Fungicides
From Halopedia, the Halo wiki
Fungicides are chemical compounds used to prevent the spread of fungi or plants in gardens and crops, which can cause serious damage resulting in loss of yield and thus profit. Though oomycetes are not fungi, they use the same mechanisms to infect plants[1] and therefore in phytopathology chemicals used to control oomycetes are also referred to as fungicides. Fungicides are also used to fight fungal infections.
Fungicides can either be contact or systemic. A contact fungicide kills fungi when sprayed on its surface; a systemic fungicide has to be absorbed by the plant.
The majority of fungicides that can be bought retail are sold in a liquid form. The most common active ingredient is sulfur, running at 0.08% for the weaker concentrates, and has high as .5% for the more potent fungicides. In powdered form, the concentration is usually around 90%, and is very toxic.
Upgrades
In Halo however, the fungicide used is harmless to humans, other than the familiar cough or sneeze caused by the dust.[2]
