关系。

The disease of Chinese fir [Cunninghamia lanceolata (lamb). Hook. ] familiarly known as 'Big Head Disease' found in shaowu, Fujian province was proved to be a physiological disease caused by boron deficiency by means of optical microscope inspertion, electronic microscope analysis. Transplantation, grafting , exploratory control, elemental analysis and fertilization. Results of correlation between disease rate and environment factors such as soil, climate in different nurseries have showed that the disease develops easily in acid, light soils with low organic matter and boron contents. High temperature and drought could aggravate the disease all the more. Furthermore the root-shoot ratio measurement showed that the diaeased plant has low root-shoot ratio, and this was thought to becaused by inner boron deficiency in the Chinese fir.