Bacterial Infections

In last months blog we referred to both good and bad fungi and bacteria being present everywhere in the environment, and many of which cause diseases in plants while others help plants, animals and humans.

For instance – Penicillin (extracted from the fungi Penicillin)
could be called ‘Good Bacteria’ because it can be used in medicine to treat diseases.

But it could also be called ‘Bad Bacteria’ because it will decay your food rendering it inedible if it manages to get a foothold in a damaged or overripe piece of fruit (eg a lemon) or a slightly old piece of bread as seen in these pictures.

Edible mushrooms could be considered ‘Good Fungi‘ but other mushrooms can be ‘Bad Fungi‘ as in the case of “magic mushrooms” or toad stools.

Rhizobium (discussed in a past blog) are ‘Good Bacteria‘ creating a mutually beneficial arrangement between special Pea family plants and Rhizobia bacterium.

Fungi will grow faster and bigger when the LOCAL micro climate around and underneath the leaves of a plant are shaded.

There might be good light but no direct sun, therefore less evaporation trapping aerial moisture (fungi need moisture to continue growing as they are mainly single cell thick Mycelium – which is the equivalent of root hairs in flowering plants).

As soon as the local micro climate area becomes drier (this may be from a strong breeze, direct sun or a Fungicide) then the fungi will revert to its resting stage of a spore.

When it comes to which fungi or bacteria are going to be beneficial or harmful to your plant it is a case of “first in, gets most of the food”.

To give your plants a good fighting chance, give them a good BALANCED feed supply via some fertilizer and/or organic matter, so the cells are thicker and the plant can grow stronger. This way that plant will not let the ‘baddies’ in, resisting fungal attack. (resist attack but not totally prevent a disease attack)

The actual balance required in a fertilizer depends on the specific requirements needed for those plants. This could be that those plants require an acid soil (ie. a pH of below 7) such as azaleas & camellias. Or an alkaline soil (ie. a pH of above 7) such as citrus trees.

Most plants find that a pH of 6 to 6.5 gives them the maximum nutrient availability without excess or deficiency of most nutrients.

To treat fungi and bacteria there are some organic fungicides that can be used if you do not want to use a chemical fungicide.  Eg: Sulphur is a good general fungicide BUT do NOT use it on the cucumber family (cucumber, pumpkin, zucchini, etc) as it is toxic to them.   Look on the label as there is a warning on it to not use them on the cucumber family.

Avoidance is another method to reduce fungus attack.   Leave enough space between trees when planting to allow flow through of air, and water below the leaf line via a drip line in the soil if possible.  These two avoidance methods will help air to circulate freely through the plant so the leaves do not stay wet as fungi needs moisture to infect a plant and spread to other plants.

Today’s Did You Know…?

One of the reasons for the “Damping–off” of seedlings is bacterial infection by Pythium, Phytophthora and Rhizoctonia.  In the home garden there is no way to distinguish which bacteria might be the problem without getting the infected plant analysed by your Local Department of Agriculture.

The seeds need to be watered with fungicide in order to prevent these bacteria from destroying young growing seeds.

This of course is not worth it for the home gardener as the remedy is much the same.  However if you were farming you would want to know exactly which bacteria was the cause so you could fix the problem with a specific fungicide for that particular variety of Bacteria.

There is no good organic fungicide to reduce these bacteria so a chemical one is needed (eg: Zinib or Mancozeb) if you want to have any chance of propagating your seeds or cuttings.