PSA Stopped Spreading – The Reason is Shown Below
This is a trial running on living with PSA issue and has been tested in 3 locations throughout NZ
Te Puke orchard
This orchard has been using air8tors services for the last 3 years.
It contracted PSA the same week the Rena hit Astrolab reef. Last season the 16A block produced 15000 export trays which was about 85 % of what it was forecast to produce before PSA arrived. No summer pruning was done as it was considered too risky and would spread the psa cutting into the canopy. This left a very poor selection of canes to tie down for the 2013 crop. PSA spread through the 2 blocks and only 900 trays were harvested this season. The owner kept the 16A through too harvest in order to learn what PSA did and possibly how to control it. Before harvest the decision was made to graft over to G3.
This enable air8tors to do one last trial before it was cut out. A mix of Soilm8, Zinc, Iodine, Selenium and a few other products was sprayed on 20 rows (10 rows of each block) of the orchard on April 10th either side of the gap where the shelter had been removed. Thus leaving 2 sprayed blocks and 2 control blocks. There was no new exudates showing on the leaders. There was still a small amount of die back in the canes but no fresh exudates
The workers were in cutting out the leaders of the 16A to get it ready for grafting to G3 when they noticed as soon as they got out of the “Sprayed area” they got back into the PSA infection.
It was noticed that despite the cold weather i.e. the first frost the sprayed area did not show any signs of PSA and the control block showed a 3% infection rate. The fresh signs of PSA were noticed on the 2nd row of the control block. Where the infection did get in it was right through the leader, not just an isolated outbreak of fresh exudates. See More on Facebook
Pukekohe Orchard.
First signs were found in October 2012
This orchard got through to harvest with the size down significantly. Suspect that this is a result what products were used to fight PSA.
This was a trial done with a control block. Two blocks showed signs of infection, One was treated and the other left. Both blocks had been subjected to the owners regime that seemed to bring it under control and got it through to harvest.
The sprayed block had 2 of our sprays put on it 21 days apart.
( The same mix as had been used in the BOP. )
On inspection we found that there was no fresh exudates around the sprayed infection. The control block had fresh infection in all the plants in the immediate area. This is the first time I have seen Psa stop so clearly.
The difference was enough for the owner to spray the entire orchard with this mix. 1.7 hectares is being cut out to remove the 2 infection sites and the remaining 2.4 hectares will be left for another season. Unfortunately our trial is now gone but not before we were able to see a significant change.
Oropi Orchard.
This was the first time we tried this mix. The idea was to focus on getting the nutrients into the sap to
This orchard had been using our regime since November with some additions by the owners.
The first spray applied a week before Easter was not exactly what we had wanted but served to show us we were on the right track. Unfortunately it appeared to knock a lot of leaves off around the fruit.
It did appear to stop the spread of PSA.
After the crop was harvested the same spray was applied on the 16th of May exactly as we wanted it.
As of June 17th the manager has the opinion that PSA has not just slowed down but stopped spreading altogether. This has since changed and the worst infected block had spread but the healthier block did not appear to get any worse. Both these blocks have since been cut out for G3
I have reason to believe from our other trials that this spray could be effective for 6 to 10 weeks. If this proves to be the case a similar spray can be put on at the same time that hicane would normally be used. The intent of this spray is to get in through the wood of the plant as well as the leaf, so it can still be used after leaf fall.
Yeti Trial
Pictures show where the bark has been scraped back to remove the PSA infection. The bark has calloused over in a few months. I found this quite remarkable. I have put these photo’s on as I think this product is compatible with what we do. It is targeting the nutrition as we do but from the inside of the plant. Air8tors have tried to change the sap content to combat the PSA. Yeti seems to do that very well.
Plants treated with Yeti have showed that the bark can callous over where the PSA has been removed, there is still some die back on the canes but the improvement in the leaders was quite remarkable.
Hicane trial.
A Te puke orchard has used a substitute mix of ours for 2 seasons now. Results for this season are below
Block 1 & 2 normal hicane practice. 10500 trays size 32
Block 6, 7 & 8 = 1 year hicane substitute produced 10500 trays / hectare
Block 5 = 2nd year of hicane substitute produced 13100 trays size 32 with the best TZG.
The owner has seen enough to do the entire orchard without Hicane this year. The biggest difference was in the labour taken to keep the canopy under control. Block 5 required 30% of the labour and still produced enough replacement canes for the coming season.
If you want to know anymore about these trials contact Clive Umbers on 021 2422866
