HERBICIDES AND MECHANICAL CONTROL OF IMPERATA-CYLINDRICA AS A FIRST STEP IN GRASSLAND REHABILITATION

This review is prefaced by an introduction to biological characteristi cs of Imperata cylindrica which relate to its control by chemical and mechanical methods. Of the many herbicides tested and used against I. cylindrica, glyphosate has became the market leader but the potential of imazapyr is also recognized. The activity of additives to improve g lyphosate and imazapyr performance is summarised and linked to a revie w of spray volume rates and the use of three types of application equi pment: hydraulic (knapsack) sprayers, spinning discs and weed wipers. An example of the practical use of glyphosate in an estate crop is giv en. The role of tillage in the management of I. cylindrica is discusse d but emphasis is given to pressing as a technique for promoting natur al regeneration of forestry species. An integrated approach is conside red to be essential for the management of I. cylindrica whereby fire p revention and methods of control are deployed in the conversion of Imp erata-dominated land into sustainable, productive systems. Examples ar e given of integrated management in commodity plantations, rehabilitat ion of Imperata grasslands through reforestation, and conservation til lage to sustain soil fertility and productivity.