A few weeks back I asked if any body had experienced Zucchini Black Jack growing rather attractive, but completely wrong, round fruit.
I had a number of responses to this question, fortunately no gardeners have had the same experience. I wonder now if our staff who took the plants home and reported the problem did not take plants that we had trial grown. We tested this seed first because it was old, my friend James had given me a stack of seed he no longer needed. Unfortunately the Zucchini did not germinate properly so we chose not to use it. Perhaps some members of our team, always on the lookout for a bargain snaffled the few plants that did grow.
Anyway, a number of correspondents did report Zucchini problems this season. In particular: “Why do some of them rot from the flower up? A customer swears that it's not a water problem and I must admit that a few of my own have done this but not all of them by any means.” I think, and a little research agrees that the symptom is very similar to Blossom End Rot in Tomatoes. Blossom End Rot is a response to irregular soil moisture, especially when transpiration rates are high (hot dry conditions). This problem is accentuated if the dry conditions are preceded by a period of high moisture (Think December in
Tricky problem to solve in the current climate, our rain water tank is now dry. The only real solution that I have is get right on top of your water management. Mulch! And don’t forget that drip irrigation systems are both highly effective and usable under the current water restrictions.