You seem like the best person to ask this question:
When I encourage my Opo plants (basically a snake gourd) to bloom by using Schulz Bloom Booster or similar products, I get lots of male flowers but very few female flowers. (Before said application, I was getting some male flowers but almost no female flowers. (Kinda like my ill-fated pumpkin plant.) The Bloom Booster, of course, in addition to high phosphate content has some nitrogen and potassium.
Last week (very late to be trying to do ANYTHING with Opo, as it’s a semi-tropical variety), I finally went back to “Super Phosphate”, which is of course just phosphate, on one plant. (Super Phosphate is not available locally any more, it would seem — will have to order online.)
POW! That plant has now produced several female flowers, a few of which are already growing into fruits.
Maybe female flower making in this case requires a higher ratio of phosphate to the other nutrients than does making male flowers?
Yes, fertilizing with the Phosphorus WILL help produce more female flowers. N-P-K. You always want a higher ‘middle number’ (P) for blooming and fruiting. In a ‘Bloom Booster’ there is also Nitrogen (N), so if your soil already had enough nitrogen, a bloom booster would give you even MORE nitrogen and that could be the reason for less female flowers; it would be cancelling out whatever the (P) portion of the fertilizer could offer the plant.
Here are some other tips for future squash growing:
“One common mistake to avoid when trying to maximize female flowers on squash plants is over-fertilizing. Excessive nitrogen in the soil can promote lush foliage growth at the expense of flower production. It is important to use a balanced fertilizer and follow recommended application rates to ensure that your plants receive the nutrients they need without hindering flower development. Additionally, planting squash in overcrowded conditions can lead to competition for resources and limit the number of female flowers that form. Providing adequate spacing between plants can help promote healthy growth and encourage the production of more female flowers for a successful harvest.”
https://flowerspress.com/how-to-get-more-female-flowers-on-squash/