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Disease Tomato Fusarium Wilt Fungi Resistant

You may have had your own tears, and understandably so. Late Blight of potatoes and tomatoes was the disease responsible for the Irish potato famine in the mid-nineteenth century. Spores are spread by rain/watering splash, insects, and wind, and through our hands and tools and through these mediums they can travel distances. Spore spread is most rapid during conditions of high moisture, marine layer days, and moderate temperatures, 60°-80°F.  Once established, the fungi can over-winter in your garden soil, on debris and weeds.

Fusarium Wilt is commonly found throughout the United States, is a soil-borne pathogen. Plants susceptible to Fusarium Wilt are cucumber, potato, tomato, eggplant, pepper and beans. Fusarium wilt causes foliage to yellow, brown spots on leaves, leaves to curve the length of the leaf, wilt, then turn brown and die. Your plants become stunted because they can no longer function properly.

The list of plants susceptible to Verticillium Wilt is impressive. You might have thought it was just tomatoes, but look: Peanut, Horseradish, Rutabaga, Cabbage, Brussels sprouts, Pepper, Safflower, Hemp, Watermelon, citron Cantaloupe, honey dew, Pumpkin, Cotton, Okra, Mint, Radish, Rhubarb, Castor bean, Eggplant, Potato, Spinach, New Zealand spinach, SaIsify, Yard-long bean, Cowpea! Cucumber, tomatoes and strawberries are particularly susceptible.

Verticillium wilt is most active in humid climates. Cool nights and moist conditions, the kind that favors peas, tend to encourage it. It lives in the soil, entering plants through the roots and is drawn up to stems, leaves and fruit through water uptake. At the same time, it is robbing the plant of moisture. The first symptoms of verticillium are usually seen in wilting, yellowing and curling leaves. Discolored streaks are often seen in strawberry stems and runners, and in berry canes.

To determine if a plant is infected with bacterial wilt, press together two freshly cut sections of a stem and slowly pull them apart. If a “stringy” sap (bacterial growth and associated resins) extends between the cut ends, the plant has bacterial wilt.

Especially Tomatoes! And of those, Heirlooms are particularly susceptible to the wilts. Instead, get varieties that have VFN or VF on the tag at the nursery. The V is for Verticillium, the F Fusarium wilt, N nematodes. Ace, Early Girl, Champion, Celebrity, are some that are wilt resistant/tolerant. In these drought conditions, consider getting only indeterminates. In the Mother Earth News tomato survey, they found gardeners chose heirlooms over hybrids if their soil is wilt/blight free. Otherwise, the longer the gardener has gardened, they more they chose wilt resistant toms if their soil has the fungi.

Western striped cucumber beetles are deadly to cucumbers. They are referred to as ‘plant-wounding insects’ and also transmit bacterial wilt. Feeding on blossoms and leaves, they carry the wilts and also spread it among squash, melons, and pumpkins. Cucumber beetles also vector viruses such as cucumber mosaic but do so much less efficiently than aphids. Spiders are one of the predators that eat the beetles. Let those spiders live! A tachinid fly and a braconid parasitoid wasp parasitize them. Grow plenty of flowers for these beneficial insects!

Radish have become my new religion! Radish repel the beetles! You do have to plant your radish ahead of installing your transplants or have it up before the seedlings start growing from seed. Grow your radish companion along where you will let the vine travel. The part of the vine growing up over an arch won’t be helped, so if you have space and infected soil, you may opt to keep your vines on the ground. Plant enough radish so you can eat some, but let  some grow out so the whole plant is big and protecting your cukes and other vines. Broccoli also repel cucumber beetles. Grow cucumbers under over summering Broccoli. Put in plenty of straw mulch to keep the brocs cool and the cukes off the ground. Whenever you see these beetles don’t fall for how cute they are. Squish.
Transplant rather than direct seed! Tiny seedlings are most susceptible to cucumber beetle feeding damage and to bacterial wilts.

Washington State Extension says:

Apply straw mulch! Straw mulch can help reduce cucumber beetle problems in at least 3 different ways. First, mulch might directly slow beetle movement from one plant to another. Second, the mulch provides refuge for wolf spiders and other predators from hot and dry conditions, helping predator conservation. Third, the straw mulch is food for springtails and other insects that eat decaying plant material; these decomposers are important non-pest prey for spiders, helping to further build spider numbers. It is important that straw mulch does not contain weed seeds and to make certain that it does not contain herbicide residues which can take years to fully break down.

