Much has been reported on the agronomic aspects of canola (Brassica napus L.), but there is a lack of information on the crop's transpiration (T). The objective of this study was to evaluate the influence of soils and growth periods on the T, transpiration efficiency (TE) and transpiration efficiency coefficient (TEC) of canola under irrigation. Twenty‐four lysimeters (2.5 m²) were used for the study. The experimental treatments comprised two soil forms and four growth phases during the reproductive stage, all replicated three times. Irrigation was applied weekly through a surface drip system and a water table was maintained at 1200 mm from the surface through subirrigation. Soil water content was monitored using a neutron probe. The contribution of an accessible water table was up to 60% of the total T requirement of the crop during the investigation period. TE, calculated as above‐ground biomass per unit transpiration, ranged between 2.81 and 3.32 g m⁻² mm⁻¹. TEC, obtained by normalizing TE to the vapour pressure deficit, resulted in values between 3.82 and 4.99 g kPa mm⁻¹. Both TE and TEC were significantly different between growth periods and not amongst soils. © 2020 John Wiley & Sons, Ltd.

中文翻译：

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土壤和生殖生长期的不同阶段对灌溉油菜的蒸腾效率的影响

关于双低油菜籽（甘蓝型油菜）的农艺方面的报道很多，但缺乏有关作物蒸腾作用（T）的信息。这项研究的目的是评估土壤和生长期对灌溉条件下双低油菜籽的T，蒸腾效率（TE）和蒸腾效率系数（TEC）的影响。二十四个测渗仪（2.5 m ²）用于研究。在繁殖阶段，实验处理包括两种土壤形式和四个生长期，全部重复了三遍。每周通过地面滴灌系统进行灌溉，并通过次灌溉将地下水位保持在距地面1200毫米处。使用中子探针监测土壤水分。在调查期间，可利用的地下水位占作物总T需求的60％。TE，按单位蒸腾量的地上生物量计算，范围为2.81至3.32 gm ^-2 mm ^-1。通过将TE归一化为蒸气压不足而获得的TEC值在3.82至4.99 g kPa mm ^-1之间。TE和TEC在生长期之间存在显着差异，在土壤之间也没有显着差异。分级为4 +©2020 John Wiley＆Sons，Ltd.