This is a long story!

The last few weeks I have been setting up a new spraying system and trialing it. Its for spraying the olive trees, not with herbicides or pesticides...no toxins at all. The plan is to spray the trees with a foliar molasses mix. Its been a slow process, with lots of problems.

Perhaps some explanation is needed. In discussing Lacebug with Gamila, an olive grower in Beechworth, she told me that she prevented Lacebug with a molasses spray. I parked that idea undigested, but in the last year have followed it up. There is a grounded basis to this idea. The idea is that sap-sucking insects expect a particular level of sugar in the plants they are adapted to attacking. If the plant is healthy, and consequently has some higher sugar levels, the insects cannot digest the content they get from the leaves and starve. No toxins required, just healthy trees. Lace bug are known to attack trees that are in lesser health...parched, weakened by other pests and diseases.....

To get the trees to a healthier state, and to promote the sugar level as part of that process, you can spray the trees with a beneficial foliar spray. In this case, its a mix of diluted molasses mixed with Seasol, (an organic liquid seaweed concentrate.) The molasses is rich in trace elements, and Seasol is a well-known agricultural fertilizer. If this is a new concept to you ( it was to me) there is plenty of information about it. I was surprised I hadn't heard any of this previously. If you want to find out more about this, look up Dr Tom Dykstra.

The sugar level can be measured. The scale used is Brix. Lacebug on olive trees can't cope with a Brix level of more than 12%. You can measure the Brix level by crushing some olive leaves, and using a drop of the juice extracted in the Brix "meter". The device displays a scale. Notionally you can measure the Brix level, then spray, then at a later time measure it again to determine the success...or not...of the process. I was also interested to see if my relatively tough frantoio trees have a different Brix value to the table olive trees. We have had three rows of table olives decline and die over the last ten years. (I recently found an original plant tag identifying them as Manzanillo). These trees suffer more from frost and are always in the Tree Zero set when we do develop Lacebug outbreaks. It makes sense, if the sugar idea is valid, that these trees have a lower Brix value.

There's a lot more to tree health than just spraying them with a booster, like measuring and improving soil ph and pasture health, but that's a different discussion.

So, building a new spray system.

Best news is, no toxins, so the difficulties of spraying large volumes and big trees without poisoning yourself are avoided. I am using a basic 1000litre IBC cube with a river fire-fighter pump, both mounted on the back of my ute. There's lots of stopping and starting when I do this job by myself, and it would be exhausting to kick-start the pump then shut it for each move. So I built into the plumbing a return pipe back to the IBC. That way I can redirect the liquid back into the IBC while leaving the pump running as I move from tree to tree.

I'm ok with plumbing fittings and built it to be quite flexible and able to be adapted. I used camlock fittings to easily connect and disconnect the flexible firehose pipes.

The spray medium itself is mostly water, with a small percentage of molasses and seasol added. (Some suggest using a detergent to soften the water but my return process would suds the whole thing to madness.) But it means I'll use a lot of water. In tests it looked like I would need 40-50 litres per tree, depending on the size of the tree, to cover it all.

We have had a lot of rain the last two months and our water tank is full, but it would be foolish to use all that water for spraying. Better to directly fill the IBC from the river. So that required completing the usual Spring task of repairing my river pump inlet and pipe. Most winters the river rips it downstream, bending it at right angles. Usually after not being used for awhile the heard of the inlet is clogged. This year that's happened, but also a big tree has been dumped in top of the pipe and I can't get it out of the river. The water is still too cold to go in and running too fast to safely submerge myself while I wrestle with the fittings . Although I made a big thing about the new inlet head I made, I've ended up re-using the old one that I replaced just to get a quick result. (When the river drops a bit I'll get it out.)

I did make a big mistake of buying the molasses in a 250 kg barrel. I saved a couple of hundred dollars by not buying it in 20 litre/25 kb tubs. But I don't have a forklift, so I couldn't get it off my ute, and it was cold, and the molasses would NOT siphon out of the drum. I ended up making up a ridiculous lowering system using trucking straps and winches and tipped it on its side...not without some nervous moments. Once it was in its side I siphoned it out into smaller containers. It took me....8 hours. Never doing that again! ( I bought the Seasol in a 200 litre drum, too, but that has the viscosity of water and I could siphon that easily enough.)

After a few runs with the IBC and pump mounted on the ute, I decided the ute was not the right choice. I use the ute a lot, and I can't be driving around with this ridiculous setup in the back, so I had to unload and load it every day. Too much work. I've mounted the setup on my big trailer and it'll stay there until I've finished.

So I've been spraying. Its works well when it works. The pump hasn't had a lot of use and needed a cleanout, and the air filter was stuffed, but its all running correctly now. Its great not to be using anything toxic and not need a spray suit. Now that its all working I can spray to the top of a very tall tree with high pressure. As I said to my wide, I could knock a tourist off the fence with it now. So different to the misting spray from the little pump that runs my semi-commercial spray unit! I'll talk about the Brix meter in another post, but at this stage I think the process is working. As in, I measured before and after and went from a 0% to 15% reading. Next step is to measure the trees after the remnant spray has been washed off to see what the tree has retained. The best plus out of this is that when it does rain the wash-off will drop into the canopy shadow giving the tree another go at absorbing the nutrients.

I thought about putting a dye in the spray so I can track the trees that have been done, but I come in at the end of a session with a light covering of molasses and seasol. I don't need blue dye all over me and my car and trailer. Instead I mark the trees with a spray can. Mostly works, but I found late in the session yesterday I was doing a row for the second time by mistake. Mostly its been ok.

I've only been doing one session each morning, as its been getting warm quickly, so I've got a few more weeks of this to go.

Oddly, I have seen no Lace Bug this year anyway. Its been warm, muggy...perfect conditions. I know they are about, I've seen some in Myrtleford.