Project Description

Fight PSA With Nutrition – Ongoing Trials

Te Puke orchard

PSA-Test-Comparisons2This 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