Hello Sir
Grevillea robusta:
Cultivation tips:
Altitude: 0-2300 m, Mean annual temperature: 14-23 to 25-31 deg. C, Mean annual rainfall: 600-1700 mm.
Soil type: Establishes well in riverine habitats, on alluvial soils that are free of waterlogging and mildly acid to neutral.
Loam soil is preferred. It also occurs on clay loam and sand.
Moderate to fast growing. When climate and soil are suitable and weed competition is not severe, annual height and diameter increments of at least 2 m and 2 cm, respectively, are usually achieved for the 1st few years in row planting on farms. Annual height increments of 3 m have been observed at the most favourable sites. G. robusta regrows well after complete defoliation following pruning and pollarding, which can be carried out repeatedly to yield wood and to regulate shading and competition with adjacent crops. A growth reduction after 20 years is reported. The species is known to produce substances toxic to its own seedlings.
Collection of seeds from mature trees is very difficult because the seeds are borne on thin and inaccesible branches at great heights and are easily lost during collection. 60- 70% germination following 2 years of hermetic storage at -7 deg. C with 10% mc; 35% germination following 12 months of open storage. Seeds were maintained for 4 years in commercial storage conditions; viability was maintained for 2 years in hermetic air-dry storage at 3 deg. C. There are between 24 000 and 105 000 seeds/kg.