Cucumber Beetles have their preferences! Bitter is their favorite. Not interested in watermelon at all, but watermelon does get the wilts, just from other sources! Anyway, see more details and rankings of varieties of different kinds of veggies. Varieties make a huge difference.

Special Planting and growing tips! 

  • Regarding soil fungi like Fusarium and Verticillium wilts/fungi, how you care for cukes and toms is super important! Cucumbers are even more susceptible than tomatoes to the wilts fungi, die pretty instantly, in about 3 days, if they get infected. So when you plant them, treat them similarly to your tomatoes if you have wilts fungi in your garden.
  • Plant cukes and toms on a raised mound/basin with the bottom of the basin above the regular soil level. This allows good drainage. Top that with a 1/2″ of compost, cover that with only 1″ of straw to let in air and sun to dry the soil. Keep the LEAVES OFF THE GROUND from the get go. Leaves touching the soil is the main way toms get the wilts. Remove lower leaves that might touch soil when weighted with dew or water from watering. Keep a regular watch for new foliage at ground level and remove it. AVOID WATER SPLASH when watering at ground level. The fuzzy damp leaves of toms and eggplant are perfect fungi habitat.
  • When they are about a foot tall, water neighboring plants, but not your toms.  That keeps the soil drier near your plant, so the fungi can’t thrive there. Since toms have a deep taproot, they will get plenty of water from what you give neighboring plants. Water near them but not at them or on them. In fact there are farmers who dry farm tomatoes! Read more!
  • If you are comingling beans with cukes lower along a trellis, plant the beans between the raised cucumber mounds. Beans don’t get the wilts, but love the water, so lower is good. They are a big plant with continuous high production and short roots that need to be kept moist. Mulch ASAP with straw under cukes to keep leaves and fruit off the ground, and out of the insect zone. Put a stake in the middle of the basin so you know where to water when the leaves get dense. Water gently below the leaves at ground level, no splash. Keep those leaves dry. When your plant gets bigger you can remove lower leaves.
  • Since the fungi are airborne as well as soil borne, plant in different places as far apart as possible. Plant so leaves of one plant are not touching another plant. Remove sickened foliage ASAP to reduce fungi population and slow spreading. Prune on hot, dry, unwindy days, mid morning to midday, after dew has dried, so cuts can dry and heal with less chance of airborne fungi getting into them. Try not to touch the cuts after they have been made.  Use clippers for a clean cut. Wash your tools and hands often.Trimming away infected leaves is a sad and tedious process. It’s practically impossible not to spread the fungi as your touch leaves that have it and try to remove them without touching any other stems or leaves. The very cuts you make are open to fungi. Then, naked stems are susceptible to sunscald – see image below. You come back a few days later and more leaves are wilting. The disease is internal, has spread out to the leaves. At some point soon after that, a lot of gardeners pull the suffering plant. It’s done. Not good to leave it and let windborne fungi infect neighboring plants.

    Do not compost infected plants or trimmings. The fungi has amazing survival ability and being soil borne, it is right at home in your compost. Put it in the trash, carefully bagged so as not to spread or leave any trace. Wash your hands. If you can, burn the infected plants.

  • The wilts can’t be stopped. Sooner or later the plant leaves curl lengthwise, get the dark spots, turn brown then blacken and hang sadly. Plants can produce but the fruit doesn’t ripen properly if it does produce. It’s agonizing to watch. Sometimes they somewhat recover later in the season after looking totally dead. You had stopped watering them, summer heat dries the soil and kills enough of the fungi for the plant to be able to try again. But production is so little and fruits don’t ripen properly. It’s better to pull it, reduce the fungi population that can blow to other plants. The safest bet is to remove the entire plant. Get all of the root as best you can. The root is where the wilt’s mycelium first congregate and infected roots left in the ground will start the whole process again. Replant in a different place if possible.

Tomatoes pruned to remove diseased leaves of Fusarium and Verticilllium wilts are susceptible to sunscald.Preventive Foliar Mix that can help! 

Apply to newly installed transplants, and during the season every 2 to 3 weeks, so new growth will be covered. Wet both the undersides and tops of leaves. Per gallon add:

  • One dissolved regular strength aspirin
  • 1/4 Cup nonfat powdered milk
  • Heaping tablespoon baking soda
  • 1/2 Teaspoon mild liquid dish soap

After the tomatoes set, add some nitrogen. Boost your plant’s immune system with some worm castings at the same time. You don’t want to add too much nitrogen to your tomatoes before they set fruit. Too much nitrogen before fruiting leads to more leaves and less fruit. Add N only once. Stressed plants are the most susceptible to the fungus. Water regularly and deeply. Use well-balanced, slow-release organic fertilizers that aren’t overly heavy with nitrogen. A healthy plant tends to fight off the spores.

