Fruit set in hot weather
 

Is there any science on varieties that can set fruit at high temps? Craig offered his experience that the Cherokees seem to do better. I have had better luck with Uncle Mark Bagby.

I ask this because my efforts to introduce AT and LC to my NGO farm in Northern Thailand resulted in a disappoingly low yield--it is hot here.

So if you have experience please share it. If you know science by all means educate me.

See this thread:
[url]http://www.tomatoville.com/showthread.php?t=16112[/url]

Not exactly what you are asking, but sort of relevant in
how environmental conditions affected the test results:
[url]http://tgc.ifas.ufl.edu/vol1/v1p11.html[/url]

I attached a PDF that is a Pub doc on this subject that might be of some help to you.

Also wanted to say that in your climate heat is one issue but another issue is the humidity. High humidity causes the pollen to clump up as well which also affects fruit set. The Uncle Mark Bagby was grown for a long time in my state of KY though from my understanding it was bought here. Either case what that tells me is that the tomato has better genetics for setting flowers in hot humid conditions. It gets hot and very humid here in KY during the summers. But not as bad as it does in Thailand. So my suggestion would be to look for a tomato that is even better known for setting fruit in a hot and humid climate. Probably the best known slicing type heirloom tomato in that class is called The Creole tomato. It is grown in southern Louisiana. I think that would probably be your best bet in your climate conditions.

Other than heat and humidity issues you will also want to make sure that the variety can hold up to some of the other various issues like fungal diseases in your area and any other tomato diseases that are common in South East Asia such as Tomato Yellow Leaf Curl Virus, etc

In your area there is a wet and dry season. There will be tricks you will have to learn to best deal with those conditions. for example in the wetter months you might consider raised beds or containers so that the soil is able to drain better. Or in Northern Thailand hill side growing. so you have good drainage. In the dryer hotter months you might need shade covers. I know in Las Vegas one trick they use in the hottest months is they line the ground with either mylar or a white plastic film so that it keeps the soil and roots of the tomato just a little bit cooler. This can also help the rest of the tomato deal with the heat a bit. Kinda like a person dangling their feet in a cool stream in the summer to cool off.

Anyways I guess the point is that there will be some challenges but hopefully I was able to get you thinking of some different solutions that might help you out.

Things I should have learned in Science class...
 

Things I would have learned in Science class if I were paying attention..

Read the linked articles.

Is fruit set based upon keeping the plant in shade and cooler soil temps (white mylar) or ambient air temp????

There is a LOT of plant science on this.

We have tried every new heat-tolerant hybrid tomato, and only two have really performed well in our extreme Texas heat/humidity - Solar Fire and Solar Set. We are 125 mile NE of Houston, which is said to have a climate similar to Calcutta, India.

Solar Fire has done best for us - a determinate production tomato - a very early, large slicer with good ripening properties, excellent crack resistance, a fair disease package and good taste if ripened on the vine (but not as good as the OP heirlooms these folks grow, of course). Seed is widely available. We buy ours from [URL="http://www.cliftonseed.com"]www.cliftonseed.com[/URL]. The seed will be pelleted and treated. No nematode resistance - fully vulnerable.

Take a look at Purshade - a calcium sunscreen, okay for organic certified tomato growers - [URL]http://www.purshade.com/cropnotes/CN-PUR-TOMPEP-2010_01.pdf[/URL]You can use it on your heirlooms. We will be using it next year for the first time. Main disadvantage is that it leaves a white calcium residue on the tomato (non-toxic, even edible) that must be removed for market (people think it's pesticide). It requires water washing before packing. It only comes in gallons -minumum order is a case of four gallons. It looks and handles similar to white latex paint. There may be a Thailand supplier - I know they market worldwide. I'm not sure if it helps hi-temp fruit-set or not. Our Solar Fire sets fruit in high temp conditions. Our problem is sunscald.

Jack

[QUOTE=maupin;192377]Things I would have learned in Science class if I were paying attention..

Read the linked articles.

Is fruit set based upon keeping the plant in shade and cooler soil temps (white mylar) or ambient air temp????[/QUOTE]

Guess I should have tried to explain it better, what I was trying to say is that there are many factors that can effect the production of fruit. humidity can effect the pollen inside the flowers, heat stress to the roots or from ambient temps can cause lack of blooms becoming fruits. Stress from winds, insect damage, diseases, etc... can all have some effect on the fruit production.

White surfaces reflect light and heat (Mylar feels like a plastic but is shiny and has a metal like surface) ((I suggested the white plastic due to its cheaper and probably more easily found))

So I guess an answer to your question is that I would start by using a white plastic as a row cover, also shade from the afternoon sun might also help a bit, In the end though its mostly trial and error on what will work best for you.

