Abstract: To investigate the key meteorological factors influencing the quality formation of the geo-authentic medicinal herb Qiai (Artemisia argyi ‘Qiai’) and their stage-specific effects, measured data on volatile oil content, total flavonoid content, and calorific value from 28 batches of Qiai leaves collected in Qichun County, Hubei Province, from 2016 to 2025 were analyzed together with concurrent daily meteorological data. In addition to conventional meteorological variables, indices such as the moisture index, the number of high-humidity and low-temperature days, and the number of consecutive rainy days were constructed. Pearson correlation, Spearman rank correlation, and stepwise multiple regression were used to analyze the relationships between meteorological factors from January to May and the quality indicators of Qiai. The results showed that all three quality indicators exhibited interannual variations, with total flavonoid content showing the highest coefficient of variation (37.89%) and calorific value showing the lowest (6.39%). Volatile oil content responded significantly to moisture and humidity conditions. The number of days with relative humidity ≤50% during the whole growth period was positively correlated with volatile oil content, whereas total precipitation and the number of high-humidity and low-temperature days in February were negatively correlated with it; the number of days with relative humidity ≤50% in May was also positively correlated with volatile oil content. Total flavonoid content showed stage-specific responses to temperature, namely being negatively correlated with the extreme maximum temperature in February and positively correlated with higher temperatures in April and May. Calorific value was closely associated with the diurnal temperature range and sunshine duration in January and the extreme maximum temperature in April, and showed a quadratic curve relationship with the diurnal temperature range (R²=0.645). The stepwise multiple regression models showed that the adjusted R² values of the models for volatile oil content, total flavonoid content, and calorific value were 0.907, 0.817, and 0.786, respectively. Specifically, total precipitation in February was negatively associated with volatile oil content; the extreme maximum temperature in February and May were negatively and positively associated with total flavonoid content, respectively; and the diurnal temperature range and sunshine duration in January, together with the extreme maximum temperature in April, were positively associated with calorific value.

Key words: Artemisia argyi ‘Qiai’, geo-authentic medicinal herb, meteorological factors, calorific value, quality