This is a vexing and a very serious issue for cherry growers/packers now that some countries we export to, have extremely low or no set MRLs.
The reality
Rarely would a grower know the likely destination of a block of cherries of mixed varieties when applying pre-harvest sprays for pest and disease control.
This is because at this point in the growing season, the quality of the cherries is not clear, much weather is still to come, the exchange rate is somewhat unknown, some bugs are still to land in the block; and even at MRL testing time, the rain can come and crack the lot.
There are too many unknowns to deal with in planning to export, without having some reasonable certainty about the end result.
Pre-harvest MRL testing
Pre-harvest MRL testing, if I understand correctly, is usually done by sampling fruit from the tree.
In most situations cherries would go through a water shower or dip, and travel the packing line in water.
If that is the case, then the testing is not fully representative of the condition of the cherries in the packed export box. (For more information, check out the Oregon State University extension article, How MRLs can ruin your day.)
Trials needed
In my opinion this is an industry matter. Trials are needed to assist with planning so that the desired result can be attained—and so that packing sheds can be clear about the state of the product being exported.
Developing export markets is expensive and time consuming, and requires ongoing commitment.
Use existing information
New Zealand growers look at short residuals versus long residuals, and an MRL database.
This issue is common to most fruit and vegetable crops and countries. We do not have to invent the wheel, but need to use information already existing and put it into a form that can be used by cherry growers in all cherry growing states of Australia.
It should be in a form that is updated regularly as changes occur in regulations.
Make it a reality
If someone considers that this is a worthwhile project for our industry, then go ahead and design it, plan what is required, and drive it to reality.
See this article in Tree Fruit January 2014
