Hello does anyone know what is wrong with my cucumbers?

نقص عنصري البرون والكالسيوم وافضل تسميد من الرش وتكون البرون اقل من ٢% والكالسيوم ١٣%

وتسميد فسفور عالي حتى تتم الاستتطاله

I made a fertilizer from cow manure and gave it to them couple of times now there looking a little better

Are you hand pollinating these flowers? In addition to the comments above, the more pollen your female flowers get the bigger the fruit will be. Check out videos on how to hand pollinate. It's very easy, and they key is to pollinate each female flower with at least 2 male flowers, the more the better. I do it with all my cukes, melons, and squash. Without this technique I would have to fruit because we have very few pollinators left