عنوان مقاله [English]
This study was done as a pot experiment to investigate the effect of biochar applying in drought stress conditions on yield and water productivity of French lettuce. It was carried out from November 2019 to February 2020 in the greenhouse of Zanjan University Research Farm as a factorial experiment based on randomized complete blocks design with three replications. The experimental treatments included biochar at three levels (zero (B0), one (B1) and two (B2) percent w/w) and irrigation at two levels (70 (I70) and 100 (I100) percent of crop water requirement). The water requirements of the control treatment crops were determined by weight method. Based on the results, application of deficit irrigation significantly reduced means of plant canopy diameter, shoot dimeter, plant hight, chlorophyll content, relative water content and plant wet mass (yield) compared to the control treatment (8.0, 19.8, 26.1, 13.6, 6.20 and 21.1 percent, respectively). Application of one and two percent biochar significantly increased means of plant canopy diameter (13.1 and 7.8 percent, respectively), shoot dimeter (31.9 and 15.5 percent, respectively), plant hight (26.1 and 12.5 percent, respectively), chlorophyll content (25.5 and 13.7 percent, respectively), relative water content (11.61 and 5.30 percent, respectively), plant wet mass (yield) (23.6 and 12.1 percent, respectively) and water productivily (24.6 and 12.3 percent, respectively) compared to the control treatment (B0). Based on the results of the treatments interaction effects, maximum and minimum mean of water productivity were in I70B2 and I70B0 (27.30 and 20.02 kg.m-3, respectively) as well as in the yield they were in I100B2 and I70B0 (15.54 and 10.39 t.ha-1, respectively).