Psidium guajava (guava) is recognised as the third most important invasive alien plant species in the moist savanna biome of South Africa, Lesotho and Swaziland. The cost of initial clearing of alien plants reaches up to R3 000-00 per ha, therefore the application of correct control methods is essential for cost-effective reduction of the spread. The aim of this study was to test the cost effectiveness of applying various herbicides to guava in the Swaziland Sour Bushveld. Four plots were selected for standing plant treatments, five for cut stump treatments and two for controls. Within each of these plots, five sub-plots were randomly located and the number of plant stems, base diameter, maximum height, and crown diameter was recorded before application of the herbicides. Picloram, fluroxypyr, bromacil, tebuthiuron and imazapyr were used either alone or in combinations. Eleven months after herbicide application, the treated plants were measured again. Bromacil/tebuthiuron liquid soil application gave the best results in terms of cost (0.09 c/stem) for standing plant treatments. The picloram/fluroxypyr cut stump treatment (4.5% concentration) cost the least to apply (0.05 c/stem), and no resprouting was observed. Results from this study can be used as baseline figures for managers planning to control guava.
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.