EFFECT OF PLANTING DATES AND DIFFERENT CONCENTRATIONS OF INDOLE BUTYRIC ACID (IBA) ON THE CUTTING ROOTING OF Carissa grandiflora

Abstract

This experiment was carried out during the period from April, 20th 2004 to June, 25th 2005 in a plastic house at Al-Shallal nursery in Mosul, to investigate the effects of four planting dates (April, July, October and January) and four IBA concentrations (0, 500, 1000 and 2000) mg.L-1, using talc, on rooting of Carissa geandiflora shoot tip cuttings. A Complete Randomized Design (CRD) was applied including 16 treatments each was replicated three times and each experimental unit consists of 10 cuttings. Data were tested by Duncan multiple test at 5%. Results could be summerized as follows : Planting cuttings in 20th April and 20th July gave best results 95.8% and 97.5% rooting percentage respectively but then declined to 49.2% in October and without rooting in January after 10 weeks from planting date. All IBA treatments caused a significant increase in all rooting parameters, the most effective treatment was 2000 mg.L-1. Using 2000 mg.L-1 in April gave rooting percentage 100%, number of roots/cutting 16.6, average length of roots 12.2 cm, dry root weight 0.35 gm, average cutting length 17.4 cm and number of pear leaves 10.46 pear, with 1.5 shoots/cutting.