There are certain signs that we see as farmers to know that our plants are actually doing well. We don't need to run a test to see that the small vines you had planted just two months back are doing so well that harvesting is not far away anymore.
It doesn't look like it is burdened by anything at all, the season we are in lacks rainfall, but ideally, this is the best stage for the potato to be in, cause it doesn't need much water during the period when the tubers start to develop.
Too much water to the root, which is the exact location of the tuber, will result in the tubers getting spoiled.
There are no signs of pest after observation, though I can't say much about underground pests that might end up destroying and burrowing holes into the tubers underneath the ground.
But one thing is certain, right now, this is probably the best you will see any potatoes look like if they have good yield potential.
And it can be planted anytime of the year as long as you can take proper care for it and it's very close to water it will do very good and will yield a good harvest