II

downwards towards the base of the leaf. If the cut is shallow all of the thorns on one side of the leaf can be removed in a single cut and the strength of the leaf will not be affected. A knife designed for cutting lino flooring material is suitable for the job. Heavy gloves should also be worn to protect against thorns on other fronds. Fronds are removed when they are of no further use to the plant, have turned brown and are bent towards the ground. They should be removed as they make management difficult and will encourage pests and disease. Healthy green fronds should not be removed unless absolutely necessary as they are a functioning part of the plant. Some outer fronds on offshoots may need to be removed to gain access to the palm or to prepare the offshoot for removal from the p'arent palm. Frond& are removed by using secateurs, a pruning saw, pneumatic secateurs or hydraulic secateurs on large established plants. After flowering, the male and female flowers which have not been used for pollination or have not been pollinated are removed. In addition, the remnants of the bunch stalk after harvest are also removed. 1.4.8 Pests and their control production in Central Australia has been relatively free of pests causing economic damage to the plants and fruit. However, as plantings continue to develop there is a possibility of native inhabiting vegetation in the vicinity of the date plantings becoming a problem. These insects could move from their native hosts to the date palms and cause damage to the plant or fruit. Already damage caused by a native borer tunnelling into fruit has been recorded. scale (Parlatoria blanchardi) is a major pest of date palms in many parts of Australia and overseas countries (Carpenter and Elmer, 1978). The scale originates from Middle Eastern countries where dates are grown. Besides infesting date palms it can also infest the Canary Island palm (), the California fan palm (Washingtonia jilifera), the pygmy date palm (Phoenix roebellini) and the doum palm (Hyphaena thebaica) (Boyden, 1941). It is thought the scale was introduced to Australia on offshoot material in the early 1900's. It is a major pest of date palms in commercial and ornamental plantings in Central Australia. The scale is a proclaimed pest under the Northern Territory Plant Pest and Diseases Act. Scale infests the leaves, leaf stalks and fruit (Plate 5 and Plate 6). It favours the white succulent tissues at the base of the leaf stalk where it is protected by the fibrous material on the trunk. As the popUlation increases the scales move up onto the leaf surface and onto fruit. It can