Did you know that tomatoes can easily polinized by hand?. While your plants are there, try the following things to improve production (all this information gathered over the web, with lots of excellent channels in you tube explaining this.
1- polinize. This is done by shaking the flowers of the tomato plant by tickling them with your finger for a few seconds. This is done as soon as blooms open. For a garden this is perfectly realizable. I normally grow about 40 plants per year and I have got 65 kg of tomatoes on my best summer.
2-Apply posassium rich fertilizer. Tomato plants are demanding in potassium and react vigorously to it. You can use ashes, of other sources. I use potassium sulfate which i dissolve in water about 10g/l and apply at the foot of each plant. Sometimes i use anout 1g/l and shower the entire plants with it.
3- Trim the plant during growth and make sure it is well supported such that no leave becomes in contact with the soil. The plants are to be well aereated.
4-In hot and very dry weather the red mite (Arachnida: Acari) can decimate your plans in a couple of weeks. Combat it by sprinking fine sulfur powder on the entire plants before the red mite hits. Do this on late in the evening as soon as dry hot weather arrives. Sulfur is non toxic to humans and it does not scare polinizers like bees.
I hope this helps
Sorry for such a long reply, but yep, I do all those things...
1. I've tried manual pollination, "plant tapping", using an electric toothbrush on the blossoms to simulate the vibrations of pollinating insects (bees in particular), etc.
2. My plants always get a good diet of potassium, magnesium and calcium for good blossom and fruit production, to prevent blossom end rot, and to promote overall good plant health.
3. I always trim excess growth to keep the plant's energy going into the fruits and blossoms instead of unneeded excess foliage. I also remove suckers in a timely fashion and limit the main stalks to only three at the most (again, too many is too much). But I never take too many stalks or branches so that it compromises the plant's ability to take up its required amount of sun for proper photosynthesis and overall plant health and vigour. I also remove the bottom 18-20 inches of all branches and foliage to prevent any contact with the soil, and I also use a good layer of mulch to reduce rain splash back as well.
4. Red mites have never been an issue for me since I do companion planting that repels literally all pest insects away from my plants. I used to have issues with tomato hornworms and other pests, but ever since I started companion planting I have never had an issue with any pest at all. The difference is like night and day, all without the use of any sprays, powders or other chemicals of any kind, which is ideal.
I also keep my plants regularly watered throughout the season and never allow the watering to fluctuate too much, or let them get dry. I also don't allow the foliage to get wet while watering (only during regular rains), and apply water to the soil only. I use high quality soil with a healthy amount of well-composted organic matter for most of the nutrients they need, but also not too much nitrogen, which can limit and stunt blossom production if there's too much. There are several other things I do to assure good, healthy plants, and I could go on, but I digress.
Every year my plants get hoards of blossoms, but despite all my efforts to help them get pollinated and to give them the right balance of all the nutrients they need to form and grow into healthy fruits, it's all been, well...very unfruitful. The issues I have been having have
directly coincided with the severe loss of pollinating insects in my area. I can try to assist the blossoms to pollinate in every which way possible, but there's just something about the way insects do it, as nature intended, that just can't be replicated. I never used to have these issues.
Ten to fifteen years ago there were more bees, species of bees, and pollinating insects of all kinds than you could even count. At any given time of day there were literally dozens of them flying around all of my various plants and during that time my tomato plants grew fantastically. But over the last 10-15 years there has not only been a slow decline of bees in particular, but all pollinators too, and over the last 5 years the decline has been STARTLINGLY scary. Now, I'm lucky to see one bee in a day, if that, and insects of all kinds are disappearing as well. Even crickets and other nighttime insects have disappeared.
As mentioned, birds have all but disappeared in my area too. Every year I used to get TONS of sparrows, robins, chickadees, gold finches, wood thrushes, cardinals, blue jays, mourning doves, Baltimore orioles, orchard orioles, grackles, catbirds, mockingbirds, starlings, redwing blackbirds...the list goes on. From before dawn to dusk, everyday it was a
constant cacophony of birds and cicadas. Now, from July onward in particular, I can go outside at any point during the day and hear hardly a single sound except for the wind and the rush of cars going by on a nearby street. There's
nothing out there anymore. Most times it's literally sheer silence other than human activity. The only birds that haven't disappeared completely are a few cardinals and blue jays, and maybe a chickadee or two (the blue jays only call early in the morning, and that's it). I can only assume the birds are disappearing because there are no insects for them to eat. This is the fourth summer in a row like this and it's
eerily scary.
Even in my grocery store, local Ontario produce from June all the way through to October is as reliable as the sun coming up every morning, but this year I'm seeing less and less Ontario produce in the stores, as well as the amount being advertised. I even bought a cantaloupe the other day without even thinking of where it came from, just assuming it would be an Ontario cantaloupe as they ALWAYS are this time of year, and before cutting it open I saw the sticker on it looked different (it was on the underside), and it was from Guatemala! That's just
unheard of here while the local ones are in season. Again, I digress.
Something is WAY wrong in my area and things are getting dire. It's not just me either. I've been hearing about other people having all kinds of mysterious issues with plants of all kinds in recent years, and I have also been reading anecdotal incidences of other gardeners having sporadic issues they never had in the surround area, and even surround states to where I am. I really hope this isn't the beginning signs of some kind of ecological collapse, but with what I have been witnessing in my area, it's hard to call it anything else.