Abstract: 【Objective】Grain yield is one of the most important indicators in evaluating foxtail millet productivity and is greatly affected by the fluctuation of climatic factors. The researches on the effects of climatic factors on grain yield and the varietal response of grain yield to different ecological conditions in Shandong can provide scientific basis for selecting, breeding and planting high-quality foxtail millet. 【Method】 Eight newly released foxtail millet cultivars selected from the summer-sown region of North China were planted at five locations in two consecutive years (2016 and 2017). Grain yields of these cultivars were measured. Analysis of Variance (ANOVA) was used to determine the significance of differences in grain yields by Duncan’s Multiple Range Test. And correlation analysis between grain yield and air temperature, rainfall, and sunshine duration were conducted by Pearson’s method. 【Result】 ANOVA showed that growing years, growing locations × growing years, and growing locations × cultivar genotypes had highly significant effects on the variations in grain yields (P<0.01). Similarly, cultivar genotypes, cultivar genotypes × growing years, and growing years × cultivar genotypes × growing years showed significant influence on grain yields (P<0.05). Growing locations, growing locations × growing years, growing locations × cultivar genotypes and cultivar genotypes had high contribution rates (50.05%, 19.76%, 12.32%, and 8.67%, respectively), whereas growing years, cultivar genotypes × growing years had low contribution rates (2.70% and 1.69%, respectively) to the variations in grain yields. In 2017, the average yield per unit area of eight foxtail millet cultivars was 4.55% higher than that in 2016, however, that was not consistent between growing locations. The annual outputs from Jinan, Linyi and Jining in 2017 were increased by 21.64%, 18.47% and 3.96%, respectively, while from Dezhou and Taian the annual outputs were decreased by 8.66% and 9.78%, respectively, compared with those in 2016. The average yields of eight cultivars from five locations across two years were 5 657.2 kg·hm^-2 ranging from 5 267.8 kg·hm^-2 to 5 926.0 kg·hm^-2. The yield of Yugu18 had the lowest yield while Jigu20 had the highest yield. No significant difference in grain yields was observed between cultivars Jigu20, Jigu22, Jilügu1, Jinuogu2 and Zhonggu2, however, grain yields of these cultivars were significantly higher than Jigu19 and Yugu18. Correlation analysis showed that the grain yield was positively but not significantly correlated with the average temperature and maximum temperature at each time period (P>0.05). However, it was significantly positively correlated with the total average temperature of the whole growth period (P<0.05). On the other hand, grain yield was negatively correlated with the rainfall at seedling stage (middle and late June) (P>0.05), and the rainfall during the periods from pregnancy heading to flowering (from late July to middle August) (P>0.05). Furthermore, grain yield was positively correlated with sunshine duration in middle and late September (P>0.05). 【Conclusion】 Growing years, growing locations, cultivar genotypes, growing locations × growing years and growing locations × cultivar genotypes had significant effects on the yields of foxtail millet in Shandong. The fluctuation of ecological factors across different years and different locations, especially the air temperature and rainfall were the important factors affecting the yields. Higher average air temperature during the whole growth period was beneficial to increasing grain yield. Excessive rainfall at seedling and heading stages had negative effects on grain yields. The yield of testing cultivars was significantly different between years and between experimental sites. The cultivars, Jigu20, Jigu22, Jilügu1, Jinuogu2 and Zhonggu2 had good fertility and stability across ecological conditions.

Key words: foxtail millet, yield, ecological conditions, air temperature, rainfall, sunshine