Analysis of main climatic factors affecting potato yields of western Guizhou.

The climatic factors affecting potato yields in western Guizhou were analyzed by using the way of grey correlation degree and principal component analysis.The average yield of potato from 1978 to 2008 in western Guizhou was used as the sequence of numbers for reference.And the climatic factors including accumulated temperature,average temperature,precipitation,sunshine hours,daily average maximum temperature and daily average minimum temperature of ≥5 ℃ from March to August of potato at growth stage were used as the series for comparison.The results showed that the three integrative factors including temperature,moisture and light had a synergistic effect on potato production.The heat factor played a leading role in potato production with abundant light and ample water supply.Gray correlation analysis and principal component analysis could be used to estimate the influence factors of potato yield in western Guizhou.Very good agreement was found between the evaluation results obtained by the above-mentioned two methods.