In search of.... Better disease resistance

[Fusion_power]

It is common for vigorous growing plants to appear resistant to foliage disease. The cycle of foliage disease involves fruit load on the plant. As fruit load increases, the plant diverts more energy to sustaining and developing the fruit and less to leaves and new shoot growth. Said another way, heavy fruit load increases disease susceptibility. I agree that Neves Azorean Red has better tolerance than most open pollinated tomatoes. I would rank Cherokee Purple, Arkansas Traveler, and Eva Purple Ball a bit better.


One of the problems we get into is that it is difficult to identify disease problems. I recently got my hair cut and while there looked at the barber's tomato plants. She was concerned because they were showing quite a bit of foliage disease. I saw gray mold, septoria, and early blight on the leaves. There may have been other diseases present. She only knew that her plants were diseased. The biggest problem was that she had not fertilized them adequately. As they loaded up with tomatoes, the fruit load depleted the leaves making them very susceptible to fungal diseases.


Quadris sprayed a couple of times goes a long way toward controlling foliage disease.

[b54red]

Just two hundred miles south of you and I have a totally different experience with disease. Neves has always been one of the most disease tolerant of all the open pollinated varieties that I have grown but sometimes like you say when the fruit load is so heavy even it is susceptible. From my past experience trying to grow tomatoes before grafting in my fusarium infested soil Neves was the most dependable variety that wasn't a hybrid and in fact frequently tolerated the fusarium as well as Big Beef, Goliath and Bella Rosa. In fact the last year I grew un-grafted plants it even outperformed all of the double FF resistant hybrids I was growing then. I actually had my longest vine ever from a NAR grafted plant about five years ago. It was over 25 feet long and still producing after eight months in the ground when it froze.

Since Arkansas Traveler is one of my absolute favorites and one of the more dependable producers I hate to say it but it can show more susceptibility to Early Blight than many other varieties some years. Even with that weakness it still out produces most varieties year after year in the sweltering heat of lower Alabama.

I no longer grow Cherokee Purple due to disease issues I had with it and the lower fruit production that I had with it. But the potato leaf variety of CP known as Spudakee is one of my favorites. I should say that if I had some CP seed I might see if it did much better now since I am grafting because it was so much more susceptible to fusarium than was Spudakee which I replaced it with. From the one or two successful plants that I did grow I do remember it as very good tasting and producing larger fruit than Spudakee usually does. Maybe I'll give it a try when grafting next year since you speak so highly of it.

Bill

[Fusion_power]

Early blight resistance is very hard to find. Randy Gardner even bemoans the difficulty of breeding for resistance since most breeding material is only slightly resistant. The material he used in breeding the Mountain lines could stand up to disease pressure a week or two longer than lines without EB resistance.

If I were ranking tomatoes in terms of breeding value, Eva Purple Ball would be near the top because it produces highly productive hybrids, is tolerant and/or resistant to most of the foliage diseases, and has exceptionally small core which passes through to the F1. I really need to cross it to the resistant lines I have from LA0417.

While fusarium is a yearly problem in your soil, I have not had a case at all this year. I've dealt with lots of other problems including septoria, gray mold, and early blight, but not one single plant went down to fusarium.

Grafting is a wonderful way to improve performance of a low producing variety. As an example, I grafted Little Lucky onto a vigorous and disease tolerant rootstock and was rewarded with doubled fruit production.

[sic transit gloria]

Where can I read up on how to graft tomato plants? What do you guys use as your root stock? Thanks.

[elight]

Originally Posted by Fusion_power

Quadris sprayed a couple of times goes a long way toward controlling foliage disease.

I have never heard of Quadris. How is it different/better than Daconil or other common fungicides? It looks like it's only available in 1 gallon size at a price of $200! Would love to know more.

[Fusion_power]

Strobilurin was isolated from the basidiomycete fungus Strobilurus tenacellus. Azoxystrobin is a photo-stable form of Strobilurin. Quadris is a mix of Difenoconazole and Azoxystrobiin. Azoxystrobin is uniquely able to prevent growth of fungi as it is a poisonous compound developed by a fungus to protect itself. While it is an organic compound, you can't make it from mushrooms. It has to be synthesized. It is active against fungi, not people or animals.


Daconil is not really a fungicide. It is like painting the leaves with a coating that prevents growth of hyphae. That is a drastically different mode of action than Azoxystrobin which is systemic.

