Plant Quality

[bushboy]

My plants are being decimated by caterpillars and just don't seem to be thriving.

Readings (av)- pH 6.4 NH3 tr NO2 tr NO3 5 fish - about 100 silver perch in 1250l tank , 4 x 250l grow beds -flood and drain every 20mins

I have given them some Fe chelate and 1 /week seasol type folar spray

I know it is coming into a tough time of year to grow in Brisbane but would appreciate any hints -
how often are people spraying dipel? ,
how often using folar sprays?,
and from those doing ap for a few years - is netting the go to exclude bugs and provide some climate modification?

So far I have been a bit disappointed with the vegetables grown in my growbeds compared to those grown in garden soil

[Murray]

I reckon the message has gone out....the grubs have arrived in force at my place.
I spray every week with Dipel from now on.
Also I will make up another garlic brew to spray with mid week, every week.
Doesn't stop them all, but it sure helps.
Veggies are going great ...except for the grubs.

Fish are doing well also.

I have covered 3/4 of the bottom of the Murray Cod tank with hides made from 90mm pipe cut to short (approx 250mm) lengths. Murrays take up residence immediately.

[Jason Palenske]

You know Bushboy you may want to look at want plants you have planted next to each other, some plants are beneficial next to each other while others actually harm causing plant growth to suck. You may want to google companion planting and see if that helps, tomatoes are good next to some things but like acidic conditions where lettuce likes less acidic conditions. I'll try and find more stuff to help out.

[Outbackozzie]

I have not foliar sprayed anything for a long time, except for dipel.

Use dipel every day for the first 3 days, then once a week or fortnight usually keeps the caterpillars away.

Plant onions near your lettuce, keeps tha aphids away.

Dont plant big clumps of the same type of vegetable, the moths see a large target a lot easier than a couple of plants scattered throughout the beds. This is probably the best way to limit caterpillar attack.

Dont Plant too densly - having everything squished together gives the bugs somewhere to hide. The worst aphid infestations happen on very tightly bunched up plants, like celery. Spraying the aphid affected plants with a relatively strong solution of seasol works ok - the aphids get stuck in the seasol as it dries. Wash off the next day.

Aphids and caterpillars are all I usally have trouble with. Caterpillars are the most destructive by far. I have not netted yet, if I had to I would I suppose.

If your not an AP purist :rolleyes: ...

add 1 cup (250ml) of seasol per 1000 liters of fish tank, once per month.

[Dufflight]

On your tomatoes trim all the branches and leaves under the bottom setting fruit. This stops the moths from laying eggs on leaves close to fruit and makes the plant produce more flowers. I mix chilli's with garlic for a spray. Try to spray under the leaves as well. Moths can sit on top of a leaf and lay the eggs under it to protect them from rain.

[bushboy]

Thanks for those tips chaps - I am slowly getting my brain around the quite different gardening style of aquaponics compared to using soil which is obviously what I have done (and still do) pre setting up my ap systems.

Using weekly or more freq dipel sprays is something I wouldn't do in a normal garden - just some derris dust when needed- which is about all I need to do for pest control. I suspect ap plants are more susceptible to caterpillars as they are possibly not " healthy" - I know this will be controversial - but we all know there are incipient or actual deficiencies present in our systems that need addressing from time to time - such as Fe , Ca and Mg. As such the plants are stressed to some extent and this "attracts" the bugs.

I am ok with this understanding as I love the concept of growing fish and plants combined

Re companion planting and grouping - already aware of this and do this especially in my normal vegetable patches - haven't really considered it in my ap system as my initial system gb were the small 250l ones

I intend to test the Brix meter reading on ap grown silverbeet vs garden grown in the next few days - it will be interesting to compare the 2. This is the only vegetable I can do this on at present as I have removed my brassicas completely from the gb

[Outbackozzie]

Using weekly or more freq dipel sprays is something I wouldn't do in a normal garden - just some derris dust when needed- which is about all I need to do for pest control. I suspect ap plants are more susceptible to caterpillars as they are possibly not " healthy"

Wrong.

Derris dust is stronger, thats why you use it less in the dirt garden.

[Hamish]

I use a sprinkle of Murrays granular mineral fertiliser on my beds once efer ouple of months - I think this has helped a lot with the health and vigor of my plants. Although I also have had a problem with grubs eating my leafy greens - little bug (ers).

[GaryD]

Hamish,

Regular application of DIPEL will help with the caterpillars.

Gary

[Outbackozzie]

+1 for dipel :)

Add a little bit of seasol (just enought to tinge the water) into the spray bottle - makes the dipel stick around even longer.

[DaveOponic]

What is DIPEL?

[bushboy]

Dipel is a proprietary product of which the ingredient is Bacillus Thuringiensis.
This bacteria when ingested by caterpillars ( and I think feeding butterflies and moths) causes
their gut system to implode and thus the caterpillar to die. It is harmless to other life forms -specifically affects Lepidoptera

You might have the same thing as a different brand - it is easy to use as it comes as a powder with a small measuring cup
- I mix 1gm into 5l of water

Thanks for the tip on mixing some seasol and dipel - I'll try that

[bushboy]

Brix readings - I can only compare Silverbeet at present

GB silverbeet brix reading 1.5
Soil based silverbeet reading 2.5

Note they are the same variety - planted the same time and I used juice from the same part of the stem for both tests.

Does this mean much? The silverbeet in the GB looks better and is larger
in size and I was surprised the Brix reading was lower than the soil based plant.
Maybe it confirms my initial impression that the plant quality is lower in aquaponics due to various possible deficiencies.
It is hardly conclusive though!

I am really pleased with Dipel - it has really worked well on cleaning up the caterpillars

[Murray]

As I understand it a Brix reading demonstrates the amount of sugars in a plant together with an indication of minerals particularly Calcium.
AP systems can suffer from 3 mineral deficiencies, Iron, Calcium and Potassium all of which can be added from time to time.

Tom, it is very likely the silver beet from your AP system is down on Iron and Calcium.

Could that be right ?

[bushboy]

Yeah - I did add some Fe chelate about 2 weeks ago but nil since as comments
seem to tend to be only to add it if the plants are showing signs of deficiency.
Similarly there is no shell grit in this system as the pH has been ok (slightly acid so I guess I could add some back safely enough)

This might be interesting to do - add some Fe chelate and shell grit
and recheck the brix reading in a few days time