Glenda,

I have found it to be true to a certain extent in my garden. Potato leaf (PL) and rugose (R) leaved varieties seem to have better resistance to foliar diseases, but some of them still are affected by foliar diseases to some extent. If you look at the foliage on PL plants and R plants, you'll notice the leaves are generally significantly thicker than the leaves on most RL tomatoes and I think that is the reason they resist most foliar diseases better.

Martino's Roma, Brandy Boy, Aunt Ginny's Purple, New Big Dwarf, Sudduth's Brandywine and the entire Husky line of hybrids are a few of the ones I have grown that have shown great disease resistance. However, there are plenty of RL plants that have shown equally good resistance to most foliar diseases, and Dr. Wyche's Yellow and Sophie's Choice are a couple that come to mind.

I'm not saying they have no disease issues (far from it)--they all are prone to some early blight (the Husky line less than all the others, but the tomatoes themselves are tough-skinned and have only average flavor) and some of them get Septoria Leaf Spot or Bacterial Speck or Bacterial Spot during extremely wet periods. However, the disease that does show up is minor compared to what you see on most RL plants at the same time, and the plants tend to drop the diseased leaves, regrow new ones and carry on without the disease spreading as much as it does on the RL ones.

I have the best success keeping my tomato plants (whether they are potato leaf, regular leaf or rugose leaf types) relatively disease free in drier years and by keeping them well-mulched to reduce soil splash and by using only drip irrigation or soaker hoses. In a very wet spring/summer like 2009, it is almost impossible to keep the foliar totally disease-free so you just do all you can and cross your fingers and hope for the best.

Dawn

Glenda,
Another question that you will get many opinions on. In some years I've felt that way and then the next I felt that RL had more. Last week while listening to one of Tom Wagoner's seminars in England on tape I heard him discuss that and he feels the jury is out and isn't convinced it is so. He has done extensive breeding with tomatoes and potatoes for many years. Many including myself consider him one of the most knowledgeable breeders and authorities on tomatoes. There are several of his open pollinated tomato varieties being grown today. I chat on another site where there is several serious growers and breeders. And many there don't see the difference that others claim they do. I can just go by the results in my garden. I try to write down everything that dies and my best guess why. This year and last the percentage was about the same with both. Now I've found varieites of both that are more disease resistant. And I'm trying to grow more of those every year. Like Dawn said keeping them well mulched helps. Don't water so that it splashes up. Many think spacing them further apart helps. I haven't noticed that big of a difference with spacing. I do use close to 4 ft each way now on sprawlers and at least 40 inches on caged plants. Just my opinion. Jay

Jay,

I am not even as convinced as I used to be that wider spacing makes a huge difference, although it seems to make more of a difference in my garden with Early Blight....but seems less important with septoria, bacterial speck and bacterial spot. Or, maybe I should say wider spacing doesn't matter as much in a dry year as in a wet year, and my experience tends to run more towards dry years than wet ones. There! Could I make it any more complicated?

I do know one gentleman who spaces his tomato plants 8' apart and I've never seen diseased leaves on them ever. (I think he uses Daconil, but I'm not sure, so that could account for it too.) However, whenever I look at them up close they are very thick and dense with a huge amount of very dark green leaf cover and few fruit, so I think he overfeeds them.

Dawn

I do my tomatoes ala Ruth Stout so they are always under mulch and last year were never watered. Worst year ever!

The one thing I have never done that would be interesting is lay down plastic and plant in slits so no soil is showing. I may do a couple that way next year just to keep it interesting.

Dawn I feel the wider spaicing is more critical in areas with less wind and more humidity. Here with the hot dry winds they can be closer together and get more air circulation than they need. Sprawlers do better here because fo the winds. In other areas caged plants do because they need the air circulation. So goes back to knowing your garden, climate and soil. What works in one area won't in another.

After posting here I went over and asked it at the chat forum. And the the feeling of some is they haven't seen a noticeable difference in disease resistance. But one mentioned in hot sunny areas he felt many PL's offered more sun protection but in cooler climates that could also be detrimental. As one mentioned if they were superior in disease resistance why don't you see them used more in developing the resistant varieties? One summer I planted a big percentage of PL plants and saw no marked improvement. So now I select for plants that have know resistance or that I really want to grow and don't pay much attention to the leaf type. I do try to avoid those with the sparse wispy foliage because of sunburn issues. Jay

Jay,

They do give you more sun protection and, living here in OK, I really appreciate that. Sprawlers totally don't work for me because of our clay soil's propensity to hold water, etc. but I can see why they work for you. It also depends on the year. I'll have one set of tomato issues in a year with 18 or 20 or 22 inches of rain and completely different issues in a year with 40 or 42 or 49 (!) inches of rain. The problem is that when I compile my 'grow list' in the fall/winter and start seeds in mid-winter, I have no idea if we're going to have a year with 22" of rain or 42" of rain. I wish I had a crystal ball....

The only hybrid tomatoes I've grown that were delibaerately bred PL are the Husky Line, and I've Grown Husky Red, Husky Gold, Husky Pink, Husky Red Cherry and Husky Gold Cherry. The plants had absolutely no foliar disease in a year when my other plants had moderate foliar disease. They produced a lot of tomatoes, especially Husky Red and Husky Red Cherry. However, the 'maters weren't even worth eating...their skin was tough and they really didn't have much flavor. So, to me the disease resistance was nice but really not worth anything in the end because the tomatoes weren't worth eating. Maybe that's why the PLs aren't used more in breeding---because good foliar coverage and disease resistance doesn't matter to us tomato addicts as much as great flavor and texture!

I don't care for the wispy-leaved ones either. Here in my garden, the fruit sunscalds something fierce, so I avoid those nowadays.

For anyone who doesn't understand why we grow 40 or 50 varieties of tomatoes a year, this thread illustrates why....it is so hard to find varieties that perform well here and so we increase our odds of getting a good crop by growing a little of this and a little of that! I'm still looking for the perfect tomato that is the 'perfect' combination of disease-resistance, high production and incredible flavor, but I am not sure such a variety exists.

Dawn

Dawn, if it worked one year, the odds are it wouldn't the next!
In this part of the country the weather is so variable that we can't really count on anything. I think that is what keeps us going......we just know next year with be the perfect year.

I like Opalka and it's wispy, but not as productive for me as many others. I can't think of a potato leaf plant that I was wild about the taste of.

Glenda, That is so very, very true! I don't know about anyone else's weather, but in my part of Oklahoma the weather fluctuates so wildly that we almost never have two identical years in a row. I'll use 2008 and 2009 as an example.

Here in southcentral OK, 2008 was a drought-plagued year. We only had a little over 23" of rainfall, and almost none of that during the hot months. My plants had fewer disease issues, but we also had huge water bills and lower production. Some drought years, I just give up and quit watering because no amount of irrigation helps once the soil reaches a certain point.

2009 started out dry and droughty and with massive wildfires, but rain started falling in April and didn't stop here until July. We've had 49" of rain so far, and had huge disease issues because the ground stayed wet and so did the plant foliage. Production ended up being great in general but was impeded by the foliar diseases.

I'm willing to bet that 2010 won't be as wet as 2009 nor as dry as 2008, but we never really know what we'll get and we never can predict what the harvest will give us. Still it is all good. Every flower, fruit and veggie we produce in any given year is enjoyed and appreciated.

Dawn