Abstract:

The study aims to analyze the climate suitability of late rice growth and development, evaluate its suitable sowing date, and provide a theoretical basis for making full use of climate resources for late rice production. Using daily meteorological data from 1980 to 2024 at the Zhaoqing National Meteorological Station, the climatic suitability models of light, temperature and water for each growth period and the whole growth period of late rice were established to evaluate the suitable sowing date for local late rice planting. The results showed that the temperature suitability index was the highest during the entire growth period of late rice, followed by solar radiation suitability, while precipitation suitability was the lowest, which decreased with the delay of sowing date; the temperature and precipitation had significant effects on the growth and development of late rice, and the sunshine had the least effect; in terms of spatial distribution, the climate suitability decreased from south to north, and the high value area of climate suitability gradually decreased with the delay of sowing date; the high value area of climate suitability was the widest in sowing date 1 (July 8), followed by sowing date 2 (July 15). In short, based on the comprehensive climate suitability indices, the moderately suitable sowing period of late rice in Zhaoqing is from July 8 to 29 (from the first ten days of July to the last ten days of July), and the most suitable sowing date is July 8, which is about 7 days earlier than the perennial sowing. If the sowing is delayed, it is recommended that it should not be later than July 22 (in the early ten days of July) in the western and northern mountainous areas, and early sowing is preferred.

Key words: late rice, meteorological factors, climate suitability, suitable sowing date, Zhaoqing