It’s been mentioned several times before that going around import laws of countries puts food crops and farmers at risk. The cost of imported insect pests and diseases is enormous.
Citrus canker was eradicated twice from the U.S. costing taxpayers millions and destroying the livelihood of many farmers, only to be introduced again. The third eradication attempt, again cost millions, and livelihoods, but was finally deemed unfeasible by the USDA in 2006. Now citrus farmers just live with the losses from citrus canker. The only means of introduction was illegally importing scionwood, or illegally bringing in fruit from an infected country.
Likewise when plum pox was introduced to the U.S. in PA and spread to NY, and MI. It took 20 years and the destruction of millions of trees of stone fruit, and of course millions of dollars to eradicate the disease.
It was thought by experts in the field that plum pox entered the U.S. from illegally imported infected plant materials.
Canada attempted to eradicate plum pox, but was unsuccessful. Their farmers are forced to live with it, and suffer the losses associated with it.
These are just a couple examples. There are multitudes of similar examples. It always ends up with farmers suffering large economic losses, higher pesticide usage, and higher costs to consumers.
In the historical past there were no rules importing plants (or animals for that matter) but there are also countless examples that this policy moved destructive insect pests and destructive diseases, as well as invasive plants, and animals, which destroyed native habitats.
Phytosanitary from state departments of agriculture are fairly meaningless. The inspections are merely visible inspections, detecting plants showing obvious symptoms, if that. I once received a peach tree with a visible crown gall. It had a state dept. of ag. phytosanitary certificate on the box.
Using legal channels to import plant materials from other countries is the only way to ensure the plant materials are free from potentially devastating diseases. Yes, it’s more expensive than just sending scionwood through the mail. And it’s much more time consuming, but it’s the law for good reason.
Here is a recent example where a farmer is fighting for compensation due to a citrus greening eradication program in Florida.