Germination characteristics of seven Stylosanthes species

Abstract

The germination response of dehulled, scarified seeds to a range of constant and alternating temperatures, and to moisture stress was measured in seven Stylosanthes species. Rates of water uptake and loss were also measured. With constant temperatures, both total germination and germination rate were greatest at 25¦C for all species except for S. hamata which germinated faster at 30¦C. Both higher and lower temperatures slowed and depressed germination. Constant and alternating temperatures produced similar results except at high temperatures where germination was less with the alternating regime. Moisture stress greatly reduced germination of S. guyanensis cv. Cook, S. scabra and S. viscosa but had little effect on S. fruticosa, S. guyanensis CPI 40294 and S. subsericea. Initial rate of water uptake was greatest for S. hamata and S. subsericea but moisture content was similar for all species by 18 hours. There were no differences between species in rate of water loss from imbibed seeds.