Abstract:

To guide scientific irrigation of sweet maize, the experiment on evapotranspiration and influence factors of fresh sweet maize irrigated by drip irrigation under film was conducted in Yuanmou of Yunnan, based on real-time monitoring of the moisture content and meteorological factors. The results showed that the depth of wetting layer from seedling stage to filling stage increased from 20 cm to 60 cm. The growing season of sweet maize was 117 days and the evapotranspiration was 184.2 mm, the evapotranspiration intensity was 1.6 mm/d under drip irrigation in the whole growth period of sweet maize. The daily evapotranspiration intensity in tasseling stage was the highest, followed by that in filling stage and jointing stage, and that in seedling stage was the smallest. The evapotranspiration of sweet maize was significantly and positively correlated with sunshine duration, daily maximum temperature, daily minimum temperature and daily average temperature, and significantly and negatively correlated with daily relative humidity. In conclusion, the daily evapotranspiration of sweet maize is mainly affected by temperature, sunshine and relative humidity, the critical period of water requirement is tasseling stage and filling stage, and since the growth period of winter sweet maize is longer than others, so supplementary irrigation is needed when the rainfall is limited.

Key words: Yuanmou, sweet maize, evapotranspiration, SPSS, correlation coefficient