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Until further investigations have clarified seed storage behaviour, coconut must remain classified as probably recalcitrant. Seed dormancy in coconut has been reviewed elsewhere (5). In view of their large size it is unlikely that the fruits will be tested for germination in laboratory tests. The following procedure has been proposed for germinating whole coconut fruits in nursery sowings: place the seednuts close together in a moist sandy soil (6, 11, 17) in full sun, either with the fruits' broadest face down (7, 13) or - in the case of spherical fruits - on their end with the calyx uppermost, and irrigate frequently with an overhead sprinkler (10). The most suitable constant temperatures for germination in nursery sowings are between 30° and 35°C (17), but alternating temperatures, roughly 20°/30°C, are reported to be more effective in promoting germination (11, 14). The duration of the germination test should be at least 100 days for those varieties which germinate more readily, and 150 days for the slower germinating varieties (10). Pre-treatments to the seednuts will probably be required. A 1 to 2 week pre-soak is probably the most effective method of promoting germination (2, 4, 10) - particularly where the fruit has dried (2). The removal of part of the mesocarp at the base of the fruits above the eyes also promotes germination, but if this is done it is essential that the fruits be prevented from drying throughout the subsequent germination test.

Extraction of the embryo from the fruits with subsequent embryo culture is required for laboratory germination tests. Embryo culture has been achieved in a variety of combinations of media (1,5,9), including coconut milk alone (9). The most favoured combination appears to be White's major elements plus vitamins, plus Nitsch's trace elements, plus sucrose, plus coconut milk (1). This has the following composition: 100 ml of White's major elements (50 ppm Ca, 72 ppm Mg, 70 ppm Na, 65 ppm K, 47 ppm N - as nitrate, 4 ppm P - as phosphate, 140 ppm S - as sulphate, 31 ppm Cl, 1 ppm Fe - as ferric citrate, 1.67 ppm Mn, 0.005 ppm Cu, 0.59 ppm Zn, 0.26 ppm B, 0.001 Mo), 1 ml of Nitsch's trace elements (3 ppm managanese sulphate, 0.5 ppm zinc sulphate, 0.025 ppm copper sulphate, 0.5 ppm boric acid, 0.025 ppm sodium molybdate) but also including 25 ppm of cobalt chloride, 4 ml of a 0.25% solution of ferric citrate, 5 ml of White's vitamins (0.57 ppm I, 0.1 ppm thiamin, 0.5 ppm nicotinic acid, 0.1 ppm pyridoxine, 3 ppm glycine, 20000 ppm sucrose) with the addition of 50 ppm calcium pantothenate and 2 ml of a 0.1% solution of indoleacetic acid in alcohol; it is then made up to 1 litre with double distilled water and 0.2g casein hydrolysate, 8g agar, and 20g sucrose added; after autoclaving and subsequent cooling 2 litres of coconut milk are added, the solution mixed, and then left overnight (1). Germination and growth have occurred at temperatures between 15° to 28°C (1) - but it is expected that germination will be most rapid at the higher temperatures. A greater proportion of embryos germinate in light than in dark (9). Germination can be quite rapid - 2 to 4 weeks - but subsequent growth can be very slow (9).