关键词: 定向槽, 温度, 山药, 块茎, 膨大发育

Abstract: Taking the supergene planting in directional trough pattern，this paper studied the effect of temperature of directional trough on Chinese yam tuber expansion and development by straw mulching measure．The results showed that the high temperature in directional trough during Chinese yam expansion period was mainly caused by the combined action of air temperature and sunshine．Straw mulching measure had reduced the daily average temperature，daily maximum temperature and daily range of temperature in the directional trough and tuber deformity rate，yet the yield was improved．Straw mulching measure had promoted the yam tuber expansion mainly through improving the accumulation rate of fresh and dry weights during the expansion accelerating period and rapid expansion period of yam tubers．Then，the yield of Chinese yam was increased．Furthermore，straw mulching measure had increased the contents of starch，saponin and polysaccharide in tubers，thus improved the quality of Chinese yam．

Key words: directional trough, temperature, Chinese yam, tuber, expansion and development