Abstract: Identifying the main limiting climatic factors and the extent of these limitations to crop growth and development can provide scientific basis for agricultural adaptation to climate change and efficient use of climate resources. Using an ecological-climatic suitability method, we analyzed the main limiting climatic factors and the extent of the limitations in the three stages of maize growth, emergence-jointing, jointing-tasseling, and tasselingmaturity, with daily meteorological data and agrometeorological observation data from 1980 to 2018 in Suizhong and Jianchang counties of Huludao, Liaoning. The results showed that the effectiveness model can be used to clarify the limiting factors and quantify the limitations at different growth stages of maize. The average limitation of climate in the study area was over 30%, the greatest limitation occurred during the period from jointing to tasseling, and the limitation of climate decreased from emergence to jointing. Precipitation was the most limiting factor on the effectiveness of climate resources in Huludao City, with a value of 27%-61%, followed sunshine hour. Temperature was the least limiting factor. The limitation of climate is closely related to maize yield. Severe climate fluctuations are an important environmental factor driving the instability of rainfed maize yield. Improving the utilization of climate resources is a key step to ensure high and stable maize yield.

Key words: maize, effectiveness model, climatic limiting factor, climatic resource.