DQ Farm (est. 1991)

This is what we use as a preventive, especially during rainy weather against bacterial and fungal attacks on our plants (leaves and stems, not roots);

Take 500 grams gelenggang ( cassia alata ) leaves and 400 grams lengkuas rhizomes ( alpinia galanga ) and pound them.

Lengkuas

Gelenggang

Mix Well

Then squeeze out active ingredients in 30 liters of water

After mixing and squeezing well in 30 liters of water, filter, then spray immediately without dilution.  Remember, use immediately.

We find the spray effective as a prevention against most fungal and bacterial infections on stems and leaves.  Spray regularly but lightly (sparingly) twice a week.  During bad weather or where there are early signs of disease, spray once a day sparingly (lightly) until disease is arrested. It is not effective if disease is well on its way.

Note however that no amount of spraying is going to help you if your soil is unhealthy, your plant is from weak seeds, and your plant is generally weak from lack of nutrients. 

You have most probably noticed this plant at the roadside, especially near earth-drains and low-lying wet areas.  It is called Cassia Alata or Gelenggang.