收获时气象因子对苏格兰型*留兰香精油产量和品质的影响

Influence of Meteorological Factors During Harvesting Time on Yield and Quality of Essential Oil of Scotchish Spearmint(Mentha cardiaca L.)

通过对2001—2005年连续5a在西安市长安区种植苏格兰型留兰香小区试验及收获期气象资料分析，研究了收获时的降雨和温度对其精油产量和品质的影响。结果表明：收获时的降雨量和温度对苏格兰型留兰香精油产量有明显的影响。降雨量越大，出油率越低，精油产量越低，大雨之后可下降50％左右，一般雨后有连续3～5d晴天，出油率和精油产量可基本恢复到雨前水平；收获时温度越高，出油率越高，精油产量越高，日均温20℃以上，出油率和精油产量高。因此，苏格兰型留兰香应在连续3d以上晴天、日均温20℃以上收获为宜。

Based on the data of field plot experiments and meteorology during the harvesting time in Xi＇ an, the influence of meteorological factors such as precipitation and temperature, on the yield and quality of the essential oil of the Scotch Spearmint was studied. The results showed that precipitation and temperature during harvest time strongly influenced yield of essential oil of the Seotehish Spearmint. The rate of essential oil extraction and the essential oil yield were negatively related to the precipitation. The heavy rain might lead to reduction of the essential oil yield by 50%. However, if there was three to five fine days, the same rate of essential oil extraction and the essential oil yield could be got as that before the heavy rain. The rate of essential oil extraction and the essential oil yield were positively related to the temperature during harvest time, in partieular as the daily average temperature above 20℃. The appropriate harvest time of the Scotch Spearmint was with continuous three fine days and the daily average temperature above 20℃.