Bush control in grassland by aerial spraying

Abstract

The results are reported of three trials in which chemicals were applied from an aircraft to control bush on severely infested natural grassland in Moçambique. Acacia nilotica, A. borleae and Dichrostachys cinerea were killed by a mixture of 2,4‐D and 2,4,5‐T at 1,8 kg/ha, by 2,4,5‐T alone at 1,8 kg/ha and by silvex at 0,5 kg/ha. Scholia brachypetala was killed by the last two treatments. Picloram formulations (Tordon 101, 155 and 225) were effective against all these species and also against A. Senegal, but they are too expensive for use on beef farms. A large number of bush species were resistant to the treatments, which can therefore be used only in areas where susceptible species are prevalent.

Uittreksel

Versing word gedoen van drie proewe waar van lugbespuiting gebruik gemaak is om digte bos in natuurlike grasveld te beheer. Die spesies Acacia nilotica, A. borleae en Dichrostachys cinerea is volkome beheer deur ‘n mengsel van 2,4‐D en 2,4,5‐T teen 1,8 kg/ha, deur 2,4,5‐T alleen teen 1,8 kg/ha, asook deur silvex teen 0,5 kg/ha. Schotia brachypetala is deur die twee laasgenoemde behandelings beheer. Al die spesies asook A. Senegal is doeltreffend deur verskillende Picloram formulasies (Tordon 101, 155 en 225) beheer, maar dié middel is te duur vir gebruik op beesplase. ‘n Groot aantal bossoorte is egter bestand teen dié behandelings, en kan dus net gebruik word waar vatbare soorte oorheers.