TEMPERATURE REQUIREMENTS FOR GERMINATION OF DRY‐STORED, COLD‐STORED AND BURIED SEEDS OF <i>SOLANUM DULCAMARA</i> L.

Abstract

SUMMARY Freshly collected seeds of Solarium dulcamara L. germinated almost completely at daily alternating temperatures of 10/25°, 10/30° and 20/30°C but only 20% at constant 30°C, less than 10% at 25°C and not at all at 10°, 15° or 20°C. The only change in 12 months of dry storage was a decrease in capacity for germination at 25° and 30°C. Almost complete germination at these temperatures and also at 20°C was obtained by moistening with 300 ppm of a mixture of gibberellins A 4 and A 7 instead of water. When stored moist at 4°C for 1 month, germination at 25° and 30°C increased to 80% and there was a progressive increase in germination at lower temperatures during the first 3 months, alternating temperatures gave more than 90% germination. Similar changes occurred during winter in seeds buried 5 cm deep outdoors, and by mid‐April all the seeds had germinated in situ.