Five chitosan samples (3.8×10^5, 7.8×10^4, 4.8×10^4, 1.7×10^4, 2.3×10^3) were used to investigate their activity in vitr采用平板法研究了壳聚糖系列样品对大叶黄杨炭疽病、沿阶草炭疽病、广玉兰炭疽病和对节白蜡腐烂病等庭院植物病原真菌的体外抗菌性能。