PEST CONTROL

Nitrophilic bacteria are a relatively unknown problem in hydroponics. It is a very aggressive bacteria with an appearance of a white slimy scum or slag in the nutrient concentrate or working tank solution. This most often makes the grower think they have had a bad batch of nutrient, not an introduced bacteria. If Nitrophilic bacteria is left untreated it can establish itself in the root zone of almost all hydroponically grown crops, and once there it is extremely difficult to get rid of. Most often found in potted plants grown in a medium such as Perlite, granulated rockwool or coconut coir fibre, the latter being a perfect host for the bacteria as it is an organic matter and can become very moist from over watering.

Nitrophilic bacteria is an organism which feeds on nitrate ions and excretes an ammonia smell. They especially develop in areas of excessive wetness in the root zones and absolutely thrive in cold stagnant nutrient solutions. If they become established, the level of Nitrate (NO3) in the nutrient will drop very rapidly. This will result in decreased growth rates and a rapid yellowing of the leaves. Yellowing will affect the entire plant and will eventually lead to total necrosis and death. The first symptom is often the yellowing of the foliage but this may be accompanied by the development of unpleasant ammonia smells from the reservoirs and the root zone. It has also been found in water storage tanks and in some cases even in town water supplies.

Nitrophilic bacteria can even be introduced by some nutrient concentrates that are manufactured by companies who have adopted sloppy mixing practices by not using a water purification system or they have re-used storage drums that have already been infected by the bacteria. All nutrient manufacturing companies must run their water supplies through a 2 or 5 stage water filtration system before mixing nutrient concentrates, even chlorine will not kill this pathogen.

The recommended treatment for some time has been by dosing tanks with high levels of hydrogen peroxide. This is expensive, labour intensive and is quite drastic treatment as it is a volatile substance. The aim is mainly one of trying to save already infected plants that might otherwise be lost. No guarantees though are given even with this treatment.

Microbial is a recommended alternative treatment for Nitrophilic bacteria as well as a host of other rootzone problems.

Dosing at 1ml per litre of working nutrient solution, growers are reporting that it is severely retarding the bacteria's growth and in some cases it is disappearing altogether.

Treatment of scarid fly (fungas gnats) infestations.

Step 1/. Dose tank with 2mls per litre of Microbial, make sure you also add pot volume. Totally saturate medium at least weekly. For every litre you replace you should add Microbial at the above rate. Continue this for at least a two week period.

Step 2/. The repair of the damage caused by the Scarid Fly larvae .
If the rootzone is damaged, it's ability to take up essential elements will be severely impeded and the plant will start stripping required elements from the lower shade leaves. Dose tank with a rootzone stimulant like Superthrive or Nutriboost for stress relief for the next three weeks.

Step 3/. You must also do something about the existing adult fly populations. We find that by using yellow white fly traps and Mortien House and Garden we can keep their numbers down to insignificance. Remember that this is where the problem starts, and if you have these in the grow room you will be constantly battling with this pest.

If yellowing is occurring you can foliar spray with a high nitrogen and magnesium supplement like Green-Up or the "B" side of a reputable grow nutrient, but do this at no higher than 7CF. You can also apply this as a tank additive at 5mls per litre (increase C.F level by 5). Foliar feeding has the quickest response however. Plant health should start to improve over a 2 to 3 week period, and once this has been achieved you can adjust the dosage rate of Microbial back to the prevention rate.

Note - do not use any beneficial bacteria while using Microbial. Microbial must make contact with the entire root zone to be an effective preventative against bacterial pathogens.

It is also important to note as plant varieties vary greatly it is recommended that growers test for plant sensitivity before applying Microbial on a large scale.

Do not use Microbial in conjunction with any other root zone treatments.

Microbial should be applied as a stand alone root zone treatment.

Aphid treatment using chillies:

Blend 1 super hot chilli, either Habenero's or Jalapenos into half a cup of water until the chilli is completely disolved. Then strain the contents through a stocking or a net used for fish tanks. Add another 600mls of water. Pour into a hand held sprayer and spray plants to run off. Repeat process every 2 to 3 days. Be sure to wear gloves and goggles as the spray may drift back at you if its windy.

Aphid treatment using garlic and onions:

To a blender add 1 small peeled onion. 2 medium cloves of garlic. 1 tablespoon of baby shampoo or liquid dishwasher soap. Add 2 cups of water. Then blend on high and let sit for 24 hours. Strain contents through a fine net or coffe filter. Pour liquid into a hand held sprayer and pray plant to run off. Be sure to get both sides of the leave surface. 2 applications should do it 3 to 4 days apart.

Aphid treatment using Neem Oil:

Neem oil dosage rates 5 mls per 1 litre of luke warm water. Spray to run off repeat weekly.