关键词: 稻瘟病, 预报方法, 降水量, 平均气温, 一季稻

Abstract:

This research aims to clarify the relationship between the incidence and prevalence of rice blast disease and meteorological conditions for single season rice, and to improve the prediction and forecasting capability of rice blast disease. The phenology data, disease index data and daily meteorological data of single−season rice in Xuancheng city, Anhui province, from 1986 to 2024 were used to identify the main meteorological factors affecting the incidence and the specific date of the critical period for rice blast by analyzing the correlation among the severity levels of rice blast and different meteorological factors across different period. And then according to differential effects of precipitation grades, consecutive rainy days and average temperature on rice blast, the study introduced the rainfall coefficient, the precipitation continuity coefficient and the temperature coefficient, and constructed a comprehensive meteorological index and a rice blast forecasting model based on the meteorological factors by adopting numerical simulation techniques and regression analysis, followed by model validation. The results showed as follows: the primary meteorological factor affecting the incidence of rice blast for single season rice in Xuancheng was the precipitation days, followed by average temperature. The key period for the incidence of rice blast was identified as 6 days before to 19 days after full heading stage. The rainfall coefficient was 0.8, 1.1, 1.7 and 2.2, with corresponding precipitation grades for daily precipitation of light rain, moderate rain, heavy rain and torrential rain and over respectively during critical period of rice blast. The rice blast forecasting model based on the comprehensive meteorological index could effectively integrated the impacts of precipitation days, precipitation grades, continuous rainy days and average temperature on the rice blast in Xuancheng, achieving a modeling accuracy of 73.5% and validation accuracy of 80.0%. The forecasting model established in the study demonstrated practical applicability for rice blast forecasting services for single season rice in Xuancheng.

Key words: Rice blast disease, Forecasting method, Precipitation, Average temperature, Single season rice