Development and growth of some agricultural species on a subantarctic island
(1) Six annual agricultural species were grown in summer at South Georgia (54⚬S) and in the winter-spring growing season at Melbourne (38⚬S). (2) The mean daily air temperature at South Georgia was 5⚬ C (slightly higher at plant level) compared with about 10⚬ C at Melbourne. (3) Day-neutral cultivars of pea and barley flowered at South Georgia ten days later than at Melbourne. Day-sensitive cultivars of rye and ryegrass flowered about ten days earlier than at Melbourne. All species failed to set seed at South Georgia. (4) All species grew more slowly at South Georgia, despite the higher daily radiation. We conclude that this was due to both lower temperatures and lower soil fertility. (5) Of the species tested, rye grew most at South Georgia, compared with growth at Melbourne, and subterranean clover grew least.