dave said:

something is biting the stem of my watermelon transplants. if anyone's
seen this before please do tell me what you learned from the
experience. thanks!

The pictures (especially #2) remind me of the bird damage I get sometimes
on my squash plants. For some reason I get birds pecking at the leaves
and stems of my squash. These are usually young bird which will
peck at almost anything that has a remote chance of being food. I also
suspect that they are inexperienced enough that they may be pecking at
something legitimate and missing wildly. (I've directly observed such
awkwardness in young robins feeding in my front yard.

Netting over your watermelons (temporarily) will keep them safe from bird
juvenile delinquents.

--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)