Hi Evan,

The link you shared is targeting a commercial orchard audience, so it doesn't completely apply to your situation (and yes, is more technical then a home gardener needs).

We recommend home fruit growers follow the much-more-local VA Tech fruit guide [link on that page], which outlines what to spray and when for specific pests/diseases; it's a long document that is updated every year, and it can be keyword-searched, like for "plum" to find the appropriate section. It looks like it is around page 101/102.

Regular treatments as preventative measures are needed to increase the likelihood of a good-quality crop and a decent-size harvest.

When to Spray Fruit Trees explains the typical terms used to describe bud development and progression as we enter the growing season; these are the timing benchmarks used instead of calendar dates since weather can vary from year to year, so sprays are based on plant growth stage instead since that is mainly what impacts their degree of vulnerability to infection or pest activity.

You can explore our resources for those specific fruit trees (our content is grouped for related species, like apple and pear, peach and cherry, etc.) since there's a lot of ground to cover with susceptibilities to multiple pests and diseases. That will give you a better idea of what to apply when and for what problems you are dealing with. Specifically managing the plum curculio in a non-chemical way is described on this webpage for stone fruit insects.

We hope this helps with a better understanding of how to manage your fruit trees.

Emily