s:2197:"TI Potential limitations of natural repellents against early destructive browsing by livestock and game 
AU Carlowitz, P.G. 
AU Wolf, G.V. 
AB In a series of pre-screening trials and experiments, 5 different inexpensive and readily available materials were tested for their capability for effectively preventing or reducing destructive browsing by livestock and game on recently established woody perennials. These materials were fluffed-up sheep wool, sisal fibres, fibres from pods of the kapok tree (Ceiba pentandra), extracts from the fruits of Solanum campylacanthum, and the latex of Euphorbia tirucalli. In all trials and experiments, Leucaena leucocephala was used as the test species. Seedlings were planted in April 1986 on contour lines at a spacing of 5×5 m on a 0.7-ha fenced plot at ICRAF's field station at Machakos, Kenya. All plants were pollarded twice so that they reached a height that allowed goats to reach the terminal shoots at the time of the test. All leader shoots of the test plants, except one to which the repellent was to be applied, were removed before the test, as was alternative browse; grass was slashed. In a first trial, carried out in August 1977, concentrated Solanum fruit extract damaged terminal buds and mature leaves of L. leucocephala. After diluting the extract with water (2 parts extract: 1 part water) no further damaging effect on leaves and buds was observed. All treated parts of the test plant proved tolerant to latex of Euphorbia tirucalli. In a subsequent short-term (24 hours) pre-screening of the 5 repellents in which 3 goats in an enclosure of 5×10 m were used as test animals, all but the latex of Euphorbia tirucalli showed promise as effective repellents, so the latex was excluded from subsequent experiments. The remaining 4 materials were then exposed to 2 consecutive larger-scale experiments. In spite of the deliberately increased stocking rate (8 goats on 0.7 ha and 5 goats on 0.45 ha) and the removal of all alternative browse, all 4 repellents proved to have a retarding effect on browsing. However, fluffed-up sheep wool, and to a lesser extent, fibres from pods of the kapok tree, gave the most promising results. 
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