A Contribution to the Study of the Natural Control of Gorse

Extract

In order to investigate the possible means of controlling introduced plant pests, the course that has been considered advisable to follow has been that of a general biological survey of the particular species under its native conditions and, so far as is possible, a comparison between this and a similar survey in the country to which it has become introduced. Such a survey should include the following aspects :—

Germination of seed : Normal percentage germination, germination of fresh and old seed, dormancy, “ hard ” seed, effect of varying external conditions or previous treatment upon germination of hard seed (if present). Seed reserves in soil ; continuous or discontinuous germination.

Establishment of seedlings : Effect of grass, leaf debris, bare soil, etc. ; root development ; causes of mortality.

Flowering : Periods of flowering, number of flowers ; mode of pollination.

Seeds and dispersal : Number of seeds, manner of dispersal, mortality before germination.

Relation to plant communities.

Relation to climate and soil types.

Geographical distribution.

Relation to insects : Insects found on the plant at different seasons ; nature and extent of damage to vegetative parts, flowers and fruits.