For virus testing including hop latent viroid, leaf tissue is best. Be sure to take one leaf from each of the main growing stems. Leaves in the 3’’-5” range work well, with 3 leaves to make up one sample.
It is important to note that because of the latent nature of HpLVd, a minimum 3-4 tests on each plant is suggested before you can ensure a plant is truly negative. Testing should occur every 1-2 weeks.
darkheartnursery.com
In 4 weeks you can have better more accurate results from testing though. Would take about 10-14 the other way. Also you are neglecting the odds of choosing a branch that may be asymptomatic or not infected.
I am still 100% for testing as my assurance.
How am I neglecting that a branch may be asymptomatic when I'm the one that brought up the need for multiple tests? You said it takes 4 weeks for it to "fully spread", now you're saying it doesn't fully spread.
This is the first time I've seen you even acknowledge the need for multiple tests.
Interesting, mine was evident in veg. I don't have an opinion about best practices for clone vendors.
It can lay dormant in a plant and the plant can look completely healthy until stress factors trigger it, not always visible in veg.
Flowering it out should be standard practice, not just for determining if the donor plant is healthy but to also verify you're selling a legit cut.