调亏灌溉对粤北烤烟农艺性状及耗水规律的影响

利用18个不同水分处理的大田试验探讨了调亏灌溉对旱坡地浓香型烤烟农艺性状、经济特性及耗水规律的影响。结果显示,伸根期调亏处理后复水补偿效果显著,其轻旱处理(60%~70%FC)有利于获得较高产量和水分效率;旺长期亏水后复水补偿效果有限,此时的亏水对烤烟产量和质量负面影响显著,需维持正常水分处理(70%~80%FC);成熟期轻旱处理(60%~70%FC)有利于提高上等烟比例;伸根期、成熟期都为轻旱处理(60%~70%FC)的可以在不减产情况下获得较高的水分效率和上等烟比例。产量、上等烟比例和水分效率与耗水量的关系为具有极大值的二次函数,产量的极值偏后于水分效率和上等烟比例的极值。利用18个试验数据所建立的水分生产函数符合烤烟生长规律,能为该地区水利工程规模的确定及产量的预测提供依据。

Effect of RDI on Agronomic Traits and Water Consumption Law of Flue-cured Tobacco in Northern Guangdong

Field trials with 18 different water treatments were conducted to explore the effects of water stress on the agronomic traits , economic attributes and the rule of water consumption of full flavor flue-tobacco on sloping uplands .The results indicated that there was a significant compensation effect in growth after re-watering when water stress happened in the root extending stage ,and it was good for obtaining higher yield and water use coefficient by slight-drought treatments (soil moisture content was 60% ~70% of field capacity ) .Comparatively ,the compensatory effect was limited after re-watering when water stress happened in the vigorous growing stage ,the yield and quality of flue-cured tobacco suffered negative effects significantly due to water stress in this stage ,so the appro-priate content of soil moisture should be 70% ~80% of field capacity .Slight-drought treatments could help to raise high-class-leaf proportion in the mature period .High-water-use efficiency and high-class-leaf proportion could be obtained without reduction of out-put when the soil moisture was 60% ~70% of field capacity in the root extending stage and mature period .The relationship of yield , water use efficiency and high-class-leaf proportion with water consumption was a quadratic parabola .The time for the highest output occurred later than that of water use efficiency and high-class-leaf proportion .Based on the experimental data of full flavor flue-to-bacco in the fields ,the water production function that accorded with the laws of tobacco growth was established for Northern Guang-dong ,and it could be used for formulating irrigation system and determining the scale of irrigation project in the condition of deficit irrigation .