Topsin M-4A

Systemic Fungicide

Topsin M-4A is recommended as a pasture spray for the control of the fungus (Pithomyces chartarum) causing facial eczema in livestock. The addition of a non-ionic surfactant is recommended to improve coverage under dry, dusty conditions.


It is an offence for users of this product to cause residues exceeding the relevant MRL in the New Zealand (Maximum Residues Limits of Agricultural Compounds) Food Standards.


Topsin M-4A can be applied with conventional ground or aerial spraying equipment. Screens and nozzle strainers finer than 300 micrometres should not be used. Flush equipment with clean water after use.

Pour the correct amount of Topsin M-4A into the partly-filled spray tank and while agitating, add the remainder of the water.

Treatment of long or short pasture is equally effective. One treatment should normally be effective for a minimum of 6 weeks. However, spore numbers should be monitored from the fourth week following application so any spore build-up is detected and re-treated. Where a total of 100–150mm of rain falls after treatment a reduction in the period of protection may occur. Should greater than 25mm of rain fall within 72 hours of application re-treatment is necessary. For ground application the use of an off-centre tip is recommended for spraying into fence lines and hedgerows, also around troughs and similar obstacles.

Warm, moist areas such as sheltered gullies and shaded pasture should be treated first since spore levels normally rise more rapidly in these areas.

Consider treating pastures from mid-December. The actual time of treatment should be based on the results of spore count sampling on the farm or checked with the local Facial Eczema Warning Committee.

Spraying of the whole farm is recommended to reduce errors in deciding when to graze sprayed pasture. Where this is not possible, initially treat 1⁄4 – 1⁄3 of the farm (one hectare should provide grazing for about 35 cows or 250 sheep for a 7–10 day period). Treat all other areas intended for grazing, ideally not less than 7 days before putting stock on, for as long as the facial eczema warnings continue. In an emergency some worthwhile protection may be obtained by grazing 24 hours after treatment.