Blight can also be transmitted through seed, so NO seed saving from infected plants. Fresh seeds and resistant varieties are in order.

Remove volunteer tomatoes and potatoes. If they are a not a resistant or tolerant variety, when they get sick, they increase the chances of your resistant varieties having to fight harder to live, and your good dear plants may not win the battle.

Air circulation, plant staking and no touching. Air circulation allows the wind to blow through your plants. This allows the timely drying of leaves and it helps break up micro climates. If your plants are packed too tightly together, they themselves become barriers to drying. Staking your plants to poles and using cages helps them grow upright and it creates gaps between the tomato plants. You want wind and sun to reach through and around your plants. Moisture is needed for fungi to spread. Dry is good. Tomatoes should be planted with enough distance that only minor pruning is needed to keep them from touching each other.

Spray proactively. Wettable sulfur works. It is acceptable as an organic pesticide/fungicide, is a broad spectrum poison, follow the precautions. It creates an environment on the leaves the spores don’t like. The key to spraying with wettable sulfur is to do it weekly BEFORE signs of the disease shows. Other products also help stop the spread. Whatever you select, the key is to spray early and regularly.

At the end of the season remove all infected debris, don’t compost. Don’t leave dead tomato, eggplant or peppers in the garden to spend the winter. Pull weeds because spores can over-winter on weed hosts. Many weeds, including dandelions and lambsquarters, are known to host verticillium wilt. During our winter season, turn your soil about 10 inches deep. Let the soil dry and the fungi die. Burying the spores helps remove them, it disturbs cucumber beetle eggs and exposes snail eggs to die!

If you have space, crop rotation is an important tool in fighting wilt. If you’ve had trouble with wilt, don’t plant potatoes, eggplant, or other solanaceous vegetables where any of them have grown for at least four years.

Practice prevention, be vigilant. If you don’t have wilts in your soil you are so blessed! 

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The Green Bean Connection started as correspondence for the Santa Barbara CA USA Pilgrim Terrace Community Garden. All three of Santa Barbara city’s community gardens are very coastal. During late spring/summer we are often in a fog belt/marine layer most years, locally referred to as the May grays, June glooms and August fogusts. Keep that in mind compared to the microclimate niche where your veggie garden is. Bless you for being such a wonderful Earth Steward!

Love your Mother! Plant bird & bee food! Think grey water! Grow organic!

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What’s happening with my tomatoes?! 

Early BlightFusarium Wilt, Verticillium WiltLate Blight

Tomato – Healthy SunGold!

Tomato – Verticillium Wilt

This?!                                                 Or this?

This is bar none, the most common summer question I get asked! Potatoes, tomatoes, and the various forms of lettuce are the top three favorite vegetables in the US, so you can see why this is THE question!  Since fungi spread as simply as by the wind, I will be campaigning for more tomato plant care, starting with what people can do now to keep the fungi from overwintering, then in the spring to lessen its chances.  There are more things that can be done than I knew!  Read on! About Fungi   To emphasize the potency of these fungi:  Late Blight of potatoes and tomatoes, the disease that was responsible for the Irish potato famine in the mid-nineteenth century, is caused by the fungus-like oomycete pathogen Phytophthora infestans. It can infect and destroy the leaves, stems, fruits, and tubers of potato and tomato plants. Before the disease appeared in Ireland it caused a devastating epidemic in the early 1840s in the northeastern United States. Not only do the fungi feed on your tomato plants, but take a look at your potatoes, peppers, eggplant, cucumbers and beans!  See those yellowing leaves?  Remove and dispose of them ASAP!  That removes zillions of spores so they can’t spread.  The wilts and blights also affect trees!  Sadly, not only do your plants look depressing, production is zilch, they die an unnatural death.  Remove, replace.  Be happy. How do fungi work?  Spores are spread by rain/watering splash, insects, and wind, and through our hands and tools (wash your hands and tools after handling infected plants) and through these mediums, can travel distances.  That’s why it is so important, in our community garden, to tend our plants, so our neighbors’ plants won’t also be infected.  Educate your plot neighbors, better yet, send this to them!  Spore spread is most rapid during conditions of high moisture, marine layer days, and moderate temperatures (60°-80°F).  Once established, the fungi can over winter in your garden on debris and weeds. What they look like on your plant: 

Tomato – Early Blight

14 Fungi Preventions!

Cultural control practices alone won’t prevent disease during seasons with wet, cool weather. However, the following measures will improve your chances of raising a successful crop.

