Study the effect of iron chelate on Chlorophyll content, Photochemical efficiency and some biochemical traits in Safflower under deficit irrigation condition

In order to study the effect of iron chelate (Fe-EDDHA) on some biochemical characteristic of safflower (Carthamus tinctorius L.) under two irrigation regimes, a field experiment was set up a split-plot based on randomized block design with four replication in 2011 in a research field of the faculty of Agriculture at Shahed University. In this study the main plots consisted of two levels of irrigation treatments that included: full irrigation and deficit irrigation at the flowering stage (irrigation to 50% and 75% soil moisture depletion relative to field capacity, respectively). The subplots consisted of eight levels of Fe-EDDHA, half of which were soil applications (S1:0, S2:50, S3: 100 and S4:150 kg.ha-1) and the remaining half of which were foliar applications (F1:foliar application of water, F2:1000, F3:2000 and F4:3000 mg.l-1).The results showed that in desirable condition of irrigation, using of foliar application of iron chelate led to increase the chlorophyll a, chlorophyll b, total chlorophyll and chlorophyll a/b ratio. Application of low amount of iron chelate in water stress condition resulted in significant increase in chlorophyll a, total chlorophyll and carotenoids content while use of large amount of iron chelate in soil, led to increase in chlorophyll b content and Fv/Fm. In the two levels of irrigation, foliar application of iron chelate at 2000 mg.l-1 led to increase in chlorophyll a/b ratio. The results of this experiment showed that in water stress levels, with increased level of use of soil and foliar application of iron chelate, content of anthocyanins and flavonoids increased, respectively. It appears that use of iron chelate, can increase the tolerance of safflower to water deficit condition by increase in content of photosynthetic pigment.