The message
from Alan Gould contains these words:

In article , Janet Baraclough
writes
A supermarket branch manager is near the end of the distribution line.
S/he is unlikely to select producers/suppliers and would have no
responsibility for, or knowledge of, checking their production methods.
That would be done further up the chain of supermarket purchase and
distribution, so your request should be directed higher up.

Any retailer is responsible in law to see that customers are supplied
with goods they pay for in the quantity, quality and condition claimed
for them when they are selling them.

In the case of organic food, the first thing they should be able to tell
a customer is that each item offered is certified as organic by carrying
the officially approved symbol.

Agreed,supermarkets managers should know about their stock's
provenance and the trade standards it claims to meet. IME most
supermarkets provide multiple customer information leaflets detailing
their food-production policies and defining the symbols used on
labelling. That isn't the issue which the op raised.

The question the OP wanted his supermarket manager to answer, was, "what
CHECKS do you make on your suppliers/ producers?". That implies an
ongoing process to ensure that suppliers comply with contracted
standards at the production end; as in "The man from Del Monte" adverts.
I was merely pointing out, that within the management hierarchy of
supermarket companies, that CHECKING task is not a branch managers'
remit.

Janet.