Effect of Different Chemical Additives on Growth and Flowering of African Marigold (Tagetes erecta L.) Grown under Cadmium Stress

2 Abstract: This study was carried out at the experimental field of the Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, during the two successive seasons of 2012 and 2013. The aim of this study was to investigate the possibility of reducing the harmful effect of cadmium soil pollution on the growth and flowering of Tagetes erecta (Marigold) plants by the addition of nickel, salicylic acid and Fe+EDTA to the soil. Plants were grown in 20cm pots filled with clay + sand (1:1,v/v) and were treated twice with cadmium acetate ((CH COO) Cd.2H O) as a soil drench at 0, 2.5, 7.5 and 12.5 mg/pot, in addition to three different 32 2 chemicals(nickel sulphate (NiSO .H O)) as a soil drench at 3 and 6 mg/pot, EDTA+Fe Na (C H N O.FeNa) as 4 2 10 12 28 a foliar spray at 15 and 30 ppm and salicylic acid (C H O ) as a foliar spray at 50 and 100 ppm). Control plants 763 received the Cd treatments only. The recorded results showed that Cd acetate at12.5 mg/pot gave the lowest values for the studied vegetative growth and flowering characteristics. In most cases, the different chemical additives (except salicylic acid at 100 ppm)also decreased the number of branches and flower heads per plant, as well as the fresh and dry weights of shoots and flower heads. From the results of this study, it was concluded that salicylic acid can be applied at 100 ppm in the nursery or the production field to increase yield of Tagetes erecta (Marigold) under cadmium stress.