You are right. You never know what is going to happen long term with any of these preventative measures. Sometimes it takes a long time to finally figure out if it is good or bad. Nothing is perfect. Pretty impossible to grow anything on a large scale without some kind of chemicals involved. One good thing about having a small garden you can pick out the insects and know what is going onto your plate. I have been growing apples,pears, and peaches for years and there is no way you can grow them with out chemicals. I have tried and never pervailed. My best crops were when I did a weekly spray program which is a lot of work. Miss one application and the dam bugs take over and that doesn't take into consideration the disease's that plague fruit trees too. You wouldn't belive how much spraying goes into fruit tree's and veggies too. There are so many insects and disease's that love apples that I am ready to give up.
Way too much work for the rewards. Not to mention the crappy,cold springs the last few years. No pollination with the limited wild bees around who hate the cold wet weather and will not work in those conditions. Thank goodness for bumble's because they will work in that kind of weather. You almost need to keep bees if you want to have even a few fruit trees. Insects will rule the earth someday. Man sorry for the rant. My wife is right I am grumpy. Paul