Another approach I have recently seen suggested was to plant the tomatoes in closer blocks instead of rows. The ideal is that in very hot places if you place the tomatoes closer together and plant in blocks of four that the tomatoes help shade each other, I am not sure that would work in your area due to humidity, if the tomatoes are too close together the humidity might cause more damage from fungal diseases and could make them harder to spray.

Also different people have different ideals about what humidity is, I have lived in Florida and its humid but where I live in KY is more humid. Where you are is probably the most humid place I have ever been and I have been around the world twice. I know in Bangkok you could walk outside and within 5 mins feel like you need to change clothes as they would be soaked.

All the hybrid heat setting tomatoes that are suggested should work well for you. Only other option would be to find others in Thailand that grow tomatoes and see what things work for them as well.

I have seen people grow tomatoes right up against houses in Thailand and have some luck with it but not sure that will help you in the field

Stephen is right. Planting them close together will provide shade to protect the fruit from the sun - for vining varieties, but doesn't help much with bush varieties. Instead of the normal 36", plant them 30" or even 24". He is also correct about creating disease problems in block planting in our SE TX climate.

This will help sunscald, but I don't think it will help in setting fruit when the ambient temp passes a certain temperature at night. I can't remember what it is exactly - I want to say a nighttime low of 60 (I'll look it up) It's the overnight low that counts, though. I have no idea why. :-)

With our hot, muggy, mid-summer nights only specially bred, hybrid varieties can set fruit, with the possible exception of the old Pearson (my mother planted that one), which, as I recall, would make a few toms when planted in July if temps weren't too extreme. There may be others I never heard of.

But I can assure you, other factors aside, that Solar Fire will will set fruit with highs around 100 and nights in the seventies. However, those late plantings do not yield nearly as well as the early (3/15 for us) crop with cool nights and moderate highs - partly because they are subject to increased damage by nematodes and other pests.

If want some late, fairly decent tomatoes, I would urge you to go with one of the newer heat-set hybrids. None of the older ones worked for me - Cajun Fire, Hawaiian - it's long list and they all disappointed me except Solar Fire, and to a lesser extent Solar Set.

Jack

Check out this thread. Ami

[url]http://www.tomatoville.com/showthread.php?t=15367[/url]

However planting tomatoes close together reduces air circulation and can result in higher residual heat or humidity lingering around plants.

I'm curious if you have employees going around with electric toothbrushes or other agitating tool/implement early in the morning to touch the flowers and branches to encourage pollination. I know I used to.

Hello Feldon--

No, we have never had a pollination problem, They always seem to set well enough - maybe with those practices, however, we could do even better. Our "employees" are all volunteers -we are a church project- and they all do pretty much what they want. :-)

Jack

Moderator - please delete

I opened this by error. No message.

Jack

Fighting the kind of humidity that you have to deal with I would keep the plants spaced nicely and try to grow them on a trellis instead of caging or staking. Keep them pruned enough to allow air flow. Make sure to water well during the early stages of blossoming and fruit set and water often.
Since most summer days here have humidity nearly 100% the biggest problem is disease and I would think that will be your biggest problem. Keep them sprayed for diseases and insects which spread them. The very best tomato of the hundred I have tried in the heat and humidity has been Big Beef. I call it my insurance tomato because if I put out a couple and keep them sprayed and pruned a little I am usually rewarded with a decent crop from them even when the conditions are terrible.

We don't have electricity on our farm exept for a solar panel donated by Border Green Energy Team to power the aquarium pump to make aerated compost tea, so no elec toothbrushes for pollination.

I can plant under the trellace we grow long bean on-- soil is shaded, have the bamboo trellace posts to maybe try a Florida Weave for support. Since the plants will be well shaded, I think I will plant at regular distances. White plastic couldn't hurt, readily available, and cheap, so I'll do half in white plastic and half without and chart any impact this would have on shaded soil.

I would very much prefer OP seeds, as part of the point of this effort is seed saving and distribution. My experience with AT has been unimpressive in the States and here--never saw any greater heat tolerance with them.

So my instinct--easily changed by input from y'all-- is to go with Cherokee Purple and Mark Bagby. Maybe Opalka--only because it looks like the tomato they grow here and set well for me in heat back home.

I only mentioned Big Beef because of it's superior performance during times of high heat and humidity. I had excellent results with several OPs in those conditions. Some of them were Indian Stripe, Neves Azorean Red, JD's Special C Tex, Stump of the World, Old Virginia, Linnies Oxheart and Gary O' Sena.

[quote=b54red;193023]I only mentioned Big Beef because of it's superior performance during times of high heat and humidity. I had excellent results with several OPs in those conditions. Some of them were Indian Stripe, Neves Azorean Red, JD's Special C Tex, Stump of the World, Old Virginia, Linnies Oxheart and Gary O' Sena.[/quote]

Bill, How tall did your Big Beef plants get?
I ordered some Big Beef seed and plan to try them for the first time this year.