Territory Stories

Technical annual report 2000-01



Technical annual report 2000-01


Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295




Made available via the Publications (Legal Deposit) Act 2004 (NT).






Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals

Publisher name

Dept. of Primary Industry and Fisheries

Place of publication



Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295



Copyright owner

Check within Publication or with content Publisher.

Parent handle


Citation address


Page content

Department of Primary Industry and Fisheries 26 PROJECT: Evaluation of the Herbicide Metsulfuron methyl for the Control of Senna obtusifolia Project Officers: G. Schultz and N. Hartley Location: Beatrice Hill Farm Objective: To test the suitability of Metsulfuron methyl for the control of Senna obtusifolia in a rangeland situation. Background: Senna obtusifolia (sicklepod) is a significant weed on the fringes of floodplains around many river systems. This weed often grows in combination with similar or related species and then competes for resources on these valuable grazing areas during the Wet season. They also hide feral animals and are problem weeds in natural ecosystems. They are generally dispersed by water, in mud on machinery and by stock movement. When senna is combined with Calopogonium mucunoides (calopo) they are capable of forming a dense impenetrable cover. Senna does not have any beneficial attributes but calopo is considered a desirable grazing plant in the late Wet/early Dry season. Senna is difficult to control except as seedlings and can react differently to control methods in different areas. Method: A trial was conducted using different rates of Metsulfuron methyl (Brush-off) on slashed old growth senna at Beatrice Hill farm in 2001. The rates applied were 0,5,10,15,20 gm of Brush-off per hectare mixed with 0.01% wetter and applied at 133 L/ha by a precision sprayer. Results: Efficacy of Metsulfuron methyl was measured on eight different species in the period January to April 2001. Table 1 shows a summary of the data for three test dates. Discussion: Metsulfuron methyl is a suitable herbicide for the control of a range of weed species provided it is applied at a sufficient rate and on new growth. The herbicide does not have any residual control on these weeds, gives good initial control but dormant seed of the weeds can develop a new stand later in the Wet season. This means that at least two applications are needed to give a season-long control. This product has limited effect on grass production where plants like senna and calopo quickly produce a dense cover, which has the capacity to smother any grass growing underneath.