ISHS Acta Horticulturae 153: IX African Symposium on Horticultural Crops
EFFECT OF GROWTH REGULATORS IN SHORTENING THE JUVENILE PERIOD AND ROOTING OF APPLE (MALUS SYLVESTRIS L.) AND PEACH (PRUNUS PERSICA L.) CUTTINGS |
| Author: | A.M.S. Nyomora |
| Abstract:
Growth retardants TIBA (50 ppm applied in July), SADH (1500 ppm applied in June), CEPA (1000 ppm), CCC (2500 ppm) and NAA (100 ppm) applied mid-June in Norway retarded tree height, stem circumference and flowering of apple seedlings when applied before the end of the juvenile period. MH (500 ppm) and BA (1000 ppm) applied in June did not affect growth, but effectively promoted flowering. A combination of GA (50 ppm) applied in July and calcium nitrate (300 g per tree) applied in June promoted tree height, stem circumference and flowering. It is concluded that the growth retardants SADH, CCC, CEPA, TIBA and high concentrations of NAA (100 ppm) should not be applied to seedling trees before they have attained a minimum height of 200 cm, 10 cm thickness and have outgrown the juvenile period. However, the growth stimulants GA and/or nitrogenous fertilisers could be applied to hasten growth. Juvenile cuttings of apple (cv. Golden Delicious) and peach (cv. Local) rooted better than adult cuttings and cuttings collected in July and September rooted best. IBA at 0.8% in talcum was most effective for apple cuttings, and IBA at 0.1% in talcum or at 200 ppm with 24 hours soaking was most effective for peach cuttings. It is concluded that both the hormone IBA and the choice of an appropriate phase of growth are beneficial in promoting rooting, but that the effect of season, rather than IBA treatment, is the major determinant in rooting responses. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
