湖北烟草靶斑病消长规律及其与环境因子的关系分析

Occurrence Dynamics of Tobacco Target Spot and Its Relationship with Environmental Factors in Hubei Province

为对湖北烟区烟草靶斑病进行合理预测预报和精准防控,本研究通过定点系统调查和统计分析,确定了湖北烟区烟草靶斑病流行动态,明确了烟草靶斑病的发生与土壤中立枯丝核菌(Rhizoctonia solani)带菌量及气象因子的关系。结果表明,烟草靶斑病病情阶段表现为病情始发(移栽后35~40 d)—病情扩展(移栽后40~60 d)—病情迅速蔓延(移栽后60~105 d)。Logistic模型能较好地描述烟草靶斑病的流行动态,可根据该模型进行病害发生的预测。发病烟田10 cm耕层土壤R.solani带菌量高于其他耕层土壤;土壤R.solani带菌量在烟草大田生长期基本呈现持续增加的态势,与靶斑病病情指数具有显著正相关关系。气温和降雨量是影响烟草靶斑病发生与流行的主要气象因子,田间气温高于23℃时,烟草靶斑病迅速蔓延;各病情阶段的总降雨量决定病害各病情阶段的严重度。本研究阐明了烟草靶斑病在湖北省的扩散蔓延规律及影响因素,为该病害的预测预报和合理防控奠定了理论基础。

In order to forecast reasonably and prevent precisely the occurrence of tobacco target spot(TTS) in Hubei Province,the epidemic dynamics were confirmed,the relationship between the occurrence of TTS and contents of Rhizoctonia solani in soil,meteorological conditions were revealed by using system investigation and statistical analysis in this study.Results showed that the disease stages of TTS in Hubei Province behaved as the followings:Disease onset(35-40 d after transplantation)-Disease expansion(40-60 d after transplantation)-Disease rapid spread(60-105 d after transplantation).The logistic model well reflected the epidemic dynamics of TTS,thus the occurrence of this disease could be predicted by using this model.The contents of R.solani at 10 cm tillage depth was higher than that of other tillage depths.The contents of R.solani in soil exhibited a trend of continuous increase during the field growth period of tobacco,and significantly positively correlated with the disease index of TTS.Temperature and rainfall were the main meteorological factors affecting the occurrence and prevalence of TTS.When temperature in field exceeded 23 ℃,TTS spread rapidly.At each disease stage,the severity of disease depends on the total rainfall.This study highlights the occurrence dynamics and influenced factors of TTS in Hubei Province,and provides a theoretical foundation for the prediction,forecast,reasonable prevention and control of TTS.