INFLUENCE OF WATER DEFICIT ON IRON AND ZINC UPTAKE BY Matricaria chamomilla L.

Iron and zinc deficiency are a yield-limiting factor with major implications for field crop production in many agricultural regions of the world; this production is essential source of Fe and Zn in human and animal diets. Two experiments were conducted under greenhouse conditions to evaluate Fe and Zn uptake by German chamomile (Matricaria chamomilla L.) grown under several drought conditions. Treatments were arranged in four irrigation regimes (95%, 80%, 65%, and 50% field capacity) and six irrigation disruptions (stem formation, flower onset, full bloom, first harvest, second harvest, and control without disruption) based on a randomized complete block design with five and four replicates in experiments 1 and 2, respectively. In Experiment 1, the irrigation regimes had no significant effect on Fe and Zn uptake by German chamomile, which reached total means of Fe (39.68 mg kg(-1)) and Zn (29.15 mg kg(-1)). In Experiment 2, the highest amount of Fe (39.0 mg kg(-1)) was obtained from irrigation disruption at first harvest; this is similar to the results of irrigation disruption at flower onset and full bloom. However, irrigation disruption in stem formation (21.3 mg kg(-1)), second harvest (12.95 mg kg(-1)), and the control (7.79 mg kg(-1)) had a decreasing trend of Fe uptake. The maximum value of Zn (40.0 mg kg(-1)) occurred at irrigation disruption at the full bloom stage, which was also similar to irrigation disruption at flower onset and stem formation. However, later irrigation disruptions at the first and second harvest stages caused lower amounts of Zn uptake by chamomile. Therefore, the lowest Zn values were obtained from irrigation disruption at second harvest (5.0 mg kg(-1)) and the control (5.5 mg kg(-1)). Regressions between both Fe or Zn uptake and irrigation showed a binomial function.