I doubt any farmers would go to a plant nursery for their supplies, it is for house owners. I was caught out with my vegetable planting. My original plans were to go to Europe for 10 weeks April to June, our Autumn/early winter, so I did not plant any winter vegetables. Then as my trip was cancelled and lockdown approached (we were given 2 days notice) I went to the nursery for spinach seedlings and also checked at the Farmers market but there was a rush on them and I missed out. I have bought some since lockdown ended but they had not grown much when I last looked, they are under snow this morning. There were TV items about producers ploughlng all their flowers back into the ground as florists were all closed. No weddings and no mourners at funerals.
I do not know what happened with the agricultural sector. They kept producing under strict distancing rules. I do not think NZ has much chemical production, it would all be imported. I know medicines were restricted. usually I visit my GP every 3 months then go to the pharmacy and get 3 months supply. On my last visit, I received 1 month supply and have to go back every month for repeats. However they are free and the phamacy sent me a text reminder. We only pay $5 for 3 months supply of any prescribed medicine.
New Zealand had a hard lockdown and we are reaping the benefits now with no restrictions. Unlike Australia which kept many things open and at least one state is now having the worst numbers of Covid cases ever and is returning to lockdown.
There was an article in the Australian press yesterday discussing that New Zealand aimed for eradication and, fingers crossed, has succeeded while Australia only aimed for suppression and it seems to have not worked, at least in one state.