The production of field plants of the clove Tree.

Abstract

The paper describes the nursery methods used in the production of clove plants from selected seed for sale to growers in Zanzibar. The method produces a greatly improved plant in comparison with the self-sown seedlings which are commonly employed. The fruit is collected from under the selected tree at regular intervals, the ground being swept after each collection. The fruits are soaked for 2 or 3 days in water to remove the outer flesh and assist germination. The single seed (rarely two) then disclosed consists of two large green cotyledons and a well-developed radicle. Desirable characters for selection are described, the chief of these being that the cotyledons should be of a fresh olive green colour and not reddish, and the radicle should not be blackened. The weight of good seed is about 400 to the pound. Rigorous selection rejects about 48% and should ensure a germination of about 96% from the remainder. Seed beds are prepared some time in advance and the fine tilth maintained by a thick litter of old leaves. Removable overhead shade is provided 7 feet above the bed. When sowing the litter is raked off and a bed marked with a band drill roller in lines 8 inches apart. Over these lines a batten provided with pegs 4 inches apart is pressed and in the holes so formed the seed is placed radicle downwards, half the seed extruding. The litter is then replaced without further covering with soil. Seed inserted in other than the correct position produces contorted plants. As the seeds germinate they are freed by the drawing back of the litter, which, however, must remain on the beds. The first pair of leaves should have expanded in a month from sowing. Transplanting to nursery rows is done when the seedlings are 2-3 months old. The ball of earth must be left on the roots but long main roots may be reduced. A month or two before the plants leave the nursery for the field they are again lifted, the ball of soil wrapped in banana leaves (failing a more satisfactory material) and the plants stood under shade close together for mutual support. This results in the production of many turgid white roots. The need for the ball of soil creates a serious problem for the nursery for, as the authors point out, a nursery distributing 40-50, 000 plants a year would at the same time distribute about 200 tons of its best soil. Experiments with bare root planting on a field scale have been unsuccessful, though bare root plants pre-treated as above have been established in sterile sand for pot culture experiments without any sign of shock.