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Roselle, IL GJGEM@sbcglobal.net

Has anybody added soil to diseased soil to try to correct the problem? I will add manure,top soil and sand this year to try to off set the fungus of gummy stem blight. I have dug pits and added over 10 yards of material so far on my 1600sq/ft patch. I do have Quadris and other fungicdes to spray next year. I also have Basamid, not sure I want to use this yet. plus I do not think it is effective against GSB.
George

9/26/2003 11:42:56 PM

Ctpumpkin@optonline.net

If using the Basamid, add the amendments first.
New soil won't negate disease. Though you could get lucky & the enivironmental factors favorable to that disease might not arise. Maybe. -Steve

9/27/2003 7:07:01 AM

Garden State Pumpkins

Hey George, Can't answer all that about GSB but I do know if the pathogens are present and you give them a good growing medium they will grow...Adding to the soil and then planting a plant they will like will only help em. If the directions is four years fallow then you better find something like basamid for your pathogens or you have to starve them from part of their life cycle for the time required for the last vestiges of the soil born part is gone. Then innoculate with good bacteria that will compete for the food chain with em...lost 2 years to fusaria myself
better to get on it right away then waiting to see the vines get hit again... Chuck

9/27/2003 7:11:07 AM

Ctpumpkin@optonline.net

I should mention something. Basamid is not labeled for every single thing it controls. This is because years of testing for each labeled pathogen is required before the fed's allow that pathogen to be on the label. And that costs millions of dollars. While it might not be labeled specifiacally for GSB, it will control the causal pathogen if it is active at the time of treatment. Basamid does kill every single thing that is in active repiration at the time of the treatment. So we must study the causal pathogen & it's incubation period. Duplicate this condition. Then treat. The pathogen is destroyed. Period. Let me snoop around some more.

Steve

9/27/2003 3:15:16 PM

Ctpumpkin@optonline.net

Some data from Cornell that would support this concept:

Gummy stem blight, caused by the fungus Didymella bryoniae as the sexual stage (perithecia giving rise to ascospores) and Phoma cucurbitacearum as the asexual stage (pycnidia producing conidia), is a common disease of all major cucurbits and is present wherever they are grown. Both stages of the pathogen can occur on infected tissue during the season, but they vary in importance as inoculum sources. The disease has been reported in New York since the early 1900s. Gummy stem blight refers to the foliar and stem-infecting phase of the disease, black rot to the fruit rot phase

The gummy stem blight fungus is both seed- and soil-borne. The pathogen may be carried in or on infested seed. In the absence of host plants, the fungus can overwinter for a year and a half or more on infected crop residue. The exact length of survival in the Northeast is currently being studied. The fungus survives as dormant mycelium or as chlamydospores (thick-walled modifications of the mycelium). In northern areas of the country in the spring, pycnidia are produced, giving rise to conidia, which serve as the primary inoculum. Under laboratory conditions, young pycnidia appear light brown (fig. 4, left), whereas perithecia already are black (fig. 4, right). As the pycnidia age, they become black, as shown in figure 3. Conidia are released through a pore (ostiole) in the pycnidia (fig. 5), and if moisture is high, conidia exude as "spore horns" containing thousands of conidia (fig. 6). Conidia vary in size, are short and cylindrical, with usually one septum near the middle, or they may be unicellular. Under moist conditions, they are readily dispersed by splashing water.

9/27/2003 3:53:27 PM

Ctpumpkin@optonline.net

Both temperature and moisture are critical for germination, sporulation, penetration of conidia, and subsequent symptom development, but moisture (relative humidity over 85 percent, rainfall and duration of leaf wetness from 1 to 10 hours) has the greatest influence. The optimal temperature for symptom development varies depending on the cucurbit; for watermelon 75° F is optimal, for cucumber 75-77° F, and for muskmelon 65° F. The optimal temperature for muskmelon reportedly is lower because its resistance increases at high temperatures. This can be significant to determine when early-season disease scouting should be initiated for future control. Penetration by conidia is probably direct and does not need to occur through stomates or wounds. Wounding, striped cucumber beetles, and aphid feeding, along with powdery mildew infection, predispose plants to infection. The additional nutrients provided by such injuries enhance gummy stem blight infection. Symptoms of gummy stem blight (black rot) fruit infection may be evident in the field, as shown on butternut squash in figure 7, or develop later in storage

9/27/2003 3:53:39 PM

Ctpumpkin@optonline.net

In other words if the season ends early enough to encounter these environmental conditions (or fall stays warm enough where you are as I think it does), then Basamid should work.

Steve

9/27/2003 3:55:28 PM

Roselle, IL GJGEM@sbcglobal.net

Thanks for all the info. It sounds as if Basamid is the way to go. I do have a silver maple on the north side of the patch and a row of tall hedge on the south side. How far should I keep the Basamid from these plantings?

George

9/28/2003 8:58:04 AM

Ctpumpkin@optonline.net

George,

All invading roots must first be severed with a trencher or similar. Then keep 4 feet from the cut trench. Soil from the trench is used to make a berm that will keep Basamid in (if a deluge of rain occurs) & to keep wind blown contaminated debris or water out.

I authored a cool technical piece that I should have sent to John & Ken by now. I keep forgetting to get BASF's permission to publish it. And I was with the BASF rep just last week too....Sigh....Tough getting old....

It's on my other computer. Send me an email & I'll try to forward it along. It's a huge document & only arrives about half the time. LOL

Steve

9/28/2003 9:06:08 AM