some tomato plants not setting fruit
I'm hoping to get some help. I'm confused about what is going on with my tomato plants. I have the following:
Momotaro, Bush Early Girl, Pink Brandywine, Goliath, and Fourth of July.
They are all growing beautifully and appear quite healthy. They all also have had tons of flowers. However, they are not all setting fruit. My early girl has set around 7 tomatoes and one Fourth of July has set only one tomato, which happened only several days ago. None of the others have set fruit.
I am in Utah and our weather has not been optimal. It was quite hot for a while (90's during the day and low 70's at night), and then it got much colder (50's during the day and 30's at night) with it bouncing back quickly to 80's during the day and 60's at night for around a week or two. These temperature changes were in May. For the last couple of weeks we have been warm again, with daytime in the 90's and nighttime in the low 70's.
I know this is not ideal and so I shouldn't expect much. However, what I am wondering is why there is so much variability in the fruit set. Why am I getting so many Early Girls and none of anything else? They are all dealing with the same temperature, water, soil, etc. I've had fruit on that for around two weeks, and nothing on anything else. So, should I be doing something different? What are your thoughts?
Thank you so much for your help in advance!!!