Abstract
A study was carried out on three month-old seeds of Grevillea robusta A. Cunn., to improve the germination and vigour potential through growth hormone and nutrient treatments. The seeds were soaked in water, potassium nitrate and thiourea (each 1.0, 1.5 and 2.0 per cent), GA3 (100, 250 and 500 ppm) and mixture of the three (1:1:1 proportion) solutions for 24 hours prior to sowing. The results of germination and vigour evaluation 28 days after sowing revealed the beneficial effects of GA3 (250 ppm) over the rest with 43 per cent germination as against 9 per cent in control. Improvement in vigour was six-fold higher than the control. 150 days after sowing the seedling growth in terms of root length, shoot length, number of leaves, collar diameter, root dry weight and shoot dry weight has been greatly enhanced by pre-soaking seed treatment with 250 ppm GA followed by the combined treatment. While thiourea showed deleterious effect.
Keywords