Consumptive use of water in Brassica napus L. from flowering to ripening stage under rainless region conditions

This study provides a contribution towards increased knowledge on the consumptive water use by arable crops within the temperate climatic zone under specified weather conditions in the field as the main aim of this work. Water demands of Brassica napus L. (Navajo variety) crops were evaluated by the T 4.2 (EMS Brno, CZ) sapflow meter under the field conditions of central Bohemia during the years 2005, 2007 and 2008. The evaluation took place during the BBCH 65–87 growth stages. Daily average values of sapflow (Q, kg day−1), measured for individual plants in 2005, fluctuated from the beginning to the end of the fruit development stage (BBCH 79) within the interval ranging from 0.002 to 0.117 kg day−1. In 2007 they fluctuated from 0.002 to 0.075 kg day−1 for the same period and in 2008 from 0.014 to 0.201 kg day−1. The average water consumption (average of 2005, 2007 and 2008) by the crop estimated for BBCH 77–80 stages fluctuated within a 3.2–4.1 mm interval. In the BBCH 81 stage the average water consumption of crop reached 2.3 mm and in the BBCH 85 stage only 0.5 mm. Copyright © 2010 John Wiley & Sons, Ltd.