本论文通过分析梨黑斑病菌防治的方法，论述了一种以银杏提取物来防治的方法

本论文通过分析梨黑斑病菌防治的方法，论述了一种以银杏提取物来防治的方法，并对此方法可有效抑制梨黑斑病菌生长展开了深入的研究。本论文首先论述了梨黑斑病的发生，通过对国内最新研究的分析，本论文以离体梨叶为实验材料，通过体外抑菌试验，在实验室内测定了银杏叶提取物对梨叶黑斑病的毒性，并筛选出银杏叶提取物抑制梨叶黑斑病的最佳浓度和浸泡时间。实验过程中采用十字交叉法测量病斑面积从而计算抑制率，九极法记录病情指数等方法得出结果。结果证明：不同浓度的银杏提取物可抑制梨叶片黑斑病菌面积的扩展，叶片最佳浸泡时间为3小时，浓度为2000mg/L的溶液抑制效果最好，毒力也是最强，病情指数降到最低22.22%，防治效果达到最大值33.33%。抑制率能达到47.76%，EC50值是3585.842mg/L。

本论文通过分析梨黑斑病菌防治的方法，论述了一种以银杏提取物来防治的方法，并对此方法可有效抑制梨黑斑病菌生长展开了深入的研究。 本论文首先论述了梨黑斑病的发生，通过对国内最新研究的分析，本论文以离体梨叶为实验材料，通过体外抑菌试验，在实验室内测定了银杏叶提取物对梨叶黑斑病的毒性，并筛选出银杏叶提取物抑制梨叶黑斑病的最佳浓度和浸泡时间。 实验过程中采用十字交叉法测量病斑面积从而计算抑制率，九极法记录病情指数等方法得出结果。 结果证明：不同浓度的银杏提取物可抑制梨叶片黑斑病菌面积的扩展，叶片最佳浸泡时间为3小时，浓度为2000mg/L的溶液抑制效果最好，毒力也是最强，病情指数降到最低22.22%，防治效果达到最大值33.33%。 抑制率能达到47.76%，EC50值是3585.842mg/L。

In this paper, through the analysis of the control methods of pear black spot, we discussed a method to control pear black spot by Ginkgo extract, and this method can effectively inhibit the growth of pear black spot. This paper first discusses the occurrence of pear black spot, through the analysis of the latest domestic research, this paper takes the pear leaf as the experimental material, through the in vitro bacteriostatic test, in the laboratory to determine the toxicity of Ginkgo biloba extract to pear leaf black spot, and selects the best concentration and soaking time of Ginkgo biloba extract to inhibit pear leaf black spot. In the process of the experiment, the cross method was used to measure the area of the lesion and calculate the inhibition rate, and the nine pole method was used to record the disease index. The results showed that Ginkgo biloba extract with different concentrations could inhibit the expansion of the pathogen area in pear leaves. The best soaking time of leaves was 3 hours. The best inhibition effect was the solution with concentration of 2000 mg / L, and the most virulent. The disease index decreased to the lowest 22.22%, and the control effect reached the highest 33.33%. The inhibition rate was 47.76% and EC50 was 3585.842mg/l.<br>