Tomatoes and Blite

topic posted Sat, July 12, 2008 - 1:13 PM by  Roxanne
How do I prevent my tomato plants from getting blite? I currently have a commercial-grade, black, breathable plastic down with about four inch square cut-outs where I have planted my tomatoes. I know I should have paid more attention to keeping the bottom leaves trimmed off but life happened and I started to get the spots on the bottom leaves and they are dying. I have removed most of affected leaves in the past few days but anticipate that the disease will continue its course. I understand that the disease comes from the soil and do rotate my tomatoes back and forth in the garden every year. Any suggestions would be appreciated.
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  • Re: Tomatoes and Blite

    Sat, July 12, 2008 - 4:02 PM
    Wow, Rodales Organic guide to disease and insect control doesn't have much to say for once you have late blight other than to remove the infected areas, buy certified resistant varieties, do not buy toms that were grown near potatoes, thats all I had time to look up.

    Great book though. highly recommended. good luck
    • Re: Tomatoes and Blite

      Mon, July 14, 2008 - 5:32 AM
      I have Rodale's Organic Guide and I agree that it is a wonderful book. It did not, however, have a lot of suggestions about blite. I believe this is a harder year for tomatoes, due to the heavy rains we have had here. I will keep after the bottom leaves and hope for the best. I appreciate your post...thank you.
      • Re: Tomatoes and Blite

        Mon, July 14, 2008 - 8:55 AM
        You got me worrying about the spots on mine, and while i wasn't thinking about it at all, hydrogen peroxide popped into my head as a possible remedy. This makes sense to me, and so i googled it and found a good bit, including this:
        Several natural remedies may be employed by organic farmers for foliar disease management. These include a wide range of products and practices including: compost watery extracts; hydrogen peroxide; sodium bicarbonate; foliar fertilizers; plant extracts (fermented nettle tea, equisetum tea, comfrey tea); and biostimulants (seaweed, humates). The precise mode of action for many of these materials remains to be discovered.

        Of these, compost watery extracts and hydrogen peroxide look promising for the control of tomato diseases like early blight. Compost extracts have proven effective for several vegetable diseases, including late blight of tomatoes.(51) See the ATTRA publication Notes on Compost Teas for references and resources.

        Little information is available on the use and efficacy of hydrogen peroxide. Growers in New Jersey are using 35% hydrogen peroxide and diluting it to a 0.5%-1% foliar spray solution, though lower rates are also common. Rates of 2% and 4% are being used as a post-harvest wash. A 1% solution is equivalent to 3.7 oz in 124.3 oz of water, while a 0.5% solution is equivalent to 1.8 oz in 126.2 oz of water.(52)

        Biological fungicides are a relatively new tool available to organic growers. Biological fungicides contain beneficial bacteria or fungi (microbial antagonists) which help suppress pathogens that cause plant disease. For example, F-Stop™, registered as a seed treatment for tomatoes, contains a biocontrol agent called Trichoderma viride sensu. T-22G Biological Plant Protectant Granules™, registered as an in-furrow soil treatment on tomatoes and other vegetables, contains Trichoderma harzianum, strain KRL-AG2.

        and also this:
        Compost and Manure Teas
        Many people have success with manure tea keeping blight and other pathogens away from plant. Soak the area around plants and use as a foliar spray. Do not use on seedlings as it may encourage damping-off disease.
        Fill a 30 gallon trash can with water. Let sit for 24 hours to evaporate the additives (use rain water if you can). Add about 4 shovels worth of manure to this and cover. Let it sit for 2-3 weeks, stirring once a day. Strain and apply as needed.
        Various manures supply nutrients as follows:

        * Chicken manure: nitrogen rich: use for heavy feeders such as corn, tomatoes and squash.
        * Cow Manure: potash: use for root crops.
        * Rabbit manure: promotes strong leaves and stems.
        * Horse manure: leaf development.

        Compost Tea: Make and use just the same as you would the manure tea. This is another terrific reason to compost all those prunings, grass clipping and kitchen wastes. Or you can use our HumAcid for a ready made foliar spray with all the goodness of compost!
        • Re: Tomatoes and Blite

          Tue, July 15, 2008 - 10:22 AM
          Hello Wil:

          I have to laugh at the synchronicity of life as I was just thinking about using hydrogen peroxide this morning. I am going to put the solution in a spray bottle and spray on the lower leaves. I was also thinking yesterday that continuing to nourish the plants will make them stronger and more resistant. I used a product yesterday from Neptune with fish emulsion and seaweed. I also have an organic product called Tomatotone that I have applied and will add to the dirt, again, next week. I know that having fear will not help my plants either...I just need to nourish and love them the best I can and let them do what they need to do (I realized that I was in a bit of a panic the other day when I was removing some of the infected leaves and knew that having that kind of energy go out to them would certainly not help the situation). You did some wonderful research and I appreciate you sharing it with me. I am going to print it out so that I can put it in my Organic Growing Guide to have for future reference.
  • Re: Tomatoes and Blite

    Sat, July 12, 2008 - 5:50 PM
    I got my tomatoes in just like you describe this year too. The lower leaves on a few of mine are curling up and looking bad and i think i'll take them off or even take the plants out. Seems to be only one type of the many i have out, and i have rather too many planted. I was thinking (hoping) it might be burn from the hot plastic. I'm not too worried about it. Blight happens, early and late. We get it every year, it's just a question of how soon. In wet years, we can get the blight early and nobody gets much for tomatoes. When it happens, it happens to pretty much every garden in the county. It is good to plant in a place where morning sun burns the dew off as early as possible. Sprays i know of have to be used all season, and still don't work all that great.
    • Re: Tomatoes and Blite

      Mon, July 14, 2008 - 5:28 AM
      Thank you, Wil, for the reply on the tomatoes. We have had a great deal of rain this year and that is probably why the blite is coming early. I will just keep after it the best I can and hope for the best.