[GreenThumbGal_07]

I just had to rip out some previously healthy-looking plants (Prue, Dufresne, Rinaldo) from a corner of the yard that apparently doesn't have adequate air circulation (it's next to a concrete wall, concrete on each side, good sun but high wall). All container plants. Early blight, some sort of mold spot, and the killer, fusarium wilt. Game over, man. Sorry to see them go. I picked and gave away about 12 lbs. of green tomatoes.
Oddly enough, the plants that I'd set out earlier, in the cold, in old potting soil (St. Pierre, Santa Clara Canner) have the foliar disease and have leaves dying from the bottom up, but have not yet suffered vascular collapse and are still erect and healthy. Of course it's just a matter of time, but at least these have lasted longer, and I've even gotten ripe fruit from St. Pierre (nice tomato, by the way, thanks for earlier recommendations all).
I've never seen "in ground" plants suffer this way; I guess having a robust root system helps, and the early transplants set out when the weather hasn't yet warmed up enough for above-ground growth are apparently very busy underground getting good roots in place.

[Hntrss]

I would love to try the seeds if you get enough. My garden has Fusarium, and not much survives past the second truss. I have decent luck with Large Red Cherry for some reason though

[frogsleap farm]

I have nurseries each year in NC, PA and WI, and would love to try a plant or two next year. I've incorporated molecular markers for vertical resistance to the common viruses, vascular wilts and to late blight and leaf mold, and making progress on hortizontal resistance (tolerance) to Septoria and early blight. I could use your line as a putative "resistant" control in those nurseries.

[Fusion_power]

I have enough seed now to make a general offer. I will send a pack of LA0417, a pack of Piennolo X LA0417 plant #4 (best overall traits in the offspring), a pack of Cherokee Jumbo, and a pack of Hibor as long as I have seed to spare. Please plan to grow these next year!

Send me a message with your mailing address. I have plenty of stamps and envelopes so no need for sase or exchange. Also, note that I will NOT retain these messages and/or addresses. As soon as I have the letter addressed, they will be deleted. I would normally not make this offer in the general forum, but this thread is here and is being watched by quite a few people. Please be patient as I am very busy collecting seed. It may be a month or so before I can mail them out.

LA0417 is a very vigorous decent flavored cherry tomato. The cross with Piennolo gained a bit of size and incorporated genes for storage. Please do not expect this to wipe out disease problems. The plants will be more resistant than most of the purported resistant lines available but will still get some disease as the season advances.

Frogleap, if you have time, please give me a call, cell number is on my website selectedplants.com. I have a couple of items we should probably discuss before sending seed. I can send you a few hundred of the LA0417 which would make the best "control" for comparison.

[frogsleap farm]

Will do.

[PhilaGardener]

Fusion_power , I'd be interested in giving them a try. My tomatoes suffer a lot of foliar issues here in humid PA - mostly bacterial and fungal problems like septoria, however, but it sounds like your line may be carrying some resistance to those as well. Glad to report back on what happens! Sending you a PM now.

[Fusion_power]

I put seed packs in the mail today. Please anticipate some delays in the mail, but they should still arrive by early next week.

[Fusion_power]

I have decided to name the tomato I refer to above as LA0417. The reason for this choice is that my selection is a single plant pulled out of a group of a dozen or so when I first grew LA0417 8 years ago. LA0417 is a population, i.e. a group of plants in a Peruvian field with seed collected from multiple plants and many different fruits. The description says they range from small S. Pimpinellifolium up to larger fasciated fruit. As such, my single plant selection is not representative of LA0417 therefore the accession designation is not correct when referring to my selection.


I am naming this tomato "Lorelei" which is a reference to the sirens who lured sailors. Lorelei is a red fruited medium to large cherry tomato about 5/8 to 3/4 inch diameter. It is slightly oval. Some fruits may show a slight nipple on the blossom end. Flavor ranges from good to excellent. Sweetness is moderate. The star attribute of Lorelei is that it is highly tolerant to fungal foliage diseases. Part of this tolerance is because the plant is very vigorous, but there is also a strong genetic component. It has the best Septoria resistance I have seen in a tomato including Iron Lady and others bred for resistance.


I will continue to ship seed based on the seed offer in this thread, but will also be providing plenty of seed to Glenn at Sandhill Preservation to list for sale next year. Please consider growing this cherry tomato as it is better in many aspects than most of the red cherry varieties I have grown. I class it as better than Camp Joy and Anait and while not as sweet as sweet 100, has distinctly better tomato flavor. The combination of flavor and disease resistance is rarely found in open pollinated tomato varieties.


Lorelei will eventually go down from Septoria but usually lasts 3 to 4 weeks longer than most other tomato varieties. It produces very heavily with ripe fruit on the plant for about 6 to 7 weeks in my climate.

[Tormato]

Thanks, Fusion.

Now I can't get that Styx tune out of my head.