We are starting to see results from the Oak bud cap trial. The results are encouraging.
New bud growth just began in the past week (2nd - 3rd week of May). The buds which are completely surrounded by the paper bud cap seemed to be a day or two behind the exposed buds in terms of leaf development. I was concerned about it for a few days, and was preparing to rip the paper bud caps off. But then the leaves started to sprout and almost within hours the capped buds were right there with the uncapped buds.
The papers which had the manually torn openings definitely seem to work better in terms of allowing for penetration of the buds through the paper. In nearly all cases, the paper buds without tears did not allow penetration of the bud through the paper. The leafs and stems look like they want to grow out the side of the bud cap. It will be interesting to observe whether or not the the stems are forced to deviate enough to cause significant stem deformation. I don't think the deformation will be significant. However, I do think it is preferable to use caps with a tear in the fold of the cap.
The balloon caps continue to deteriorate and certainly work. The advantage of the paper caps vs. the balloon caps is material cost and time.