Things you can still do this season!** Things you can do now to prepare for next season!**
  1. Buy toms that are tagged VFN, or just VF – that’s Verticillium Wilt and Fusarium resistant or tolerant. Varieties that set fruit early, at lower temps, are Early Girl Improved, Fourth of July, Enchantment. Excellent resistant varieties are Champion, Husky Red, Better Boy, Ace Hybrid, Celebrity.  
  2. Plant only healthy-appearing tomato transplants. Check to make sure plants are free of dark lesions on leaves or stems. If starting transplants from seed, air-dry freshly harvested seed at least 3 days.  
  3. Remove volunteer tomatoes and potatoes.  If they are a not a resistant or tolerant variety, when they get sick, they increase the chances of your resistant varieties having to fight harder to live, and your good plants may not win the battle.  Do not let volunteers grow, even on compost piles, cute as they are. Infected tomato refuse should be put in the trash.  
  4. **Create a soil barrier, mulch!  You can layer newspaper/cardboard covered with mulch or grass clippings.  Anything organic, as you wish.  One to 2 inches of straw is easy to lay on.  You want to create a splash barrier. Seal the soil and you reduce the chances of spores finding your plant. Bottom line, you don’t want your soil to contact your plant.  
  5. **Avoid wetting foliage when watering, especially in late afternoon and evening. Water at the ground!  Watering the leaves creates a humid micro climate; the fungus produces spores. Dry leaves. Dry leaves. Dry leaves.  No moisture, no spores.  
  6. **Air circulation, plant staking and no touching. Air circulation allows the wind to blow through your plants. This allows the timely drying of leaves and it helps break up micro climates. If your plants are packed too tightly together, they themselves become barriers to drying. Staking your plants to poles and using cages helps them grow upright and it creates gaps between the tomato plants. You want to wind and sun to reach through and around your plants. Moisture is needed for fungi to spread. Dry is good. Tomatoes should be planted with enough distance that only minor pruning is needed to keep them from touching each other.  
  7. **Spray proactively. Wettable sulfur works.  It is acceptable as an organic pesticide/fungicide, is a broad spectrum poison, follow the precautions. It creates an environment on the leaves the spores don’t like. The key to spraying with wettable sulfur is to do it weekly BEFORE signs of the disease shows. Other products also help stop the spread. Whatever you select, the key is to spray early and regularly.  
  8. **When they are about a foot tall, water neighboring plants, but not your toms.  That keeps the soil drier near your plant, so the fungi can’t thrive there.  Your tomatoes will get plenty of water from their deeper roots.  
  9. **Remove bottom leaves, again, no touching (the ground), and prune your plants.  Barbara Pleasant at Mother Earth News says, ‘When the lowest leaves are removed just as the first leaf spots appear, you also remove millions (zillions) of spores. And, because the bases of pruned plants dry quickly, the spread of the disease is slowed because early blight fungi need damp leaves in order to germinate and grow.’  Create an 18 to 24 inch barrier gap or safe space between your garden soil or mulch and the first leaves of the tomato plant. If the spores can’t splash upwards and reach the leaves, they can’t take hold. The stem usually isn’t a place for the spores, though it can be. Best is to remove the bottom leaves before the spores start!  If you have large plants, you might consider cutting off some branches to let the sun and wind blow through the main body of your tomato plant.  But, some gardeners don’t recommend pruning or snipping the suckers, the mini branches formed between the trunk and branches, because spores can enter through these cuts.  If you decide to prune, the less cuts the better.  Prune on hot, dry, unwindy days, mid morning to midday, after dew has dried, so cuts can dry and heal with less chance of airborne fungi getting into them.  Try not to touch the cuts after they have been made.  Use clippers for a clean cut.  
  10. **Remove infected leaves immediately. A leaf should be completely green. Look for brown spots or yellow spots or distress. Remove leaves and prune when it is dry and sunny, not windy. Wash your tools and hands often.  
  11. After the tomatoes set, add some nitrogen. A healthy plant tends to fight off the spores. You don’t want to add too much nitrogen to your tomatoes before they set fruit. Too much nitrogen before fruiting leads to more leaves and less fruit. Add N only once.  
  12. **Rotate your crop if possible. Because fungi also affect other plants, rotation in small gardens isn’t practical or even possible. But if you have the room, move your tomatoes to areas that are fungi free.  
  13. ****At the end of the season remove, don’t compost, all infected debris and surrounding debris. Pull all the weeds because spores can over winter on weed hosts. You want to reduce the number of spores laying in wait.  
  14. **The spores aren’t super spores. During our winter season, turn your soil about 10 inches, burying the spores helps remove them, and it also exposes snail eggs to die.

