Influence of indole acetic acid (IAA) on the establishment of stem cuttings in lemon (Citrus limon L.)

Effect of indole acetic acid (IAA) on the establishment of stem cuttings of lemon (Citrus limon L.) was studied in the Department of Crop Sciences, Faculity of Agriculture, Eastern University, Chenkalady, Sri Lanka during the year 2009. The treatments included five IAA concentrations (500, 1000, 1500, 2000 and 2500 ppm) alongwith a control (distrilled water). Lemon cuttings having three nodes were dipped in IAA concentrations and distilled water as control. Then these cuttings were planted in polythene bags (12 cm long and 6.5 cm wide) containing soil and cow manure with ratio of 2:1. IAA treated cuttings performed better in all growth parameters compared to control. It was further noted that after 8 th weeks of planting, shoot length (5.73 cm), rooting percentage (73.33%) and survival rate (90.0%) of cuttings were significantly higher in cuttings dipped in 2500 ppm IAA concentration than other treatments. The data also showed that growth parameters were gradually increased with increase in IAA concentration from 0 ppm to 2500 ppm. The exogenous supply of IAA had a positive effect on the establishment of stem cuttings of lemon and application of 2500 ppm IAA prove to be the best treatment for better root and shoot formations.