Preventive Foliar Mix that does wonders! 

Apply every 2 to 3 weeks, so new growth will be covered.  Wet under and over the leaves.  Per gallon add:

  • One dissolved regular strength aspirin
  • 1/4 Cup nonfat powdered milk
  • Heaping tablespoon baking soda
  • 1/2 Teaspoon mild liquid dish soap

Water your plants with an aspirin?!  Salicylic acid, in aspirin, triggers a defense response in tomatoes and other plants as well! Adapted from eHow:  The main benefit of aspirin in planting involves aspirin’s ability to fend off potential plant diseases.

  1. Purchase regular strength aspirin. The brand does not matter; purchase the cheapest brand that is available.
  2. Mix together one aspirin with one gallon of water. Combine the ingredients well, so that the aspirin is distributed evenly throughout the liquid.
  3. Add a dash of mild liquid soap to the mixture. This is used as a way to help the aspirin water stick better to the tomato plants. Once the soap is added, attach a spray nozzle to the gallon jug and it is ready to use.
  4. Spray the tomatoes when you first set them in the ground. Aspirin sprayed directly on seeds improves germination, on plants it stimulates the growing process. There is no need to soak the area. A light and gentle spray will suffice.
  5. Continue to spray the aspirin mixture on the tomato plants every 2 to 3 weeks. You are going to notice that the plants stay healthier and attract fewer insects.

Per a comment by Leroy Cheuvront at Heavy Petal blog:  I have had the blight and have stopped it from destroying my tomato plants. All you have to do is mix 2 ounces of bleach to a gallon of water and drown the plant from top to bottom, it will not kill the plant. I do it every seven days and the blight has not returned.  — June 18, 2010.  It sounds scary, but I bet it works! I would test this principle on ONE plant to be sure it is safe to use. Solarization  In the past ten years, some enterprising Israelis came up with solarizing. Moist soil is covered with transparent plastic film for four to six/eight weeks in the summer.  It takes that long to heat the soil to a temperature and depth that will kill harmful fungi, bacteria, nematodes, weeds, and certain insects in the soil. Solarization can be a useful soil disinfestation method in regions with full sun and high temperatures, but it is not effective where lower temperatures, clouds, or fog limit soil heating. Solarization stimulates the release of nutrients from organic matter present in the soil.

Solarization

Solarization also kills grass by heating up the soil when daily temperatures exceed 80°F. Weed eat or mow the area as short as possible. Moisten the soil and cover the area in clear plastic for 10-14 days, until the grass is dead.     Although cloudy weather will slow things down by cooling the soil under the film, a few weeks of sunshine will improve your soil dramatically, easily, and inexpensively. If you live in an area with cool or cloudy summers, or if you just don’t want to wait all season, you can speed up the process by adding a second sheet of plastic. Using the hoops commonly used to elevate row covers or bird netting, raise the second sheet of plastic over the ground-level sheet. The airspace between acts as a temperature buffer zone during cloudy weather and the combination of the two sheets of plastic serves to raise the soil temperature an additional 6 degrees.  The goal is to raise and maintain temperatures in the top 6 inches of soil to a level between 110 to 125 degrees F.  After several days of sunshine, soil temperatures rise to as high as 140 degrees at the surface and well over 100 degrees as far down as 18 inches. Do not mix untreated soil into the solarized bed And please, do NOT compost diseased tomatoes, or any other diseased plant.  That’s how you spread soil born fungi, let alone that they are also spread by wind, are airborne.  If your neighbor has a diseased plant, don’t be shy to respectfully and gently ask them to remove it.  Remember, they raised that child.  How hard was it for you to give up your plant?  Especially the first time.  See?  They may not even know about wilts.  Educate them if possible.  Tell them how you learned about it.  Offer to send them the link to this page. See also Biofumigation  Biofumigation is a sustainable strategy to manage soil-borne pathogens, nematodes, insects, and weeds. Initially it was defined as the pest suppressive action of decomposing Brassica tissues, but it was later expanded to include animal and plant residues.  Other Tomato Questions & Cures – Holes, spots, brown areas?  Here is an IPM (Integrated Pest Management) image page from UC Davis that is likely to answer your question!  It includes diseases and pests.  See more images at Colorado State U Extension. Marion Owen, Fearless Weeder for PlanTea, Inc. and Co-author of Chicken Soup for the Gardener’s Soul says ‘Keep your hands in the dirt, and your dreams on a star!’  I agree! To the fattest, bestest tomatoes ever!!!! Cerena

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